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)
 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 #if NET_4_0
 194                 SLE.Expression MakeAssignExpression (BuilderContext ctx);
 195 #endif
 196         }
 197
 198         //
 199         // Base dynamic expression statement creator
 200         //
 201         class DynamicExpressionStatement : ExpressionStatement
 202         {
 203                 class StaticDataClass : CompilerGeneratedClass
 204                 {
 205                         public StaticDataClass ()
 206                                 : base (new RootDeclSpace (new NamespaceEntry (null, null, null)),
 207                                         new MemberName (CompilerGeneratedClass.MakeName (null, "c", "DynamicSites", 0)),
 208                                         Modifiers.INTERNAL | Modifiers.STATIC)
 209                         {
 210                         }
 211                 }
 212
 213                 //
 214                 // Binder flag dynamic constant, the value is combination of
 215                 // flags known at resolve stage and flags known only at emit
 216                 // stage
 217                 //
 218                 protected class BinderFlags : EnumConstant
 219                 {
 220                         DynamicExpressionStatement statement;
 221                         CSharpBinderFlags flags;
 222
 223                         public BinderFlags (CSharpBinderFlags flags, DynamicExpressionStatement statement)
 224                                 : base (statement.loc)
 225                         {
 226                                 this.flags = flags;
 227                                 this.statement = statement;
 228                         }
 229
 230                         protected override Expression DoResolve (ResolveContext ec)
 231                         {
 232                                 Child = new IntConstant ((int) (flags | statement.flags), statement.loc).Resolve (ec);
 233
 234                                 type = TypeManager.binder_flags;
 235                                 eclass = Child.eclass;
 236                                 return this;
 237                         }
 238                 }
 239
 240                 static StaticDataClass global_site_container;
 241                 static int field_counter;
 242                 static int container_counter;
 243
 244                 readonly Arguments arguments;
 245                 protected IDynamicBinder binder;
 246                 protected Expression binder_expr;
 247
 248                 // Used by BinderFlags
 249                 protected CSharpBinderFlags flags;
 250
 251                 public DynamicExpressionStatement (IDynamicBinder binder, Arguments args, Location loc)
 252                 {
 253                         this.binder = binder;
 254                         this.arguments = args;
 255                         this.loc = loc;
 256                 }
 257
 258                 public Arguments Arguments {
 259                         get {
 260                                 return arguments;
 261                         }
 262                 }
 263
 264                 static TypeContainer CreateSiteContainer ()
 265                 {
 266                         if (global_site_container == null) {
 267                                 global_site_container = new StaticDataClass ();
 268                                 RootContext.ToplevelTypes.AddCompilerGeneratedClass (global_site_container);
 269                                 global_site_container.CreateType ();
 270                                 global_site_container.DefineType ();
 271                                 global_site_container.Define ();
 272                         }
 273
 274                         return global_site_container;
 275                 }
 276
 277                 static Field CreateSiteField (FullNamedExpression type)
 278                 {
 279                         TypeContainer site_container = CreateSiteContainer ();
 280                         Field f = new Field (site_container, type, Modifiers.PUBLIC | Modifiers.STATIC,
 281                                 new MemberName ("Site" +  field_counter++), null);
 282                         f.Define ();
 283
 284                         site_container.AddField (f);
 285                         return f;
 286                 }
 287
 288                 public override Expression CreateExpressionTree (ResolveContext ec)
 289                 {
 290                         ec.Report.Error (1963, loc, "An expression tree cannot contain a dynamic operation");
 291                         return null;
 292                 }
 293
 294                 protected override Expression DoResolve (ResolveContext ec)
 295                 {
 296                         if (DoResolveCore (ec))
 297                                 binder_expr = binder.CreateCallSiteBinder (ec, arguments);
 298
 299                         return this;
 300                 }
 301
 302                 protected bool DoResolveCore (ResolveContext rc)
 303                 {
 304                         int errors = rc.Report.Errors;
 305
 306                         if (TypeManager.binder_type == null) {
 307                                 var t = TypeManager.CoreLookupType (rc.Compiler,
 308                                         "Microsoft.CSharp.RuntimeBinder", "Binder", MemberKind.Class, true);
 309                                 if (t != null)
 310                                         TypeManager.binder_type = new TypeExpression (t, Location.Null);
 311                         }
 312
 313                         if (TypeManager.call_site_type == null)
 314                                 TypeManager.call_site_type = TypeManager.CoreLookupType (rc.Compiler,
 315                                         "System.Runtime.CompilerServices", "CallSite", MemberKind.Class, true);
 316
 317                         if (TypeManager.generic_call_site_type == null)
 318                                 TypeManager.generic_call_site_type = TypeManager.CoreLookupType (rc.Compiler,
 319                                         "System.Runtime.CompilerServices", "CallSite", 1, MemberKind.Class, true);
 320
 321                         if (TypeManager.binder_flags == null) {
 322                                 TypeManager.binder_flags = TypeManager.CoreLookupType (rc.Compiler,
 323                                         "Microsoft.CSharp.RuntimeBinder", "CSharpBinderFlags", MemberKind.Enum, true);
 324                         }
 325
 326                         eclass = ExprClass.Value;
 327
 328                         if (type == null)
 329                                 type = InternalType.Dynamic;
 330
 331                         if (rc.Report.Errors == errors)
 332                                 return true;
 333
 334                         rc.Report.Error (1969, loc,
 335                                 "Dynamic operation cannot be compiled without `Microsoft.CSharp.dll' assembly reference");
 336                         return false;
 337                 }
 338
 339                 public override void Emit (EmitContext ec)
 340                 {
 341                         EmitCall (ec, binder_expr, arguments,  false);
 342                 }
 343
 344                 public override void EmitStatement (EmitContext ec)
 345                 {
 346                         EmitCall (ec, binder_expr, arguments, true);
 347                 }
 348
 349                 protected void EmitCall (EmitContext ec, Expression binder, Arguments arguments, bool isStatement)
 350                 {
 351                         int dyn_args_count = arguments == null ? 0 : arguments.Count;
 352                         TypeExpr site_type = CreateSiteType (RootContext.ToplevelTypes.Compiler, arguments, dyn_args_count, isStatement);
 353                         FieldExpr site_field_expr = new FieldExpr (CreateSiteField (site_type), loc);
 354
 355                         SymbolWriter.OpenCompilerGeneratedBlock (ec);
 356
 357                         Arguments args = new Arguments (1);
 358                         args.Add (new Argument (binder));
 359                         StatementExpression s = new StatementExpression (new SimpleAssign (site_field_expr, new Invocation (new MemberAccess (site_type, "Create"), args)));
 360
 361                         BlockContext bc = new BlockContext (ec.MemberContext, null, TypeManager.void_type);
 362                         if (s.Resolve (bc)) {
 363                                 Statement init = new If (new Binary (Binary.Operator.Equality, site_field_expr, new NullLiteral (loc), loc), s, loc);
 364                                 init.Emit (ec);
 365                         }
 366
 367                         args = new Arguments (1 + dyn_args_count);
 368                         args.Add (new Argument (site_field_expr));
 369                         if (arguments != null) {
 370                                 foreach (Argument a in arguments) {
 371                                         if (a is NamedArgument) {
 372                                                 // Name is not valid in this context
 373                                                 args.Add (new Argument (a.Expr, a.ArgType));
 374                                                 continue;
 375                                         }
 376
 377                                         args.Add (a);
 378                                 }
 379                         }
 380
 381                         Expression target = new DelegateInvocation (new MemberAccess (site_field_expr, "Target", loc).Resolve (bc), args, loc).Resolve (bc);
 382                         if (target != null)
 383                                 target.Emit (ec);
 384
 385                         SymbolWriter.CloseCompilerGeneratedBlock (ec);
 386                 }
 387
 388                 public static MemberAccess GetBinderNamespace (Location loc)
 389                 {
 390                         return new MemberAccess (new MemberAccess (
 391                                 new QualifiedAliasMember (QualifiedAliasMember.GlobalAlias, "Microsoft", loc), "CSharp", loc), "RuntimeBinder", loc);
 392                 }
 393
 394                 public static MemberAccess GetBinder (string name, Location loc)
 395                 {
 396                         return new MemberAccess (TypeManager.binder_type, name, loc);
 397                 }
 398
 399                 TypeExpr CreateSiteType (CompilerContext ctx, Arguments arguments, int dyn_args_count, bool is_statement)
 400                 {
 401                         int default_args = is_statement ? 1 : 2;
 402
 403                         bool has_ref_out_argument = false;
 404                         FullNamedExpression[] targs = new FullNamedExpression[dyn_args_count + default_args];
 405                         targs [0] = new TypeExpression (TypeManager.call_site_type, loc);
 406                         for (int i = 0; i < dyn_args_count; ++i) {
 407                                 TypeSpec arg_type;
 408                                 Argument a = arguments [i];
 409                                 if (a.Type == TypeManager.null_type)
 410                                         arg_type = TypeManager.object_type;
 411                                 else
 412                                         arg_type = a.Type;
 413
 414                                 if (a.ArgType == Argument.AType.Out || a.ArgType == Argument.AType.Ref)
 415                                         has_ref_out_argument = true;
 416
 417                                 targs [i + 1] = new TypeExpression (arg_type, loc);
 418                         }
 419
 420                         TypeExpr del_type = null;
 421                         if (!has_ref_out_argument) {
 422                                 string d_name = is_statement ? "Action" : "Func";
 423
 424                                 TypeSpec t = TypeManager.CoreLookupType (ctx, "System", d_name, dyn_args_count + default_args, MemberKind.Delegate, false);
 425                                 if (t != null) {
 426                                         if (!is_statement)
 427                                                 targs [targs.Length - 1] = new TypeExpression (type, loc);
 428
 429                                         del_type = new GenericTypeExpr (t, new TypeArguments (targs), loc);
 430                                 }
 431                         }
 432
 433                         //
 434                         // Create custom delegate when no appropriate predefined one is found
 435                         //
 436                         if (del_type == null) {
 437                                 TypeSpec rt = is_statement ? TypeManager.void_type : type;
 438                                 Parameter[] p = new Parameter [dyn_args_count + 1];
 439                                 p[0] = new Parameter (targs [0], "p0", Parameter.Modifier.NONE, null, loc);
 440
 441                                 for (int i = 1; i < dyn_args_count + 1; ++i)
 442                                         p[i] = new Parameter (targs[i], "p" + i.ToString ("X"), arguments[i - 1].Modifier, null, loc);
 443
 444                                 TypeContainer parent = CreateSiteContainer ();
 445                                 Delegate d = new Delegate (parent.NamespaceEntry, parent, new TypeExpression (rt, loc),
 446                                         Modifiers.INTERNAL | Modifiers.COMPILER_GENERATED,
 447                                         new MemberName ("Container" + container_counter++.ToString ("X")),
 448                                         new ParametersCompiled (ctx, p), null);
 449
 450                                 d.CreateType ();
 451                                 d.DefineType ();
 452                                 d.Define ();
 453                                 d.Emit ();
 454
 455                                 parent.AddDelegate (d);
 456                                 del_type = new TypeExpression (d.Definition, loc);
 457                         }
 458
 459                         TypeExpr site_type = new GenericTypeExpr (TypeManager.generic_call_site_type, new TypeArguments (del_type), loc);
 460                         return site_type;
 461                 }
 462
 463                 public static void Reset ()
 464                 {
 465                         global_site_container = null;
 466                         field_counter = container_counter = 0;
 467                 }
 468         }
 469
 470         //
 471         // Dynamic member access compound assignment for events
 472         //
 473         class DynamicEventCompoundAssign : DynamicExpressionStatement, IDynamicBinder
 474         {
 475                 string name;
 476                 Statement condition;
 477
 478                 public DynamicEventCompoundAssign (string name, Arguments args, ExpressionStatement assignment, ExpressionStatement invoke, Location loc)
 479                         : base (null, args, loc)
 480                 {
 481                         this.name = name;
 482                         base.binder = this;
 483
 484                         // Used by += or -= only
 485                         type = TypeManager.bool_type;
 486
 487                         condition = new If (
 488                                 new Binary (Binary.Operator.Equality, this, new BoolLiteral (true, loc), loc),
 489                                 new StatementExpression (invoke), new StatementExpression (assignment),
 490                                 loc);
 491                 }
 492
 493                 public Expression CreateCallSiteBinder (ResolveContext ec, Arguments args)
 494                 {
 495                         Arguments binder_args = new Arguments (3);
 496
 497                         binder_args.Add (new Argument (new BinderFlags (0, this)));
 498                         binder_args.Add (new Argument (new StringLiteral (name, loc)));
 499                         binder_args.Add (new Argument (new TypeOf (new TypeExpression (ec.CurrentType, loc), loc)));
 500
 501                         return new Invocation (GetBinder ("IsEvent", loc), binder_args);
 502                 }
 503
 504                 public override void EmitStatement (EmitContext ec)
 505                 {
 506                         condition.Emit (ec);
 507                 }
 508         }
 509
 510         class DynamicConversion : DynamicExpressionStatement, IDynamicBinder
 511         {
 512                 public DynamicConversion (TypeSpec targetType, CSharpBinderFlags flags, Arguments args, Location loc)
 513                         : base (null, args, loc)
 514                 {
 515                         type = targetType;
 516                         base.flags = flags;
 517                         base.binder = this;
 518                 }
 519
 520                 public Expression CreateCallSiteBinder (ResolveContext ec, Arguments args)
 521                 {
 522                         Arguments binder_args = new Arguments (3);
 523
 524                         flags |= ec.HasSet (ResolveContext.Options.CheckedScope) ? CSharpBinderFlags.CheckedContext : 0;
 525
 526                         binder_args.Add (new Argument (new BinderFlags (flags, this)));
 527                         binder_args.Add (new Argument (new TypeOf (new TypeExpression (ec.CurrentType, loc), loc)));
 528                         binder_args.Add (new Argument (new TypeOf (new TypeExpression (type, loc), loc)));
 529                         return new Invocation (GetBinder ("Convert", loc), binder_args);
 530                 }
 531         }
 532
 533         class DynamicConstructorBinder : DynamicExpressionStatement, IDynamicBinder
 534         {
 535                 public DynamicConstructorBinder (TypeSpec type, Arguments args, Location loc)
 536                         : base (null, args, loc)
 537                 {
 538                         this.type = type;
 539                         base.binder = this;
 540                 }
 541
 542                 public Expression CreateCallSiteBinder (ResolveContext ec, Arguments args)
 543                 {
 544                         Arguments binder_args = new Arguments (3);
 545
 546                         binder_args.Add (new Argument (new BinderFlags (0, this)));
 547                         binder_args.Add (new Argument (new TypeOf (new TypeExpression (ec.CurrentType, loc), loc)));
 548                         binder_args.Add (new Argument (new ImplicitlyTypedArrayCreation (args.CreateDynamicBinderArguments (ec), loc)));
 549
 550                         return new Invocation (GetBinder ("InvokeConstructor", loc), binder_args);
 551                 }
 552         }
 553
 554         class DynamicIndexBinder : DynamicMemberAssignable
 555         {
 556                 public DynamicIndexBinder (Arguments args, Location loc)
 557                         : base (args, loc)
 558                 {
 559                 }
 560
 561                 protected override Expression CreateCallSiteBinder (ResolveContext ec, Arguments args, bool isSet)
 562                 {
 563                         Arguments binder_args = new Arguments (3);
 564
 565                         binder_args.Add (new Argument (new BinderFlags (0, this)));
 566                         binder_args.Add (new Argument (new TypeOf (new TypeExpression (ec.CurrentType, loc), loc)));
 567                         binder_args.Add (new Argument (new ImplicitlyTypedArrayCreation (args.CreateDynamicBinderArguments (ec), loc)));
 568
 569                         return new Invocation (GetBinder (isSet ? "SetIndex" : "GetIndex", loc), binder_args);
 570                 }
 571         }
 572
 573         class DynamicInvocation : DynamicExpressionStatement, IDynamicBinder
 574         {
 575                 ATypeNameExpression member;
 576
 577                 public DynamicInvocation (ATypeNameExpression member, Arguments args, Location loc)
 578                         : base (null, args, loc)
 579                 {
 580                         base.binder = this;
 581                         this.member = member;
 582                 }
 583
 584                 //
 585                 // When a return type is known not to be dynamic
 586                 //
 587                 public DynamicInvocation (ATypeNameExpression member, Arguments args, TypeSpec type, Location loc)
 588                         : this (member, args, loc)
 589                 {
 590                         this.type = type;
 591                 }
 592
 593                 public static DynamicInvocation CreateSpecialNameInvoke (ATypeNameExpression member, Arguments args, Location loc)
 594                 {
 595                         return new DynamicInvocation (member, args, loc) {
 596                                 flags = CSharpBinderFlags.InvokeSpecialName
 597                         };
 598                 }
 599
 600                 public Expression CreateCallSiteBinder (ResolveContext ec, Arguments args)
 601                 {
 602                         Arguments binder_args = new Arguments (member != null ? 5 : 3);
 603                         bool is_member_access = member is MemberAccess;
 604
 605                         CSharpBinderFlags call_flags;
 606                         if (!is_member_access && member is SimpleName) {
 607                                 call_flags = CSharpBinderFlags.InvokeSimpleName;
 608                                 is_member_access = true;
 609                         } else {
 610                                 call_flags = 0;
 611                         }
 612
 613                         binder_args.Add (new Argument (new BinderFlags (call_flags, this)));
 614
 615                         if (is_member_access)
 616                                 binder_args.Add (new Argument (new StringLiteral (member.Name, member.Location)));
 617
 618                         if (member != null && member.HasTypeArguments) {
 619                                 TypeArguments ta = member.TypeArguments;
 620                                 if (ta.Resolve (ec)) {
 621                                         var targs = new ArrayInitializer (ta.Count, loc);
 622                                         foreach (TypeSpec t in ta.Arguments)
 623                                                 targs.Add (new TypeOf (new TypeExpression (t, loc), loc));
 624
 625                                         binder_args.Add (new Argument (new ImplicitlyTypedArrayCreation (targs, loc)));
 626                                 }
 627                         } else if (is_member_access) {
 628                                 binder_args.Add (new Argument (new NullLiteral (loc)));
 629                         }
 630
 631                         binder_args.Add (new Argument (new TypeOf (new TypeExpression (ec.CurrentType, loc), loc)));
 632
 633                         Expression real_args;
 634                         if (args == null) {
 635                                 // Cannot be null because .NET trips over
 636                                 real_args = new ArrayCreation (
 637                                         new MemberAccess (GetBinderNamespace (loc), "CSharpArgumentInfo", loc),
 638                                         new ArrayInitializer (0, loc), loc);
 639                         } else {
 640                                 real_args = new ImplicitlyTypedArrayCreation (args.CreateDynamicBinderArguments (ec), loc);
 641                         }
 642
 643                         binder_args.Add (new Argument (real_args));
 644
 645                         return new Invocation (GetBinder (is_member_access ? "InvokeMember" : "Invoke", loc), binder_args);
 646                 }
 647
 648                 public override void EmitStatement (EmitContext ec)
 649                 {
 650                         flags |= CSharpBinderFlags.ResultDiscarded;
 651                         base.EmitStatement (ec);
 652                 }
 653         }
 654
 655         class DynamicMemberBinder : DynamicMemberAssignable
 656         {
 657                 readonly string name;
 658
 659                 public DynamicMemberBinder (string name, Arguments args, Location loc)
 660                         : base (args, loc)
 661                 {
 662                         this.name = name;
 663                 }
 664
 665                 protected override Expression CreateCallSiteBinder (ResolveContext ec, Arguments args, bool isSet)
 666                 {
 667                         Arguments binder_args = new Arguments (4);
 668
 669                         binder_args.Add (new Argument (new BinderFlags (0, this)));
 670                         binder_args.Add (new Argument (new StringLiteral (name, loc)));
 671                         binder_args.Add (new Argument (new TypeOf (new TypeExpression (ec.CurrentType, loc), loc)));
 672                         binder_args.Add (new Argument (new ImplicitlyTypedArrayCreation (args.CreateDynamicBinderArguments (ec), loc)));
 673
 674                         return new Invocation (GetBinder (isSet ? "SetMember" : "GetMember", loc), binder_args);
 675                 }
 676         }
 677
 678         //
 679         // Any member binder which can be source and target of assignment
 680         //
 681         abstract class DynamicMemberAssignable : DynamicExpressionStatement, IDynamicBinder, IAssignMethod
 682         {
 683                 Expression setter;
 684                 Arguments setter_args;
 685
 686                 protected DynamicMemberAssignable (Arguments args, Location loc)
 687                         : base (null, args, loc)
 688                 {
 689                         base.binder = this;
 690                 }
 691
 692                 public Expression CreateCallSiteBinder (ResolveContext ec, Arguments args)
 693                 {
 694                         //
 695                         // DoResolve always uses getter
 696                         //
 697                         return CreateCallSiteBinder (ec, args, false);
 698                 }
 699
 700                 protected abstract Expression CreateCallSiteBinder (ResolveContext ec, Arguments args, bool isSet);
 701
 702                 public override Expression DoResolveLValue (ResolveContext rc, Expression right_side)
 703                 {
 704                         if (right_side == EmptyExpression.OutAccess.Instance) {
 705                                 right_side.DoResolveLValue (rc, this);
 706                                 return null;
 707                         }
 708
 709                         if (DoResolveCore (rc)) {
 710                                 setter_args = new Arguments (Arguments.Count + 1);
 711                                 setter_args.AddRange (Arguments);
 712                                 setter_args.Add (new Argument (right_side));
 713                                 setter = CreateCallSiteBinder (rc, setter_args, true);
 714                         }
 715
 716                         eclass = ExprClass.Variable;
 717                         return this;
 718                 }
 719
 720                 public override void Emit (EmitContext ec)
 721                 {
 722                         // It's null for ResolveLValue used without assignment
 723                         if (binder_expr == null)
 724                                 EmitCall (ec, setter, Arguments, false);
 725                         else
 726                                 base.Emit (ec);
 727                 }
 728
 729                 public override void EmitStatement (EmitContext ec)
 730                 {
 731                         // It's null for ResolveLValue used without assignment
 732                         if (binder_expr == null)
 733                                 EmitCall (ec, setter, Arguments, true);
 734                         else
 735                                 base.EmitStatement (ec);
 736                 }
 737
 738                 #region IAssignMethod Members
 739
 740                 public void Emit (EmitContext ec, bool leave_copy)
 741                 {
 742                         throw new NotImplementedException ();
 743                 }
 744
 745                 public void EmitAssign (EmitContext ec, Expression source, bool leave_copy, bool prepare_for_load)
 746                 {
 747                         EmitCall (ec, setter, setter_args, !leave_copy);
 748                 }
 749
 750                 #endregion
 751         }
 752
 753         class DynamicUnaryConversion : DynamicExpressionStatement, IDynamicBinder
 754         {
 755                 string name;
 756
 757                 public DynamicUnaryConversion (string name, Arguments args, Location loc)
 758                         : base (null, args, loc)
 759                 {
 760                         this.name = name;
 761                         base.binder = this;
 762                         if (name == "IsTrue" || name == "IsFalse")
 763                                 type = TypeManager.bool_type;
 764                 }
 765
 766                 public Expression CreateCallSiteBinder (ResolveContext ec, Arguments args)
 767                 {
 768                         Arguments binder_args = new Arguments (4);
 769
 770                         MemberAccess sle = new MemberAccess (new MemberAccess (
 771                                 new QualifiedAliasMember (QualifiedAliasMember.GlobalAlias, "System", loc), "Linq", loc), "Expressions", loc);
 772
 773                         var flags = ec.HasSet (ResolveContext.Options.CheckedScope) ? CSharpBinderFlags.CheckedContext : 0;
 774
 775                         binder_args.Add (new Argument (new BinderFlags (flags, this)));
 776                         binder_args.Add (new Argument (new MemberAccess (new MemberAccess (sle, "ExpressionType", loc), name, loc)));
 777                         binder_args.Add (new Argument (new TypeOf (new TypeExpression (ec.CurrentType, loc), loc)));
 778                         binder_args.Add (new Argument (new ImplicitlyTypedArrayCreation (args.CreateDynamicBinderArguments (ec), loc)));
 779
 780                         return new Invocation (GetBinder ("UnaryOperation", loc), binder_args);
 781                 }
 782         }
 783 }