Make more SimpleAST nodes singletons (fewer allocations)

src/Castle.Core/DynamicProxy/Contributors/ClassProxySerializableContributor.cs

@@ -1,4 +1,4 @@
-// Copyright 2004-2025 Castle Project - http://www.castleproject.org/
+// Copyright 2004-2026 Castle Project - http://www.castleproject.org/
 // 
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
@@ -187,7 +187,8 @@ private void GenerateSerializationConstructor(ClassEmitter emitter)
 				                              	                      typeof(object),
 				                              	                      getValue)));
 			}
-			ctor.CodeBuilder.AddStatement(new ReturnStatement());
+
+			ctor.CodeBuilder.AddStatement(ReturnStatement.Instance);
 		}
 
 		private bool VerifyIfBaseImplementsGetObjectData(Type baseType, MetaType model, out MetaMethod getObjectData)

src/Castle.Core/DynamicProxy/Contributors/ProxyTargetAccessorContributor.cs

@@ -1,4 +1,4 @@
-// Copyright 2004-2025 Castle Project - http://www.castleproject.org/
+// Copyright 2004-2026 Castle Project - http://www.castleproject.org/
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
@@ -63,7 +63,7 @@ public void Generate(ClassEmitter emitter)
 					new ThrowStatement(typeof(InvalidOperationException), "Cannot change the target of the class proxy."));
 			}
 
-			dynProxySetTarget.CodeBuilder.AddStatement(new ReturnStatement());
+			dynProxySetTarget.CodeBuilder.AddStatement(ReturnStatement.Instance);
 
 			var getInterceptors = emitter.CreateMethod(nameof(IProxyTargetAccessor.GetInterceptors), typeof(IInterceptor[]));
 

src/Castle.Core/DynamicProxy/Contributors/SerializableContributor.cs

@@ -1,4 +1,4 @@
-// Copyright 2004-2025 Castle Project - http://www.castleproject.org/
+// Copyright 2004-2026 Castle Project - http://www.castleproject.org/
 // 
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
@@ -125,7 +125,7 @@ protected void ImplementGetObjectData(ClassEmitter emitter)
 
 			CustomizeGetObjectData(getObjectData.CodeBuilder, info, getObjectData.Arguments[1], emitter);
 
-			getObjectData.CodeBuilder.AddStatement(new ReturnStatement());
+			getObjectData.CodeBuilder.AddStatement(ReturnStatement.Instance);
 		}
 
 		protected virtual void AddAddValueInvocation(ArgumentReference serializationInfo, MethodEmitter getObjectData,

src/Castle.Core/DynamicProxy/Generators/BaseProxyGenerator.cs

@@ -1,4 +1,4 @@
-// Copyright 2004-2025 Castle Project - http://www.castleproject.org/
+// Copyright 2004-2026 Castle Project - http://www.castleproject.org/
 // 
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
@@ -156,7 +156,7 @@ protected void CheckNotGenericTypeDefinitions(IEnumerable<Type> types, string ar
 
 		protected void CompleteInitCacheMethod(CodeBuilder constCodeBuilder)
 		{
-			constCodeBuilder.AddStatement(new ReturnStatement());
+			constCodeBuilder.AddStatement(ReturnStatement.Instance);
 		}
 
 		protected virtual void CreateFields(ClassEmitter emitter)
@@ -281,7 +281,7 @@ protected void GenerateConstructor(ClassEmitter emitter, ConstructorInfo baseCon
 				constructor.CodeBuilder.AddStatement(new ConstructorInvocationStatement(emitter.BaseType));
 			}
 
-			constructor.CodeBuilder.AddStatement(new ReturnStatement());
+			constructor.CodeBuilder.AddStatement(ReturnStatement.Instance);
 		}
 
 		protected void GenerateConstructors(ClassEmitter emitter, Type baseType, params FieldReference[] fields)
@@ -339,7 +339,7 @@ protected void GenerateParameterlessConstructor(ClassEmitter emitter, Type baseC
 
 			constructor.CodeBuilder.AddStatement(new ConstructorInvocationStatement(defaultConstructor));
 
-			constructor.CodeBuilder.AddStatement(new ReturnStatement());
+			constructor.CodeBuilder.AddStatement(ReturnStatement.Instance);
 		}
 
 		protected ConstructorEmitter GenerateStaticConstructor(ClassEmitter emitter)

src/Castle.Core/DynamicProxy/Generators/Emitters/ConstructorEmitter.cs

@@ -1,4 +1,4 @@
-// Copyright 2004-2025 Castle Project - http://www.castleproject.org/
+// Copyright 2004-2026 Castle Project - http://www.castleproject.org/
 // 
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
@@ -76,7 +76,7 @@ public virtual void Generate()
 					CodeBuilder.AddStatement(new ConstructorInvocationStatement(mainType.BaseType));
 				}
 
-				CodeBuilder.AddStatement(new ReturnStatement());
+				CodeBuilder.AddStatement(ReturnStatement.Instance);
 			}
 
 			CodeBuilder.Generate(builder.GetILGenerator());

src/Castle.Core/DynamicProxy/Generators/Emitters/MethodEmitter.cs

@@ -131,7 +131,7 @@ public virtual void Generate()
 			{
 				if (ReturnType == typeof(void))
 				{
-					CodeBuilder.AddStatement(new ReturnStatement());
+					CodeBuilder.AddStatement(ReturnStatement.Instance);
 				}
 				else
 				{

src/Castle.Core/DynamicProxy/Generators/Emitters/SimpleAST/EndExceptionBlockStatement.cs

@@ -1,4 +1,4 @@
-// Copyright 2004-2021 Castle Project - http://www.castleproject.org/
+// Copyright 2004-2026 Castle Project - http://www.castleproject.org/
 // 
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
@@ -16,8 +16,14 @@ namespace Castle.DynamicProxy.Generators.Emitters.SimpleAST
 {
 	using System.Reflection.Emit;
 
-	internal class EndExceptionBlockStatement : IStatement
+	internal sealed class EndExceptionBlockStatement : IStatement
 	{
+		public static readonly EndExceptionBlockStatement Instance = new EndExceptionBlockStatement();
+
+		private EndExceptionBlockStatement()
+		{
+		}
+
 		public void Emit(ILGenerator gen)
 		{
 			gen.EndExceptionBlock();

src/Castle.Core/DynamicProxy/Generators/Emitters/SimpleAST/FinallyStatement.cs

@@ -1,4 +1,4 @@
-// Copyright 2004-2021 Castle Project - http://www.castleproject.org/
+// Copyright 2004-2026 Castle Project - http://www.castleproject.org/
 // 
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
@@ -16,8 +16,14 @@ namespace Castle.DynamicProxy.Generators.Emitters.SimpleAST
 {
 	using System.Reflection.Emit;
 
-	internal class FinallyStatement : IStatement
+	internal sealed class FinallyStatement : IStatement
 	{
+		public static readonly FinallyStatement Instance = new FinallyStatement();
+
+		private FinallyStatement()
+		{
+		}
+
 		public void Emit(ILGenerator gen)
 		{
 			gen.BeginFinallyBlock();

src/Castle.Core/DynamicProxy/Generators/Emitters/SimpleAST/ReturnStatement.cs

@@ -1,4 +1,4 @@
-// Copyright 2004-2025 Castle Project - http://www.castleproject.org/
+// Copyright 2004-2026 Castle Project - http://www.castleproject.org/
 // 
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
@@ -18,11 +18,13 @@ namespace Castle.DynamicProxy.Generators.Emitters.SimpleAST
 {
 	using System.Reflection.Emit;
 
-	internal class ReturnStatement : IStatement
+	internal sealed class ReturnStatement : IStatement
 	{
+		public static readonly ReturnStatement Instance = new ReturnStatement();
+
 		private readonly IExpression? expression;
 
-		public ReturnStatement()
+		private ReturnStatement()
 		{
 		}
 

src/Castle.Core/DynamicProxy/Generators/Emitters/SimpleAST/TryStatement.cs

@@ -1,4 +1,4 @@
-// Copyright 2004-2021 Castle Project - http://www.castleproject.org/
+// Copyright 2004-2026 Castle Project - http://www.castleproject.org/
 // 
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
@@ -16,8 +16,14 @@ namespace Castle.DynamicProxy.Generators.Emitters.SimpleAST
 {
 	using System.Reflection.Emit;
 
-	internal class TryStatement : IStatement
+	internal sealed class TryStatement : IStatement
 	{
+		public static readonly TryStatement Instance = new TryStatement();
+
+		private TryStatement()
+		{
+		}
+
 		public void Emit(ILGenerator gen)
 		{
 			gen.BeginExceptionBlock();

src/Castle.Core/DynamicProxy/Generators/InvocationTypeGenerator.cs

@@ -1,4 +1,4 @@
-// Copyright 2004-2025 Castle Project - http://www.castleproject.org/
+// Copyright 2004-2026 Castle Project - http://www.castleproject.org/
 // 
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
@@ -179,7 +179,7 @@ protected virtual void ImplementInvokeMethodOnTarget(ClassEmitter invocation, Pa
 
 			if (byRefArguments.Count > 0)
 			{
-				invokeMethodOnTarget.CodeBuilder.AddStatement(new TryStatement());
+				invokeMethodOnTarget.CodeBuilder.AddStatement(TryStatement.Instance);
 			}
 
 			var methodOnTargetInvocationExpression = GetCallbackMethodInvocation(invocation, args, callbackMethod, targetField, invokeMethodOnTarget);
@@ -225,7 +225,7 @@ protected virtual void ImplementInvokeMethodOnTarget(ClassEmitter invocation, Pa
 				invokeMethodOnTarget.CodeBuilder.AddStatement(setRetVal);
 			}
 
-			invokeMethodOnTarget.CodeBuilder.AddStatement(new ReturnStatement());
+			invokeMethodOnTarget.CodeBuilder.AddStatement(ReturnStatement.Instance);
 		}
 
 		private void AssignBackByRefArguments(MethodEmitter invokeMethodOnTarget, Dictionary<int, LocalReference> byRefArguments)
@@ -235,7 +235,8 @@ private void AssignBackByRefArguments(MethodEmitter invokeMethodOnTarget, Dictio
 				return;
 			}
 
-			invokeMethodOnTarget.CodeBuilder.AddStatement(new FinallyStatement());
+			invokeMethodOnTarget.CodeBuilder.AddStatement(FinallyStatement.Instance);
+
 			foreach (var byRefArgument in byRefArguments)
 			{
 				var index = byRefArgument.Key;
@@ -265,7 +266,8 @@ private void AssignBackByRefArguments(MethodEmitter invokeMethodOnTarget, Dictio
 						new LiteralIntExpression(index),
 						localValue));
 			}
-			invokeMethodOnTarget.CodeBuilder.AddStatement(new EndExceptionBlockStatement());
+
+			invokeMethodOnTarget.CodeBuilder.AddStatement(EndExceptionBlockStatement.Instance);
 		}
 
 		private void CreateConstructor(ClassEmitter invocation)
@@ -275,7 +277,7 @@ private void CreateConstructor(ClassEmitter invocation)
 
 			var constructor = CreateConstructor(invocation, baseCtorArguments);
 			constructor.CodeBuilder.AddStatement(new ConstructorInvocationStatement(baseConstructor, baseCtorArguments));
-			constructor.CodeBuilder.AddStatement(new ReturnStatement());
+			constructor.CodeBuilder.AddStatement(ReturnStatement.Instance);
 		}
 
 		private ConstructorEmitter CreateConstructor(ClassEmitter invocation, ArgumentReference[] baseCtorArguments)
@@ -292,7 +294,7 @@ private void EmitCallThrowOnNoTarget(MethodEmitter invokeMethodOnTarget)
 			var throwOnNoTarget = new MethodInvocationExpression(InvocationMethods.ThrowOnNoTarget);
 
 			invokeMethodOnTarget.CodeBuilder.AddStatement(throwOnNoTarget);
-			invokeMethodOnTarget.CodeBuilder.AddStatement(new ReturnStatement());
+			invokeMethodOnTarget.CodeBuilder.AddStatement(ReturnStatement.Instance);
 		}
 
 		private MethodInfo GetCallbackMethod(ClassEmitter invocation)
@@ -336,7 +338,7 @@ private void ImplementChangeInvocationTarget(ClassEmitter invocation, FieldRefer
 			changeInvocationTarget.CodeBuilder.AddStatement(
 				new AssignStatement(targetField,
 				                    new ConvertExpression(targetType, changeInvocationTarget.Arguments[0])));
-			changeInvocationTarget.CodeBuilder.AddStatement(new ReturnStatement());
+			changeInvocationTarget.CodeBuilder.AddStatement(ReturnStatement.Instance);
 		}
 
 		private void ImplementChangeProxyTarget(ClassEmitter invocation, ClassEmitter @class)
@@ -357,7 +359,7 @@ private void ImplementChangeProxyTarget(ClassEmitter invocation, ClassEmitter @c
 					VirtualCall = true
 				});
 
-			changeProxyTarget.CodeBuilder.AddStatement(new ReturnStatement());
+			changeProxyTarget.CodeBuilder.AddStatement(ReturnStatement.Instance);
 		}
 
 		private void ImplementChangeProxyTargetInterface(ClassEmitter @class, ClassEmitter invocation,

src/Castle.Core/DynamicProxy/Generators/MethodWithInvocationGenerator.cs

@@ -1,4 +1,4 @@
-// Copyright 2004-2025 Castle Project - http://www.castleproject.org/
+// Copyright 2004-2026 Castle Project - http://www.castleproject.org/
 // 
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
@@ -118,22 +118,22 @@ protected override MethodEmitter BuildProxiedMethodBody(MethodEmitter emitter, C
 
 			if (hasByRefArguments)
 			{
-				emitter.CodeBuilder.AddStatement(new TryStatement());
+				emitter.CodeBuilder.AddStatement(TryStatement.Instance);
 			}
 
 			var proceed = new MethodInvocationExpression(invocationLocal, InvocationMethods.Proceed);
 			emitter.CodeBuilder.AddStatement(proceed);
 
 			if (hasByRefArguments)
 			{
-				emitter.CodeBuilder.AddStatement(new FinallyStatement());
+				emitter.CodeBuilder.AddStatement(FinallyStatement.Instance);
 			}
 
 			GeneratorUtil.CopyOutAndRefParameters(dereferencedArguments, invocationLocal, MethodToOverride, emitter);
 
 			if (hasByRefArguments)
 			{
-				emitter.CodeBuilder.AddStatement(new EndExceptionBlockStatement());
+				emitter.CodeBuilder.AddStatement(EndExceptionBlockStatement.Instance);
 			}
 
 			if (MethodToOverride.ReturnType != typeof(void))
@@ -172,7 +172,7 @@ protected override MethodEmitter BuildProxiedMethodBody(MethodEmitter emitter, C
 			}
 			else
 			{
-				emitter.CodeBuilder.AddStatement(new ReturnStatement());
+				emitter.CodeBuilder.AddStatement(ReturnStatement.Instance);
 			}
 
 			return emitter;

src/Castle.Core/DynamicProxy/Generators/MinimalisticMethodGenerator.cs

@@ -1,4 +1,4 @@
-// Copyright 2004-2025 Castle Project - http://www.castleproject.org/
+// Copyright 2004-2026 Castle Project - http://www.castleproject.org/
 // 
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
@@ -34,7 +34,7 @@ protected override MethodEmitter BuildProxiedMethodBody(MethodEmitter emitter, C
 
 			if (emitter.ReturnType == typeof(void))
 			{
-				emitter.CodeBuilder.AddStatement(new ReturnStatement());
+				emitter.CodeBuilder.AddStatement(ReturnStatement.Instance);
 			}
 			else
 			{

src/Castle.Core/DynamicProxy/Generators/OptionallyForwardingMethodGenerator.cs

@@ -67,7 +67,7 @@ private IStatement IfNull(Type returnType)
 
 			if (returnType == typeof(void))
 			{
-				statements.AddStatement(new ReturnStatement());
+				statements.AddStatement(ReturnStatement.Instance);
 			}
 			else
 			{