class/System.Core/System.Linq.Expressions/MemberAssignment.cs

   1 //
   2 // MemberAssignement.cs
   3 //
   4 // Author:
   5 //   Jb Evain (jbevain@novell.com)
   6 //
   7 // (C) 2008 Novell, Inc. (http://www.novell.com)
   8 //
   9 // Permission is hereby granted, free of charge, to any person obtaining
  10 // a copy of this software and associated documentation files (the
  11 // "Software"), to deal in the Software without restriction, including
  12 // without limitation the rights to use, copy, modify, merge, publish,
  13 // distribute, sublicense, and/or sell copies of the Software, and to
  14 // permit persons to whom the Software is furnished to do so, subject to
  15 // the following conditions:
  16 //
  17 // The above copyright notice and this permission notice shall be
  18 // included in all copies or substantial portions of the Software.
  19 //
  20 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  21 // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  22 // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  23 // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
  24 // LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
  25 // OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  26 // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  27 //
  28
  29 using System;
  30 using System.Reflection;
  31 using System.Reflection.Emit;
  32 using System.Text;
  33
  34 namespace System.Linq.Expressions {
  35
  36         public sealed class MemberAssignment : MemberBinding {
  37
  38                 Expression expression;
  39
  40                 public Expression Expression {
  41                         get { return expression; }
  42                 }
  43
  44                 internal MemberAssignment (MemberInfo member, Expression expression)
  45                         : base (MemberBindingType.Assignment, member)
  46                 {
  47                         this.expression = expression;
  48                 }
  49
  50                 internal override void Emit (EmitContext ec, LocalBuilder local)
  51                 {
  52                         this.Member.OnFieldOrProperty (
  53                                 field => EmitFieldAssignment (ec, field, local),
  54                                 prop => EmitPropertyAssignment (ec, prop, local));
  55                 }
  56
  57                 void EmitFieldAssignment (EmitContext ec, FieldInfo field, LocalBuilder local)
  58                 {
  59                         ec.EmitLoadSubject (local);
  60                         expression.Emit (ec);
  61                         ec.ig.Emit (OpCodes.Stfld, field);
  62                 }
  63
  64                 void EmitPropertyAssignment (EmitContext ec, PropertyInfo property, LocalBuilder local)
  65                 {
  66                         var setter = property.GetSetMethod (true);
  67                         if (setter == null)
  68                                 throw new InvalidOperationException ();
  69
  70                         ec.EmitLoadSubject (local);
  71                         expression.Emit (ec);
  72                         ec.EmitCall (setter);
  73                 }
  74         }
  75 }