--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/Source/Aspects/Builders/MixinAspectBuilder.cs	Thu Mar 27 21:46:09 2014 +0400
@@ -0,0 +1,210 @@
+using System;
+using System.Reflection;
+using System.Reflection.Emit;
+
+using BLToolkit.TypeBuilder.Builders;
+using BLToolkit.Reflection.Emit;
+using BLToolkit.TypeBuilder;
+
+namespace BLToolkit.Aspects.Builders
+{
+	public class MixinAspectBuilder : AbstractTypeBuilderBase
+	{
+		public MixinAspectBuilder(
+			Type targetInterface, string memberName, bool throwExceptionIfNull, string exceptionMessage)
+		{
+			_targetInterface      = targetInterface;
+			_memberName           = memberName;
+			_throwExceptionIfNull = throwExceptionIfNull;
+			_exceptionMessage     = exceptionMessage;
+		}
+
+		private readonly Type   _targetInterface;
+		private readonly string _memberName;
+		private readonly bool   _throwExceptionIfNull;
+		private readonly string _exceptionMessage;
+
+		public override bool IsApplied(BuildContext context, AbstractTypeBuilderList builders)
+		{
+			return context.BuildElement == BuildElement.InterfaceMethod;
+		}
+
+		public override Type[] GetInterfaces()
+		{
+			return new Type[] { _targetInterface };
+		}
+
+		public override void Build(BuildContext context)
+		{
+			Context = context;
+
+			if (CheckOverrideAttribute())
+				return;
+
+			EmitHelper      emit   = Context.MethodBuilder.Emitter;
+			MethodInfo      method = Context.MethodBuilder.OverriddenMethod;
+			ParameterInfo[] ps     = method.GetParameters();
+			Type            memberType;
+
+			FieldInfo field = Context.Type.GetField(_memberName);
+
+			if (field != null)
+			{
+				if (field.IsPrivate)
+					throw new TypeBuilderException(string.Format(
+						"Field '{0}.{1}' must be protected or public.",
+						Context.Type.Name, _memberName));
+
+				memberType = field.FieldType;
+
+				emit
+					.ldarg_0
+					.ldfld   (field)
+					;
+
+				CheckNull(emit);
+
+				emit
+					.ldarg_0
+					.ldfld   (field)
+					;
+			}
+			else
+			{
+				PropertyInfo prop = Context.Type.GetProperty(_memberName);
+
+				if (prop != null)
+				{
+					MethodInfo mi = prop.GetGetMethod(true);
+
+					if (mi == null)
+						throw new TypeBuilderException(string.Format(
+							"Property '{0}.{1}' getter not found.",
+							Context.Type.Name, _memberName));
+
+					memberType = prop.PropertyType;
+
+					if (mi.IsPrivate)
+						throw new TypeBuilderException(string.Format(
+							"Property '{0}.{1}' getter must be protected or public.",
+							Context.Type.Name, _memberName));
+
+					emit
+						.ldarg_0
+						.callvirt (mi)
+						;
+
+					CheckNull(emit);
+
+					emit
+						.ldarg_0
+						.callvirt (mi)
+						;
+				}
+				else
+				{
+					throw new TypeBuilderException(string.Format(
+						"Member '{0}.{1}' not found.",
+						Context.Type.Name, _memberName));
+				}
+			}
+
+			emit.CastIfNecessary(_targetInterface, memberType);
+
+			for (int i = 0; i < ps.Length; i++)
+				emit.ldarg(i + 1);
+
+			emit.callvirt(method);
+
+			if (Context.ReturnValue != null)
+				emit.stloc(Context.ReturnValue);
+		}
+
+		private void CheckNull(EmitHelper emit)
+		{
+			if (_throwExceptionIfNull == false && string.IsNullOrEmpty(_exceptionMessage))
+			{
+				emit
+					.brfalse (Context.ReturnLabel)
+					;
+			}
+			else
+			{
+				string message = string.Format(
+					string.IsNullOrEmpty(_exceptionMessage)?
+						"'{0}.{1}' is not initialized." : _exceptionMessage,
+					_targetInterface.Name, _memberName, _targetInterface.FullName);
+
+				Label label = emit.DefineLabel();
+
+				emit
+					.brtrue    (label)
+					.ldstr     (message)
+					.newobj    (typeof(InvalidOperationException), typeof(string))
+					.@throw
+					.MarkLabel (label)
+					;
+			}
+		}
+
+		private bool CheckOverrideAttribute()
+		{
+			MethodInfo      method = Context.MethodBuilder.OverriddenMethod;
+			ParameterInfo[] ps     = method.GetParameters();
+
+			MethodInfo[] methods = Context.Type.GetMethods(
+				BindingFlags.Instance | BindingFlags.Public | BindingFlags.NonPublic);
+
+			foreach (MethodInfo mi in methods)
+			{
+				if (mi.IsPrivate)
+					continue;
+
+				object[] attrs = mi.GetCustomAttributes(typeof(MixinOverrideAttribute), true);
+
+				if (attrs == null || attrs.Length == 0)
+					continue;
+
+				foreach (MixinOverrideAttribute attr in attrs)
+				{
+					if (attr.TargetInterface != null &&
+						attr.TargetInterface != Context.CurrentInterface.Type)
+						continue;
+
+					string name = string.IsNullOrEmpty(attr.MethodName)?
+						mi.Name: attr.MethodName;
+
+					if (name != method.Name || mi.ReturnType != method.ReturnType)
+						continue;
+
+					ParameterInfo[] mips = mi.GetParameters();
+
+					if (mips.Length != ps.Length)
+						continue;
+
+					bool equal = true;
+
+					for (int i = 0; equal && i < ps.Length; i++)
+						equal = ps[i].ParameterType == mips[i].ParameterType;
+
+					if (equal)
+					{
+						EmitHelper emit = Context.MethodBuilder.Emitter;
+
+						for (int i = -1; i < ps.Length; i++)
+							emit.ldarg(i + 1);
+
+						emit.callvirt(mi);
+
+						if (Context.ReturnValue != null)
+							emit.stloc(Context.ReturnValue);
+
+						return true;
+					}
+				}
+			}
+
+			return false;
+		}
+	}
+}