Tools/DynamicProxy/Castle.DynamicProxy/Builder/CodeBuilder/SimpleAST/ConditionExpression.cs

   1 // Copyright 2004-2007 Castle Project - http://www.castleproject.org/
   2 //
   3 // Licensed under the Apache License, Version 2.0 (the "License");
   4 // you may not use this file except in compliance with the License.
   5 // You may obtain a copy of the License at
   6 //
   7 //     http://www.apache.org/licenses/LICENSE-2.0
   8 //
   9 // Unless required by applicable law or agreed to in writing, software
  10 // distributed under the License is distributed on an "AS IS" BASIS,
  11 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  12 // See the License for the specific language governing permissions and
  13 // limitations under the License.
  14
  15 namespace Castle.DynamicProxy.Builder.CodeBuilder.SimpleAST
  16 {
  17         using System;
  18         using System.Reflection.Emit;
  19         using System.Collections;
  20
  21         /// <summary>
  22         /// Summary description for ConditionExpression.
  23         /// </summary>
  24         [CLSCompliant(false)]
  25         public class ConditionExpression : Expression
  26         {
  27                 private OpCode _operation = OpCodes.Brfalse_S;
  28                 private ArrayList _trueStmts;
  29                 private ArrayList _falseStmts;
  30                 private Expression _left;
  31                 private Expression _right;
  32
  33                 public ConditionExpression( Expression left ) : this(OpCodes.Brfalse_S, left)
  34                 {
  35                 }
  36
  37                 public ConditionExpression( OpCode operation, Expression left ) : this(operation, left, null)
  38                 {
  39                 }
  40
  41                 public ConditionExpression( OpCode operation, Expression left, Expression right )
  42                 {
  43                         _trueStmts = new ArrayList();
  44                         _falseStmts = new ArrayList();
  45
  46                         _operation = operation;
  47                         _left = left;
  48                         _right = right;
  49                 }
  50
  51                 public void AddTrueStatement( Statement stmt )
  52                 {
  53                         _trueStmts.Add( stmt );
  54                 }
  55
  56                 public void AddFalseStatement( Statement stmt )
  57                 {
  58                         _falseStmts.Add( stmt );
  59                 }
  60
  61                 public override void Emit(IEasyMember member, ILGenerator gen)
  62                 {
  63                         if (OpCodes.Brfalse.Equals(_operation) ||
  64                                 OpCodes.Brfalse_S.Equals(_operation) ||
  65                                 OpCodes.Brtrue.Equals(_operation) ||
  66                                 OpCodes.Brtrue_S.Equals(_operation) )
  67                         {
  68                                 // Unary operators
  69                                 _left.Emit(member, gen);
  70                         }
  71                         else
  72                         {
  73                                 // Binary operators
  74                                 _left.Emit(member, gen);
  75                                 _right.Emit(member, gen);
  76                         }
  77
  78                         Label truePart = gen.DefineLabel();
  79                         Label exitPart = gen.DefineLabel();
  80
  81                         gen.Emit(_operation, truePart);
  82
  83                         if (_falseStmts.Count != 0)
  84                         {
  85                                 foreach(Statement stmt in _falseStmts)
  86                                 {
  87                                         stmt.Emit(member, gen);
  88                                 }
  89                         }
  90
  91                         gen.Emit(OpCodes.Br_S, exitPart);
  92
  93                         gen.MarkLabel(truePart);
  94                         if (_trueStmts.Count != 0)
  95                         {
  96                                 foreach(Statement stmt in _trueStmts)
  97                                 {
  98                                         stmt.Emit(member, gen);
  99                                 }
 100                         }
 101
 102                         gen.MarkLabel(exitPart);
 103                 }
 104         }
 105 }