mcs/dynamic.cs

   1 //
   2 // dynamic.cs: support for dynamic expressions
   3 //
   4 // Authors: Marek Safar (marek.safar@gmail.com)
   5 //
   6 // Dual licensed under the terms of the MIT X11 or GNU GPL
   7 //
   8 // Copyright 2009 Novell, Inc
   9 //
  10
  11 using System;
  12 using System.Collections;
  13 using System.Reflection.Emit;
  14
  15 #if NET_4_0
  16 using System.Dynamic;
  17 using SLE = System.Linq.Expressions;
  18 #endif
  19
  20 namespace Mono.CSharp
  21 {
  22         //
  23         // A copy of Microsoft.CSharp/Microsoft.CSharp.RuntimeBinder/CSharpBinderFlags.cs
  24         // has to be kept in sync
  25         //
  26         [Flags]
  27         public enum CSharpBinderFlags
  28         {
  29                 None = 0,
  30                 CheckedContext = 1,
  31                 InvokeSimpleName = 1 << 1,
  32                 InvokeSpecialName = 1 << 2,
  33                 BinaryOperationLogical = 1 << 3,
  34                 ConvertExplicit = 1 << 4,
  35                 ConvertArrayIndex = 1 << 5,
  36                 ResultIndexed = 1 << 6,
  37                 ValueFromCompoundAssignment = 1 << 7,
  38                 ResultDiscarded = 1 << 8
  39         }
  40
  41         //
  42         // Type expression with internal dynamic type symbol
  43         //
  44         class DynamicTypeExpr : TypeExpr
  45         {
  46                 public DynamicTypeExpr (Location loc)
  47                 {
  48                         this.loc = loc;
  49
  50                         type = InternalType.Dynamic;
  51                         eclass = ExprClass.Type;
  52                 }
  53
  54                 public override bool CheckAccessLevel (IMemberContext ds)
  55                 {
  56                         return true;
  57                 }
  58
  59                 protected override TypeExpr DoResolveAsTypeStep (IMemberContext ec)
  60                 {
  61                         return this;
  62                 }
  63         }
  64
  65         //
  66         // Expression created from runtime dynamic object value
  67         //
  68         public class RuntimeValueExpression : Expression, IDynamicAssign
  69         {
  70 #if !NET_4_0
  71                 public class DynamicMetaObject { public Type RuntimeType; }
  72 #endif
  73
  74                 readonly DynamicMetaObject obj;
  75
  76                 public RuntimeValueExpression (DynamicMetaObject obj)
  77                 {
  78                         this.obj = obj;
  79                         this.type = obj.RuntimeType;
  80                         this.eclass = ExprClass.Variable;
  81                 }
  82
  83                 public override Expression CreateExpressionTree (ResolveContext ec)
  84                 {
  85                         throw new NotImplementedException ();
  86                 }
  87
  88                 public override Expression DoResolve (ResolveContext ec)
  89                 {
  90                         return this;
  91                 }
  92
  93                 public override Expression DoResolveLValue (ResolveContext ec, Expression right_side)
  94                 {
  95                         return this;
  96                 }
  97
  98                 public override void Emit (EmitContext ec)
  99                 {
 100                         throw new NotImplementedException ();
 101                 }
 102
 103                 #region IAssignMethod Members
 104
 105                 public void Emit (EmitContext ec, bool leave_copy)
 106                 {
 107                         throw new NotImplementedException ();
 108                 }
 109
 110                 public void EmitAssign (EmitContext ec, Expression source, bool leave_copy, bool prepare_for_load)
 111                 {
 112                         throw new NotImplementedException ();
 113                 }
 114
 115                 #endregion
 116
 117 #if NET_4_0
 118                 public SLE.Expression MakeAssignExpression (BuilderContext ctx)
 119                 {
 120                         return obj.Expression;
 121                 }
 122
 123                 public override SLE.Expression MakeExpression (BuilderContext ctx)
 124                 {
 125                         return SLE.Expression.Convert (obj.Expression, type);
 126                 }
 127 #endif
 128
 129                 public DynamicMetaObject MetaObject {
 130                         get { return obj; }
 131                 }
 132         }
 133
 134         //
 135         // Creates dynamic binder expression
 136         //
 137         interface IDynamicBinder
 138         {
 139                 Expression CreateCallSiteBinder (ResolveContext ec, Arguments args);
 140         }
 141
 142         //
 143         // Extends standard assignment interface for expressions
 144         // supported by dynamic resolver
 145         //
 146         interface IDynamicAssign : IAssignMethod
 147         {
 148 #if NET_4_0
 149                 SLE.Expression MakeAssignExpression (BuilderContext ctx);
 150 #endif
 151         }
 152
 153         //
 154         // Base dynamic expression statement creator
 155         //
 156         class DynamicExpressionStatement : ExpressionStatement
 157         {
 158                 class StaticDataClass : CompilerGeneratedClass
 159                 {
 160                         public StaticDataClass ()
 161                                 : base (new RootDeclSpace (new NamespaceEntry (null, null, null)),
 162                                         new MemberName (CompilerGeneratedClass.MakeName (null, "c", "DynamicSites", 0)),
 163                                         Modifiers.INTERNAL | Modifiers.STATIC)
 164                         {
 165                                 ModFlags &= ~Modifiers.SEALED;
 166                         }
 167                 }
 168
 169                 //
 170                 // Binder flag dynamic constant, the value is combination of
 171                 // flags known at resolve stage and flags known only at emit
 172                 // stage
 173                 //
 174                 protected class BinderFlags : EnumConstant
 175                 {
 176                         DynamicExpressionStatement statement;
 177                         CSharpBinderFlags flags;
 178
 179                         public BinderFlags (CSharpBinderFlags flags, DynamicExpressionStatement statement)
 180                                 : base ()
 181                         {
 182                                 this.flags = flags;
 183                                 this.statement = statement;
 184                         }
 185
 186                         public override Expression DoResolve (ResolveContext ec)
 187                         {
 188                                 Child = new IntConstant ((int) (flags | statement.flags), statement.loc);
 189
 190                                 type = TypeManager.binder_flags;
 191                                 eclass = Child.eclass;
 192                                 return this;
 193                         }
 194                 }
 195
 196                 static StaticDataClass global_site_container;
 197                 static int field_counter;
 198                 static int container_counter;
 199
 200                 readonly Arguments arguments;
 201                 protected IDynamicBinder binder;
 202                 Expression binder_expr;
 203
 204                 // Used by BinderFlags
 205                 protected CSharpBinderFlags flags;
 206
 207                 public DynamicExpressionStatement (IDynamicBinder binder, Arguments args, Location loc)
 208                 {
 209                         this.binder = binder;
 210                         this.arguments = args;
 211                         this.loc = loc;
 212                 }
 213
 214                 public Arguments Arguments {
 215                         get {
 216                                 return arguments;
 217                         }
 218                 }
 219
 220                 static TypeContainer CreateSiteContainer ()
 221                 {
 222                         if (global_site_container == null) {
 223                                 global_site_container = new StaticDataClass ();
 224                                 RootContext.ToplevelTypes.AddCompilerGeneratedClass (global_site_container);
 225                                 global_site_container.DefineType ();
 226                                 global_site_container.Define ();
 227 //                              global_site_container.EmitType ();
 228
 229                                 RootContext.RegisterCompilerGeneratedType (global_site_container.TypeBuilder);
 230                         }
 231
 232                         return global_site_container;
 233                 }
 234
 235                 static Field CreateSiteField (FullNamedExpression type)
 236                 {
 237                         TypeContainer site_container = CreateSiteContainer ();
 238                         Field f = new Field (site_container, type, Modifiers.PUBLIC | Modifiers.STATIC,
 239                                 new MemberName ("Site" +  field_counter++), null);
 240                         f.Define ();
 241
 242                         site_container.AddField (f);
 243                         return f;
 244                 }
 245
 246                 public override Expression CreateExpressionTree (ResolveContext ec)
 247                 {
 248                         throw new NotImplementedException ();
 249                 }
 250
 251                 public override Expression DoResolve (ResolveContext ec)
 252                 {
 253                         if (eclass != ExprClass.Invalid)
 254                                 return this;
 255
 256                         if (DoResolveCore (ec))
 257                                 binder_expr = binder.CreateCallSiteBinder (ec, arguments);
 258
 259                         return this;
 260                 }
 261
 262                 protected bool DoResolveCore (ResolveContext rc)
 263                 {
 264                         int errors = rc.Report.Errors;
 265
 266                         if (TypeManager.call_site_type == null)
 267                                 TypeManager.call_site_type = TypeManager.CoreLookupType (rc.Compiler,
 268                                         "System.Runtime.CompilerServices", "CallSite", Kind.Class, true);
 269
 270                         if (TypeManager.generic_call_site_type == null)
 271                                 TypeManager.generic_call_site_type = TypeManager.CoreLookupType (rc.Compiler,
 272                                         "System.Runtime.CompilerServices", "CallSite`1", Kind.Class, true);
 273
 274                         if (TypeManager.binder_type == null) {
 275                                 var t = TypeManager.CoreLookupType (rc.Compiler,
 276                                         "Microsoft.CSharp.RuntimeBinder", "Binder", Kind.Class, true);
 277                                 if (t != null)
 278                                         TypeManager.binder_type = new TypeExpression (t, Location.Null);
 279                         }
 280
 281                         if (TypeManager.binder_flags == null) {
 282                                 TypeManager.binder_flags = TypeManager.CoreLookupType (rc.Compiler,
 283                                         "Microsoft.CSharp.RuntimeBinder", "CSharpBinderFlags", Kind.Enum, true);
 284                         }
 285
 286                         eclass = ExprClass.Value;
 287
 288                         if (type == null)
 289                                 type = InternalType.Dynamic;
 290
 291                         return rc.Report.Errors == errors;
 292                 }
 293
 294                 public override void Emit (EmitContext ec)
 295                 {
 296                         EmitCall (ec, binder_expr, arguments,  false);
 297                 }
 298
 299                 public override void EmitStatement (EmitContext ec)
 300                 {
 301                         EmitCall (ec, binder_expr, arguments, true);
 302                 }
 303
 304                 protected void EmitCall (EmitContext ec, Expression binder, Arguments arguments, bool isStatement)
 305                 {
 306                         int dyn_args_count = arguments == null ? 0 : arguments.Count;
 307                         TypeExpr site_type = CreateSiteType (RootContext.ToplevelTypes.Compiler, arguments, dyn_args_count, isStatement);
 308                         FieldExpr site_field_expr = new FieldExpr (CreateSiteField (site_type).FieldBuilder, loc);
 309
 310                         SymbolWriter.OpenCompilerGeneratedBlock (ec.ig);
 311
 312                         Arguments args = new Arguments (1);
 313                         args.Add (new Argument (binder));
 314                         StatementExpression s = new StatementExpression (new SimpleAssign (site_field_expr, new Invocation (new MemberAccess (site_type, "Create"), args)));
 315
 316                         BlockContext bc = new BlockContext (ec.MemberContext, null, TypeManager.void_type);
 317                         if (s.Resolve (bc)) {
 318                                 Statement init = new If (new Binary (Binary.Operator.Equality, site_field_expr, new NullLiteral (loc)), s, loc);
 319                                 init.Emit (ec);
 320                         }
 321
 322                         args = new Arguments (1 + dyn_args_count);
 323                         args.Add (new Argument (site_field_expr));
 324                         if (arguments != null) {
 325                                 foreach (Argument a in arguments) {
 326                                         if (a is NamedArgument) {
 327                                                 // Name is not valid in this context
 328                                                 args.Add (new Argument (a.Expr, a.ArgType));
 329                                                 continue;
 330                                         }
 331
 332                                         args.Add (a);
 333                                 }
 334                         }
 335
 336                         Expression target = new DelegateInvocation (new MemberAccess (site_field_expr, "Target", loc).Resolve (bc), args, loc).Resolve (bc);
 337                         if (target != null)
 338                                 target.Emit (ec);
 339
 340                         SymbolWriter.CloseCompilerGeneratedBlock (ec.ig);
 341                 }
 342
 343                 public static MemberAccess GetBinderNamespace (Location loc)
 344                 {
 345                         return new MemberAccess (new MemberAccess (
 346                                 new QualifiedAliasMember (QualifiedAliasMember.GlobalAlias, "Microsoft", loc), "CSharp", loc), "RuntimeBinder", loc);
 347                 }
 348
 349                 public static MemberAccess GetBinder (string name, Location loc)
 350                 {
 351                         return new MemberAccess (TypeManager.binder_type, name, loc);
 352                 }
 353
 354                 TypeExpr CreateSiteType (CompilerContext ctx, Arguments arguments, int dyn_args_count, bool is_statement)
 355                 {
 356                         int default_args = is_statement ? 1 : 2;
 357
 358                         bool has_ref_out_argument = false;
 359                         FullNamedExpression[] targs = new FullNamedExpression[dyn_args_count + default_args];
 360                         targs [0] = new TypeExpression (TypeManager.call_site_type, loc);
 361                         for (int i = 0; i < dyn_args_count; ++i) {
 362                                 Type arg_type;
 363                                 Argument a = arguments [i];
 364                                 if (a.Type == TypeManager.null_type)
 365                                         arg_type = TypeManager.object_type;
 366                                 else
 367                                         arg_type = TypeManager.TypeToReflectionType (a.Type);
 368
 369                                 if (a.ArgType == Argument.AType.Out || a.ArgType == Argument.AType.Ref)
 370                                         has_ref_out_argument = true;
 371
 372                                 targs [i + 1] = new TypeExpression (arg_type, loc);
 373                         }
 374
 375                         TypeExpr del_type = null;
 376                         if (!has_ref_out_argument) {
 377                                 string d_name = is_statement ? "Action`" : "Func`";
 378
 379                                 Type t = TypeManager.CoreLookupType (ctx, "System", d_name + (dyn_args_count + default_args), Kind.Delegate, false);
 380                                 if (t != null) {
 381                                         if (!is_statement)
 382                                                 targs [targs.Length - 1] = new TypeExpression (TypeManager.TypeToReflectionType (type), loc);
 383
 384                                         del_type = new GenericTypeExpr (t, new TypeArguments (targs), loc);
 385                                 }
 386                         }
 387
 388                         //
 389                         // Create custom delegate when no appropriate predefined one is found
 390                         //
 391                         if (del_type == null) {
 392                                 Type rt = is_statement ? TypeManager.void_type : type;
 393                                 Parameter[] p = new Parameter [dyn_args_count + 1];
 394                                 p[0] = new Parameter (targs [0], "p0", Parameter.Modifier.NONE, null, loc);
 395
 396                                 for (int i = 1; i < dyn_args_count + 1; ++i)
 397                                         p[i] = new Parameter (targs[i], "p" + i.ToString ("X"), arguments[i - 1].Modifier, null, loc);
 398
 399                                 TypeContainer parent = CreateSiteContainer ();
 400                                 Delegate d = new Delegate (parent.NamespaceEntry, parent, new TypeExpression (TypeManager.TypeToReflectionType (rt), loc),
 401                                         Modifiers.INTERNAL | Modifiers.COMPILER_GENERATED,
 402                                         new MemberName ("Container" + container_counter++.ToString ("X")),
 403                                         new ParametersCompiled (p), null);
 404
 405                                 d.DefineType ();
 406                                 d.Define ();
 407
 408                                 parent.AddDelegate (d);
 409                                 del_type = new TypeExpression (d.TypeBuilder, loc);
 410                         }
 411
 412                         TypeExpr site_type = new GenericTypeExpr (TypeManager.generic_call_site_type, new TypeArguments (del_type), loc);
 413                         return site_type;
 414                 }
 415
 416                 public static void Reset ()
 417                 {
 418                         global_site_container = null;
 419                         field_counter = container_counter = 0;
 420                 }
 421         }
 422
 423         //
 424         // Dynamic member access compound assignment for events
 425         //
 426         class DynamicEventCompoundAssign : DynamicExpressionStatement, IDynamicBinder
 427         {
 428                 string name;
 429                 ExpressionStatement assignment;
 430                 ExpressionStatement invoke;
 431
 432                 public DynamicEventCompoundAssign (string name, Arguments args, ExpressionStatement assignment, ExpressionStatement invoke, Location loc)
 433                         : base (null, args, loc)
 434                 {
 435                         this.name = name;
 436                         this.assignment = assignment;
 437                         this.invoke = invoke;
 438                         base.binder = this;
 439
 440                         // Used by += or -= only
 441                         type = TypeManager.bool_type;
 442                 }
 443
 444                 public Expression CreateCallSiteBinder (ResolveContext ec, Arguments args)
 445                 {
 446                         Arguments binder_args = new Arguments (2);
 447
 448                         binder_args.Add (new Argument (new StringLiteral (name, loc)));
 449                         binder_args.Add (new Argument (new TypeOf (new TypeExpression (ec.CurrentType, loc), loc)));
 450
 451                         return new Invocation (GetBinder ("IsEvent", loc), binder_args);
 452                 }
 453
 454                 public override void EmitStatement (EmitContext ec)
 455                 {
 456                         Statement cond = new If (
 457                                 new Binary (Binary.Operator.Equality, this, new BoolLiteral (true, loc)),
 458                                 new StatementExpression (invoke),
 459                                 new StatementExpression (assignment),
 460                                 loc);
 461                         cond.Emit (ec);
 462                 }
 463         }
 464
 465         class DynamicConversion : DynamicExpressionStatement, IDynamicBinder
 466         {
 467                 public DynamicConversion (Type targetType, CSharpBinderFlags flags, Arguments args, Location loc)
 468                         : base (null, args, loc)
 469                 {
 470                         type = targetType;
 471                         base.flags = flags;
 472                         base.binder = this;
 473                 }
 474
 475                 public Expression CreateCallSiteBinder (ResolveContext ec, Arguments args)
 476                 {
 477                         Arguments binder_args = new Arguments (2);
 478
 479                         flags |= ec.HasSet (ResolveContext.Options.CheckedScope) ? CSharpBinderFlags.CheckedContext : 0;
 480
 481                         binder_args.Add (new Argument (new BinderFlags (flags, this)));
 482                         binder_args.Add (new Argument (new TypeOf (new TypeExpression (type, loc), loc)));
 483                         return new Invocation (GetBinder ("Convert", loc), binder_args);
 484                 }
 485         }
 486
 487         class DynamicIndexBinder : DynamicMemberAssignable
 488         {
 489                 public DynamicIndexBinder (Arguments args, Location loc)
 490                         : base (args, loc)
 491                 {
 492                 }
 493
 494                 protected override Expression CreateCallSiteBinder (ResolveContext ec, Arguments args, bool isSet)
 495                 {
 496                         Arguments binder_args = new Arguments (3);
 497
 498                         binder_args.Add (new Argument (new BinderFlags (0, this)));
 499                         binder_args.Add (new Argument (new TypeOf (new TypeExpression (ec.CurrentType, loc), loc)));
 500                         binder_args.Add (new Argument (new ImplicitlyTypedArrayCreation ("[]", args.CreateDynamicBinderArguments (), loc)));
 501
 502                         return new Invocation (GetBinder (isSet ? "SetIndex" : "GetIndex", loc), binder_args);
 503                 }
 504         }
 505
 506         class DynamicInvocation : DynamicExpressionStatement, IDynamicBinder
 507         {
 508                 ATypeNameExpression member;
 509
 510                 public DynamicInvocation (ATypeNameExpression member, Arguments args, Location loc)
 511                         : base (null, args, loc)
 512                 {
 513                         base.binder = this;
 514                         this.member = member;
 515                 }
 516
 517                 public DynamicInvocation (ATypeNameExpression member, Arguments args, Type type, Location loc)
 518                         : this (member, args, loc)
 519                 {
 520                         // When a return type is known not to be dynamic
 521                         this.type = type;
 522                 }
 523
 524                 public Expression CreateCallSiteBinder (ResolveContext ec, Arguments args)
 525                 {
 526                         Arguments binder_args = new Arguments (member != null ? 5 : 3);
 527                         bool is_member_access = member is MemberAccess;
 528
 529                         CSharpBinderFlags call_flags;
 530                         if (!is_member_access && member is SimpleName) {
 531                                 call_flags = CSharpBinderFlags.InvokeSimpleName;
 532                                 is_member_access = true;
 533                         } else {
 534                                 call_flags = 0;
 535                         }
 536
 537                         binder_args.Add (new Argument (new BinderFlags (call_flags, this)));
 538
 539                         if (is_member_access)
 540                                 binder_args.Add (new Argument (new StringLiteral (member.Name, member.Location)));
 541
 542                         if (member != null && member.HasTypeArguments) {
 543                                 TypeArguments ta = member.TypeArguments;
 544                                 if (ta.Resolve (ec)) {
 545                                         ArrayList targs = new ArrayList (ta.Count);
 546                                         foreach (Type t in ta.Arguments)
 547                                                 targs.Add (new TypeOf (new TypeExpression (t, loc), loc));
 548
 549                                         binder_args.Add (new Argument (new ImplicitlyTypedArrayCreation ("[]", targs, loc)));
 550                                 }
 551                         } else if (is_member_access) {
 552                                 binder_args.Add (new Argument (new NullLiteral (loc)));
 553                         }
 554
 555                         binder_args.Add (new Argument (new TypeOf (new TypeExpression (ec.CurrentType, loc), loc)));
 556
 557                         Expression real_args;
 558                         if (args == null) {
 559                                 // Cannot be null because .NET trips over
 560                                 real_args = new ArrayCreation (new MemberAccess (GetBinderNamespace (loc), "CSharpArgumentInfo", loc), "[]", new ArrayList (0), loc);
 561                         } else {
 562                                 real_args = new ImplicitlyTypedArrayCreation ("[]", args.CreateDynamicBinderArguments (), loc);
 563                         }
 564
 565                         binder_args.Add (new Argument (real_args));
 566
 567                         return new Invocation (GetBinder (is_member_access ? "InvokeMember" : "Invoke", loc), binder_args);
 568                 }
 569
 570                 public override void EmitStatement (EmitContext ec)
 571                 {
 572                         flags = CSharpBinderFlags.ResultDiscarded;
 573                         base.EmitStatement (ec);
 574                 }
 575         }
 576
 577         class DynamicMemberBinder : DynamicMemberAssignable
 578         {
 579                 readonly string name;
 580
 581                 public DynamicMemberBinder (string name, Arguments args, Location loc)
 582                         : base (args, loc)
 583                 {
 584                         this.name = name;
 585                 }
 586
 587                 protected override Expression CreateCallSiteBinder (ResolveContext ec, Arguments args, bool isSet)
 588                 {
 589                         Arguments binder_args = new Arguments (4);
 590
 591                         binder_args.Add (new Argument (new BinderFlags (0, this)));
 592                         binder_args.Add (new Argument (new StringLiteral (name, loc)));
 593                         binder_args.Add (new Argument (new TypeOf (new TypeExpression (ec.CurrentType, loc), loc)));
 594                         binder_args.Add (new Argument (new ImplicitlyTypedArrayCreation ("[]", args.CreateDynamicBinderArguments (), loc)));
 595
 596                         return new Invocation (GetBinder (isSet ? "SetMember" : "GetMember", loc), binder_args);
 597                 }
 598         }
 599
 600         //
 601         // Any member binder which can be source and target of assignment
 602         //
 603         abstract class DynamicMemberAssignable : DynamicExpressionStatement, IDynamicBinder, IAssignMethod
 604         {
 605                 Expression setter;
 606                 Arguments setter_args;
 607
 608                 protected DynamicMemberAssignable (Arguments args, Location loc)
 609                         : base (null, args, loc)
 610                 {
 611                         base.binder = this;
 612                 }
 613
 614                 public Expression CreateCallSiteBinder (ResolveContext ec, Arguments args)
 615                 {
 616                         //
 617                         // DoResolve always uses getter
 618                         //
 619                         return CreateCallSiteBinder (ec, args, false);
 620                 }
 621
 622                 protected abstract Expression CreateCallSiteBinder (ResolveContext ec, Arguments args, bool isSet);
 623
 624                 public override Expression DoResolveLValue (ResolveContext rc, Expression right_side)
 625                 {
 626                         if (DoResolveCore (rc)) {
 627                                 setter_args = new Arguments (Arguments.Count + 1);
 628                                 setter_args.AddRange (Arguments);
 629                                 setter_args.Add (new Argument (right_side));
 630                                 setter = CreateCallSiteBinder (rc, setter_args, true);
 631                         }
 632
 633                         return this;
 634                 }
 635
 636                 #region IAssignMethod Members
 637
 638                 public void Emit (EmitContext ec, bool leave_copy)
 639                 {
 640                         throw new NotImplementedException ();
 641                 }
 642
 643                 public void EmitAssign (EmitContext ec, Expression source, bool leave_copy, bool prepare_for_load)
 644                 {
 645                         EmitCall (ec, setter, setter_args, !leave_copy);
 646                 }
 647
 648                 #endregion
 649         }
 650
 651         class DynamicUnaryConversion : DynamicExpressionStatement, IDynamicBinder
 652         {
 653                 string name;
 654
 655                 public DynamicUnaryConversion (string name, Arguments args, Location loc)
 656                         : base (null, args, loc)
 657                 {
 658                         this.name = name;
 659                         base.binder = this;
 660                         if (name == "IsTrue" || name == "IsFalse")
 661                                 type = TypeManager.bool_type;
 662                 }
 663
 664                 public Expression CreateCallSiteBinder (ResolveContext ec, Arguments args)
 665                 {
 666                         Arguments binder_args = new Arguments (3);
 667
 668                         MemberAccess sle = new MemberAccess (new MemberAccess (
 669                                 new QualifiedAliasMember (QualifiedAliasMember.GlobalAlias, "System", loc), "Linq", loc), "Expressions", loc);
 670
 671                         var flags = ec.HasSet (ResolveContext.Options.CheckedScope) ? CSharpBinderFlags.CheckedContext : 0;
 672
 673                         binder_args.Add (new Argument (new BinderFlags (flags, this)));
 674                         binder_args.Add (new Argument (new MemberAccess (new MemberAccess (sle, "ExpressionType", loc), name, loc)));
 675                         binder_args.Add (new Argument (new ImplicitlyTypedArrayCreation ("[]", args.CreateDynamicBinderArguments (), loc)));
 676
 677                         return new Invocation (GetBinder ("UnaryOperation", loc), binder_args);
 678                 }
 679         }
 680 }