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         interface IDynamicBinder
 135         {
 136                 Expression CreateCallSiteBinder (ResolveContext ec, Arguments args);
 137         }
 138
 139         //
 140         // Extends standard assignment interface for expressions
 141         // supported by dynamic resolver
 142         //
 143         interface IDynamicAssign : IAssignMethod
 144         {
 145 #if NET_4_0
 146                 SLE.Expression MakeAssignExpression (BuilderContext ctx);
 147 #endif
 148         }
 149
 150         class DynamicExpressionStatement : ExpressionStatement
 151         {
 152                 class StaticDataClass : CompilerGeneratedClass
 153                 {
 154                         public StaticDataClass ()
 155                                 : base (new RootDeclSpace (new NamespaceEntry (null, null, null)),
 156                                         new MemberName (CompilerGeneratedClass.MakeName (null, "c", "DynamicSites", 0)),
 157                                         Modifiers.INTERNAL | Modifiers.STATIC)
 158                         {
 159                                 ModFlags &= ~Modifiers.SEALED;
 160                         }
 161                 }
 162
 163                 //
 164                 // Binder flag dynamic constant, the value is combination of
 165                 // flags known at resolve stage and flags known only at emit
 166                 // stage
 167                 //
 168                 protected class BinderFlags : EnumConstant
 169                 {
 170                         DynamicExpressionStatement statement;
 171                         CSharpBinderFlags flags;
 172
 173                         public BinderFlags (CSharpBinderFlags flags, DynamicExpressionStatement statement)
 174                                 : base ()
 175                         {
 176                                 this.flags = flags;
 177                                 this.statement = statement;
 178                         }
 179
 180                         public override Expression DoResolve (ResolveContext ec)
 181                         {
 182                                 Child = new IntConstant ((int) (flags | statement.flags), statement.loc);
 183
 184                                 type = TypeManager.binder_flags;
 185                                 eclass = Child.eclass;
 186                                 return this;
 187                         }
 188                 }
 189
 190                 static StaticDataClass global_site_container;
 191                 static int field_counter;
 192                 static int container_counter;
 193
 194                 readonly Arguments arguments;
 195                 protected IDynamicBinder binder;
 196                 Expression binder_expr;
 197
 198                 // Used by BinderFlags
 199                 protected CSharpBinderFlags flags;
 200
 201                 public DynamicExpressionStatement (IDynamicBinder binder, Arguments args, Location loc)
 202                 {
 203                         this.binder = binder;
 204                         this.arguments = args;
 205                         this.loc = loc;
 206                 }
 207
 208                 public Arguments Arguments {
 209                         get {
 210                                 return arguments;
 211                         }
 212                 }
 213
 214                 static TypeContainer CreateSiteContainer ()
 215                 {
 216                         if (global_site_container == null) {
 217                                 global_site_container = new StaticDataClass ();
 218                                 RootContext.ToplevelTypes.AddCompilerGeneratedClass (global_site_container);
 219                                 global_site_container.DefineType ();
 220                                 global_site_container.Define ();
 221 //                              global_site_container.EmitType ();
 222
 223                                 RootContext.RegisterCompilerGeneratedType (global_site_container.TypeBuilder);
 224                         }
 225
 226                         return global_site_container;
 227                 }
 228
 229                 static Field CreateSiteField (FullNamedExpression type)
 230                 {
 231                         TypeContainer site_container = CreateSiteContainer ();
 232                         Field f = new Field (site_container, type, Modifiers.PUBLIC | Modifiers.STATIC,
 233                                 new MemberName ("Site" +  field_counter++), null);
 234                         f.Define ();
 235
 236                         site_container.AddField (f);
 237                         return f;
 238                 }
 239
 240                 public override Expression CreateExpressionTree (ResolveContext ec)
 241                 {
 242                         throw new NotImplementedException ();
 243                 }
 244
 245                 public override Expression DoResolve (ResolveContext ec)
 246                 {
 247                         if (eclass != ExprClass.Invalid)
 248                                 return this;
 249
 250                         if (TypeManager.call_site_type == null)
 251                                 TypeManager.call_site_type = TypeManager.CoreLookupType (ec.Compiler,
 252                                         "System.Runtime.CompilerServices", "CallSite", Kind.Class, true);
 253
 254                         if (TypeManager.generic_call_site_type == null)
 255                                 TypeManager.generic_call_site_type = TypeManager.CoreLookupType (ec.Compiler,
 256                                         "System.Runtime.CompilerServices", "CallSite`1", Kind.Class, true);
 257
 258                         if (TypeManager.binder_type == null) {
 259                                 var t = TypeManager.CoreLookupType (ec.Compiler,
 260                                         "Microsoft.CSharp.RuntimeBinder", "Binder", Kind.Class, true);
 261                                 if (t != null)
 262                                         TypeManager.binder_type = new TypeExpression (t, Location.Null);
 263                         }
 264
 265                         if (TypeManager.binder_flags == null) {
 266                                 TypeManager.binder_flags = TypeManager.CoreLookupType (ec.Compiler,
 267                                         "Microsoft.CSharp.RuntimeBinder", "CSharpBinderFlags", Kind.Enum, true);
 268                         }
 269
 270                         eclass = ExprClass.Value;
 271
 272                         if (type == null)
 273                                 type = InternalType.Dynamic;
 274
 275                         // TODO: If any core type fails to load, skip this ?
 276                         binder_expr = binder.CreateCallSiteBinder (ec, arguments);
 277                         return this;
 278                 }
 279
 280                 public override void Emit (EmitContext ec)
 281                 {
 282                         EmitCall (ec,  false);
 283                 }
 284
 285                 public override void EmitStatement (EmitContext ec)
 286                 {
 287                         EmitCall (ec, true);
 288                 }
 289
 290                 void EmitCall (EmitContext ec, bool isStatement)
 291                 {
 292                         int dyn_args_count = arguments == null ? 0 : arguments.Count;
 293                         TypeExpr site_type = CreateSiteType (RootContext.ToplevelTypes.Compiler, dyn_args_count, isStatement);
 294                         FieldExpr site_field_expr = new FieldExpr (CreateSiteField (site_type).FieldBuilder, loc);
 295
 296                         SymbolWriter.OpenCompilerGeneratedBlock (ec.ig);
 297
 298                         Arguments args = new Arguments (1);
 299                         args.Add (new Argument (binder_expr));
 300                         StatementExpression s = new StatementExpression (new SimpleAssign (site_field_expr, new Invocation (new MemberAccess (site_type, "Create"), args)));
 301
 302                         BlockContext bc = new BlockContext (ec.MemberContext, null, TypeManager.void_type);
 303                         if (s.Resolve (bc)) {
 304                                 Statement init = new If (new Binary (Binary.Operator.Equality, site_field_expr, new NullLiteral (loc)), s, loc);
 305                                 init.Emit (ec);
 306                         }
 307
 308                         args = new Arguments (1 + dyn_args_count);
 309                         args.Add (new Argument (site_field_expr));
 310                         if (arguments != null) {
 311                                 foreach (Argument a in arguments) {
 312                                         if (a is NamedArgument) {
 313                                                 // Name is not valid in this context
 314                                                 args.Add (new Argument (a.Expr, a.ArgType));
 315                                                 continue;
 316                                         }
 317
 318                                         args.Add (a);
 319                                 }
 320                         }
 321
 322                         Expression target = new DelegateInvocation (new MemberAccess (site_field_expr, "Target", loc).Resolve (bc), args, loc).Resolve (bc);
 323                         if (target != null)
 324                                 target.Emit (ec);
 325
 326                         SymbolWriter.CloseCompilerGeneratedBlock (ec.ig);
 327                 }
 328
 329                 public static MemberAccess GetBinderNamespace (Location loc)
 330                 {
 331                         return new MemberAccess (new MemberAccess (
 332                                 new QualifiedAliasMember (QualifiedAliasMember.GlobalAlias, "Microsoft", loc), "CSharp", loc), "RuntimeBinder", loc);
 333                 }
 334
 335                 public static MemberAccess GetBinder (string name, Location loc)
 336                 {
 337                         return new MemberAccess (TypeManager.binder_type, name, loc);
 338                 }
 339
 340                 TypeExpr CreateSiteType (CompilerContext ctx, int dyn_args_count, bool is_statement)
 341                 {
 342                         int default_args = is_statement ? 1 : 2;
 343
 344                         bool has_ref_out_argument = false;
 345                         FullNamedExpression[] targs = new FullNamedExpression[dyn_args_count + default_args];
 346                         targs [0] = new TypeExpression (TypeManager.call_site_type, loc);
 347                         for (int i = 0; i < dyn_args_count; ++i) {
 348                                 Type arg_type;
 349                                 Argument a = arguments [i];
 350                                 if (a.Type == TypeManager.null_type)
 351                                         arg_type = TypeManager.object_type;
 352                                 else
 353                                         arg_type = TypeManager.TypeToReflectionType (a.Type);
 354
 355                                 if (a.ArgType == Argument.AType.Out || a.ArgType == Argument.AType.Ref)
 356                                         has_ref_out_argument = true;
 357
 358                                 targs [i + 1] = new TypeExpression (arg_type, loc);
 359                         }
 360
 361                         TypeExpr del_type = null;
 362                         if (!has_ref_out_argument) {
 363                                 string d_name = is_statement ? "Action`" : "Func`";
 364
 365                                 Type t = TypeManager.CoreLookupType (ctx, "System", d_name + (dyn_args_count + default_args), Kind.Delegate, false);
 366                                 if (t != null) {
 367                                         if (!is_statement)
 368                                                 targs [targs.Length - 1] = new TypeExpression (TypeManager.TypeToReflectionType (type), loc);
 369
 370                                         del_type = new GenericTypeExpr (t, new TypeArguments (targs), loc);
 371                                 }
 372                         }
 373
 374                         // No appropriate predefined delegate found
 375                         if (del_type == null) {
 376                                 Type rt = is_statement ? TypeManager.void_type : type;
 377                                 Parameter[] p = new Parameter [dyn_args_count + 1];
 378                                 p[0] = new Parameter (targs [0], "p0", Parameter.Modifier.NONE, null, loc);
 379
 380                                 for (int i = 1; i < dyn_args_count + 1; ++i)
 381                                         p[i] = new Parameter (targs[i], "p" + i.ToString ("X"), arguments[i - 1].Modifier, null, loc);
 382
 383                                 TypeContainer parent = CreateSiteContainer ();
 384                                 Delegate d = new Delegate (parent.NamespaceEntry, parent, new TypeExpression (TypeManager.TypeToReflectionType (rt), loc),
 385                                         Modifiers.INTERNAL | Modifiers.COMPILER_GENERATED,
 386                                         new MemberName ("Container" + container_counter++.ToString ("X")),
 387                                         new ParametersCompiled (p), null);
 388
 389                                 d.DefineType ();
 390                                 d.Define ();
 391
 392                                 parent.AddDelegate (d);
 393                                 del_type = new TypeExpression (d.TypeBuilder, loc);
 394                         }
 395
 396                         TypeExpr site_type = new GenericTypeExpr (TypeManager.generic_call_site_type, new TypeArguments (del_type), loc);
 397                         return site_type;
 398                 }
 399
 400                 public static void Reset ()
 401                 {
 402                         global_site_container = null;
 403                         field_counter = container_counter = 0;
 404                 }
 405         }
 406
 407         //
 408         // Dynamic member access compound assignment for events
 409         //
 410         class DynamicEventCompoundAssign : DynamicExpressionStatement, IDynamicBinder
 411         {
 412                 string name;
 413                 ExpressionStatement assignment;
 414                 ExpressionStatement invoke;
 415
 416                 public DynamicEventCompoundAssign (string name, Arguments args, ExpressionStatement assignment, ExpressionStatement invoke, Location loc)
 417                         : base (null, args, loc)
 418                 {
 419                         this.name = name;
 420                         this.assignment = assignment;
 421                         this.invoke = invoke;
 422                         base.binder = this;
 423
 424                         // Used by += or -= only
 425                         type = TypeManager.bool_type;
 426                 }
 427
 428                 public Expression CreateCallSiteBinder (ResolveContext ec, Arguments args)
 429                 {
 430                         Arguments binder_args = new Arguments (2);
 431
 432                         binder_args.Add (new Argument (new StringLiteral (name, loc)));
 433                         binder_args.Add (new Argument (new TypeOf (new TypeExpression (ec.CurrentType, loc), loc)));
 434
 435                         return new Invocation (GetBinder ("IsEvent", loc), binder_args);
 436                 }
 437
 438                 public override void EmitStatement (EmitContext ec)
 439                 {
 440                         Statement cond = new If (
 441                                 new Binary (Binary.Operator.Equality, this, new BoolLiteral (true, loc)),
 442                                 new StatementExpression (invoke),
 443                                 new StatementExpression (assignment),
 444                                 loc);
 445                         cond.Emit (ec);
 446                 }
 447         }
 448
 449         class DynamicConversion : DynamicExpressionStatement, IDynamicBinder
 450         {
 451                 public DynamicConversion (Type targetType, CSharpBinderFlags flags, Arguments args, Location loc)
 452                         : base (null, args, loc)
 453                 {
 454                         type = targetType;
 455                         base.flags = flags;
 456                         base.binder = this;
 457                 }
 458
 459                 public Expression CreateCallSiteBinder (ResolveContext ec, Arguments args)
 460                 {
 461                         Arguments binder_args = new Arguments (2);
 462
 463                         flags |= ec.HasSet (ResolveContext.Options.CheckedScope) ? CSharpBinderFlags.CheckedContext : 0;
 464
 465                         binder_args.Add (new Argument (new BinderFlags (flags, this)));
 466                         binder_args.Add (new Argument (new TypeOf (new TypeExpression (type, loc), loc)));
 467                         return new Invocation (GetBinder ("Convert", loc), binder_args);
 468                 }
 469         }
 470
 471         class DynamicIndexBinder : DynamicExpressionStatement, IDynamicBinder, IAssignMethod
 472         {
 473                 readonly bool isSet;
 474
 475                 public DynamicIndexBinder (bool isSet, Arguments args, Location loc)
 476                         : base (null, args, loc)
 477                 {
 478                         base.binder = this;
 479                         this.isSet = isSet;
 480                 }
 481
 482                 public Expression CreateCallSiteBinder (ResolveContext ec, Arguments args)
 483                 {
 484                         Arguments binder_args = new Arguments (3);
 485
 486                         binder_args.Add (new Argument (new BinderFlags (0, this)));
 487                         binder_args.Add (new Argument (new TypeOf (new TypeExpression (ec.CurrentType, loc), loc)));
 488                         binder_args.Add (new Argument (new ImplicitlyTypedArrayCreation ("[]", args.CreateDynamicBinderArguments (), loc)));
 489
 490                         return new Invocation (GetBinder (isSet ? "SetIndex" : "GetIndex", loc), binder_args);
 491                 }
 492
 493                 #region IAssignMethod Members
 494
 495                 public void Emit (EmitContext ec, bool leave_copy)
 496                 {
 497                         throw new NotImplementedException ();
 498                 }
 499
 500                 public void EmitAssign (EmitContext ec, Expression source, bool leave_copy, bool prepare_for_load)
 501                 {
 502                         if (leave_copy)
 503                                 Emit (ec);
 504                         else
 505                                 EmitStatement (ec);
 506                 }
 507
 508                 #endregion
 509         }
 510
 511         class DynamicInvocation : DynamicExpressionStatement, IDynamicBinder
 512         {
 513                 ATypeNameExpression member;
 514
 515                 public DynamicInvocation (ATypeNameExpression member, Arguments args, Location loc)
 516                         : base (null, args, loc)
 517                 {
 518                         base.binder = this;
 519                         this.member = member;
 520                 }
 521
 522                 public DynamicInvocation (ATypeNameExpression member, Arguments args, Type type, Location loc)
 523                         : this (member, args, loc)
 524                 {
 525                         // When a return type is known not to be dynamic
 526                         this.type = type;
 527                 }
 528
 529                 public Expression CreateCallSiteBinder (ResolveContext ec, Arguments args)
 530                 {
 531                         Arguments binder_args = new Arguments (member != null ? 5 : 3);
 532                         bool is_member_access = member is MemberAccess;
 533
 534                         CSharpBinderFlags call_flags;
 535                         if (!is_member_access && member is SimpleName) {
 536                                 call_flags = CSharpBinderFlags.InvokeSimpleName;
 537                                 is_member_access = true;
 538                         } else {
 539                                 call_flags = 0;
 540                         }
 541
 542                         binder_args.Add (new Argument (new BinderFlags (call_flags, this)));
 543
 544                         if (is_member_access)
 545                                 binder_args.Add (new Argument (new StringLiteral (member.Name, member.Location)));
 546
 547                         if (member != null && member.HasTypeArguments) {
 548                                 TypeArguments ta = member.TypeArguments;
 549                                 if (ta.Resolve (ec)) {
 550                                         ArrayList targs = new ArrayList (ta.Count);
 551                                         foreach (Type t in ta.Arguments)
 552                                                 targs.Add (new TypeOf (new TypeExpression (t, loc), loc));
 553
 554                                         binder_args.Add (new Argument (new ImplicitlyTypedArrayCreation ("[]", targs, loc)));
 555                                 }
 556                         } else if (is_member_access) {
 557                                 binder_args.Add (new Argument (new NullLiteral (loc)));
 558                         }
 559
 560                         binder_args.Add (new Argument (new TypeOf (new TypeExpression (ec.CurrentType, loc), loc)));
 561
 562                         Expression real_args;
 563                         if (args == null) {
 564                                 // Cannot be null because .NET trips over
 565                                 real_args = new ArrayCreation (new MemberAccess (GetBinderNamespace (loc), "CSharpArgumentInfo", loc), "[]", new ArrayList (0), loc);
 566                         } else {
 567                                 real_args = new ImplicitlyTypedArrayCreation ("[]", args.CreateDynamicBinderArguments (), loc);
 568                         }
 569
 570                         binder_args.Add (new Argument (real_args));
 571
 572                         return new Invocation (GetBinder (is_member_access ? "InvokeMember" : "Invoke", loc), binder_args);
 573                 }
 574
 575                 public override void EmitStatement (EmitContext ec)
 576                 {
 577                         flags = CSharpBinderFlags.ResultDiscarded;
 578                         base.EmitStatement (ec);
 579                 }
 580         }
 581
 582         class DynamicMemberBinder : DynamicExpressionStatement, IDynamicBinder, IAssignMethod
 583         {
 584                 readonly bool isSet;
 585                 readonly string name;
 586
 587                 public DynamicMemberBinder (bool isSet, string name, Arguments args, Location loc)
 588                         : base (null, args, loc)
 589                 {
 590                         base.binder = this;
 591                         this.isSet = isSet;
 592                         this.name = name;
 593                 }
 594
 595                 public Expression CreateCallSiteBinder (ResolveContext ec, Arguments args)
 596                 {
 597                         Arguments binder_args = new Arguments (4);
 598
 599                         binder_args.Add (new Argument (new BinderFlags (0, this)));
 600                         binder_args.Add (new Argument (new StringLiteral (name, loc)));
 601                         binder_args.Add (new Argument (new TypeOf (new TypeExpression (ec.CurrentType, loc), loc)));
 602                         binder_args.Add (new Argument (new ImplicitlyTypedArrayCreation ("[]", args.CreateDynamicBinderArguments (), loc)));
 603
 604                         return new Invocation (GetBinder (isSet ? "SetMember" : "GetMember", loc), binder_args);
 605                 }
 606
 607                 #region IAssignMethod Members
 608
 609                 public void Emit (EmitContext ec, bool leave_copy)
 610                 {
 611                         throw new NotImplementedException ();
 612                 }
 613
 614                 public void EmitAssign (EmitContext ec, Expression source, bool leave_copy, bool prepare_for_load)
 615                 {
 616                         if (leave_copy)
 617                                 Emit (ec);
 618                         else
 619                                 EmitStatement (ec);
 620                 }
 621
 622                 #endregion
 623         }
 624
 625         class DynamicUnaryConversion : DynamicExpressionStatement, IDynamicBinder
 626         {
 627                 string name;
 628
 629                 public DynamicUnaryConversion (string name, Arguments args, Location loc)
 630                         : base (null, args, loc)
 631                 {
 632                         this.name = name;
 633                         base.binder = this;
 634                         if (name == "IsTrue" || name == "IsFalse")
 635                                 type = TypeManager.bool_type;
 636                 }
 637
 638                 public Expression CreateCallSiteBinder (ResolveContext ec, Arguments args)
 639                 {
 640                         Arguments binder_args = new Arguments (3);
 641
 642                         MemberAccess sle = new MemberAccess (new MemberAccess (
 643                                 new QualifiedAliasMember (QualifiedAliasMember.GlobalAlias, "System", loc), "Linq", loc), "Expressions", loc);
 644
 645                         var flags = ec.HasSet (ResolveContext.Options.CheckedScope) ? CSharpBinderFlags.CheckedContext : 0;
 646
 647                         binder_args.Add (new Argument (new BinderFlags (flags, this)));
 648                         binder_args.Add (new Argument (new MemberAccess (new MemberAccess (sle, "ExpressionType", loc), name, loc)));
 649                         binder_args.Add (new Argument (new ImplicitlyTypedArrayCreation ("[]", args.CreateDynamicBinderArguments (), loc)));
 650
 651                         return new Invocation (GetBinder ("UnaryOperation", loc), binder_args);
 652                 }
 653         }
 654 }