Fix bugs in Expression.Quote/Expression.Invoke handling

Fix bugs in operator handling

ICSharpCode.Decompiler.Tests/TestCases/Pretty/ExpressionTrees.cs

@@ -93,7 +93,7 @@ public class ExpressionTrees
 	
 	public void ArrayIndex()
 	{
-		ExpressionTrees.ToCode(ExpressionTrees.X(), () => (new[] {
+		ExpressionTrees.ToCode(ExpressionTrees.X(), () => (new int[3] {
 			3,
 			4,
 			5
@@ -119,7 +119,7 @@ public class ExpressionTrees
 	
 	public void ComplexGenericName()
 	{
-		ExpressionTrees.ToCode(ExpressionTrees.X(), () => ((Func<int, bool>)(x => x > 0))(0));
+		ExpressionTrees.ToCode(ExpressionTrees.X(), () => ((Func<int, bool>)((int x) => x > 0))(0));
 	}
 	
 	public void DefaultValue()
@@ -134,7 +134,7 @@ public class ExpressionTrees
 	
 	public void IndexerAccess()
 	{
-		var dict = Enumerable.Range(1, 20).ToDictionary(n => n.ToString());
+		Dictionary<string, int> dict = Enumerable.Range(1, 20).ToDictionary((int n) => n.ToString());
 		ExpressionTrees.ToCode(ExpressionTrees.X(), () => dict["3"] == 3);
 	}
 	
@@ -213,28 +213,28 @@ public class ExpressionTrees
 	public void MembersDefault()
 	{
 		ExpressionTrees.ToCode(ExpressionTrees.X(), () => default(DateTime).Ticks == 0);
-		ExpressionTrees.ToCode(ExpressionTrees.X(), () => default(int[]).Length == 0);
-		ExpressionTrees.ToCode(ExpressionTrees.X(), () => default(Type).IsLayoutSequential);
-		ExpressionTrees.ToCode(ExpressionTrees.X(), () => default(List<int>).Count);
-		ExpressionTrees.ToCode(ExpressionTrees.X(), () => default(int[]).Clone() == null);
-		ExpressionTrees.ToCode(ExpressionTrees.X(), () => default(Type).IsInstanceOfType(new object()));
-		ExpressionTrees.ToCode(ExpressionTrees.X(), () => default(List<int>).AsReadOnly());
+		ExpressionTrees.ToCode(ExpressionTrees.X(), () => ((Array)null).Length == 0);
+		ExpressionTrees.ToCode(ExpressionTrees.X(), () => ((Type)null).IsLayoutSequential);
+		ExpressionTrees.ToCode(ExpressionTrees.X(), () => ((List<int>)null).Count);
+		ExpressionTrees.ToCode(ExpressionTrees.X(), () => ((Array)null).Clone() == null);
+		ExpressionTrees.ToCode(ExpressionTrees.X(), () => ((Type)null).IsInstanceOfType(new object()));
+		ExpressionTrees.ToCode(ExpressionTrees.X(), () => ((List<int>)null).AsReadOnly());
 	}
 	
 	public void DoAssert()
 	{
-		field = 37;
-		ExpressionTrees.ToCode(ExpressionTrees.X(), () => field != C());
-		ExpressionTrees.ToCode(ExpressionTrees.X(), () => !ReferenceEquals(this, new ExpressionTrees()));
-		ExpressionTrees.ToCode(ExpressionTrees.X(), () => MyEquals(this) && !MyEquals(default(ExpressionTrees)));
+		this.field = 37;
+		ExpressionTrees.ToCode(ExpressionTrees.X(), () => this.field != this.C());
+		ExpressionTrees.ToCode(ExpressionTrees.X(), () => !object.ReferenceEquals(this, new ExpressionTrees()));
+		ExpressionTrees.ToCode(ExpressionTrees.X(), () => this.MyEquals(this) && !this.MyEquals(null));
 	}
 	
-	int C()
+	private int C()
 	{
 		return field + 5;
 	}
-	
-	bool MyEquals(ExpressionTrees other)
+
+	private bool MyEquals(ExpressionTrees other)
 	{
 		return other != null && field == other.field;
 	}
@@ -295,18 +295,18 @@ public class ExpressionTrees
 	{
 		ExpressionTrees.ToCode<int, Func<int, Func<int, int>>>(ExpressionTrees.X(), a => b => c => a + b + c);
 	}
-	
-	bool Fizz(Func<int, bool> a)
+
+	private bool Fizz(Func<int, bool> a)
 	{
 		return a(42);
 	}
-	
-	bool Buzz(Func<int, bool> a)
+
+	private bool Buzz(Func<int, bool> a)
 	{
 		return a(42);
 	}
-	
-	bool Fizz(Func<string, bool> a)
+
+	private bool Fizz(Func<string, bool> a)
 	{
 		return a("42");
 	}
@@ -322,7 +322,15 @@ public class ExpressionTrees
 	
 	public void NewArrayAndExtensionMethod()
 	{
-		ExpressionTrees.ToCode(ExpressionTrees.X(), () => new[] { 1.0, 2.01, 3.5 }.SequenceEqual(new[] { 1.0, 2.01, 3.5 }));
+		ExpressionTrees.ToCode(ExpressionTrees.X(), () => new double[3] {
+			1.0,
+			2.01,
+			3.5
+		}.SequenceEqual(new double[3] {
+			1.0,
+			2.01,
+			3.5
+		}));
 	}
 	
 	public void NewMultiDimArray()
@@ -351,7 +359,10 @@ public class ExpressionTrees
 			CloseInput = false,
 			CheckCharacters = false
 		};
-		ExpressionTrees.ToCode(ExpressionTrees.X(), () => new XmlReaderSettings { CloseInput = s.CloseInput, CheckCharacters = s.CheckCharacters }.Equals(s));
+		ExpressionTrees.ToCode(ExpressionTrees.X(), () => new XmlReaderSettings {
+			CloseInput = s.CloseInput,
+			CheckCharacters = s.CheckCharacters
+		}.Equals(s));
 	}
 	
 	public void Quoted()
@@ -366,7 +377,12 @@ public class ExpressionTrees
 	
 	public void QuotedWithAnonymous()
 	{
-		ExpressionTrees.ToCode(ExpressionTrees.X(), () => new[] { new { X = "a", Y = "b" } }.Select(o => o.X + o.Y).Single());
+		ExpressionTrees.ToCode(ExpressionTrees.X(), () => new[] {
+			new {
+				X = "a",
+				Y = "b"
+			}
+		}.Select(o => o.X + o.Y).Single());
 	}
 	
 	public void StaticCall()

ICSharpCode.Decompiler/IL/Transforms/TransformExpressionTrees.cs

@@ -19,6 +19,7 @@
 using System;
 using System.Collections.Generic;
 using System.Linq;
+using ICSharpCode.Decompiler.CSharp.Resolver;
 using ICSharpCode.Decompiler.TypeSystem;
 using ICSharpCode.Decompiler.TypeSystem.Implementation;
 using ICSharpCode.Decompiler.Util;
@@ -134,7 +135,7 @@ namespace ICSharpCode.Decompiler.IL.Transforms
 		/// Converts a Expression.Lambda call into an ILFunction.
 		/// If the conversion fails, null is returned.
 		/// </summary>
-		ILFunction ConvertLambda(CallInstruction instruction)
+		ILInstruction ConvertLambda(CallInstruction instruction)
 		{
 			if (instruction.Method.Name != "Lambda" || instruction.Arguments.Count != 2 || instruction.Method.ReturnType.FullName != "System.Linq.Expressions.Expression" || instruction.Method.ReturnType.TypeArguments.Count != 1)
 				return null;
@@ -142,9 +143,12 @@ namespace ICSharpCode.Decompiler.IL.Transforms
 			var parameterVariablesList = new List<ILVariable>();
 			if (!ReadParameters(instruction.Arguments[1], parameterList, parameterVariablesList, new SimpleTypeResolveContext(context.Function.Method)))
 				return null;
+			bool isQuotedLambda = instruction.Parent is CallInstruction call && call.Method.FullName == "System.Linq.Expressions.Expression.Quote";
 			var container = new BlockContainer();
-			var function = new ILFunction(instruction.Method.ReturnType.TypeArguments[0].TypeArguments.LastOrDefault() ?? context.TypeSystem.Compilation.FindType(KnownTypeCode.Void), parameterList, container);
-			function.ExpressionTreeType = instruction.Method.ReturnType;
+			var functionType = instruction.Method.ReturnType.TypeArguments[0];
+			var function = new ILFunction(functionType.TypeArguments.LastOrDefault() ?? context.TypeSystem.Compilation.FindType(KnownTypeCode.Void), parameterList, container);
+			if (isQuotedLambda || lambdaStack.Count == 0)
+				function.ExpressionTreeType = instruction.Method.ReturnType;
 			function.Variables.AddRange(parameterVariablesList);
 			lambdaStack.Push(function);
 			var bodyInstruction = ConvertInstruction(instruction.Arguments[0]);
@@ -153,6 +157,10 @@ namespace ICSharpCode.Decompiler.IL.Transforms
 				return null;
 			container.ExpectedResultType = bodyInstruction.ResultType;
 			container.Blocks.Add(new Block() { Instructions = { new Leave(container, bodyInstruction) } });
+			if (!isQuotedLambda && lambdaStack.Count > 0)
+				return new NewObj(functionType.GetConstructors().Single()) {
+					Arguments = { new LdNull(), function }
+				};
 			return function;
 		}
 
@@ -348,10 +356,12 @@ namespace ICSharpCode.Decompiler.IL.Transforms
 						Arguments = { left, right }
 					};
 				case 4:
-					//if (!trueOrFalse.IsMatch(invocation.Arguments[2]))
-					//	return null;
+					if (!invocation.Arguments[2].MatchLdcI4(out var isLifted))
+						return null;
 					if (!MatchGetMethodFromHandle(invocation.Arguments[3], out method))
 						return null;
+					if (isLifted != 0)
+						method = CSharpOperators.LiftUserDefinedOperator((IMethod)method);
 					return new Call((IMethod)method) {
 						Arguments = { left, right }
 					};
@@ -459,7 +469,10 @@ namespace ICSharpCode.Decompiler.IL.Transforms
 			var right = ConvertInstruction(invocation.Arguments[1]);
 			if (right == null)
 				return null;
-			if (invocation.Arguments.Count == 3 && MatchGetMethodFromHandle(invocation.Arguments[2], out var method)) {
+			if (invocation.Arguments.Count == 4 && invocation.Arguments[2].MatchLdcI4(out var isLifted) && MatchGetMethodFromHandle(invocation.Arguments[3], out var method)) {
+				if (isLifted != 0) {
+					method = CSharpOperators.LiftUserDefinedOperator((IMethod)method);
+				}
 				return new Call((IMethod)method) { Arguments = { left, right } };
 			}
 			// TODO: Sign??
@@ -617,10 +630,12 @@ namespace ICSharpCode.Decompiler.IL.Transforms
 						Arguments = { left, right }
 					};
 				case 4:
-					//if (!trueOrFalse.IsMatch(invocation.Arguments[2]))
-					//	return null;
+					if (!invocation.Arguments[2].MatchLdcI4(out var isLifted))
+						return null;
 					if (!MatchGetMethodFromHandle(invocation.Arguments[3], out method))
 						return null;
+					if (isLifted != 0)
+						method = CSharpOperators.LiftUserDefinedOperator((IMethod)method);
 					return new Call((IMethod)method) {
 						Arguments = { left, right }
 					};