Improve array initializer support.

ICSharpCode.Decompiler/Ast/AstMethodBodyBuilder.cs

@@ -393,9 +393,11 @@ namespace ICSharpCode.Decompiler.Ast
 				case ILCode.Initblk:     return InlineAssembly(byteCode, args);
 				case ILCode.Initobj:
 					if (args[0] is DirectionExpression)
-						return new AssignmentExpression(((DirectionExpression)args[0]).Expression.Detach(), new DefaultValueExpression { Type = operandAsTypeRef });
+						return new AssignmentExpression(((DirectionExpression)args[0]).Expression.Detach(), MakeDefaultValue((TypeReference)operand));
 					else
 						return InlineAssembly(byteCode, args);
+				case ILCode.DefaultValue:
+					return MakeDefaultValue((TypeReference)operand);
 				case ILCode.Jmp: return InlineAssembly(byteCode, args);
 				case ILCode.Ldarg: {
 					if (methodDef.HasThis && ((ParameterDefinition)operand).Index < 0) {
@@ -418,7 +420,7 @@ namespace ICSharpCode.Decompiler.Ast
 						return MakeRef(new Ast.IdentifierExpression(((ParameterDefinition)operand).Name).WithAnnotation(operand));
 					}
 				case ILCode.Ldc_I4: return AstBuilder.MakePrimitive((int)operand, byteCode.InferredType);
-				case ILCode.Ldc_I8:
+				case ILCode.Ldc_I8: return AstBuilder.MakePrimitive((long)operand, byteCode.InferredType);
 				case ILCode.Ldc_R4:
 				case ILCode.Ldc_R8:
 				case ILCode.Ldc_Decimal:
@@ -512,6 +514,28 @@ namespace ICSharpCode.Decompiler.Ast
 			}
 		}
 		
+		Expression MakeDefaultValue(TypeReference type)
+		{
+			TypeDefinition typeDef = type.Resolve();
+			if (typeDef != null) {
+				if (TypeAnalysis.IsIntegerOrEnum(typeDef))
+					return AstBuilder.MakePrimitive(0, typeDef);
+				else if (!typeDef.IsValueType)
+					return new NullReferenceExpression();
+				switch (typeDef.FullName) {
+					case "System.Nullable`1":
+						return new NullReferenceExpression();
+					case "System.Single":
+						return new PrimitiveExpression(0f);
+					case "System.Double":
+						return new PrimitiveExpression(0.0);
+					case "System.Decimal":
+						return new PrimitiveExpression(0m);
+				}
+			}
+			return new DefaultValueExpression { Type = AstBuilder.ConvertType(type) };
+		}
+		
 		static AstNode TransformCall(bool isVirtual, object operand, MethodDefinition methodDef, List<Ast.Expression> args)
 		{
 			Cecil.MethodReference cecilMethod = ((MethodReference)operand);

ICSharpCode.Decompiler/ILAst/ArrayInitializers.cs

@@ -30,28 +30,33 @@ namespace ICSharpCode.Decompiler.ILAst
 					return;
 				if (initializeArrayPattern.Match(block.Body.ElementAtOrDefault(i + 1))) {
 					if (HandleStaticallyInitializedArray(newArrPattern, block, i, newArrInst, arrayLength)) {
-						i -= new ILInlining(method).InlineInto(block, i + 1) - 1;
+						i -= new ILInlining(method).InlineInto(block, i + 1, aggressive: true) - 1;
 					}
 					return;
 				}
-				if (i + 1 + arrayLength > block.Body.Count)
-					return;
 				List<ILExpression> operands = new List<ILExpression>();
-				for (int j = 0; j < arrayLength; j++) {
-					ILExpression expr = block.Body[i + 1 + j] as ILExpression;
+				int numberOfInstructionsToRemove = 0;
+				for (int j = i + 1; j < block.Body.Count; j++) {
+					ILExpression expr = block.Body[j] as ILExpression;
 					if (expr == null || !IsStoreToArray(expr.Code))
 						break;
 					if (!(expr.Arguments[0].Code == ILCode.Ldloc && expr.Arguments[0].Operand == newArrPattern.LastVariable))
 						break;
-					if (!(expr.Arguments[1].Code == ILCode.Ldc_I4 && (int)expr.Arguments[1].Operand == j))
+					if (expr.Arguments[1].Code != ILCode.Ldc_I4)
+						break;
+					int pos = (int)expr.Arguments[1].Operand;
+					if (pos < operands.Count || pos > operands.Count + 10)
 						break;
+					while (operands.Count < pos)
+						operands.Add(new ILExpression(ILCode.DefaultValue, newArrInst.Operand));
 					operands.Add(expr.Arguments[2]);
+					numberOfInstructionsToRemove++;
 				}
 				if (operands.Count == arrayLength) {
 					((ILExpression)block.Body[i]).Arguments[0] = new ILExpression(
 						ILCode.InitArray, newArrInst.Operand, operands.ToArray());
-					block.Body.RemoveRange(i + 1, arrayLength);
-					i -= new ILInlining(method).InlineInto(block, i + 1) - 1;
+					block.Body.RemoveRange(i + 1, numberOfInstructionsToRemove);
+					i -= new ILInlining(method).InlineInto(block, i + 1, aggressive: true) - 1;
 				}
 			};
 		}
@@ -79,21 +84,75 @@ namespace ICSharpCode.Decompiler.ILAst
 			FieldDefinition field = ((ILExpression)block.Body[i + 1]).Arguments[1].Operand as FieldDefinition;
 			if (field == null || field.InitialValue == null)
 				return false;
-			switch (TypeAnalysis.GetTypeCode(newArrInst.Operand as TypeReference)) {
+			ILExpression[] newArr = new ILExpression[arrayLength];
+			if (DecodeArrayInitializer(TypeAnalysis.GetTypeCode(newArrInst.Operand as TypeReference), field.InitialValue, newArr)) {
+				block.Body[i] = new ILExpression(ILCode.Stloc, newArrPattern.LastVariable, new ILExpression(ILCode.InitArray, newArrInst.Operand, newArr));
+				block.Body.RemoveAt(i + 1);
+				return true;
+			}
+			return false;
+		}
+		
+		static bool DecodeArrayInitializer(TypeCode elementType, byte[] initialValue, ILExpression[] output)
+		{
+			switch (elementType) {
+				case TypeCode.Boolean:
+				case TypeCode.SByte:
+				case TypeCode.Byte:
+					if (initialValue.Length == output.Length) {
+						for (int j = 0; j < output.Length; j++) {
+							output[j] = new ILExpression(ILCode.Ldc_I4, (int)initialValue[j]);
+						}
+						return true;
+					}
+					return false;
+				case TypeCode.Char:
+				case TypeCode.Int16:
+				case TypeCode.UInt16:
+					if (initialValue.Length == output.Length * 2) {
+						for (int j = 0; j < output.Length; j++) {
+							output[j] = new ILExpression(ILCode.Ldc_I4, (int)BitConverter.ToInt16(initialValue, j * 2));
+						}
+						return true;
+					}
+					return false;
 				case TypeCode.Int32:
 				case TypeCode.UInt32:
-					if (field.InitialValue.Length == arrayLength * 4) {
-						ILExpression[] newArr = new ILExpression[arrayLength];
-						for (int j = 0; j < newArr.Length; j++) {
-							newArr[j] = new ILExpression(ILCode.Ldc_I4, BitConverter.ToInt32(field.InitialValue, j * 4));
+					if (initialValue.Length == output.Length * 4) {
+						for (int j = 0; j < output.Length; j++) {
+							output[j] = new ILExpression(ILCode.Ldc_I4, BitConverter.ToInt32(initialValue, j * 4));
 						}
-						block.Body[i] = new ILExpression(ILCode.Stloc, newArrPattern.LastVariable, new ILExpression(ILCode.InitArray, newArrInst.Operand, newArr));
-						block.Body.RemoveAt(i + 1);
 						return true;
 					}
-					break;
+					return false;
+				case TypeCode.Int64:
+				case TypeCode.UInt64:
+					if (initialValue.Length == output.Length * 8) {
+						for (int j = 0; j < output.Length; j++) {
+							output[j] = new ILExpression(ILCode.Ldc_I8, BitConverter.ToInt64(initialValue, j * 8));
+						}
+						return true;
+					}
+					return false;
+				case TypeCode.Single:
+					if (initialValue.Length == output.Length * 4) {
+						for (int j = 0; j < output.Length; j++) {
+							output[j] = new ILExpression(ILCode.Ldc_R4, BitConverter.ToSingle(initialValue, j * 4));
+						}
+						return true;
+					}
+					return false;
+				case TypeCode.Double:
+					if (initialValue.Length == output.Length * 8) {
+						for (int j = 0; j < output.Length; j++) {
+							output[j] = new ILExpression(ILCode.Ldc_R8, BitConverter.ToDouble(initialValue, j * 8));
+						}
+						return true;
+					}
+					return false;
+				default:
+					return false;
 			}
-			return false;
 		}
 	}
 }

ICSharpCode.Decompiler/ILAst/ILCodes.cs

@@ -265,6 +265,7 @@ namespace ICSharpCode.Decompiler.ILAst
 		Ldc_Decimal,
 		YieldBreak,
 		YieldReturn,
+		DefaultValue, // default(T)
 		
 		Pattern // used for ILAst pattern nodes
 	}

ICSharpCode.Decompiler/ILAst/ILInlining.cs

@@ -76,7 +76,7 @@ namespace ICSharpCode.Decompiler.ILAst
 		/// Inlines instructions before pos into block.Body[pos].
 		/// </summary>
 		/// <returns>The number of instructions that were inlined.</returns>
-		public int InlineInto(ILBlock block, int pos)
+		public int InlineInto(ILBlock block, int pos, bool aggressive)
 		{
 			if (pos >= block.Body.Count)
 				return 0;
@@ -85,7 +85,7 @@ namespace ICSharpCode.Decompiler.ILAst
 				ILExpression expr = block.Body[pos] as ILExpression;
 				if (expr == null || expr.Code != ILCode.Stloc)
 					break;
-				if (InlineIfPossible(block, pos))
+				if (InlineIfPossible(block, pos, aggressive))
 					count++;
 				else
 					break;
@@ -96,7 +96,7 @@ namespace ICSharpCode.Decompiler.ILAst
 		/// <summary>
 		/// Inlines the stloc instruction at block.Body[pos] into the next instruction, if possible.
 		/// </summary>
-		public bool InlineIfPossible(ILBlock block, int pos, bool aggressive = true)
+		public bool InlineIfPossible(ILBlock block, int pos, bool aggressive)
 		{
 			ILVariable v;
 			ILExpression inlinedExpression;
@@ -251,7 +251,7 @@ namespace ICSharpCode.Decompiler.ILAst
 						}
 						
 						block.Body.RemoveAt(i);
-						InlineInto(block, i); // maybe inlining gets possible after the removal of block.Body[i]
+						InlineInto(block, i, aggressive: false); // maybe inlining gets possible after the removal of block.Body[i]
 						i--;
 					}
 				}

ICSharpCode.Decompiler/ILAst/PeepholeTransform.cs

@@ -30,8 +30,8 @@ namespace ICSharpCode.Decompiler.ILAst
 				transforms.CachedDelegateInitialization
 			};
 			Func<ILExpression, ILExpression>[] exprTransforms = {
-				EliminateDups,
-				HandleDecimalConstants
+				HandleDecimalConstants,
+				SimplifyLdObjAndStObj
 			};
 			// Traverse in post order so that nested blocks are transformed first. This is required so that
 			// patterns on the parent block can assume that all nested blocks are already transformed.
@@ -45,9 +45,10 @@ namespace ICSharpCode.Decompiler.ILAst
 						expr = block.Body[i] as ILExpression;
 						if (expr != null) {
 							// apply expr transforms to top-level expr in block
-							foreach (var t in exprTransforms)
-								expr = t(expr);
+							bool modified = ApplyExpressionTransforms(ref expr, exprTransforms);
 							block.Body[i] = expr;
+							if (modified)
+								new ILInlining(method).InlineIfPossible(block, i, aggressive: false);
 						}
 						// apply block transforms
 						foreach (var t in blockTransforms) {
@@ -63,20 +64,29 @@ namespace ICSharpCode.Decompiler.ILAst
 					// apply expr transforms to all arguments
 					for (int i = 0; i < expr.Arguments.Count; i++) {
 						ILExpression arg = expr.Arguments[i];
-						foreach (var t in exprTransforms)
-							arg = t(arg);
+						ApplyExpressionTransforms(ref arg, exprTransforms);
 						expr.Arguments[i] = arg;
 					}
 				}
 			}
 		}
 		
-		static ILExpression EliminateDups(ILExpression expr)
+		static bool ApplyExpressionTransforms(ref ILExpression expr, Func<ILExpression, ILExpression>[] exprTransforms)
 		{
-			if (expr.Code == ILCode.Dup)
-				return expr.Arguments.Single();
-			else
-				return expr;
+			bool modifiedInAnyIteration = false;
+			bool modified;
+			do {
+				modified = false;
+				ILExpression oldExpr = expr;
+				ILCode oldOpCode = oldExpr.Code;
+				foreach (var t in exprTransforms)
+					expr = t(expr);
+				if (expr != oldExpr || oldOpCode != expr.Code) {
+					modified = true;
+					modifiedInAnyIteration = true;
+				}
+			} while (modified);
+			return modifiedInAnyIteration;
 		}
 		
 		#region HandleDecimalConstants
@@ -120,6 +130,54 @@ namespace ICSharpCode.Decompiler.ILAst
 		}
 		#endregion
 		
+		#region SimplifyLdObjAndStObj
+		static ILExpression SimplifyLdObjAndStObj(ILExpression expr)
+		{
+			if (expr.Code == ILCode.Initobj) {
+				expr.Code = ILCode.Stobj;
+				expr.Arguments.Add(new ILExpression(ILCode.DefaultValue, expr.Operand));
+			}
+			if (expr.Code == ILCode.Stobj) {
+				switch (expr.Arguments[0].Code) {
+					case ILCode.Ldelema:
+						return SimplifyLdObjOrStObj(expr, ILCode.Stelem_Any);
+					case ILCode.Ldloca:
+						return SimplifyLdObjOrStObj(expr, ILCode.Stloc);
+					case ILCode.Ldarga:
+						return SimplifyLdObjOrStObj(expr, ILCode.Starg);
+					case ILCode.Ldflda:
+						return SimplifyLdObjOrStObj(expr, ILCode.Stfld);
+					case ILCode.Ldsflda:
+						return SimplifyLdObjOrStObj(expr, ILCode.Stsfld);
+				}
+			} else if (expr.Code == ILCode.Ldobj) {
+				switch (expr.Arguments[0].Code) {
+					case ILCode.Ldelema:
+						return SimplifyLdObjOrStObj(expr, ILCode.Ldelem_Any);
+					case ILCode.Ldloca:
+						return SimplifyLdObjOrStObj(expr, ILCode.Ldloc);
+					case ILCode.Ldarga:
+						return SimplifyLdObjOrStObj(expr, ILCode.Ldarg);
+					case ILCode.Ldflda:
+						return SimplifyLdObjOrStObj(expr, ILCode.Ldfld);
+					case ILCode.Ldsflda:
+						return SimplifyLdObjOrStObj(expr, ILCode.Ldsfld);
+				}
+			}
+			return expr;
+		}
+		
+		static ILExpression SimplifyLdObjOrStObj(ILExpression expr, ILCode newCode)
+		{
+			ILExpression lda = expr.Arguments[0];
+			lda.Code = newCode;
+			if (expr.Code == ILCode.Stobj)
+				lda.Arguments.Add(expr.Arguments[1]);
+			lda.ILRanges.AddRange(expr.ILRanges);
+			return lda;
+		}
+		#endregion
+		
 		#region CachedDelegateInitialization
 		void CachedDelegateInitialization(ILBlock block, ref int i)
 		{
@@ -163,7 +221,7 @@ namespace ICSharpCode.Decompiler.ILAst
 						if (parent.Arguments[j].Code == ILCode.Ldsfld && parent.Arguments[j].Operand == field) {
 							parent.Arguments[j] = newObj;
 							block.Body.RemoveAt(i);
-							i -= new ILInlining(method).InlineInto(block, i);
+							i -= new ILInlining(method).InlineInto(block, i, aggressive: true);
 							return;
 						}
 					}

ICSharpCode.Decompiler/ILAst/TypeAnalysis.cs

@@ -260,6 +260,8 @@ namespace ICSharpCode.Decompiler.ILAst
 					return null;
 				case ILCode.Initobj:
 					return null;
+				case ILCode.DefaultValue:
+					return (TypeReference)expr.Operand;
 				case ILCode.Localloc:
 					if (forceInferChildren) {
 						InferTypeForExpression(expr.Arguments[0], typeSystem.Int32);

ICSharpCode.Decompiler/Tests/ArrayInitializers.cs

@@ -22,7 +22,7 @@ public class ArrayInitializers
 	
 	public static void Array2(int a, int b, int c)
 	{
-		X(Y(), new int[] { a, b, c });
+		X(Y(), new int[] { a, 0, b, 0, c });
 	}
 	
 	public static void NestedArray(int a, int b, int c)
@@ -33,4 +33,69 @@ public class ArrayInitializers
 		  	new int[] { 1, 2, 3, 4, 5, 6 }
 		  });
 	}
+	
+	public static void ArrayBoolean()
+	{
+		X(Y(), new bool[] { true, false, true, false, false, false, true, true });
+	}
+	
+	public static void ArrayByte()
+	{
+		X(Y(), new byte[] { 1, 2, 3, 4, 5, 6, 7, 8, 254, 255 });
+	}
+	
+	public static void ArraySByte()
+	{
+		X(Y(), new sbyte[] { -128, -127, 0, 1, 2, 3, 4, 127 });
+	}
+	
+	public static void ArrayShort()
+	{
+		X(Y(), new short[] { -32768, -1, 0, 1, 32767 });
+	}
+	
+	public static void ArrayUShort()
+	{
+		X(Y(), new ushort[] { 0, 1, 32767, 32768, 65534, 65535 });
+	}
+	
+	public static void ArrayInt()
+	{
+		X(Y(), new int[] { 1, -2, 2000000000, 4, 5, -6, 7, 8, 9, 10 });
+	}
+	
+	public static void ArrayUInt()
+	{
+		X(Y(), new uint[] { 1, 2000000000, 3000000000, 4, 5, 6, 7, 8, 9, 10 });
+	}
+	
+	public static void ArrayLong()
+	{
+		X(Y(), new long[] { -4999999999999999999, -1, 0, 1, 4999999999999999999 });
+	}
+	
+	public static void ArrayULong()
+	{
+		X(Y(), new ulong[] { 1, 2000000000, 3000000000, 4, 5, 6, 7, 8, 4999999999999999999, 9999999999999999999 });
+	}
+	
+	public static void ArrayFloat()
+	{
+		X(Y(), new float[] { -1.5f, 0f, 1.5f, float.NegativeInfinity, float.PositiveInfinity, float.NaN });
+	}
+	
+	public static void ArrayDouble()
+	{
+		X(Y(), new double[] { -1.5, 0.0, 1.5, double.NegativeInfinity, double.PositiveInfinity, double.NaN });
+	}
+	
+	public static void ArrayDecimal()
+	{
+		X(Y(), new decimal[] { -100m, 0m, 100m, decimal.MinValue, decimal.MaxValue, 0.0000001m });
+	}
+	
+	public static void ArrayString()
+	{
+		X(Y(), new string[] { "", null, "Hello", "World" });
+	}
 }

ICSharpCode.Decompiler/Tests/ICSharpCode.Decompiler.Tests.csproj

@@ -53,6 +53,7 @@
     </Reference>
   </ItemGroup>
   <ItemGroup>
+    <Compile Include="Switch.cs" />
     <Compile Include="YieldReturn.cs" />
     <None Include="Types\S_EnumSamples.cs" />
     <None Include="CustomAttributes\S_AssemblyCustomAttribute.cs" />

ICSharpCode.Decompiler/Tests/Switch.cs

@@ -0,0 +1,37 @@
+// 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)
+
+using System;
+
+public static class Switch
+{
+	public static string ShortSwitchOverString(string text)
+	{
+		switch (text) {
+			case "First case":
+				return "Text";
+			default:
+				return "Default";
+		}
+	}
+	
+	public static string SwitchOverString(string text)
+	{
+		switch (text) {
+			case "First case":
+				return "Text1";
+			case "Second case":
+				return "Text2";
+			case "Third case":
+				return "Text3";
+			case "Fourth case":
+				return "Text4";
+			case "Fifth case":
+				return "Text5";
+			case "Sixth case":
+				return "Text6";
+			default:
+				return "Default";
+		}
+	}
+}