mcs/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.Reflection.Emit;
  13 using SLE = System.Linq.Expressions;
  14
  15 #if NET_4_0
  16 using System.Dynamic;
  17 #endif
  18
  19 namespace Mono.CSharp
  20 {
  21         //
  22         // A copy of Microsoft.CSharp/Microsoft.CSharp.RuntimeBinder/CSharpBinderFlags.cs
  23         // has to be kept in sync
  24         //
  25         [Flags]
  26         public enum CSharpBinderFlags
  27         {
  28                 None = 0,
  29                 CheckedContext = 1,
  30                 InvokeSimpleName = 1 << 1,
  31                 InvokeSpecialName = 1 << 2,
  32                 BinaryOperationLogical = 1 << 3,
  33                 ConvertExplicit = 1 << 4,
  34                 ConvertArrayIndex = 1 << 5,
  35                 ResultIndexed = 1 << 6,
  36                 ValueFromCompoundAssignment = 1 << 7,
  37                 ResultDiscarded = 1 << 8
  38         }
  39
  40         //
  41         // Type expression with internal dynamic type symbol
  42         //
  43         class DynamicTypeExpr : TypeExpr
  44         {
  45                 public DynamicTypeExpr (Location loc)
  46                 {
  47                         this.loc = loc;
  48
  49                         type = InternalType.Dynamic;
  50                         eclass = ExprClass.Type;
  51                 }
  52
  53                 public override bool CheckAccessLevel (IMemberContext ds)
  54                 {
  55                         return true;
  56                 }
  57
  58                 protected override TypeExpr DoResolveAsTypeStep (IMemberContext ec)
  59                 {
  60                         return this;
  61                 }
  62         }
  63
  64         #region Dynamic runtime binder expressions
  65
  66         //
  67         // Expression created from runtime dynamic object value by dynamic binder
  68         //
  69         public class RuntimeValueExpression : Expression, IDynamicAssign, IMemoryLocation
  70         {
  71 #if !NET_4_0
  72                 public class DynamicMetaObject
  73                 {
  74                         public TypeSpec RuntimeType;
  75                         public TypeSpec LimitType;
  76                         public SLE.Expression Expression;
  77                 }
  78 #endif
  79
  80                 readonly DynamicMetaObject obj;
  81
  82                 public RuntimeValueExpression (DynamicMetaObject obj, TypeSpec type)
  83                 {
  84                         this.obj = obj;
  85                         this.type = type;
  86                         this.eclass = ExprClass.Variable;
  87                 }
  88
  89                 #region Properties
  90
  91                 public bool IsSuggestionOnly { get; set; }
  92
  93                 public DynamicMetaObject MetaObject {
  94                         get { return obj; }
  95                 }
  96
  97                 #endregion
  98
  99                 public void AddressOf (EmitContext ec, AddressOp mode)
 100                 {
 101                         throw new NotImplementedException ();
 102                 }
 103
 104                 public override Expression CreateExpressionTree (ResolveContext ec)
 105                 {
 106                         throw new NotImplementedException ();
 107                 }
 108
 109                 protected override Expression DoResolve (ResolveContext ec)
 110                 {
 111                         return this;
 112                 }
 113
 114                 public override Expression DoResolveLValue (ResolveContext ec, Expression right_side)
 115                 {
 116                         return this;
 117                 }
 118
 119                 public override void Emit (EmitContext ec)
 120                 {
 121                         throw new NotImplementedException ();
 122                 }
 123
 124                 #region IAssignMethod Members
 125
 126                 public void Emit (EmitContext ec, bool leave_copy)
 127                 {
 128                         throw new NotImplementedException ();
 129                 }
 130
 131                 public void EmitAssign (EmitContext ec, Expression source, bool leave_copy, bool prepare_for_load)
 132                 {
 133                         throw new NotImplementedException ();
 134                 }
 135
 136                 #endregion
 137
 138                 public SLE.Expression MakeAssignExpression (BuilderContext ctx, Expression source)
 139                 {
 140                         return obj.Expression;
 141                 }
 142
 143                 public override SLE.Expression MakeExpression (BuilderContext ctx)
 144                 {
 145                         return SLE.Expression.Convert (obj.Expression, type.GetMetaInfo ());
 146                 }
 147         }
 148
 149         //
 150         // Wraps runtime dynamic expression into expected type. Needed
 151         // to satify expected type check by dynamic binder and no conversion
 152         // is required (ResultDiscarded).
 153         //
 154         public class DynamicResultCast : ShimExpression
 155         {
 156                 public DynamicResultCast (TypeSpec type, Expression expr)
 157                         : base (expr)
 158                 {
 159                         this.type = type;
 160                 }
 161
 162                 protected override Expression DoResolve (ResolveContext ec)
 163                 {
 164                         expr = expr.Resolve (ec);
 165                         eclass = ExprClass.Value;
 166                         return this;
 167                 }
 168
 169 #if NET_4_0
 170                 public override SLE.Expression MakeExpression (BuilderContext ctx)
 171                 {
 172                         return SLE.Expression.Block (expr.MakeExpression (ctx), SLE.Expression.Default (type.GetMetaInfo ()));
 173                 }
 174 #endif
 175         }
 176
 177         #endregion
 178
 179         //
 180         // Creates dynamic binder expression
 181         //
 182         interface IDynamicBinder
 183         {
 184                 Expression CreateCallSiteBinder (ResolveContext ec, Arguments args);
 185         }
 186
 187         //
 188         // Extends standard assignment interface for expressions
 189         // supported by dynamic resolver
 190         //
 191         interface IDynamicAssign : IAssignMethod
 192         {
 193                 SLE.Expression MakeAssignExpression (BuilderContext ctx, Expression source);
 194         }
 195
 196         //
 197         // Base dynamic expression statement creator
 198         //
 199         class DynamicExpressionStatement : ExpressionStatement
 200         {
 201                 class StaticDataClass : CompilerGeneratedClass
 202                 {
 203                         public StaticDataClass ()
 204                                 : base (new RootDeclSpace (new NamespaceEntry (null, null, null)),
 205                                         new MemberName (CompilerGeneratedClass.MakeName (null, "c", "DynamicSites", 0)),
 206                                         Modifiers.INTERNAL | Modifiers.STATIC)
 207                         {
 208                         }
 209                 }
 210
 211                 //
 212                 // Binder flag dynamic constant, the value is combination of
 213                 // flags known at resolve stage and flags known only at emit
 214                 // stage
 215                 //
 216                 protected class BinderFlags : EnumConstant
 217                 {
 218                         DynamicExpressionStatement statement;
 219                         CSharpBinderFlags flags;
 220
 221                         public BinderFlags (CSharpBinderFlags flags, DynamicExpressionStatement statement)
 222                                 : base (statement.loc)
 223                         {
 224                                 this.flags = flags;
 225                                 this.statement = statement;
 226                         }
 227
 228                         protected override Expression DoResolve (ResolveContext ec)
 229                         {
 230                                 Child = new IntConstant ((int) (flags | statement.flags), statement.loc).Resolve (ec);
 231
 232                                 type = TypeManager.binder_flags;
 233                                 eclass = Child.eclass;
 234                                 return this;
 235                         }
 236                 }
 237
 238                 static StaticDataClass global_site_container;
 239                 static int field_counter;
 240                 static int container_counter;
 241
 242                 readonly Arguments arguments;
 243                 protected IDynamicBinder binder;
 244                 protected Expression binder_expr;
 245
 246                 // Used by BinderFlags
 247                 protected CSharpBinderFlags flags;
 248
 249                 public DynamicExpressionStatement (IDynamicBinder binder, Arguments args, Location loc)
 250                 {
 251                         this.binder = binder;
 252                         this.arguments = args;
 253                         this.loc = loc;
 254                 }
 255
 256                 public Arguments Arguments {
 257                         get {
 258                                 return arguments;
 259                         }
 260                 }
 261
 262                 static TypeContainer CreateSiteContainer ()
 263                 {
 264                         if (global_site_container == null) {
 265                                 global_site_container = new StaticDataClass ();
 266                                 RootContext.ToplevelTypes.AddCompilerGeneratedClass (global_site_container);
 267                                 global_site_container.CreateType ();
 268                                 global_site_container.DefineType ();
 269                                 global_site_container.Define ();
 270                         }
 271
 272                         return global_site_container;
 273                 }
 274
 275                 static Field CreateSiteField (FullNamedExpression type)
 276                 {
 277                         TypeContainer site_container = CreateSiteContainer ();
 278                         Field f = new Field (site_container, type, Modifiers.PUBLIC | Modifiers.STATIC,
 279                                 new MemberName ("Site" +  field_counter++), null);
 280                         f.Define ();
 281
 282                         site_container.AddField (f);
 283                         return f;
 284                 }
 285
 286                 public override Expression CreateExpressionTree (ResolveContext ec)
 287                 {
 288                         ec.Report.Error (1963, loc, "An expression tree cannot contain a dynamic operation");
 289                         return null;
 290                 }
 291
 292                 protected override Expression DoResolve (ResolveContext ec)
 293                 {
 294                         if (DoResolveCore (ec))
 295                                 binder_expr = binder.CreateCallSiteBinder (ec, arguments);
 296
 297                         return this;
 298                 }
 299
 300                 protected bool DoResolveCore (ResolveContext rc)
 301                 {
 302                         int errors = rc.Report.Errors;
 303
 304                         if (TypeManager.binder_type == null) {
 305                                 var t = TypeManager.CoreLookupType (rc.Compiler,
 306                                         "Microsoft.CSharp.RuntimeBinder", "Binder", MemberKind.Class, true);
 307                                 if (t != null)
 308                                         TypeManager.binder_type = new TypeExpression (t, Location.Null);
 309                         }
 310
 311                         if (TypeManager.call_site_type == null)
 312                                 TypeManager.call_site_type = TypeManager.CoreLookupType (rc.Compiler,
 313                                         "System.Runtime.CompilerServices", "CallSite", MemberKind.Class, true);
 314
 315                         if (TypeManager.generic_call_site_type == null)
 316                                 TypeManager.generic_call_site_type = TypeManager.CoreLookupType (rc.Compiler,
 317                                         "System.Runtime.CompilerServices", "CallSite", 1, MemberKind.Class, true);
 318
 319                         if (TypeManager.binder_flags == null) {
 320                                 TypeManager.binder_flags = TypeManager.CoreLookupType (rc.Compiler,
 321                                         "Microsoft.CSharp.RuntimeBinder", "CSharpBinderFlags", MemberKind.Enum, true);
 322                         }
 323
 324                         eclass = ExprClass.Value;
 325
 326                         if (type == null)
 327                                 type = InternalType.Dynamic;
 328
 329                         if (rc.Report.Errors == errors)
 330                                 return true;
 331
 332                         rc.Report.Error (1969, loc,
 333                                 "Dynamic operation cannot be compiled without `Microsoft.CSharp.dll' assembly reference");
 334                         return false;
 335                 }
 336
 337                 public override void Emit (EmitContext ec)
 338                 {
 339                         EmitCall (ec, binder_expr, arguments,  false);
 340                 }
 341
 342                 public override void EmitStatement (EmitContext ec)
 343                 {
 344                         EmitCall (ec, binder_expr, arguments, true);
 345                 }
 346
 347                 protected void EmitCall (EmitContext ec, Expression binder, Arguments arguments, bool isStatement)
 348                 {
 349                         int dyn_args_count = arguments == null ? 0 : arguments.Count;
 350                         TypeExpr site_type = CreateSiteType (RootContext.ToplevelTypes.Compiler, arguments, dyn_args_count, isStatement);
 351                         FieldExpr site_field_expr = new FieldExpr (CreateSiteField (site_type), loc);
 352
 353                         SymbolWriter.OpenCompilerGeneratedBlock (ec);
 354
 355                         Arguments args = new Arguments (1);
 356                         args.Add (new Argument (binder));
 357                         StatementExpression s = new StatementExpression (new SimpleAssign (site_field_expr, new Invocation (new MemberAccess (site_type, "Create"), args)));
 358
 359                         BlockContext bc = new BlockContext (ec.MemberContext, null, TypeManager.void_type);
 360                         if (s.Resolve (bc)) {
 361                                 Statement init = new If (new Binary (Binary.Operator.Equality, site_field_expr, new NullLiteral (loc), loc), s, loc);
 362                                 init.Emit (ec);
 363                         }
 364
 365                         args = new Arguments (1 + dyn_args_count);
 366                         args.Add (new Argument (site_field_expr));
 367                         if (arguments != null) {
 368                                 foreach (Argument a in arguments) {
 369                                         if (a is NamedArgument) {
 370                                                 // Name is not valid in this context
 371                                                 args.Add (new Argument (a.Expr, a.ArgType));
 372                                                 continue;
 373                                         }
 374
 375                                         args.Add (a);
 376                                 }
 377                         }
 378
 379                         Expression target = new DelegateInvocation (new MemberAccess (site_field_expr, "Target", loc).Resolve (bc), args, loc).Resolve (bc);
 380                         if (target != null)
 381                                 target.Emit (ec);
 382
 383                         SymbolWriter.CloseCompilerGeneratedBlock (ec);
 384                 }
 385
 386                 public static MemberAccess GetBinderNamespace (Location loc)
 387                 {
 388                         return new MemberAccess (new MemberAccess (
 389                                 new QualifiedAliasMember (QualifiedAliasMember.GlobalAlias, "Microsoft", loc), "CSharp", loc), "RuntimeBinder", loc);
 390                 }
 391
 392                 public static MemberAccess GetBinder (string name, Location loc)
 393                 {
 394                         return new MemberAccess (TypeManager.binder_type, name, loc);
 395                 }
 396
 397                 TypeExpr CreateSiteType (CompilerContext ctx, Arguments arguments, int dyn_args_count, bool is_statement)
 398                 {
 399                         int default_args = is_statement ? 1 : 2;
 400
 401                         bool has_ref_out_argument = false;
 402                         FullNamedExpression[] targs = new FullNamedExpression[dyn_args_count + default_args];
 403                         targs [0] = new TypeExpression (TypeManager.call_site_type, loc);
 404                         for (int i = 0; i < dyn_args_count; ++i) {
 405                                 Argument a = arguments [i];
 406                                 if (a.ArgType == Argument.AType.Out || a.ArgType == Argument.AType.Ref)
 407                                         has_ref_out_argument = true;
 408
 409                                 targs [i + 1] = new TypeExpression (a.Type, loc);
 410                         }
 411
 412                         TypeExpr del_type = null;
 413                         if (!has_ref_out_argument) {
 414                                 string d_name = is_statement ? "Action" : "Func";
 415
 416                                 TypeSpec t = TypeManager.CoreLookupType (ctx, "System", d_name, dyn_args_count + default_args, MemberKind.Delegate, false);
 417                                 if (t != null) {
 418                                         if (!is_statement)
 419                                                 targs [targs.Length - 1] = new TypeExpression (type, loc);
 420
 421                                         del_type = new GenericTypeExpr (t, new TypeArguments (targs), loc);
 422                                 }
 423                         }
 424
 425                         //
 426                         // Create custom delegate when no appropriate predefined one is found
 427                         //
 428                         if (del_type == null) {
 429                                 TypeSpec rt = is_statement ? TypeManager.void_type : type;
 430                                 Parameter[] p = new Parameter [dyn_args_count + 1];
 431                                 p[0] = new Parameter (targs [0], "p0", Parameter.Modifier.NONE, null, loc);
 432
 433                                 for (int i = 1; i < dyn_args_count + 1; ++i)
 434                                         p[i] = new Parameter (targs[i], "p" + i.ToString ("X"), arguments[i - 1].Modifier, null, loc);
 435
 436                                 TypeContainer parent = CreateSiteContainer ();
 437                                 Delegate d = new Delegate (parent.NamespaceEntry, parent, new TypeExpression (rt, loc),
 438                                         Modifiers.INTERNAL | Modifiers.COMPILER_GENERATED,
 439                                         new MemberName ("Container" + container_counter++.ToString ("X")),
 440                                         new ParametersCompiled (ctx, p), null);
 441
 442                                 d.CreateType ();
 443                                 d.DefineType ();
 444                                 d.Define ();
 445                                 d.Emit ();
 446
 447                                 parent.AddDelegate (d);
 448                                 del_type = new TypeExpression (d.Definition, loc);
 449                         }
 450
 451                         TypeExpr site_type = new GenericTypeExpr (TypeManager.generic_call_site_type, new TypeArguments (del_type), loc);
 452                         return site_type;
 453                 }
 454
 455                 public static void Reset ()
 456                 {
 457                         global_site_container = null;
 458                         field_counter = container_counter = 0;
 459                 }
 460         }
 461
 462         //
 463         // Dynamic member access compound assignment for events
 464         //
 465         class DynamicEventCompoundAssign : DynamicExpressionStatement, IDynamicBinder
 466         {
 467                 string name;
 468                 Statement condition;
 469
 470                 public DynamicEventCompoundAssign (string name, Arguments args, ExpressionStatement assignment, ExpressionStatement invoke, Location loc)
 471                         : base (null, args, loc)
 472                 {
 473                         this.name = name;
 474                         base.binder = this;
 475
 476                         // Used by += or -= only
 477                         type = TypeManager.bool_type;
 478
 479                         condition = new If (
 480                                 new Binary (Binary.Operator.Equality, this, new BoolLiteral (true, loc), loc),
 481                                 new StatementExpression (invoke), new StatementExpression (assignment),
 482                                 loc);
 483                 }
 484
 485                 public Expression CreateCallSiteBinder (ResolveContext ec, Arguments args)
 486                 {
 487                         Arguments binder_args = new Arguments (3);
 488
 489                         binder_args.Add (new Argument (new BinderFlags (0, this)));
 490                         binder_args.Add (new Argument (new StringLiteral (name, loc)));
 491                         binder_args.Add (new Argument (new TypeOf (new TypeExpression (ec.CurrentType, loc), loc)));
 492
 493                         return new Invocation (GetBinder ("IsEvent", loc), binder_args);
 494                 }
 495
 496                 public override void EmitStatement (EmitContext ec)
 497                 {
 498                         condition.Emit (ec);
 499                 }
 500         }
 501
 502         class DynamicConversion : DynamicExpressionStatement, IDynamicBinder
 503         {
 504                 public DynamicConversion (TypeSpec targetType, CSharpBinderFlags flags, Arguments args, Location loc)
 505                         : base (null, args, loc)
 506                 {
 507                         type = targetType;
 508                         base.flags = flags;
 509                         base.binder = this;
 510                 }
 511
 512                 public Expression CreateCallSiteBinder (ResolveContext ec, Arguments args)
 513                 {
 514                         Arguments binder_args = new Arguments (3);
 515
 516                         flags |= ec.HasSet (ResolveContext.Options.CheckedScope) ? CSharpBinderFlags.CheckedContext : 0;
 517
 518                         binder_args.Add (new Argument (new BinderFlags (flags, this)));
 519                         binder_args.Add (new Argument (new TypeOf (new TypeExpression (type, loc), loc)));
 520                         binder_args.Add (new Argument (new TypeOf (new TypeExpression (ec.CurrentType, loc), loc)));
 521                         return new Invocation (GetBinder ("Convert", loc), binder_args);
 522                 }
 523         }
 524
 525         class DynamicConstructorBinder : DynamicExpressionStatement, IDynamicBinder
 526         {
 527                 public DynamicConstructorBinder (TypeSpec type, Arguments args, Location loc)
 528                         : base (null, args, loc)
 529                 {
 530                         this.type = type;
 531                         base.binder = this;
 532                 }
 533
 534                 public Expression CreateCallSiteBinder (ResolveContext ec, Arguments args)
 535                 {
 536                         Arguments binder_args = new Arguments (3);
 537
 538                         binder_args.Add (new Argument (new BinderFlags (0, this)));
 539                         binder_args.Add (new Argument (new TypeOf (new TypeExpression (ec.CurrentType, loc), loc)));
 540                         binder_args.Add (new Argument (new ImplicitlyTypedArrayCreation (args.CreateDynamicBinderArguments (ec), loc)));
 541
 542                         return new Invocation (GetBinder ("InvokeConstructor", loc), binder_args);
 543                 }
 544         }
 545
 546         class DynamicIndexBinder : DynamicMemberAssignable
 547         {
 548                 public DynamicIndexBinder (Arguments args, Location loc)
 549                         : base (args, loc)
 550                 {
 551                 }
 552
 553                 protected override Expression CreateCallSiteBinder (ResolveContext ec, Arguments args, bool isSet)
 554                 {
 555                         Arguments binder_args = new Arguments (3);
 556
 557                         binder_args.Add (new Argument (new BinderFlags (0, this)));
 558                         binder_args.Add (new Argument (new TypeOf (new TypeExpression (ec.CurrentType, loc), loc)));
 559                         binder_args.Add (new Argument (new ImplicitlyTypedArrayCreation (args.CreateDynamicBinderArguments (ec), loc)));
 560
 561                         return new Invocation (GetBinder (isSet ? "SetIndex" : "GetIndex", loc), binder_args);
 562                 }
 563         }
 564
 565         class DynamicInvocation : DynamicExpressionStatement, IDynamicBinder
 566         {
 567                 ATypeNameExpression member;
 568
 569                 public DynamicInvocation (ATypeNameExpression member, Arguments args, Location loc)
 570                         : base (null, args, loc)
 571                 {
 572                         base.binder = this;
 573                         this.member = member;
 574                 }
 575
 576                 //
 577                 // When a return type is known not to be dynamic
 578                 //
 579                 public DynamicInvocation (ATypeNameExpression member, Arguments args, TypeSpec type, Location loc)
 580                         : this (member, args, loc)
 581                 {
 582                         this.type = type;
 583                 }
 584
 585                 public static DynamicInvocation CreateSpecialNameInvoke (ATypeNameExpression member, Arguments args, Location loc)
 586                 {
 587                         return new DynamicInvocation (member, args, loc) {
 588                                 flags = CSharpBinderFlags.InvokeSpecialName
 589                         };
 590                 }
 591
 592                 public Expression CreateCallSiteBinder (ResolveContext ec, Arguments args)
 593                 {
 594                         Arguments binder_args = new Arguments (member != null ? 5 : 3);
 595                         bool is_member_access = member is MemberAccess;
 596
 597                         CSharpBinderFlags call_flags;
 598                         if (!is_member_access && member is SimpleName) {
 599                                 call_flags = CSharpBinderFlags.InvokeSimpleName;
 600                                 is_member_access = true;
 601                         } else {
 602                                 call_flags = 0;
 603                         }
 604
 605                         binder_args.Add (new Argument (new BinderFlags (call_flags, this)));
 606
 607                         if (is_member_access)
 608                                 binder_args.Add (new Argument (new StringLiteral (member.Name, member.Location)));
 609
 610                         if (member != null && member.HasTypeArguments) {
 611                                 TypeArguments ta = member.TypeArguments;
 612                                 if (ta.Resolve (ec)) {
 613                                         var targs = new ArrayInitializer (ta.Count, loc);
 614                                         foreach (TypeSpec t in ta.Arguments)
 615                                                 targs.Add (new TypeOf (new TypeExpression (t, loc), loc));
 616
 617                                         binder_args.Add (new Argument (new ImplicitlyTypedArrayCreation (targs, loc)));
 618                                 }
 619                         } else if (is_member_access) {
 620                                 binder_args.Add (new Argument (new NullLiteral (loc)));
 621                         }
 622
 623                         binder_args.Add (new Argument (new TypeOf (new TypeExpression (ec.CurrentType, loc), loc)));
 624
 625                         Expression real_args;
 626                         if (args == null) {
 627                                 // Cannot be null because .NET trips over
 628                                 real_args = new ArrayCreation (
 629                                         new MemberAccess (GetBinderNamespace (loc), "CSharpArgumentInfo", loc),
 630                                         new ArrayInitializer (0, loc), loc);
 631                         } else {
 632                                 real_args = new ImplicitlyTypedArrayCreation (args.CreateDynamicBinderArguments (ec), loc);
 633                         }
 634
 635                         binder_args.Add (new Argument (real_args));
 636
 637                         return new Invocation (GetBinder (is_member_access ? "InvokeMember" : "Invoke", loc), binder_args);
 638                 }
 639
 640                 public override void EmitStatement (EmitContext ec)
 641                 {
 642                         flags |= CSharpBinderFlags.ResultDiscarded;
 643                         base.EmitStatement (ec);
 644                 }
 645         }
 646
 647         class DynamicMemberBinder : DynamicMemberAssignable
 648         {
 649                 readonly string name;
 650
 651                 public DynamicMemberBinder (string name, Arguments args, Location loc)
 652                         : base (args, loc)
 653                 {
 654                         this.name = name;
 655                 }
 656
 657                 protected override Expression CreateCallSiteBinder (ResolveContext ec, Arguments args, bool isSet)
 658                 {
 659                         Arguments binder_args = new Arguments (4);
 660
 661                         binder_args.Add (new Argument (new BinderFlags (0, this)));
 662                         binder_args.Add (new Argument (new StringLiteral (name, loc)));
 663                         binder_args.Add (new Argument (new TypeOf (new TypeExpression (ec.CurrentType, loc), loc)));
 664                         binder_args.Add (new Argument (new ImplicitlyTypedArrayCreation (args.CreateDynamicBinderArguments (ec), loc)));
 665
 666                         return new Invocation (GetBinder (isSet ? "SetMember" : "GetMember", loc), binder_args);
 667                 }
 668         }
 669
 670         //
 671         // Any member binder which can be source and target of assignment
 672         //
 673         abstract class DynamicMemberAssignable : DynamicExpressionStatement, IDynamicBinder, IAssignMethod
 674         {
 675                 Expression setter;
 676                 Arguments setter_args;
 677
 678                 protected DynamicMemberAssignable (Arguments args, Location loc)
 679                         : base (null, args, loc)
 680                 {
 681                         base.binder = this;
 682                 }
 683
 684                 public Expression CreateCallSiteBinder (ResolveContext ec, Arguments args)
 685                 {
 686                         //
 687                         // DoResolve always uses getter
 688                         //
 689                         return CreateCallSiteBinder (ec, args, false);
 690                 }
 691
 692                 protected abstract Expression CreateCallSiteBinder (ResolveContext ec, Arguments args, bool isSet);
 693
 694                 public override Expression DoResolveLValue (ResolveContext rc, Expression right_side)
 695                 {
 696                         if (right_side == EmptyExpression.OutAccess.Instance) {
 697                                 right_side.DoResolveLValue (rc, this);
 698                                 return null;
 699                         }
 700
 701                         if (DoResolveCore (rc)) {
 702                                 setter_args = new Arguments (Arguments.Count + 1);
 703                                 setter_args.AddRange (Arguments);
 704                                 setter_args.Add (new Argument (right_side));
 705                                 setter = CreateCallSiteBinder (rc, setter_args, true);
 706                         }
 707
 708                         eclass = ExprClass.Variable;
 709                         return this;
 710                 }
 711
 712                 public override void Emit (EmitContext ec)
 713                 {
 714                         // It's null for ResolveLValue used without assignment
 715                         if (binder_expr == null)
 716                                 EmitCall (ec, setter, Arguments, false);
 717                         else
 718                                 base.Emit (ec);
 719                 }
 720
 721                 public override void EmitStatement (EmitContext ec)
 722                 {
 723                         // It's null for ResolveLValue used without assignment
 724                         if (binder_expr == null)
 725                                 EmitCall (ec, setter, Arguments, true);
 726                         else
 727                                 base.EmitStatement (ec);
 728                 }
 729
 730                 #region IAssignMethod Members
 731
 732                 public void Emit (EmitContext ec, bool leave_copy)
 733                 {
 734                         throw new NotImplementedException ();
 735                 }
 736
 737                 public void EmitAssign (EmitContext ec, Expression source, bool leave_copy, bool prepare_for_load)
 738                 {
 739                         EmitCall (ec, setter, setter_args, !leave_copy);
 740                 }
 741
 742                 #endregion
 743         }
 744
 745         class DynamicUnaryConversion : DynamicExpressionStatement, IDynamicBinder
 746         {
 747                 string name;
 748
 749                 public DynamicUnaryConversion (string name, Arguments args, Location loc)
 750                         : base (null, args, loc)
 751                 {
 752                         this.name = name;
 753                         base.binder = this;
 754                         if (name == "IsTrue" || name == "IsFalse")
 755                                 type = TypeManager.bool_type;
 756                 }
 757
 758                 public Expression CreateCallSiteBinder (ResolveContext ec, Arguments args)
 759                 {
 760                         Arguments binder_args = new Arguments (4);
 761
 762                         MemberAccess sle = new MemberAccess (new MemberAccess (
 763                                 new QualifiedAliasMember (QualifiedAliasMember.GlobalAlias, "System", loc), "Linq", loc), "Expressions", loc);
 764
 765                         var flags = ec.HasSet (ResolveContext.Options.CheckedScope) ? CSharpBinderFlags.CheckedContext : 0;
 766
 767                         binder_args.Add (new Argument (new BinderFlags (flags, this)));
 768                         binder_args.Add (new Argument (new MemberAccess (new MemberAccess (sle, "ExpressionType", loc), name, loc)));
 769                         binder_args.Add (new Argument (new TypeOf (new TypeExpression (ec.CurrentType, loc), loc)));
 770                         binder_args.Add (new Argument (new ImplicitlyTypedArrayCreation (args.CreateDynamicBinderArguments (ec), loc)));
 771
 772                         return new Invocation (GetBinder ("UnaryOperation", loc), binder_args);
 773                 }
 774         }
 775 }