mcs/class/System.Core/System.Linq.Expressions/EmitContext.cs

   1 //
   2 // EmitContext.cs
   3 //
   4 // Author:
   5 //   Miguel de Icaza (miguel@novell.com)
   6 //   Jb Evain (jbevain@novell.com)
   7 //
   8 // (C) 2008 Novell, Inc. (http://www.novell.com)
   9 //
  10 // Permission is hereby granted, free of charge, to any person obtaining
  11 // a copy of this software and associated documentation files (the
  12 // "Software"), to deal in the Software without restriction, including
  13 // without limitation the rights to use, copy, modify, merge, publish,
  14 // distribute, sublicense, and/or sell copies of the Software, and to
  15 // permit persons to whom the Software is furnished to do so, subject to
  16 // the following conditions:
  17 //
  18 // The above copyright notice and this permission notice shall be
  19 // included in all copies or substantial portions of the Software.
  20 //
  21 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  22 // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  23 // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  24 // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
  25 // LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
  26 // OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  27 // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  28 //
  29
  30 using System;
  31 using System.Collections.Generic;
  32 using System.IO;
  33 using System.Linq;
  34 using System.Reflection;
  35 using System.Reflection.Emit;
  36
  37 namespace System.Linq.Expressions {
  38
  39         abstract class EmitContext {
  40
  41                 protected LambdaExpression owner;
  42                 protected Type [] param_types;
  43                 protected Type return_type;
  44
  45                 public ILGenerator ig;
  46
  47                 protected EmitContext (LambdaExpression lambda)
  48                 {
  49                         this.owner = lambda;
  50
  51                         param_types = owner.Parameters.Select (p => p.Type).ToArray ();
  52                         return_type = owner.GetReturnType ();
  53                 }
  54
  55                 public static EmitContext Create (LambdaExpression lambda)
  56                 {
  57 #if !NET_2_1
  58                         if (Environment.GetEnvironmentVariable ("LINQ_DBG") != null)
  59                                 return new DebugEmitContext (lambda);
  60 #endif
  61                         return new DynamicEmitContext (lambda);
  62                 }
  63
  64                 public int GetParameterPosition (ParameterExpression p)
  65                 {
  66                         int position = owner.Parameters.IndexOf (p);
  67                         if (position == -1)
  68                                 throw new InvalidOperationException ("Parameter not in scope");
  69
  70                         return position;
  71                 }
  72
  73                 public abstract Delegate CreateDelegate ();
  74
  75                 public void Emit (Expression expression)
  76                 {
  77                         expression.Emit (this);
  78                 }
  79
  80                 public LocalBuilder EmitStored (Expression expression)
  81                 {
  82                         var local = ig.DeclareLocal (expression.Type);
  83                         expression.Emit (this);
  84                         ig.Emit (OpCodes.Stloc, local);
  85
  86                         return local;
  87                 }
  88
  89                 public void EmitLoad (Expression expression)
  90                 {
  91                         if (expression.Type.IsValueType) {
  92                                 var local = EmitStored (expression);
  93                                 ig.Emit (OpCodes.Ldloca, local);
  94                         } else
  95                                 expression.Emit (this);
  96                 }
  97
  98                 public void EmitLoad (LocalBuilder local)
  99                 {
 100                         ig.Emit (OpCodes.Ldloc, local);
 101                 }
 102
 103                 public void EmitCall (LocalBuilder local, IEnumerable<Expression> arguments, MethodInfo method)
 104                 {
 105                         EmitLoad (local);
 106                         EmitCollection (arguments);
 107                         EmitCall (method);
 108                 }
 109
 110                 public void EmitCall (Expression expression, IEnumerable<Expression> arguments, MethodInfo method)
 111                 {
 112                         if (expression != null)
 113                                 EmitLoad (expression);
 114
 115                         EmitCollection (arguments);
 116                         EmitCall (method);
 117                 }
 118
 119                 public void EmitCall (MethodInfo method)
 120                 {
 121                         ig.Emit (
 122                                 method.IsVirtual ? OpCodes.Callvirt : OpCodes.Call,
 123                                 method);
 124                 }
 125
 126                 public void EmitCollection<T> (IEnumerable<T> collection) where T : Expression
 127                 {
 128                         foreach (var expression in collection)
 129                                 expression.Emit (this);
 130                 }
 131
 132                 public void EmitCollection (IEnumerable<ElementInit> initializers, LocalBuilder local)
 133                 {
 134                         foreach (var initializer in initializers)
 135                                 initializer.Emit (this, local);
 136                 }
 137
 138                 public void EmitCollection (IEnumerable<MemberBinding> bindings, LocalBuilder local)
 139                 {
 140                         foreach (var binding in bindings)
 141                                 binding.Emit (this, local);
 142                 }
 143
 144                 public void EmitIsInst (Expression expression, Type candidate)
 145                 {
 146                         expression.Emit (this);
 147
 148                         if (expression.Type.IsValueType)
 149                                 ig.Emit (OpCodes.Box, expression.Type);
 150
 151                         ig.Emit (OpCodes.Isinst, candidate);
 152                 }
 153         }
 154
 155         class DynamicEmitContext : EmitContext {
 156
 157                 DynamicMethod method;
 158
 159                 static object mlock = new object ();
 160                 static int method_count;
 161
 162                 public DynamicMethod Method {
 163                         get { return method; }
 164                 }
 165
 166                 public DynamicEmitContext (LambdaExpression lambda)
 167                         : base (lambda)
 168                 {
 169                         // FIXME: Need to force this to be verifiable, see:
 170                         // https://bugzilla.novell.com/show_bug.cgi?id=355005
 171                         method = new DynamicMethod (GenerateName (), return_type, param_types, typeof (EmitContext), true);
 172                         ig = method.GetILGenerator ();
 173
 174                         owner.Emit (this);
 175                 }
 176
 177                 public override Delegate CreateDelegate ()
 178                 {
 179                         return method.CreateDelegate (owner.Type);
 180                 }
 181
 182                 static string GenerateName ()
 183                 {
 184                         lock (mlock) {
 185                                 return "lambda_method-" + (method_count++);
 186                         }
 187                 }
 188         }
 189
 190 #if !NET_2_1
 191         class DebugEmitContext : EmitContext {
 192
 193                 DynamicEmitContext dynamic_context;
 194
 195                 public DebugEmitContext (LambdaExpression lambda)
 196                         : base (lambda)
 197                 {
 198                         dynamic_context = new DynamicEmitContext (lambda);
 199
 200                         var name = dynamic_context.Method.Name;
 201                         var file_name = name + ".dll";
 202
 203                         var assembly = AppDomain.CurrentDomain.DefineDynamicAssembly (
 204                                 new AssemblyName (name), AssemblyBuilderAccess.RunAndSave, Path.GetTempPath ());
 205
 206                         var type = assembly.DefineDynamicModule (file_name, file_name).DefineType ("Linq", TypeAttributes.Public);
 207
 208                         var method = type.DefineMethod (name, MethodAttributes.Public | MethodAttributes.Static, return_type, param_types);
 209                         ig = method.GetILGenerator ();
 210
 211                         owner.Emit (this);
 212
 213                         type.CreateType ();
 214                         assembly.Save (file_name);
 215                 }
 216
 217                 public override Delegate CreateDelegate ()
 218                 {
 219                         return dynamic_context.CreateDelegate ();
 220                 }
 221         }
 222 #endif
 223 }