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

   1 //
   2 // MemberBinding.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
  33 namespace System.Linq.Expressions {
  34
  35         public abstract class MemberBinding {
  36
  37                 MemberBindingType binding_type;
  38                 MemberInfo member;
  39
  40                 public MemberBindingType BindingType {
  41                         get { return binding_type; }
  42                 }
  43
  44                 public MemberInfo Member {
  45                         get { return member; }
  46                 }
  47
  48                 protected MemberBinding (MemberBindingType binding_type, MemberInfo member)
  49                 {
  50                         this.binding_type = binding_type;
  51                         this.member = member;
  52                 }
  53
  54                 public override string ToString ()
  55                 {
  56                         return ExpressionPrinter.ToString (this);
  57                 }
  58
  59                 internal abstract void Emit (EmitContext ec, LocalBuilder local);
  60
  61                 internal LocalBuilder EmitLoadMember (EmitContext ec, LocalBuilder local)
  62                 {
  63                         ec.EmitLoadSubject (local);
  64
  65                         return member.OnFieldOrProperty<LocalBuilder> (
  66                                 field => EmitLoadField (ec, field),
  67                                 prop => EmitLoadProperty (ec, prop));
  68                 }
  69
  70                 LocalBuilder EmitLoadProperty (EmitContext ec, PropertyInfo property)
  71                 {
  72                         var getter = property.GetGetMethod (true);
  73                         if (getter == null)
  74                                 throw new NotSupportedException ();
  75
  76                         var store = ec.ig.DeclareLocal (property.PropertyType);
  77                         ec.EmitCall (getter);
  78                         ec.ig.Emit (OpCodes.Stloc, store);
  79                         return store;
  80                 }
  81
  82                 LocalBuilder EmitLoadField (EmitContext ec, FieldInfo field)
  83                 {
  84                         var store = ec.ig.DeclareLocal (field.FieldType);
  85                         ec.ig.Emit (OpCodes.Ldfld, field);
  86                         ec.ig.Emit (OpCodes.Stloc, store);
  87                         return store;
  88                 }
  89         }
  90 }