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