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 (Environment.GetEnvironmentVariable ("LINQ_DBG") != null)
  58                                 return new DebugEmitContext (lambda);
  59
  60                         return new DynamicEmitContext (lambda);
  61                 }
  62
  63                 public int GetParameterPosition (ParameterExpression p)
  64                 {
  65                         int position = owner.Parameters.IndexOf (p);
  66                         if (position == -1)
  67                                 throw new InvalidOperationException ("Parameter not in scope");
  68
  69                         return position;
  70                 }
  71
  72                 public abstract Delegate CreateDelegate ();
  73
  74                 public void Emit (Expression expression)
  75                 {
  76                         expression.Emit (this);
  77                 }
  78
  79                 public LocalBuilder EmitStored (Expression expression)
  80                 {
  81                         var local = ig.DeclareLocal (expression.Type);
  82                         expression.Emit (this);
  83                         ig.Emit (OpCodes.Stloc, local);
  84
  85                         return local;
  86                 }
  87
  88                 public void EmitLoad (Expression expression)
  89                 {
  90                         if (expression.Type.IsValueType) {
  91                                 var local = EmitStored (expression);
  92                                 ig.Emit (OpCodes.Ldloca, local);
  93                         } else
  94                                 expression.Emit (this);
  95                 }
  96
  97                 public void EmitLoad (LocalBuilder local)
  98                 {
  99                         ig.Emit (OpCodes.Ldloc, local);
 100                 }
 101
 102                 public void EmitCall (LocalBuilder local, IEnumerable<Expression> arguments, MethodInfo method)
 103                 {
 104                         EmitLoad (local);
 105                         EmitCollection (arguments);
 106                         EmitCall (method);
 107                 }
 108
 109                 public void EmitCall (Expression expression, IEnumerable<Expression> arguments, MethodInfo method)
 110                 {
 111                         if (expression != null)
 112                                 EmitLoad (expression);
 113
 114                         EmitCollection (arguments);
 115                         EmitCall (method);
 116                 }
 117
 118                 public void EmitCall (MethodInfo method)
 119                 {
 120                         ig.Emit (
 121                                 method.IsVirtual ? OpCodes.Callvirt : OpCodes.Call,
 122                                 method);
 123                 }
 124
 125                 public void EmitCollection<T> (IEnumerable<T> collection) where T : Expression
 126                 {
 127                         foreach (var expression in collection)
 128                                 expression.Emit (this);
 129                 }
 130
 131                 public void EmitCollection (IEnumerable<ElementInit> initializers, LocalBuilder local)
 132                 {
 133                         foreach (var initializer in initializers)
 134                                 initializer.Emit (this, local);
 135                 }
 136
 137                 public void EmitCollection (IEnumerable<MemberBinding> bindings, LocalBuilder local)
 138                 {
 139                         foreach (var binding in bindings)
 140                                 binding.Emit (this, local);
 141                 }
 142
 143                 public void EmitIsInst (Expression expression, Type candidate)
 144                 {
 145                         expression.Emit (this);
 146
 147                         if (expression.Type.IsValueType)
 148                                 ig.Emit (OpCodes.Box, expression.Type);
 149
 150                         ig.Emit (OpCodes.Isinst, candidate);
 151                 }
 152         }
 153
 154         class DynamicEmitContext : EmitContext {
 155
 156                 DynamicMethod method;
 157
 158                 static object mlock = new object ();
 159                 static int method_count;
 160
 161                 public DynamicMethod Method {
 162                         get { return method; }
 163                 }
 164
 165                 public DynamicEmitContext (LambdaExpression lambda)
 166                         : base (lambda)
 167                 {
 168                         // FIXME: Need to force this to be verifiable, see:
 169                         // https://bugzilla.novell.com/show_bug.cgi?id=355005
 170                         method = new DynamicMethod (GenerateName (), return_type, param_types, typeof (EmitContext), true);
 171                         ig = method.GetILGenerator ();
 172
 173                         owner.Emit (this);
 174                 }
 175
 176                 public override Delegate CreateDelegate ()
 177                 {
 178                         return method.CreateDelegate (owner.Type);
 179                 }
 180
 181                 static string GenerateName ()
 182                 {
 183                         lock (mlock) {
 184                                 return "lambda_method-" + (method_count++);
 185                         }
 186                 }
 187         }
 188
 189         class DebugEmitContext : EmitContext {
 190
 191                 DynamicEmitContext dynamic_context;
 192
 193                 public DebugEmitContext (LambdaExpression lambda)
 194                         : base (lambda)
 195                 {
 196                         dynamic_context = new DynamicEmitContext (lambda);
 197
 198                         var name = dynamic_context.Method.Name;
 199                         var file_name = name + ".dll";
 200
 201                         var assembly = AppDomain.CurrentDomain.DefineDynamicAssembly (
 202                                 new AssemblyName (name), AssemblyBuilderAccess.RunAndSave, Path.GetTempPath ());
 203
 204                         var type = assembly.DefineDynamicModule (file_name, file_name).DefineType ("Linq", TypeAttributes.Public);
 205
 206                         var method = type.DefineMethod (name, MethodAttributes.Public | MethodAttributes.Static, return_type, param_types);
 207                         ig = method.GetILGenerator ();
 208
 209                         owner.Emit (this);
 210
 211                         type.CreateType ();
 212                         assembly.Save (file_name);
 213                 }
 214
 215                 public override Delegate CreateDelegate ()
 216                 {
 217                         return dynamic_context.CreateDelegate ();
 218                 }
 219         }
 220 }