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 Type RuntimeType;
  75                         public Type LimitType;
  76                         public SLE.Expression Expression;
  77                 }
  78 #endif
  79
  80                 readonly DynamicMetaObject obj;
  81
  82                 public RuntimeValueExpression (DynamicMetaObject obj, bool isCompileTimeType)
  83                 {
  84                         this.obj = obj;
  85                         this.type = isCompileTimeType ? obj.LimitType : obj.RuntimeType;
  86                         this.type = obj.LimitType;
  87                         this.eclass = ExprClass.Variable;
  88                 }
  89
  90                 public void AddressOf (EmitContext ec, AddressOp mode)
  91                 {
  92                         throw new NotImplementedException ();
  93                 }
  94
  95                 public override Expression CreateExpressionTree (ResolveContext ec)
  96                 {
  97                         throw new NotImplementedException ();
  98                 }
  99
 100                 protected override Expression DoResolve (ResolveContext ec)
 101                 {
 102                         return this;
 103                 }
 104
 105                 public override Expression DoResolveLValue (ResolveContext ec, Expression right_side)
 106                 {
 107                         return this;
 108                 }
 109
 110                 public override void Emit (EmitContext ec)
 111                 {
 112                         throw new NotImplementedException ();
 113                 }
 114
 115                 #region IAssignMethod Members
 116
 117                 public void Emit (EmitContext ec, bool leave_copy)
 118                 {
 119                         throw new NotImplementedException ();
 120                 }
 121
 122                 public void EmitAssign (EmitContext ec, Expression source, bool leave_copy, bool prepare_for_load)
 123                 {
 124                         throw new NotImplementedException ();
 125                 }
 126
 127                 #endregion
 128
 129                 public SLE.Expression MakeAssignExpression (BuilderContext ctx)
 130                 {
 131                         return obj.Expression;
 132                 }
 133
 134                 public override SLE.Expression MakeExpression (BuilderContext ctx)
 135                 {
 136                         return SLE.Expression.Convert (obj.Expression, type);
 137                 }
 138
 139                 public DynamicMetaObject MetaObject {
 140                         get { return obj; }
 141                 }
 142         }
 143
 144         //
 145         // Wraps runtime dynamic expression into expected type. Needed
 146         // to satify expected type check by dynamic binder and no conversion
 147         // is required (ResultDiscarded).
 148         //
 149         public class DynamicResultCast : ShimExpression
 150         {
 151                 public DynamicResultCast (Type type, Expression expr)
 152                         : base (expr)
 153                 {
 154                         this.type = type;
 155                 }
 156
 157                 protected override Expression DoResolve (ResolveContext ec)
 158                 {
 159                         expr = expr.Resolve (ec);
 160                         eclass = ExprClass.Value;
 161                         return this;
 162                 }
 163
 164 #if NET_4_0
 165                 public override SLE.Expression MakeExpression (BuilderContext ctx)
 166                 {
 167                         return SLE.Expression.Block (expr.MakeExpression (ctx), SLE.Expression.Default (type));
 168                 }
 169 #endif
 170         }
 171
 172         #endregion
 173
 174         //
 175         // Creates dynamic binder expression
 176         //
 177         interface IDynamicBinder
 178         {
 179                 Expression CreateCallSiteBinder (ResolveContext ec, Arguments args);
 180         }
 181
 182         //
 183         // Extends standard assignment interface for expressions
 184         // supported by dynamic resolver
 185         //
 186         interface IDynamicAssign : IAssignMethod
 187         {
 188 #if NET_4_0
 189                 SLE.Expression MakeAssignExpression (BuilderContext ctx);
 190 #endif
 191         }
 192
 193         //
 194         // Base dynamic expression statement creator
 195         //
 196         class DynamicExpressionStatement : ExpressionStatement
 197         {
 198                 class StaticDataClass : CompilerGeneratedClass
 199                 {
 200                         public StaticDataClass ()
 201                                 : base (new RootDeclSpace (new NamespaceEntry (null, null, null)),
 202                                         new MemberName (CompilerGeneratedClass.MakeName (null, "c", "DynamicSites", 0)),
 203                                         Modifiers.INTERNAL | Modifiers.STATIC)
 204                         {
 205                                 ModFlags &= ~Modifiers.SEALED;
 206                         }
 207                 }
 208
 209                 //
 210                 // Binder flag dynamic constant, the value is combination of
 211                 // flags known at resolve stage and flags known only at emit
 212                 // stage
 213                 //
 214                 protected class BinderFlags : EnumConstant
 215                 {
 216                         DynamicExpressionStatement statement;
 217                         CSharpBinderFlags flags;
 218
 219                         public BinderFlags (CSharpBinderFlags flags, DynamicExpressionStatement statement)
 220                                 : base (statement.loc)
 221                         {
 222                                 this.flags = flags;
 223                                 this.statement = statement;
 224                         }
 225
 226                         protected override Expression DoResolve (ResolveContext ec)
 227                         {
 228                                 Child = new IntConstant ((int) (flags | statement.flags), statement.loc).Resolve (ec);
 229
 230                                 type = TypeManager.binder_flags;
 231                                 eclass = Child.eclass;
 232                                 return this;
 233                         }
 234                 }
 235
 236                 static StaticDataClass global_site_container;
 237                 static int field_counter;
 238                 static int container_counter;
 239
 240                 readonly Arguments arguments;
 241                 protected IDynamicBinder binder;
 242                 protected Expression binder_expr;
 243
 244                 // Used by BinderFlags
 245                 protected CSharpBinderFlags flags;
 246
 247                 public DynamicExpressionStatement (IDynamicBinder binder, Arguments args, Location loc)
 248                 {
 249                         this.binder = binder;
 250                         this.arguments = args;
 251                         this.loc = loc;
 252                 }
 253
 254                 public Arguments Arguments {
 255                         get {
 256                                 return arguments;
 257                         }
 258                 }
 259
 260                 static TypeContainer CreateSiteContainer ()
 261                 {
 262                         if (global_site_container == null) {
 263                                 global_site_container = new StaticDataClass ();
 264                                 RootContext.ToplevelTypes.AddCompilerGeneratedClass (global_site_container);
 265                                 global_site_container.DefineType ();
 266                                 global_site_container.Define ();
 267 //                              global_site_container.EmitType ();
 268
 269                                 RootContext.RegisterCompilerGeneratedType (global_site_container.TypeBuilder);
 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.ig);
 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)), 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.ig);
 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                                 Type arg_type;
 406                                 Argument a = arguments [i];
 407                                 if (a.Type == TypeManager.null_type)
 408                                         arg_type = TypeManager.object_type;
 409                                 else
 410                                         arg_type = a.Type;
 411
 412                                 if (a.ArgType == Argument.AType.Out || a.ArgType == Argument.AType.Ref)
 413                                         has_ref_out_argument = true;
 414
 415                                 targs [i + 1] = new TypeExpression (arg_type, loc);
 416                         }
 417
 418                         TypeExpr del_type = null;
 419                         if (!has_ref_out_argument) {
 420                                 string d_name = is_statement ? "Action`" : "Func`";
 421
 422                                 Type t = TypeManager.CoreLookupType (ctx, "System", d_name + (dyn_args_count + default_args), MemberKind.Delegate, false);
 423                                 if (t != null) {
 424                                         if (!is_statement)
 425                                                 targs [targs.Length - 1] = new TypeExpression (type, loc);
 426
 427                                         del_type = new GenericTypeExpr (t, new TypeArguments (targs), loc);
 428                                 }
 429                         }
 430
 431                         //
 432                         // Create custom delegate when no appropriate predefined one is found
 433                         //
 434                         if (del_type == null) {
 435                                 Type rt = is_statement ? TypeManager.void_type : type;
 436                                 Parameter[] p = new Parameter [dyn_args_count + 1];
 437                                 p[0] = new Parameter (targs [0], "p0", Parameter.Modifier.NONE, null, loc);
 438
 439                                 for (int i = 1; i < dyn_args_count + 1; ++i)
 440                                         p[i] = new Parameter (targs[i], "p" + i.ToString ("X"), arguments[i - 1].Modifier, null, loc);
 441
 442                                 TypeContainer parent = CreateSiteContainer ();
 443                                 Delegate d = new Delegate (parent.NamespaceEntry, parent, new TypeExpression (rt, loc),
 444                                         Modifiers.INTERNAL | Modifiers.COMPILER_GENERATED,
 445                                         new MemberName ("Container" + container_counter++.ToString ("X")),
 446                                         new ParametersCompiled (ctx, p), null);
 447
 448                                 d.DefineType ();
 449                                 d.Define ();
 450                                 d.Emit ();
 451
 452                                 parent.AddDelegate (d);
 453                                 del_type = new TypeExpression (d.TypeBuilder, loc);
 454                         }
 455
 456                         TypeExpr site_type = new GenericTypeExpr (TypeManager.generic_call_site_type, new TypeArguments (del_type), loc);
 457                         return site_type;
 458                 }
 459
 460                 public static void Reset ()
 461                 {
 462                         global_site_container = null;
 463                         field_counter = container_counter = 0;
 464                 }
 465         }
 466
 467         //
 468         // Dynamic member access compound assignment for events
 469         //
 470         class DynamicEventCompoundAssign : DynamicExpressionStatement, IDynamicBinder
 471         {
 472                 string name;
 473                 Statement condition;
 474
 475                 public DynamicEventCompoundAssign (string name, Arguments args, ExpressionStatement assignment, ExpressionStatement invoke, Location loc)
 476                         : base (null, args, loc)
 477                 {
 478                         this.name = name;
 479                         base.binder = this;
 480
 481                         // Used by += or -= only
 482                         type = TypeManager.bool_type;
 483
 484                         condition = new If (
 485                                 new Binary (Binary.Operator.Equality, this, new BoolLiteral (true, loc)),
 486                                 new StatementExpression (invoke), new StatementExpression (assignment),
 487                                 loc);
 488                 }
 489
 490                 public Expression CreateCallSiteBinder (ResolveContext ec, Arguments args)
 491                 {
 492                         Arguments binder_args = new Arguments (3);
 493
 494                         binder_args.Add (new Argument (new BinderFlags (0, this)));
 495                         binder_args.Add (new Argument (new StringLiteral (name, loc)));
 496                         binder_args.Add (new Argument (new TypeOf (new TypeExpression (ec.CurrentType, loc), loc)));
 497
 498                         return new Invocation (GetBinder ("IsEvent", loc), binder_args);
 499                 }
 500
 501                 public override void EmitStatement (EmitContext ec)
 502                 {
 503                         condition.Emit (ec);
 504                 }
 505         }
 506
 507         class DynamicConversion : DynamicExpressionStatement, IDynamicBinder
 508         {
 509                 public DynamicConversion (Type targetType, CSharpBinderFlags flags, Arguments args, Location loc)
 510                         : base (null, args, loc)
 511                 {
 512                         type = targetType;
 513                         base.flags = flags;
 514                         base.binder = this;
 515                 }
 516
 517                 public Expression CreateCallSiteBinder (ResolveContext ec, Arguments args)
 518                 {
 519                         Arguments binder_args = new Arguments (2);
 520
 521                         flags |= ec.HasSet (ResolveContext.Options.CheckedScope) ? CSharpBinderFlags.CheckedContext : 0;
 522
 523                         binder_args.Add (new Argument (new BinderFlags (flags, this)));
 524                         binder_args.Add (new Argument (new TypeOf (new TypeExpression (type, loc), loc)));
 525                         return new Invocation (GetBinder ("Convert", loc), binder_args);
 526                 }
 527         }
 528
 529         class DynamicConstructorBinder : DynamicExpressionStatement, IDynamicBinder
 530         {
 531                 public DynamicConstructorBinder (Type type, Arguments args, Location loc)
 532                         : base (null, args, loc)
 533                 {
 534                         this.type = type;
 535                         base.binder = this;
 536                 }
 537
 538                 public Expression CreateCallSiteBinder (ResolveContext ec, Arguments args)
 539                 {
 540                         Arguments binder_args = new Arguments (3);
 541
 542                         binder_args.Add (new Argument (new BinderFlags (0, this)));
 543                         binder_args.Add (new Argument (new TypeOf (new TypeExpression (ec.CurrentType, loc), loc)));
 544                         binder_args.Add (new Argument (new ImplicitlyTypedArrayCreation ("[]", args.CreateDynamicBinderArguments (ec), loc)));
 545
 546                         return new Invocation (GetBinder ("InvokeConstructor", loc), binder_args);
 547                 }
 548         }
 549
 550         class DynamicIndexBinder : DynamicMemberAssignable
 551         {
 552                 public DynamicIndexBinder (Arguments args, Location loc)
 553                         : base (args, loc)
 554                 {
 555                 }
 556
 557                 protected override Expression CreateCallSiteBinder (ResolveContext ec, Arguments args, bool isSet)
 558                 {
 559                         Arguments binder_args = new Arguments (3);
 560
 561                         binder_args.Add (new Argument (new BinderFlags (0, this)));
 562                         binder_args.Add (new Argument (new TypeOf (new TypeExpression (ec.CurrentType, loc), loc)));
 563                         binder_args.Add (new Argument (new ImplicitlyTypedArrayCreation ("[]", args.CreateDynamicBinderArguments (ec), loc)));
 564
 565                         return new Invocation (GetBinder (isSet ? "SetIndex" : "GetIndex", loc), binder_args);
 566                 }
 567         }
 568
 569         class DynamicInvocation : DynamicExpressionStatement, IDynamicBinder
 570         {
 571                 ATypeNameExpression member;
 572
 573                 public DynamicInvocation (ATypeNameExpression member, Arguments args, Location loc)
 574                         : base (null, args, loc)
 575                 {
 576                         base.binder = this;
 577                         this.member = member;
 578                 }
 579
 580                 public DynamicInvocation (ATypeNameExpression member, Arguments args, Type type, Location loc)
 581                         : this (member, args, loc)
 582                 {
 583                         // When a return type is known not to be dynamic
 584                         this.type = type;
 585                 }
 586
 587                 public static DynamicInvocation CreateSpecialNameInvoke (ATypeNameExpression member, Arguments args, Location loc)
 588                 {
 589                         return new DynamicInvocation (member, args, loc) {
 590                                 flags = CSharpBinderFlags.InvokeSpecialName
 591                         };
 592                 }
 593
 594                 public Expression CreateCallSiteBinder (ResolveContext ec, Arguments args)
 595                 {
 596                         Arguments binder_args = new Arguments (member != null ? 5 : 3);
 597                         bool is_member_access = member is MemberAccess;
 598
 599                         CSharpBinderFlags call_flags;
 600                         if (!is_member_access && member is SimpleName) {
 601                                 call_flags = CSharpBinderFlags.InvokeSimpleName;
 602                                 is_member_access = true;
 603                         } else {
 604                                 call_flags = 0;
 605                         }
 606
 607                         binder_args.Add (new Argument (new BinderFlags (call_flags, this)));
 608
 609                         if (is_member_access)
 610                                 binder_args.Add (new Argument (new StringLiteral (member.Name, member.Location)));
 611
 612                         if (member != null && member.HasTypeArguments) {
 613                                 TypeArguments ta = member.TypeArguments;
 614                                 if (ta.Resolve (ec)) {
 615                                         var targs = new ArrayInitializer (ta.Count, loc);
 616                                         foreach (Type t in ta.Arguments)
 617                                                 targs.Add (new TypeOf (new TypeExpression (t, loc), loc));
 618
 619                                         binder_args.Add (new Argument (new ImplicitlyTypedArrayCreation ("[]", targs, loc)));
 620                                 }
 621                         } else if (is_member_access) {
 622                                 binder_args.Add (new Argument (new NullLiteral (loc)));
 623                         }
 624
 625                         binder_args.Add (new Argument (new TypeOf (new TypeExpression (ec.CurrentType, loc), loc)));
 626
 627                         Expression real_args;
 628                         if (args == null) {
 629                                 // Cannot be null because .NET trips over
 630                                 real_args = new ArrayCreation (
 631                                         new MemberAccess (GetBinderNamespace (loc), "CSharpArgumentInfo", loc), "[]",
 632                                         new ArrayInitializer (0, loc), loc);
 633                         } else {
 634                                 real_args = new ImplicitlyTypedArrayCreation ("[]", args.CreateDynamicBinderArguments (ec), loc);
 635                         }
 636
 637                         binder_args.Add (new Argument (real_args));
 638
 639                         return new Invocation (GetBinder (is_member_access ? "InvokeMember" : "Invoke", loc), binder_args);
 640                 }
 641
 642                 public override void EmitStatement (EmitContext ec)
 643                 {
 644                         flags |= CSharpBinderFlags.ResultDiscarded;
 645                         base.EmitStatement (ec);
 646                 }
 647         }
 648
 649         class DynamicMemberBinder : DynamicMemberAssignable
 650         {
 651                 readonly string name;
 652
 653                 public DynamicMemberBinder (string name, Arguments args, Location loc)
 654                         : base (args, loc)
 655                 {
 656                         this.name = name;
 657                 }
 658
 659                 protected override Expression CreateCallSiteBinder (ResolveContext ec, Arguments args, bool isSet)
 660                 {
 661                         Arguments binder_args = new Arguments (4);
 662
 663                         binder_args.Add (new Argument (new BinderFlags (0, this)));
 664                         binder_args.Add (new Argument (new StringLiteral (name, loc)));
 665                         binder_args.Add (new Argument (new TypeOf (new TypeExpression (ec.CurrentType, loc), loc)));
 666                         binder_args.Add (new Argument (new ImplicitlyTypedArrayCreation ("[]", args.CreateDynamicBinderArguments (ec), loc)));
 667
 668                         return new Invocation (GetBinder (isSet ? "SetMember" : "GetMember", loc), binder_args);
 669                 }
 670         }
 671
 672         //
 673         // Any member binder which can be source and target of assignment
 674         //
 675         abstract class DynamicMemberAssignable : DynamicExpressionStatement, IDynamicBinder, IAssignMethod
 676         {
 677                 Expression setter;
 678                 Arguments setter_args;
 679
 680                 protected DynamicMemberAssignable (Arguments args, Location loc)
 681                         : base (null, args, loc)
 682                 {
 683                         base.binder = this;
 684                 }
 685
 686                 public Expression CreateCallSiteBinder (ResolveContext ec, Arguments args)
 687                 {
 688                         //
 689                         // DoResolve always uses getter
 690                         //
 691                         return CreateCallSiteBinder (ec, args, false);
 692                 }
 693
 694                 protected abstract Expression CreateCallSiteBinder (ResolveContext ec, Arguments args, bool isSet);
 695
 696                 public override Expression DoResolveLValue (ResolveContext rc, Expression right_side)
 697                 {
 698                         if (right_side == EmptyExpression.OutAccess.Instance) {
 699                                 right_side.DoResolveLValue (rc, this);
 700                                 return null;
 701                         }
 702
 703                         if (DoResolveCore (rc)) {
 704                                 setter_args = new Arguments (Arguments.Count + 1);
 705                                 setter_args.AddRange (Arguments);
 706                                 setter_args.Add (new Argument (right_side));
 707                                 setter = CreateCallSiteBinder (rc, setter_args, true);
 708                         }
 709
 710                         eclass = ExprClass.Variable;
 711                         return this;
 712                 }
 713
 714                 public override void Emit (EmitContext ec)
 715                 {
 716                         // It's null for ResolveLValue used without assignment
 717                         if (binder_expr == null)
 718                                 EmitCall (ec, setter, Arguments, false);
 719                         else
 720                                 base.Emit (ec);
 721                 }
 722
 723                 public override void EmitStatement (EmitContext ec)
 724                 {
 725                         // It's null for ResolveLValue used without assignment
 726                         if (binder_expr == null)
 727                                 EmitCall (ec, setter, Arguments, true);
 728                         else
 729                                 base.EmitStatement (ec);
 730                 }
 731
 732                 #region IAssignMethod Members
 733
 734                 public void Emit (EmitContext ec, bool leave_copy)
 735                 {
 736                         throw new NotImplementedException ();
 737                 }
 738
 739                 public void EmitAssign (EmitContext ec, Expression source, bool leave_copy, bool prepare_for_load)
 740                 {
 741                         EmitCall (ec, setter, setter_args, !leave_copy);
 742                 }
 743
 744                 #endregion
 745         }
 746
 747         class DynamicUnaryConversion : DynamicExpressionStatement, IDynamicBinder
 748         {
 749                 string name;
 750
 751                 public DynamicUnaryConversion (string name, Arguments args, Location loc)
 752                         : base (null, args, loc)
 753                 {
 754                         this.name = name;
 755                         base.binder = this;
 756                         if (name == "IsTrue" || name == "IsFalse")
 757                                 type = TypeManager.bool_type;
 758                 }
 759
 760                 public Expression CreateCallSiteBinder (ResolveContext ec, Arguments args)
 761                 {
 762                         Arguments binder_args = new Arguments (3);
 763
 764                         MemberAccess sle = new MemberAccess (new MemberAccess (
 765                                 new QualifiedAliasMember (QualifiedAliasMember.GlobalAlias, "System", loc), "Linq", loc), "Expressions", loc);
 766
 767                         var flags = ec.HasSet (ResolveContext.Options.CheckedScope) ? CSharpBinderFlags.CheckedContext : 0;
 768
 769                         binder_args.Add (new Argument (new BinderFlags (flags, this)));
 770                         binder_args.Add (new Argument (new MemberAccess (new MemberAccess (sle, "ExpressionType", loc), name, loc)));
 771                         binder_args.Add (new Argument (new ImplicitlyTypedArrayCreation ("[]", args.CreateDynamicBinderArguments (ec), loc)));
 772
 773                         return new Invocation (GetBinder ("UnaryOperation", loc), binder_args);
 774                 }
 775         }
 776 }