RunSharp - Reflection.Emit Has Never Been Easier

/*
 *  RunSharp - Runtime Code Generation Library
 *  http://www.sourceforge.net/projects/runsharp
 *  Copyright (C) 2007 Stefan Simek
 *
 *  This file is part of RunSharp.
 * 
 *  RunSharp is free software: you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation, either version 3 of the License, or
 *  (at your option) any later version.
 *
 *  RunSharp is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with RunSharp.  If not, see <http://www.gnu.org/licenses/>.
 */

using System;
using System.Collections.Generic;
using System.Text;
using System.Reflection;
using System.Reflection.Emit;

namespace TriAxis.RunSharp
{
	public sealed class FieldGen : Operand, IMemberInfo
	{
		TypeGen owner;
		FieldAttributes attrs;
		string name;
		Type type;
		FieldBuilder fb;

		internal FieldGen(TypeGen owner, string name, Type type, FieldAttributes attrs)
		{
			this.owner = owner;
			this.attrs = attrs;
			this.name = name;
			this.type = type;

			fb = owner.TypeBuilder.DefineField(name, type, attrs);
		}

		public override Type Type
		{
			get
			{
				return type;
			}
		}

		public string Name { get { return name; } }
		public bool IsStatic { get { return (attrs & FieldAttributes.Static) != 0; } }

		internal override void EmitGet(CodeGen g)
		{
			if (!IsStatic)
			{
				if (g.Context.IsStatic || g.Context.OwnerType != owner.TypeBuilder)
					throw new InvalidOperationException(Properties.Messages.ErrInvalidFieldContext);

				g.IL.Emit(OpCodes.Ldarg_0);
				g.IL.Emit(OpCodes.Ldfld, fb);
			}
			else
				g.IL.Emit(OpCodes.Ldsfld, fb);
		}

		internal override void EmitSet(CodeGen g, Operand value, bool allowExplicitConversion)
		{
			if (!IsStatic)
			{
				if (g.Context.IsStatic || g.Context.OwnerType != owner.TypeBuilder)
					throw new InvalidOperationException(Properties.Messages.ErrInvalidFieldContext);

				g.IL.Emit(OpCodes.Ldarg_0);
			}

			g.EmitGetHelper(value, type, allowExplicitConversion);
			g.IL.Emit(IsStatic ? OpCodes.Stsfld : OpCodes.Stfld, fb);
		}

		internal override void EmitAddressOf(CodeGen g)
		{
			if (!IsStatic)
			{
				if (g.Context.IsStatic || g.Context.OwnerType != owner.TypeBuilder)
					throw new InvalidOperationException(Properties.Messages.ErrInvalidFieldContext);

				g.IL.Emit(OpCodes.Ldarg_0);
				g.IL.Emit(OpCodes.Ldflda, fb);
			}
			else
				g.IL.Emit(OpCodes.Ldsflda, fb);
		}

		internal override bool TrivialAccess
		{
			get
			{
				return true;
			}
		}

		#region IMemberInfo Members

		MemberInfo IMemberInfo.Member
		{
			get { return fb; }
		}

		Type IMemberInfo.ReturnType
		{
			get { return type; }
		}

		Type[] IMemberInfo.ParameterTypes
		{
			get { return Type.EmptyTypes; }
		}

		bool IMemberInfo.IsParameterArray
		{
			get { return false; }
		}

		bool IMemberInfo.IsOverride
		{
			get { return false; }
		}

		#endregion
	}
}