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
  14 #if NET_4_0
  15 using System.Dynamic;
  16 using SLE = System.Linq.Expressions;
  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                 }
  77 #endif
  78
  79                 readonly DynamicMetaObject obj;
  80
  81                 public RuntimeValueExpression (DynamicMetaObject obj, bool isCompileTimeType)
  82                 {
  83                         this.obj = obj;
  84                         this.type = isCompileTimeType ? obj.LimitType : obj.RuntimeType;
  85                         this.type = obj.LimitType;
  86                         this.eclass = ExprClass.Variable;
  87                 }
  88
  89                 public void AddressOf (EmitContext ec, AddressOp mode)
  90                 {
  91                         throw new NotImplementedException ();
  92                 }
  93
  94                 public override Expression CreateExpressionTree (ResolveContext ec)
  95                 {
  96                         throw new NotImplementedException ();
  97                 }
  98
  99                 protected override Expression DoResolve (ResolveContext ec)
 100                 {
 101                         return this;
 102                 }
 103
 104                 public override Expression DoResolveLValue (ResolveContext ec, Expression right_side)
 105                 {
 106                         return this;
 107                 }
 108
 109                 public override void Emit (EmitContext ec)
 110                 {
 111                         throw new NotImplementedException ();
 112                 }
 113
 114                 #region IAssignMethod Members
 115
 116                 public void Emit (EmitContext ec, bool leave_copy)
 117                 {
 118                         throw new NotImplementedException ();
 119                 }
 120
 121                 public void EmitAssign (EmitContext ec, Expression source, bool leave_copy, bool prepare_for_load)
 122                 {
 123                         throw new NotImplementedException ();
 124                 }
 125
 126                 #endregion
 127
 128 #if NET_4_0
 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 #endif
 139
 140                 public DynamicMetaObject MetaObject {
 141                         get { return obj; }
 142                 }
 143         }
 144
 145         //
 146         // Wraps runtime dynamic expression into expected type. Needed
 147         // to satify expected type check by dynamic binder and no conversion
 148         // is required (ResultDiscarded).
 149         //
 150         public class DynamicResultCast : ShimExpression
 151         {
 152                 public DynamicResultCast (Type type, Expression expr)
 153                         : base (expr)
 154                 {
 155                         this.type = type;
 156                 }
 157
 158                 protected override Expression DoResolve (ResolveContext ec)
 159                 {
 160                         expr = expr.Resolve (ec);
 161                         eclass = ExprClass.Value;
 162                         return this;
 163                 }
 164
 165 #if NET_4_0
 166                 public override SLE.Expression MakeExpression (BuilderContext ctx)
 167                 {
 168                         return SLE.Expression.Block (expr.MakeExpression (ctx), SLE.Expression.Default (type));
 169                 }
 170 #endif
 171         }
 172
 173         #endregion
 174
 175         //
 176         // Creates dynamic binder expression
 177         //
 178         interface IDynamicBinder
 179         {
 180                 Expression CreateCallSiteBinder (ResolveContext ec, Arguments args);
 181         }
 182
 183         //
 184         // Extends standard assignment interface for expressions
 185         // supported by dynamic resolver
 186         //
 187         interface IDynamicAssign : IAssignMethod
 188         {
 189 #if NET_4_0
 190                 SLE.Expression MakeAssignExpression (BuilderContext ctx);
 191 #endif
 192         }
 193
 194         //
 195         // Base dynamic expression statement creator
 196         //
 197         class DynamicExpressionStatement : ExpressionStatement
 198         {
 199                 class StaticDataClass : CompilerGeneratedClass
 200                 {
 201                         public StaticDataClass ()
 202                                 : base (new RootDeclSpace (new NamespaceEntry (null, null, null)),
 203                                         new MemberName (CompilerGeneratedClass.MakeName (null, "c", "DynamicSites", 0)),
 204                                         Modifiers.INTERNAL | Modifiers.STATIC)
 205                         {
 206                                 ModFlags &= ~Modifiers.SEALED;
 207                         }
 208                 }
 209
 210                 //
 211                 // Binder flag dynamic constant, the value is combination of
 212                 // flags known at resolve stage and flags known only at emit
 213                 // stage
 214                 //
 215                 protected class BinderFlags : EnumConstant
 216                 {
 217                         DynamicExpressionStatement statement;
 218                         CSharpBinderFlags flags;
 219
 220                         public BinderFlags (CSharpBinderFlags flags, DynamicExpressionStatement statement)
 221                                 : base (statement.loc)
 222                         {
 223                                 this.flags = flags;
 224                                 this.statement = statement;
 225                         }
 226
 227                         protected override Expression DoResolve (ResolveContext ec)
 228                         {
 229                                 Child = new IntConstant ((int) (flags | statement.flags), statement.loc).Resolve (ec);
 230
 231                                 type = TypeManager.binder_flags;
 232                                 eclass = Child.eclass;
 233                                 return this;
 234                         }
 235                 }
 236
 237                 static StaticDataClass global_site_container;
 238                 static int field_counter;
 239                 static int container_counter;
 240
 241                 readonly Arguments arguments;
 242                 protected IDynamicBinder binder;
 243                 protected Expression binder_expr;
 244
 245                 // Used by BinderFlags
 246                 protected CSharpBinderFlags flags;
 247
 248                 public DynamicExpressionStatement (IDynamicBinder binder, Arguments args, Location loc)
 249                 {
 250                         this.binder = binder;
 251                         this.arguments = args;
 252                         this.loc = loc;
 253                 }
 254
 255                 public Arguments Arguments {
 256                         get {
 257                                 return arguments;
 258                         }
 259                 }
 260
 261                 static TypeContainer CreateSiteContainer ()
 262                 {
 263                         if (global_site_container == null) {
 264                                 global_site_container = new StaticDataClass ();
 265                                 RootContext.ToplevelTypes.AddCompilerGeneratedClass (global_site_container);
 266                                 global_site_container.DefineType ();
 267                                 global_site_container.Define ();
 268 //                              global_site_container.EmitType ();
 269
 270                                 RootContext.RegisterCompilerGeneratedType (global_site_container.TypeBuilder);
 271                         }
 272
 273                         return global_site_container;
 274                 }
 275
 276                 static Field CreateSiteField (FullNamedExpression type)
 277                 {
 278                         TypeContainer site_container = CreateSiteContainer ();
 279                         Field f = new Field (site_container, type, Modifiers.PUBLIC | Modifiers.STATIC,
 280                                 new MemberName ("Site" +  field_counter++), null);
 281                         f.Define ();
 282
 283                         site_container.AddField (f);
 284                         return f;
 285                 }
 286
 287                 public override Expression CreateExpressionTree (ResolveContext ec)
 288                 {
 289                         ec.Report.Error (1963, loc, "An expression tree cannot contain a dynamic operation");
 290                         return null;
 291                 }
 292
 293                 protected override Expression DoResolve (ResolveContext ec)
 294                 {
 295                         if (DoResolveCore (ec))
 296                                 binder_expr = binder.CreateCallSiteBinder (ec, arguments);
 297
 298                         return this;
 299                 }
 300
 301                 protected bool DoResolveCore (ResolveContext rc)
 302                 {
 303                         int errors = rc.Report.Errors;
 304
 305                         if (TypeManager.binder_type == null) {
 306                                 var t = TypeManager.CoreLookupType (rc.Compiler,
 307                                         "Microsoft.CSharp.RuntimeBinder", "Binder", Kind.Class, true);
 308                                 if (t != null)
 309                                         TypeManager.binder_type = new TypeExpression (t, Location.Null);
 310                         }
 311
 312                         if (TypeManager.call_site_type == null)
 313                                 TypeManager.call_site_type = TypeManager.CoreLookupType (rc.Compiler,
 314                                         "System.Runtime.CompilerServices", "CallSite", Kind.Class, true);
 315
 316                         if (TypeManager.generic_call_site_type == null)
 317                                 TypeManager.generic_call_site_type = TypeManager.CoreLookupType (rc.Compiler,
 318                                         "System.Runtime.CompilerServices", "CallSite`1", Kind.Class, true);
 319
 320                         if (TypeManager.binder_flags == null) {
 321                                 TypeManager.binder_flags = TypeManager.CoreLookupType (rc.Compiler,
 322                                         "Microsoft.CSharp.RuntimeBinder", "CSharpBinderFlags", Kind.Enum, true);
 323                         }
 324
 325                         eclass = ExprClass.Value;
 326
 327                         if (type == null)
 328                                 type = InternalType.Dynamic;
 329
 330                         if (rc.Report.Errors == errors)
 331                                 return true;
 332
 333                         rc.Report.Error (1969, loc,
 334                                 "Dynamic operation cannot be compiled without `Microsoft.CSharp.dll' assembly reference");
 335                         return false;
 336                 }
 337
 338                 public override void Emit (EmitContext ec)
 339                 {
 340                         EmitCall (ec, binder_expr, arguments,  false);
 341                 }
 342
 343                 public override void EmitStatement (EmitContext ec)
 344                 {
 345                         EmitCall (ec, binder_expr, arguments, true);
 346                 }
 347
 348                 protected void EmitCall (EmitContext ec, Expression binder, Arguments arguments, bool isStatement)
 349                 {
 350                         int dyn_args_count = arguments == null ? 0 : arguments.Count;
 351                         TypeExpr site_type = CreateSiteType (RootContext.ToplevelTypes.Compiler, arguments, dyn_args_count, isStatement);
 352                         FieldExpr site_field_expr = new FieldExpr (CreateSiteField (site_type).FieldBuilder, loc);
 353
 354                         SymbolWriter.OpenCompilerGeneratedBlock (ec.ig);
 355
 356                         Arguments args = new Arguments (1);
 357                         args.Add (new Argument (binder));
 358                         StatementExpression s = new StatementExpression (new SimpleAssign (site_field_expr, new Invocation (new MemberAccess (site_type, "Create"), args)));
 359
 360                         BlockContext bc = new BlockContext (ec.MemberContext, null, TypeManager.void_type);
 361                         if (s.Resolve (bc)) {
 362                                 Statement init = new If (new Binary (Binary.Operator.Equality, site_field_expr, new NullLiteral (loc)), s, loc);
 363                                 init.Emit (ec);
 364                         }
 365
 366                         args = new Arguments (1 + dyn_args_count);
 367                         args.Add (new Argument (site_field_expr));
 368                         if (arguments != null) {
 369                                 foreach (Argument a in arguments) {
 370                                         if (a is NamedArgument) {
 371                                                 // Name is not valid in this context
 372                                                 args.Add (new Argument (a.Expr, a.ArgType));
 373                                                 continue;
 374                                         }
 375
 376                                         args.Add (a);
 377                                 }
 378                         }
 379
 380                         Expression target = new DelegateInvocation (new MemberAccess (site_field_expr, "Target", loc).Resolve (bc), args, loc).Resolve (bc);
 381                         if (target != null)
 382                                 target.Emit (ec);
 383
 384                         SymbolWriter.CloseCompilerGeneratedBlock (ec.ig);
 385                 }
 386
 387                 public static MemberAccess GetBinderNamespace (Location loc)
 388                 {
 389                         return new MemberAccess (new MemberAccess (
 390                                 new QualifiedAliasMember (QualifiedAliasMember.GlobalAlias, "Microsoft", loc), "CSharp", loc), "RuntimeBinder", loc);
 391                 }
 392
 393                 public static MemberAccess GetBinder (string name, Location loc)
 394                 {
 395                         return new MemberAccess (TypeManager.binder_type, name, loc);
 396                 }
 397
 398                 TypeExpr CreateSiteType (CompilerContext ctx, Arguments arguments, int dyn_args_count, bool is_statement)
 399                 {
 400                         int default_args = is_statement ? 1 : 2;
 401
 402                         bool has_ref_out_argument = false;
 403                         FullNamedExpression[] targs = new FullNamedExpression[dyn_args_count + default_args];
 404                         targs [0] = new TypeExpression (TypeManager.call_site_type, loc);
 405                         for (int i = 0; i < dyn_args_count; ++i) {
 406                                 Type arg_type;
 407                                 Argument a = arguments [i];
 408                                 if (a.Type == TypeManager.null_type)
 409                                         arg_type = TypeManager.object_type;
 410                                 else
 411                                         arg_type = a.Type;
 412
 413                                 if (a.ArgType == Argument.AType.Out || a.ArgType == Argument.AType.Ref)
 414                                         has_ref_out_argument = true;
 415
 416                                 targs [i + 1] = new TypeExpression (arg_type, loc);
 417                         }
 418
 419                         TypeExpr del_type = null;
 420                         if (!has_ref_out_argument) {
 421                                 string d_name = is_statement ? "Action`" : "Func`";
 422
 423                                 Type t = TypeManager.CoreLookupType (ctx, "System", d_name + (dyn_args_count + default_args), Kind.Delegate, false);
 424                                 if (t != null) {
 425                                         if (!is_statement)
 426                                                 targs [targs.Length - 1] = new TypeExpression (type, loc);
 427
 428                                         del_type = new GenericTypeExpr (t, new TypeArguments (targs), loc);
 429                                 }
 430                         }
 431
 432                         //
 433                         // Create custom delegate when no appropriate predefined one is found
 434                         //
 435                         if (del_type == null) {
 436                                 Type rt = is_statement ? TypeManager.void_type : type;
 437                                 Parameter[] p = new Parameter [dyn_args_count + 1];
 438                                 p[0] = new Parameter (targs [0], "p0", Parameter.Modifier.NONE, null, loc);
 439
 440                                 for (int i = 1; i < dyn_args_count + 1; ++i)
 441                                         p[i] = new Parameter (targs[i], "p" + i.ToString ("X"), arguments[i - 1].Modifier, null, loc);
 442
 443                                 TypeContainer parent = CreateSiteContainer ();
 444                                 Delegate d = new Delegate (parent.NamespaceEntry, parent, new TypeExpression (rt, loc),
 445                                         Modifiers.INTERNAL | Modifiers.COMPILER_GENERATED,
 446                                         new MemberName ("Container" + container_counter++.ToString ("X")),
 447                                         new ParametersCompiled (ctx, p), null);
 448
 449                                 d.DefineType ();
 450                                 d.Define ();
 451                                 d.Emit ();
 452
 453                                 parent.AddDelegate (d);
 454                                 del_type = new TypeExpression (d.TypeBuilder, loc);
 455                         }
 456
 457                         TypeExpr site_type = new GenericTypeExpr (TypeManager.generic_call_site_type, new TypeArguments (del_type), loc);
 458                         return site_type;
 459                 }
 460
 461                 public static void Reset ()
 462                 {
 463                         global_site_container = null;
 464                         field_counter = container_counter = 0;
 465                 }
 466         }
 467
 468         //
 469         // Dynamic member access compound assignment for events
 470         //
 471         class DynamicEventCompoundAssign : DynamicExpressionStatement, IDynamicBinder
 472         {
 473                 string name;
 474                 Statement condition;
 475
 476                 public DynamicEventCompoundAssign (string name, Arguments args, ExpressionStatement assignment, ExpressionStatement invoke, Location loc)
 477                         : base (null, args, loc)
 478                 {
 479                         this.name = name;
 480                         base.binder = this;
 481
 482                         // Used by += or -= only
 483                         type = TypeManager.bool_type;
 484
 485                         condition = new If (
 486                                 new Binary (Binary.Operator.Equality, this, new BoolLiteral (true, loc)),
 487                                 new StatementExpression (invoke), new StatementExpression (assignment),
 488                                 loc);
 489                 }
 490
 491                 public Expression CreateCallSiteBinder (ResolveContext ec, Arguments args)
 492                 {
 493                         Arguments binder_args = new Arguments (3);
 494
 495                         binder_args.Add (new Argument (new BinderFlags (0, this)));
 496                         binder_args.Add (new Argument (new StringLiteral (name, loc)));
 497                         binder_args.Add (new Argument (new TypeOf (new TypeExpression (ec.CurrentType, loc), loc)));
 498
 499                         return new Invocation (GetBinder ("IsEvent", loc), binder_args);
 500                 }
 501
 502                 public override void EmitStatement (EmitContext ec)
 503                 {
 504                         condition.Emit (ec);
 505                 }
 506         }
 507
 508         class DynamicConversion : DynamicExpressionStatement, IDynamicBinder
 509         {
 510                 public DynamicConversion (Type targetType, CSharpBinderFlags flags, Arguments args, Location loc)
 511                         : base (null, args, loc)
 512                 {
 513                         type = targetType;
 514                         base.flags = flags;
 515                         base.binder = this;
 516                 }
 517
 518                 public Expression CreateCallSiteBinder (ResolveContext ec, Arguments args)
 519                 {
 520                         Arguments binder_args = new Arguments (2);
 521
 522                         flags |= ec.HasSet (ResolveContext.Options.CheckedScope) ? CSharpBinderFlags.CheckedContext : 0;
 523
 524                         binder_args.Add (new Argument (new BinderFlags (flags, this)));
 525                         binder_args.Add (new Argument (new TypeOf (new TypeExpression (type, loc), loc)));
 526                         return new Invocation (GetBinder ("Convert", loc), binder_args);
 527                 }
 528         }
 529
 530         class DynamicConstructorBinder : DynamicExpressionStatement, IDynamicBinder
 531         {
 532                 public DynamicConstructorBinder (Type type, Arguments args, Location loc)
 533                         : base (null, args, loc)
 534                 {
 535                         this.type = type;
 536                         base.binder = this;
 537                 }
 538
 539                 public Expression CreateCallSiteBinder (ResolveContext ec, Arguments args)
 540                 {
 541                         Arguments binder_args = new Arguments (3);
 542
 543                         binder_args.Add (new Argument (new BinderFlags (0, this)));
 544                         binder_args.Add (new Argument (new TypeOf (new TypeExpression (ec.CurrentType, loc), loc)));
 545                         binder_args.Add (new Argument (new ImplicitlyTypedArrayCreation ("[]", args.CreateDynamicBinderArguments (ec), loc)));
 546
 547                         return new Invocation (GetBinder ("InvokeConstructor", loc), binder_args);
 548                 }
 549         }
 550
 551         class DynamicIndexBinder : DynamicMemberAssignable
 552         {
 553                 public DynamicIndexBinder (Arguments args, Location loc)
 554                         : base (args, loc)
 555                 {
 556                 }
 557
 558                 protected override Expression CreateCallSiteBinder (ResolveContext ec, Arguments args, bool isSet)
 559                 {
 560                         Arguments binder_args = new Arguments (3);
 561
 562                         binder_args.Add (new Argument (new BinderFlags (0, this)));
 563                         binder_args.Add (new Argument (new TypeOf (new TypeExpression (ec.CurrentType, loc), loc)));
 564                         binder_args.Add (new Argument (new ImplicitlyTypedArrayCreation ("[]", args.CreateDynamicBinderArguments (ec), loc)));
 565
 566                         return new Invocation (GetBinder (isSet ? "SetIndex" : "GetIndex", loc), binder_args);
 567                 }
 568         }
 569
 570         class DynamicInvocation : DynamicExpressionStatement, IDynamicBinder
 571         {
 572                 ATypeNameExpression member;
 573
 574                 public DynamicInvocation (ATypeNameExpression member, Arguments args, Location loc)
 575                         : base (null, args, loc)
 576                 {
 577                         base.binder = this;
 578                         this.member = member;
 579                 }
 580
 581                 public DynamicInvocation (ATypeNameExpression member, Arguments args, Type type, Location loc)
 582                         : this (member, args, loc)
 583                 {
 584                         // When a return type is known not to be dynamic
 585                         this.type = type;
 586                 }
 587
 588                 public static DynamicInvocation CreateSpecialNameInvoke (ATypeNameExpression member, Arguments args, Location loc)
 589                 {
 590                         return new DynamicInvocation (member, args, loc) {
 591                                 flags = CSharpBinderFlags.InvokeSpecialName
 592                         };
 593                 }
 594
 595                 public Expression CreateCallSiteBinder (ResolveContext ec, Arguments args)
 596                 {
 597                         Arguments binder_args = new Arguments (member != null ? 5 : 3);
 598                         bool is_member_access = member is MemberAccess;
 599
 600                         CSharpBinderFlags call_flags;
 601                         if (!is_member_access && member is SimpleName) {
 602                                 call_flags = CSharpBinderFlags.InvokeSimpleName;
 603                                 is_member_access = true;
 604                         } else {
 605                                 call_flags = 0;
 606                         }
 607
 608                         binder_args.Add (new Argument (new BinderFlags (call_flags, this)));
 609
 610                         if (is_member_access)
 611                                 binder_args.Add (new Argument (new StringLiteral (member.Name, member.Location)));
 612
 613                         if (member != null && member.HasTypeArguments) {
 614                                 TypeArguments ta = member.TypeArguments;
 615                                 if (ta.Resolve (ec)) {
 616                                         var targs = new ArrayInitializer (ta.Count, loc);
 617                                         foreach (Type t in ta.Arguments)
 618                                                 targs.Add (new TypeOf (new TypeExpression (t, loc), loc));
 619
 620                                         binder_args.Add (new Argument (new ImplicitlyTypedArrayCreation ("[]", targs, loc)));
 621                                 }
 622                         } else if (is_member_access) {
 623                                 binder_args.Add (new Argument (new NullLiteral (loc)));
 624                         }
 625
 626                         binder_args.Add (new Argument (new TypeOf (new TypeExpression (ec.CurrentType, loc), loc)));
 627
 628                         Expression real_args;
 629                         if (args == null) {
 630                                 // Cannot be null because .NET trips over
 631                                 real_args = new ArrayCreation (
 632                                         new MemberAccess (GetBinderNamespace (loc), "CSharpArgumentInfo", loc), "[]",
 633                                         new ArrayInitializer (0, loc), loc);
 634                         } else {
 635                                 real_args = new ImplicitlyTypedArrayCreation ("[]", args.CreateDynamicBinderArguments (ec), loc);
 636                         }
 637
 638                         binder_args.Add (new Argument (real_args));
 639
 640                         return new Invocation (GetBinder (is_member_access ? "InvokeMember" : "Invoke", loc), binder_args);
 641                 }
 642
 643                 public override void EmitStatement (EmitContext ec)
 644                 {
 645                         flags |= CSharpBinderFlags.ResultDiscarded;
 646                         base.EmitStatement (ec);
 647                 }
 648         }
 649
 650         class DynamicMemberBinder : DynamicMemberAssignable
 651         {
 652                 readonly string name;
 653
 654                 public DynamicMemberBinder (string name, Arguments args, Location loc)
 655                         : base (args, loc)
 656                 {
 657                         this.name = name;
 658                 }
 659
 660                 protected override Expression CreateCallSiteBinder (ResolveContext ec, Arguments args, bool isSet)
 661                 {
 662                         Arguments binder_args = new Arguments (4);
 663
 664                         binder_args.Add (new Argument (new BinderFlags (0, this)));
 665                         binder_args.Add (new Argument (new StringLiteral (name, loc)));
 666                         binder_args.Add (new Argument (new TypeOf (new TypeExpression (ec.CurrentType, loc), loc)));
 667                         binder_args.Add (new Argument (new ImplicitlyTypedArrayCreation ("[]", args.CreateDynamicBinderArguments (ec), loc)));
 668
 669                         return new Invocation (GetBinder (isSet ? "SetMember" : "GetMember", loc), binder_args);
 670                 }
 671         }
 672
 673         //
 674         // Any member binder which can be source and target of assignment
 675         //
 676         abstract class DynamicMemberAssignable : DynamicExpressionStatement, IDynamicBinder, IAssignMethod
 677         {
 678                 Expression setter;
 679                 Arguments setter_args;
 680
 681                 protected DynamicMemberAssignable (Arguments args, Location loc)
 682                         : base (null, args, loc)
 683                 {
 684                         base.binder = this;
 685                 }
 686
 687                 public Expression CreateCallSiteBinder (ResolveContext ec, Arguments args)
 688                 {
 689                         //
 690                         // DoResolve always uses getter
 691                         //
 692                         return CreateCallSiteBinder (ec, args, false);
 693                 }
 694
 695                 protected abstract Expression CreateCallSiteBinder (ResolveContext ec, Arguments args, bool isSet);
 696
 697                 public override Expression DoResolveLValue (ResolveContext rc, Expression right_side)
 698                 {
 699                         if (right_side == EmptyExpression.OutAccess.Instance) {
 700                                 right_side.DoResolveLValue (rc, this);
 701                                 return null;
 702                         }
 703
 704                         if (DoResolveCore (rc)) {
 705                                 setter_args = new Arguments (Arguments.Count + 1);
 706                                 setter_args.AddRange (Arguments);
 707                                 setter_args.Add (new Argument (right_side));
 708                                 setter = CreateCallSiteBinder (rc, setter_args, true);
 709                         }
 710
 711                         eclass = ExprClass.Variable;
 712                         return this;
 713                 }
 714
 715                 public override void Emit (EmitContext ec)
 716                 {
 717                         // It's null for ResolveLValue used without assignment
 718                         if (binder_expr == null)
 719                                 EmitCall (ec, setter, Arguments, false);
 720                         else
 721                                 base.Emit (ec);
 722                 }
 723
 724                 public override void EmitStatement (EmitContext ec)
 725                 {
 726                         // It's null for ResolveLValue used without assignment
 727                         if (binder_expr == null)
 728                                 EmitCall (ec, setter, Arguments, true);
 729                         else
 730                                 base.EmitStatement (ec);
 731                 }
 732
 733                 #region IAssignMethod Members
 734
 735                 public void Emit (EmitContext ec, bool leave_copy)
 736                 {
 737                         throw new NotImplementedException ();
 738                 }
 739
 740                 public void EmitAssign (EmitContext ec, Expression source, bool leave_copy, bool prepare_for_load)
 741                 {
 742                         EmitCall (ec, setter, setter_args, !leave_copy);
 743                 }
 744
 745                 #endregion
 746         }
 747
 748         class DynamicUnaryConversion : DynamicExpressionStatement, IDynamicBinder
 749         {
 750                 string name;
 751
 752                 public DynamicUnaryConversion (string name, Arguments args, Location loc)
 753                         : base (null, args, loc)
 754                 {
 755                         this.name = name;
 756                         base.binder = this;
 757                         if (name == "IsTrue" || name == "IsFalse")
 758                                 type = TypeManager.bool_type;
 759                 }
 760
 761                 public Expression CreateCallSiteBinder (ResolveContext ec, Arguments args)
 762                 {
 763                         Arguments binder_args = new Arguments (3);
 764
 765                         MemberAccess sle = new MemberAccess (new MemberAccess (
 766                                 new QualifiedAliasMember (QualifiedAliasMember.GlobalAlias, "System", loc), "Linq", loc), "Expressions", loc);
 767
 768                         var flags = ec.HasSet (ResolveContext.Options.CheckedScope) ? CSharpBinderFlags.CheckedContext : 0;
 769
 770                         binder_args.Add (new Argument (new BinderFlags (flags, this)));
 771                         binder_args.Add (new Argument (new MemberAccess (new MemberAccess (sle, "ExpressionType", loc), name, loc)));
 772                         binder_args.Add (new Argument (new ImplicitlyTypedArrayCreation ("[]", args.CreateDynamicBinderArguments (ec), loc)));
 773
 774                         return new Invocation (GetBinder ("UnaryOperation", loc), binder_args);
 775                 }
 776         }
 777 }