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

   1 //
   2 // NewArrayExpression.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.Collections.ObjectModel;
  31 using System.Linq;
  32 using System.Reflection;
  33 using System.Reflection.Emit;
  34
  35 namespace System.Linq.Expressions {
  36
  37         public sealed class NewArrayExpression : Expression {
  38
  39                 ReadOnlyCollection<Expression> expressions;
  40
  41                 public ReadOnlyCollection<Expression> Expressions {
  42                         get { return expressions; }
  43                 }
  44
  45                 internal NewArrayExpression (ExpressionType et, Type type, ReadOnlyCollection<Expression> expressions)
  46                         : base (et, type)
  47                 {
  48                         this.expressions = expressions;
  49                 }
  50
  51                 void EmitNewArrayInit (EmitContext ec, Type type)
  52                 {
  53                         var size = expressions.Count;
  54
  55                         ec.ig.Emit (OpCodes.Ldc_I4, size);
  56                         ec.ig.Emit (OpCodes.Newarr, type);
  57
  58                         for (int i = 0; i < size; i++) {
  59                                 ec.ig.Emit (OpCodes.Dup);
  60                                 ec.ig.Emit (OpCodes.Ldc_I4, i);
  61                                 expressions [i].Emit (ec);
  62                                 ec.ig.Emit (OpCodes.Stelem, type);
  63                         }
  64                 }
  65
  66                 void EmitNewArrayBounds (EmitContext ec, Type type)
  67                 {
  68                         int rank = expressions.Count;
  69
  70                         ec.EmitCollection (expressions);
  71
  72                         if (rank == 1) {
  73                                 ec.ig.Emit (OpCodes.Newarr, type);
  74                                 return;
  75                         }
  76
  77                         ec.ig.Emit(OpCodes.Newobj, GetArrayConstructor (type, rank));
  78                 }
  79
  80                 static ConstructorInfo GetArrayConstructor (Type type, int rank)
  81                 {
  82                         return CreateArray (type, rank).GetConstructor (CreateTypeParameters (rank));
  83                 }
  84
  85                 static Type [] CreateTypeParameters (int rank)
  86                 {
  87                         return Enumerable.Repeat (typeof (int), rank).ToArray ();
  88                 }
  89
  90                 static Type CreateArray (Type type, int rank)
  91                 {
  92                         return type.MakeArrayType (rank);
  93                 }
  94
  95                 internal override void Emit (EmitContext ec)
  96                 {
  97                         var type = this.Type.GetElementType ();
  98
  99                         switch (this.NodeType) {
 100                         case ExpressionType.NewArrayInit:
 101                                 EmitNewArrayInit (ec, type);
 102                                 return;
 103                         case ExpressionType.NewArrayBounds:
 104                                 EmitNewArrayBounds (ec, type);
 105                                 return;
 106                         default:
 107                                 throw new NotSupportedException ();
 108                         }
 109                 }
 110         }
 111 }