mcs/dynamic.cs

   1 //
   2 // dynamic.cs: support for dynamic expressions
   3 //
   4 // Authors: Marek Safar (marek.safar@gmail.com)
   5 //
   6 // Dual licensed under the terms of the MIT X11 or GNU GPL
   7 //
   8 // Copyright 2009 Novell, Inc
   9 //
  10
  11 using System;
  12 using System.Reflection.Emit;
  13 using SLE = System.Linq.Expressions;
  14
  15 #if NET_4_0
  16 using System.Dynamic;
  17 #endif
  18
  19 namespace Mono.CSharp
  20 {
  21         //
  22         // A copy of Microsoft.CSharp/Microsoft.CSharp.RuntimeBinder/CSharpBinderFlags.cs
  23         // has to be kept in sync
  24         //
  25         [Flags]
  26         public enum CSharpBinderFlags
  27         {
  28                 None = 0,
  29                 CheckedContext = 1,
  30                 InvokeSimpleName = 1 << 1,
  31                 InvokeSpecialName = 1 << 2,
  32                 BinaryOperationLogical = 1 << 3,
  33                 ConvertExplicit = 1 << 4,
  34                 ConvertArrayIndex = 1 << 5,
  35                 ResultIndexed = 1 << 6,
  36                 ValueFromCompoundAssignment = 1 << 7,
  37                 ResultDiscarded = 1 << 8
  38         }
  39
  40         //
  41         // Type expression with internal dynamic type symbol
  42         //
  43         class DynamicTypeExpr : TypeExpr
  44         {
  45                 public DynamicTypeExpr (Location loc)
  46                 {
  47                         this.loc = loc;
  48
  49                         type = InternalType.Dynamic;
  50                         eclass = ExprClass.Type;
  51                 }
  52
  53                 public override bool CheckAccessLevel (IMemberContext ds)
  54                 {
  55                         return true;
  56                 }
  57
  58                 protected override TypeExpr DoResolveAsTypeStep (IMemberContext ec)
  59                 {
  60                         return this;
  61                 }
  62         }
  63
  64         #region Dynamic runtime binder expressions
  65
  66         //
  67         // Expression created from runtime dynamic object value by dynamic binder
  68         //
  69         public class RuntimeValueExpression : Expression, IDynamicAssign, IMemoryLocation
  70         {
  71 #if !NET_4_0
  72                 public class DynamicMetaObject
  73                 {
  74                         public TypeSpec RuntimeType;
  75                         public TypeSpec LimitType;
  76                         public SLE.Expression Expression;
  77                 }
  78 #endif
  79
  80                 readonly DynamicMetaObject obj;
  81
  82                 public RuntimeValueExpression (DynamicMetaObject obj, TypeSpec type)
  83                 {
  84                         this.obj = obj;
  85                         this.type = type;
  86                         this.eclass = ExprClass.Variable;
  87                 }
  88
  89                 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                 public SLE.Expression MakeAssignExpression (BuilderContext ctx)
 129                 {
 130                         return obj.Expression;
 131                 }
 132
 133                 public override SLE.Expression MakeExpression (BuilderContext ctx)
 134                 {
 135                         return SLE.Expression.Convert (obj.Expression, type.GetMetaInfo ());
 136                 }
 137
 138                 public DynamicMetaObject MetaObject {
 139                         get { return obj; }
 140                 }
 141         }
 142
 143         //
 144         // Wraps runtime dynamic expression into expected type. Needed
 145         // to satify expected type check by dynamic binder and no conversion
 146         // is required (ResultDiscarded).
 147         //
 148         public class DynamicResultCast : ShimExpression
 149         {
 150                 public DynamicResultCast (TypeSpec type, Expression expr)
 151                         : base (expr)
 152                 {
 153                         this.type = type;
 154                 }
 155
 156                 protected override Expression DoResolve (ResolveContext ec)
 157                 {
 158                         expr = expr.Resolve (ec);
 159                         eclass = ExprClass.Value;
 160                         return this;
 161                 }
 162
 163 #if NET_4_0
 164                 public override SLE.Expression MakeExpression (BuilderContext ctx)
 165                 {
 166                         return SLE.Expression.Block (expr.MakeExpression (ctx), SLE.Expression.Default (type.GetMetaInfo ()));
 167                 }
 168 #endif
 169         }
 170
 171         #endregion
 172
 173         //
 174         // Creates dynamic binder expression
 175         //
 176         interface IDynamicBinder
 177         {
 178                 Expression CreateCallSiteBinder (ResolveContext ec, Arguments args);
 179         }
 180
 181         //
 182         // Extends standard assignment interface for expressions
 183         // supported by dynamic resolver
 184         //
 185         interface IDynamicAssign : IAssignMethod
 186         {
 187 #if NET_4_0
 188                 SLE.Expression MakeAssignExpression (BuilderContext ctx);
 189 #endif
 190         }
 191
 192         //
 193         // Base dynamic expression statement creator
 194         //
 195         class DynamicExpressionStatement : ExpressionStatement
 196         {
 197                 class StaticDataClass : CompilerGeneratedClass
 198                 {
 199                         public StaticDataClass ()
 200                                 : base (new RootDeclSpace (new NamespaceEntry (null, null, null)),
 201                                         new MemberName (CompilerGeneratedClass.MakeName (null, "c", "DynamicSites", 0)),
 202                                         Modifiers.INTERNAL | Modifiers.STATIC)
 203                         {
 204                         }
 205                 }
 206
 207                 //
 208                 // Binder flag dynamic constant, the value is combination of
 209                 // flags known at resolve stage and flags known only at emit
 210                 // stage
 211                 //
 212                 protected class BinderFlags : EnumConstant
 213                 {
 214                         DynamicExpressionStatement statement;
 215                         CSharpBinderFlags flags;
 216
 217                         public BinderFlags (CSharpBinderFlags flags, DynamicExpressionStatement statement)
 218                                 : base (statement.loc)
 219                         {
 220                                 this.flags = flags;
 221                                 this.statement = statement;
 222                         }
 223
 224                         protected override Expression DoResolve (ResolveContext ec)
 225                         {
 226                                 Child = new IntConstant ((int) (flags | statement.flags), statement.loc).Resolve (ec);
 227
 228                                 type = TypeManager.binder_flags;
 229                                 eclass = Child.eclass;
 230                                 return this;
 231                         }
 232                 }
 233
 234                 static StaticDataClass global_site_container;
 235                 static int field_counter;
 236                 static int container_counter;
 237
 238                 readonly Arguments arguments;
 239                 protected IDynamicBinder binder;
 240                 protected Expression binder_expr;
 241
 242                 // Used by BinderFlags
 243                 protected CSharpBinderFlags flags;
 244
 245                 public DynamicExpressionStatement (IDynamicBinder binder, Arguments args, Location loc)
 246                 {
 247                         this.binder = binder;
 248                         this.arguments = args;
 249                         this.loc = loc;
 250                 }
 251
 252                 public Arguments Arguments {
 253                         get {
 254                                 return arguments;
 255                         }
 256                 }
 257
 258                 static TypeContainer CreateSiteContainer ()
 259                 {
 260                         if (global_site_container == null) {
 261                                 global_site_container = new StaticDataClass ();
 262                                 RootContext.ToplevelTypes.AddCompilerGeneratedClass (global_site_container);
 263                                 global_site_container.CreateType ();
 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);
 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);
 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                                 TypeSpec 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                                 TypeSpec 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                                 TypeSpec 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.CreateType ();
 445                                 d.DefineType ();
 446                                 d.Define ();
 447                                 d.Emit ();
 448
 449                                 parent.AddDelegate (d);
 450                                 del_type = new TypeExpression (d.Definition, loc);
 451                         }
 452
 453                         TypeExpr site_type = new GenericTypeExpr (TypeManager.generic_call_site_type, new TypeArguments (del_type), loc);
 454                         return site_type;
 455                 }
 456
 457                 public static void Reset ()
 458                 {
 459                         global_site_container = null;
 460                         field_counter = container_counter = 0;
 461                 }
 462         }
 463
 464         //
 465         // Dynamic member access compound assignment for events
 466         //
 467         class DynamicEventCompoundAssign : DynamicExpressionStatement, IDynamicBinder
 468         {
 469                 string name;
 470                 Statement condition;
 471
 472                 public DynamicEventCompoundAssign (string name, Arguments args, ExpressionStatement assignment, ExpressionStatement invoke, Location loc)
 473                         : base (null, args, loc)
 474                 {
 475                         this.name = name;
 476                         base.binder = this;
 477
 478                         // Used by += or -= only
 479                         type = TypeManager.bool_type;
 480
 481                         condition = new If (
 482                                 new Binary (Binary.Operator.Equality, this, new BoolLiteral (true, loc), loc),
 483                                 new StatementExpression (invoke), new StatementExpression (assignment),
 484                                 loc);
 485                 }
 486
 487                 public Expression CreateCallSiteBinder (ResolveContext ec, Arguments args)
 488                 {
 489                         Arguments binder_args = new Arguments (3);
 490
 491                         binder_args.Add (new Argument (new BinderFlags (0, this)));
 492                         binder_args.Add (new Argument (new StringLiteral (name, loc)));
 493                         binder_args.Add (new Argument (new TypeOf (new TypeExpression (ec.CurrentType, loc), loc)));
 494
 495                         return new Invocation (GetBinder ("IsEvent", loc), binder_args);
 496                 }
 497
 498                 public override void EmitStatement (EmitContext ec)
 499                 {
 500                         condition.Emit (ec);
 501                 }
 502         }
 503
 504         class DynamicConversion : DynamicExpressionStatement, IDynamicBinder
 505         {
 506                 public DynamicConversion (TypeSpec targetType, CSharpBinderFlags flags, Arguments args, Location loc)
 507                         : base (null, args, loc)
 508                 {
 509                         type = targetType;
 510                         base.flags = flags;
 511                         base.binder = this;
 512                 }
 513
 514                 public Expression CreateCallSiteBinder (ResolveContext ec, Arguments args)
 515                 {
 516                         Arguments binder_args = new Arguments (3);
 517
 518                         flags |= ec.HasSet (ResolveContext.Options.CheckedScope) ? CSharpBinderFlags.CheckedContext : 0;
 519
 520                         binder_args.Add (new Argument (new BinderFlags (flags, this)));
 521                         binder_args.Add (new Argument (new TypeOf (new TypeExpression (ec.CurrentType, loc), loc)));
 522                         binder_args.Add (new Argument (new TypeOf (new TypeExpression (type, loc), loc)));
 523                         return new Invocation (GetBinder ("Convert", loc), binder_args);
 524                 }
 525         }
 526
 527         class DynamicConstructorBinder : DynamicExpressionStatement, IDynamicBinder
 528         {
 529                 public DynamicConstructorBinder (TypeSpec type, Arguments args, Location loc)
 530                         : base (null, args, loc)
 531                 {
 532                         this.type = type;
 533                         base.binder = this;
 534                 }
 535
 536                 public Expression CreateCallSiteBinder (ResolveContext ec, Arguments args)
 537                 {
 538                         Arguments binder_args = new Arguments (3);
 539
 540                         binder_args.Add (new Argument (new BinderFlags (0, this)));
 541                         binder_args.Add (new Argument (new TypeOf (new TypeExpression (ec.CurrentType, loc), loc)));
 542                         binder_args.Add (new Argument (new ImplicitlyTypedArrayCreation ("[]", args.CreateDynamicBinderArguments (ec), loc)));
 543
 544                         return new Invocation (GetBinder ("InvokeConstructor", loc), binder_args);
 545                 }
 546         }
 547
 548         class DynamicIndexBinder : DynamicMemberAssignable
 549         {
 550                 public DynamicIndexBinder (Arguments args, Location loc)
 551                         : base (args, loc)
 552                 {
 553                 }
 554
 555                 protected override Expression CreateCallSiteBinder (ResolveContext ec, Arguments args, bool isSet)
 556                 {
 557                         Arguments binder_args = new Arguments (3);
 558
 559                         binder_args.Add (new Argument (new BinderFlags (0, this)));
 560                         binder_args.Add (new Argument (new TypeOf (new TypeExpression (ec.CurrentType, loc), loc)));
 561                         binder_args.Add (new Argument (new ImplicitlyTypedArrayCreation ("[]", args.CreateDynamicBinderArguments (ec), loc)));
 562
 563                         return new Invocation (GetBinder (isSet ? "SetIndex" : "GetIndex", loc), binder_args);
 564                 }
 565         }
 566
 567         class DynamicInvocation : DynamicExpressionStatement, IDynamicBinder
 568         {
 569                 ATypeNameExpression member;
 570
 571                 public DynamicInvocation (ATypeNameExpression member, Arguments args, Location loc)
 572                         : base (null, args, loc)
 573                 {
 574                         base.binder = this;
 575                         this.member = member;
 576                 }
 577
 578                 public DynamicInvocation (ATypeNameExpression member, Arguments args, TypeSpec type, Location loc)
 579                         : this (member, args, loc)
 580                 {
 581                         // When a return type is known not to be dynamic
 582                         this.type = type;
 583                 }
 584
 585                 public static DynamicInvocation CreateSpecialNameInvoke (ATypeNameExpression member, Arguments args, Location loc)
 586                 {
 587                         return new DynamicInvocation (member, args, loc) {
 588                                 flags = CSharpBinderFlags.InvokeSpecialName
 589                         };
 590                 }
 591
 592                 public Expression CreateCallSiteBinder (ResolveContext ec, Arguments args)
 593                 {
 594                         Arguments binder_args = new Arguments (member != null ? 5 : 3);
 595                         bool is_member_access = member is MemberAccess;
 596
 597                         CSharpBinderFlags call_flags;
 598                         if (!is_member_access && member is SimpleName) {
 599                                 call_flags = CSharpBinderFlags.InvokeSimpleName;
 600                                 is_member_access = true;
 601                         } else {
 602                                 call_flags = 0;
 603                         }
 604
 605                         binder_args.Add (new Argument (new BinderFlags (call_flags, this)));
 606
 607                         if (is_member_access)
 608                                 binder_args.Add (new Argument (new StringLiteral (member.Name, member.Location)));
 609
 610                         if (member != null && member.HasTypeArguments) {
 611                                 TypeArguments ta = member.TypeArguments;
 612                                 if (ta.Resolve (ec)) {
 613                                         var targs = new ArrayInitializer (ta.Count, loc);
 614                                         foreach (TypeSpec t in ta.Arguments)
 615                                                 targs.Add (new TypeOf (new TypeExpression (t, loc), loc));
 616
 617                                         binder_args.Add (new Argument (new ImplicitlyTypedArrayCreation ("[]", targs, loc)));
 618                                 }
 619                         } else if (is_member_access) {
 620                                 binder_args.Add (new Argument (new NullLiteral (loc)));
 621                         }
 622
 623                         binder_args.Add (new Argument (new TypeOf (new TypeExpression (ec.CurrentType, loc), loc)));
 624
 625                         Expression real_args;
 626                         if (args == null) {
 627                                 // Cannot be null because .NET trips over
 628                                 real_args = new ArrayCreation (
 629                                         new MemberAccess (GetBinderNamespace (loc), "CSharpArgumentInfo", loc), "[]",
 630                                         new ArrayInitializer (0, loc), loc);
 631                         } else {
 632                                 real_args = new ImplicitlyTypedArrayCreation ("[]", args.CreateDynamicBinderArguments (ec), loc);
 633                         }
 634
 635                         binder_args.Add (new Argument (real_args));
 636
 637                         return new Invocation (GetBinder (is_member_access ? "InvokeMember" : "Invoke", loc), binder_args);
 638                 }
 639
 640                 public override void EmitStatement (EmitContext ec)
 641                 {
 642                         flags |= CSharpBinderFlags.ResultDiscarded;
 643                         base.EmitStatement (ec);
 644                 }
 645         }
 646
 647         class DynamicMemberBinder : DynamicMemberAssignable
 648         {
 649                 readonly string name;
 650
 651                 public DynamicMemberBinder (string name, Arguments args, Location loc)
 652                         : base (args, loc)
 653                 {
 654                         this.name = name;
 655                 }
 656
 657                 protected override Expression CreateCallSiteBinder (ResolveContext ec, Arguments args, bool isSet)
 658                 {
 659                         Arguments binder_args = new Arguments (4);
 660
 661                         binder_args.Add (new Argument (new BinderFlags (0, this)));
 662                         binder_args.Add (new Argument (new StringLiteral (name, loc)));
 663                         binder_args.Add (new Argument (new TypeOf (new TypeExpression (ec.CurrentType, loc), loc)));
 664                         binder_args.Add (new Argument (new ImplicitlyTypedArrayCreation ("[]", args.CreateDynamicBinderArguments (ec), loc)));
 665
 666                         return new Invocation (GetBinder (isSet ? "SetMember" : "GetMember", loc), binder_args);
 667                 }
 668         }
 669
 670         //
 671         // Any member binder which can be source and target of assignment
 672         //
 673         abstract class DynamicMemberAssignable : DynamicExpressionStatement, IDynamicBinder, IAssignMethod
 674         {
 675                 Expression setter;
 676                 Arguments setter_args;
 677
 678                 protected DynamicMemberAssignable (Arguments args, Location loc)
 679                         : base (null, args, loc)
 680                 {
 681                         base.binder = this;
 682                 }
 683
 684                 public Expression CreateCallSiteBinder (ResolveContext ec, Arguments args)
 685                 {
 686                         //
 687                         // DoResolve always uses getter
 688                         //
 689                         return CreateCallSiteBinder (ec, args, false);
 690                 }
 691
 692                 protected abstract Expression CreateCallSiteBinder (ResolveContext ec, Arguments args, bool isSet);
 693
 694                 public override Expression DoResolveLValue (ResolveContext rc, Expression right_side)
 695                 {
 696                         if (right_side == EmptyExpression.OutAccess.Instance) {
 697                                 right_side.DoResolveLValue (rc, this);
 698                                 return null;
 699                         }
 700
 701                         if (DoResolveCore (rc)) {
 702                                 setter_args = new Arguments (Arguments.Count + 1);
 703                                 setter_args.AddRange (Arguments);
 704                                 setter_args.Add (new Argument (right_side));
 705                                 setter = CreateCallSiteBinder (rc, setter_args, true);
 706                         }
 707
 708                         eclass = ExprClass.Variable;
 709                         return this;
 710                 }
 711
 712                 public override void Emit (EmitContext ec)
 713                 {
 714                         // It's null for ResolveLValue used without assignment
 715                         if (binder_expr == null)
 716                                 EmitCall (ec, setter, Arguments, false);
 717                         else
 718                                 base.Emit (ec);
 719                 }
 720
 721                 public override void EmitStatement (EmitContext ec)
 722                 {
 723                         // It's null for ResolveLValue used without assignment
 724                         if (binder_expr == null)
 725                                 EmitCall (ec, setter, Arguments, true);
 726                         else
 727                                 base.EmitStatement (ec);
 728                 }
 729
 730                 #region IAssignMethod Members
 731
 732                 public void Emit (EmitContext ec, bool leave_copy)
 733                 {
 734                         throw new NotImplementedException ();
 735                 }
 736
 737                 public void EmitAssign (EmitContext ec, Expression source, bool leave_copy, bool prepare_for_load)
 738                 {
 739                         EmitCall (ec, setter, setter_args, !leave_copy);
 740                 }
 741
 742                 #endregion
 743         }
 744
 745         class DynamicUnaryConversion : DynamicExpressionStatement, IDynamicBinder
 746         {
 747                 string name;
 748
 749                 public DynamicUnaryConversion (string name, Arguments args, Location loc)
 750                         : base (null, args, loc)
 751                 {
 752                         this.name = name;
 753                         base.binder = this;
 754                         if (name == "IsTrue" || name == "IsFalse")
 755                                 type = TypeManager.bool_type;
 756                 }
 757
 758                 public Expression CreateCallSiteBinder (ResolveContext ec, Arguments args)
 759                 {
 760                         Arguments binder_args = new Arguments (4);
 761
 762                         MemberAccess sle = new MemberAccess (new MemberAccess (
 763                                 new QualifiedAliasMember (QualifiedAliasMember.GlobalAlias, "System", loc), "Linq", loc), "Expressions", loc);
 764
 765                         var flags = ec.HasSet (ResolveContext.Options.CheckedScope) ? CSharpBinderFlags.CheckedContext : 0;
 766
 767                         binder_args.Add (new Argument (new BinderFlags (flags, this)));
 768                         binder_args.Add (new Argument (new MemberAccess (new MemberAccess (sle, "ExpressionType", loc), name, loc)));
 769                         binder_args.Add (new Argument (new TypeOf (new TypeExpression (ec.CurrentType, loc), loc)));
 770                         binder_args.Add (new Argument (new ImplicitlyTypedArrayCreation ("[]", args.CreateDynamicBinderArguments (ec), loc)));
 771
 772                         return new Invocation (GetBinder ("UnaryOperation", loc), binder_args);
 773                 }
 774         }
 775 }