//
// ParameterExpression.cs
//
// Author:
// Jb Evain (jbevain@novell.com)
// Miguel de Icaza (miguel@novell.com)
//
// (C) 2008 Novell, Inc. (http://www.novell.com)
//
// Permission is hereby granted, free of charge, to any person obtaining
// a copy of this software and associated documentation files (the
// "Software"), to deal in the Software without restriction, including
// without limitation the rights to use, copy, modify, merge, publish,
// distribute, sublicense, and/or sell copies of the Software, and to
// permit persons to whom the Software is furnished to do so, subject to
// the following conditions:
//
// The above copyright notice and this permission notice shall be
// included in all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
// EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
// NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
// LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
// OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
// WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
//
using System;
using System.Reflection.Emit;
namespace System.Linq.Expressions{
public sealed class ParameterExpression : Expression {
string name;
public string Name {
get { return name; }
}
internal ParameterExpression (Type type, string name)
: base (ExpressionType.Parameter, type)
{
this.name = name;
}
void EmitLocalParameter (EmitContext ec, int position)
{
ec.ig.Emit (OpCodes.Ldarg, position);
}
void EmitHoistedLocal (EmitContext ec, int level, int position)
{
ec.EmitScope ();
for (int i = 0; i < level; i++)
ec.EmitParentScope ();
ec.EmitLoadLocals ();
ec.ig.Emit (OpCodes.Ldc_I4, position);
ec.ig.Emit (OpCodes.Ldelem, typeof (object));
ec.EmitLoadStrongBoxValue (Type);
}
internal override void Emit (EmitContext ec)
{
int position = -1;
if (ec.IsLocalParameter (this, ref position)) {
EmitLocalParameter (ec, position);
return;
}
int level = 0;
if (ec.IsHoistedLocal (this, ref level, ref position)) {
EmitHoistedLocal (ec, level, position);
return;
}
throw new InvalidOperationException ("Parameter out of scope");
}
}
}
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