mcs/mcs/anonymous.cs

   1 //
   2 // anonymous.cs: Support for anonymous methods and types
   3 //
   4 // Author:
   5 //   Miguel de Icaza (miguel@ximain.com)
   6 //   Marek Safar (marek.safar@gmail.com)
   7 //
   8 // Dual licensed under the terms of the MIT X11 or GNU GPL
   9 // Copyright 2003-2008 Novell, Inc.
  10 //
  11
  12 using System;
  13 using System.Collections.Generic;
  14
  15 #if STATIC
  16 using IKVM.Reflection;
  17 using IKVM.Reflection.Emit;
  18 #else
  19 using System.Reflection;
  20 using System.Reflection.Emit;
  21 #endif
  22
  23 namespace Mono.CSharp {
  24
  25         public abstract class CompilerGeneratedClass : Class
  26         {
  27                 protected CompilerGeneratedClass (TypeContainer parent, MemberName name, Modifiers mod)
  28                         : base (parent.NamespaceEntry, parent, name, mod | Modifiers.COMPILER_GENERATED, null)
  29                 {
  30                 }
  31
  32                 protected void CheckMembersDefined ()
  33                 {
  34                         if (HasMembersDefined)
  35                                 throw new InternalErrorException ("Helper class already defined!");
  36                 }
  37
  38                 protected static MemberName MakeMemberName (MemberBase host, string name, int unique_id, TypeParameter[] tparams, Location loc)
  39                 {
  40                         string host_name = host == null ? null : host.Name;
  41                         string tname = MakeName (host_name, "c", name, unique_id);
  42                         TypeArguments args = null;
  43                         if (tparams != null) {
  44                                 args = new TypeArguments ();
  45                                 foreach (TypeParameter tparam in tparams)
  46                                         args.Add (new TypeParameterName (tparam.Name, null, loc));
  47                         }
  48
  49                         return new MemberName (tname, args, loc);
  50                 }
  51
  52                 public static string MakeName (string host, string typePrefix, string name, int id)
  53                 {
  54                         return "<" + host + ">" + typePrefix + "__" + name + id.ToString ("X");
  55                 }
  56         }
  57
  58         public class HoistedStoreyClass : CompilerGeneratedClass
  59         {
  60                 public sealed class HoistedField : Field
  61                 {
  62                         public HoistedField (HoistedStoreyClass parent, FullNamedExpression type, Modifiers mod, string name,
  63                                   Attributes attrs, Location loc)
  64                                 : base (parent, type, mod, new MemberName (name, loc), attrs)
  65                         {
  66                         }
  67
  68                         protected override bool ResolveMemberType ()
  69                         {
  70                                 if (!base.ResolveMemberType ())
  71                                         return false;
  72
  73                                 HoistedStoreyClass parent = ((HoistedStoreyClass) Parent).GetGenericStorey ();
  74                                 if (parent != null && parent.Mutator != null)
  75                                         member_type = parent.Mutator.Mutate (MemberType);
  76
  77                                 return true;
  78                         }
  79                 }
  80
  81                 protected TypeParameterMutator mutator;
  82
  83                 public HoistedStoreyClass (TypeContainer parent, MemberName name, TypeParameter[] tparams, Modifiers mod)
  84                         : base (parent, name, mod | Modifiers.PRIVATE)
  85                 {
  86                         if (tparams != null) {
  87                                 type_params = new TypeParameter[tparams.Length];
  88                                 var src = new TypeParameterSpec[tparams.Length];
  89                                 var dst = new TypeParameterSpec[tparams.Length];
  90
  91                                 for (int i = 0; i < type_params.Length; ++i) {
  92                                         type_params[i] = tparams[i].CreateHoistedCopy (this, spec);
  93
  94                                         src[i] = tparams[i].Type;
  95                                         dst[i] = type_params[i].Type;
  96                                 }
  97
  98                                 // A copy is not enough, inflate any type parameter constraints
  99                                 // using a new type parameters
 100                                 var inflator = new TypeParameterInflator (this, null, src, dst);
 101                                 for (int i = 0; i < type_params.Length; ++i) {
 102                                         src[i].InflateConstraints (inflator, dst[i]);
 103                                 }
 104
 105                                 mutator = new TypeParameterMutator (tparams, type_params);
 106                         }
 107                 }
 108
 109                 #region Properties
 110
 111                 public TypeParameterMutator Mutator {
 112                         get {
 113                                 return mutator;
 114                         }
 115                         set {
 116                                 mutator = value;
 117                         }
 118                 }
 119
 120                 #endregion
 121
 122                 public HoistedStoreyClass GetGenericStorey ()
 123                 {
 124                         DeclSpace storey = this;
 125                         while (storey != null && storey.CurrentTypeParameters == null)
 126                                 storey = storey.Parent;
 127
 128                         return storey as HoistedStoreyClass;
 129                 }
 130         }
 131
 132
 133         //
 134         // Anonymous method storey is created when an anonymous method uses
 135         // variable or parameter from outer scope. They are then hoisted to
 136         // anonymous method storey (captured)
 137         //
 138         public class AnonymousMethodStorey : HoistedStoreyClass
 139         {
 140                 struct StoreyFieldPair
 141                 {
 142                         public readonly AnonymousMethodStorey Storey;
 143                         public readonly Field Field;
 144
 145                         public StoreyFieldPair (AnonymousMethodStorey storey, Field field)
 146                         {
 147                                 this.Storey = storey;
 148                                 this.Field = field;
 149                         }
 150                 }
 151
 152                 //
 153                 // Needed to delay hoisted _this_ initialization. When an anonymous
 154                 // method is used inside ctor and _this_ is hoisted, base ctor has to
 155                 // be called first, otherwise _this_ will be initialized with
 156                 // uninitialized value.
 157                 //
 158                 sealed class ThisInitializer : Statement
 159                 {
 160                         readonly HoistedThis hoisted_this;
 161
 162                         public ThisInitializer (HoistedThis hoisted_this)
 163                         {
 164                                 this.hoisted_this = hoisted_this;
 165                         }
 166
 167                         protected override void DoEmit (EmitContext ec)
 168                         {
 169                                 hoisted_this.EmitHoistingAssignment (ec);
 170                         }
 171
 172                         protected override void CloneTo (CloneContext clonectx, Statement target)
 173                         {
 174                                 // Nothing to clone
 175                         }
 176                 }
 177
 178                 // Unique storey ID
 179                 public readonly int ID;
 180                 static int unique_id;
 181
 182                 public readonly Block OriginalSourceBlock;
 183
 184                 // A list of StoreyFieldPair with local field keeping parent storey instance
 185                 List<StoreyFieldPair> used_parent_storeys;
 186                 List<ExplicitBlock> children_references;
 187
 188                 // A list of hoisted parameters
 189                 protected List<HoistedParameter> hoisted_params;
 190                 protected List<HoistedVariable> hoisted_locals;
 191
 192                 // Hoisted this
 193                 protected HoistedThis hoisted_this;
 194
 195                 // Local variable which holds this storey instance
 196                 public LocalTemporary Instance;
 197
 198                 public AnonymousMethodStorey (Block block, TypeContainer parent, MemberBase host, TypeParameter[] tparams, string name)
 199                         : base (parent, MakeMemberName (host, name, unique_id, tparams, block.StartLocation),
 200                                 tparams, Modifiers.SEALED)
 201                 {
 202                         OriginalSourceBlock = block;
 203                         ID = unique_id++;
 204                 }
 205
 206                 public void AddCapturedThisField (EmitContext ec)
 207                 {
 208                         TypeExpr type_expr = new TypeExpression (ec.CurrentType, Location);
 209                         Field f = AddCompilerGeneratedField ("<>f__this", type_expr);
 210                         f.Define ();
 211                         hoisted_this = new HoistedThis (this, f);
 212
 213                         // Inflated type instance has to be updated manually
 214                         if (Instance.Type is InflatedTypeSpec) {
 215                                 var inflator = new TypeParameterInflator (this, Instance.Type, TypeParameterSpec.EmptyTypes, TypeSpec.EmptyTypes);
 216                                 Instance.Type.MemberCache.AddMember (f.Spec.InflateMember (inflator));
 217
 218                                 inflator = new TypeParameterInflator (this, f.Parent.CurrentType, TypeParameterSpec.EmptyTypes, TypeSpec.EmptyTypes);
 219                                 f.Parent.CurrentType.MemberCache.AddMember (f.Spec.InflateMember (inflator));
 220                         }
 221                 }
 222
 223                 public Field AddCapturedVariable (string name, TypeSpec type)
 224                 {
 225                         CheckMembersDefined ();
 226
 227                         FullNamedExpression field_type = new TypeExpression (type, Location);
 228                         if (!IsGeneric)
 229                                 return AddCompilerGeneratedField (name, field_type);
 230
 231                         const Modifiers mod = Modifiers.INTERNAL | Modifiers.COMPILER_GENERATED;
 232                         Field f = new HoistedField (this, field_type, mod, name, null, Location);
 233                         AddField (f);
 234                         return f;
 235                 }
 236
 237                 protected Field AddCompilerGeneratedField (string name, FullNamedExpression type)
 238                 {
 239                         const Modifiers mod = Modifiers.INTERNAL | Modifiers.COMPILER_GENERATED;
 240                         Field f = new Field (this, type, mod, new MemberName (name, Location), null);
 241                         AddField (f);
 242                         return f;
 243                 }
 244
 245                 //
 246                 // Creates a link between hoisted variable block and the anonymous method storey
 247                 //
 248                 // An anonymous method can reference variables from any outer block, but they are
 249                 // hoisted in their own ExplicitBlock. When more than one block is referenced we
 250                 // need to create another link between those variable storeys
 251                 //
 252                 public void AddReferenceFromChildrenBlock (ExplicitBlock block)
 253                 {
 254                         if (children_references == null)
 255                                 children_references = new List<ExplicitBlock> ();
 256
 257                         if (!children_references.Contains (block))
 258                                 children_references.Add (block);
 259                 }
 260
 261                 public void AddParentStoreyReference (EmitContext ec, AnonymousMethodStorey storey)
 262                 {
 263                         CheckMembersDefined ();
 264
 265                         if (used_parent_storeys == null)
 266                                 used_parent_storeys = new List<StoreyFieldPair> ();
 267                         else if (used_parent_storeys.Exists (i => i.Storey == storey))
 268                                 return;
 269
 270                         TypeExpr type_expr = storey.CreateStoreyTypeExpression (ec);
 271                         Field f = AddCompilerGeneratedField ("<>f__ref$" + storey.ID, type_expr);
 272                         used_parent_storeys.Add (new StoreyFieldPair (storey, f));
 273                 }
 274
 275                 public void CaptureLocalVariable (ResolveContext ec, LocalVariable local_info)
 276                 {
 277                         ec.CurrentBlock.Explicit.HasCapturedVariable = true;
 278                         if (ec.CurrentBlock.Explicit != local_info.Block.Explicit)
 279                                 AddReferenceFromChildrenBlock (ec.CurrentBlock.Explicit);
 280
 281                         if (local_info.HoistedVariant != null)
 282                                 return;
 283
 284                         HoistedVariable var = new HoistedLocalVariable (this, local_info, GetVariableMangledName (local_info));
 285                         local_info.HoistedVariant = var;
 286
 287                         if (hoisted_locals == null)
 288                                 hoisted_locals = new List<HoistedVariable> ();
 289
 290                         hoisted_locals.Add (var);
 291                 }
 292
 293                 public void CaptureParameter (ResolveContext ec, ParameterReference param_ref)
 294                 {
 295                         ec.CurrentBlock.Explicit.HasCapturedVariable = true;
 296                         AddReferenceFromChildrenBlock (ec.CurrentBlock.Explicit);
 297
 298                         if (param_ref.GetHoistedVariable (ec) != null)
 299                                 return;
 300
 301                         if (hoisted_params == null)
 302                                 hoisted_params = new List<HoistedParameter> (2);
 303
 304                         var expr = new HoistedParameter (this, param_ref);
 305                         param_ref.Parameter.HoistedVariant = expr;
 306                         hoisted_params.Add (expr);
 307                 }
 308
 309                 TypeExpr CreateStoreyTypeExpression (EmitContext ec)
 310                 {
 311                         //
 312                         // Create an instance of storey type
 313                         //
 314                         TypeExpr storey_type_expr;
 315                         if (CurrentTypeParameters != null) {
 316                                 //
 317                                 // Use current method type parameter (MVAR) for top level storey only. All
 318                                 // nested storeys use class type parameter (VAR)
 319                                 //
 320                                 TypeParameter[] tparams = ec.CurrentAnonymousMethod != null && ec.CurrentAnonymousMethod.Storey != null ?
 321                                         ec.CurrentAnonymousMethod.Storey.TypeParameters :
 322                                         ec.CurrentTypeParameters;
 323
 324                                 TypeArguments targs = new TypeArguments ();
 325
 326                                 //
 327                                 // Use type parameter name instead of resolved type parameter
 328                                 // specification to resolve to correctly nested type parameters
 329                                 //
 330                                 for (int i = 0; i < tparams.Length; ++i)
 331                                         targs.Add (new SimpleName (tparams [i].Name, Location)); //  new TypeParameterExpr (tparams[i], Location));
 332
 333                                 storey_type_expr = new GenericTypeExpr (Definition, targs, Location);
 334                         } else {
 335                                 storey_type_expr = new TypeExpression (CurrentType, Location);
 336                         }
 337
 338                         return storey_type_expr;
 339                 }
 340
 341                 public void SetNestedStoryParent (AnonymousMethodStorey parentStorey)
 342                 {
 343                         Parent = parentStorey;
 344                         type_params = null;
 345                         spec.IsGeneric = false;
 346                         spec.DeclaringType = parentStorey.CurrentType;
 347                         MemberName.TypeArguments = null;
 348                 }
 349
 350                 protected override bool DoResolveTypeParameters ()
 351                 {
 352                         // Although any storey can have type parameters they are all clones of method type
 353                         // parameters therefore have to mutate MVAR references in any of cloned constraints
 354                         if (type_params != null) {
 355                                 for (int i = 0; i < type_params.Length; ++i) {
 356                                         var spec = type_params[i].Type;
 357                                         spec.BaseType = mutator.Mutate (spec.BaseType);
 358                                         if (spec.InterfacesDefined != null) {
 359                                                 var mutated = new TypeSpec[spec.InterfacesDefined.Length];
 360                                                 for (int ii = 0; ii < mutated.Length; ++ii) {
 361                                                         mutated[ii] = mutator.Mutate (spec.InterfacesDefined[ii]);
 362                                                 }
 363
 364                                                 spec.InterfacesDefined = mutated;
 365                                         }
 366
 367                                         if (spec.TypeArguments != null) {
 368                                                 spec.TypeArguments = mutator.Mutate (spec.TypeArguments);
 369                                         }
 370                                 }
 371                         }
 372
 373                         //
 374                         // Update parent cache as we most likely passed the point
 375                         // where the cache was constructed
 376                         //
 377                         Parent.CurrentType.MemberCache.AddMember (this.spec);
 378
 379                         return true;
 380                 }
 381
 382                 //
 383                 // Initializes all hoisted variables
 384                 //
 385                 public void EmitStoreyInstantiation (EmitContext ec, ExplicitBlock block)
 386                 {
 387                         // There can be only one instance variable for each storey type
 388                         if (Instance != null)
 389                                 throw new InternalErrorException ();
 390
 391                         SymbolWriter.OpenCompilerGeneratedBlock (ec);
 392
 393                         //
 394                         // Create an instance of a storey
 395                         //
 396                         var storey_type_expr = CreateStoreyTypeExpression (ec);
 397
 398                         ResolveContext rc = new ResolveContext (ec.MemberContext);
 399                         rc.CurrentBlock = block;
 400                         Expression e = new New (storey_type_expr, null, Location).Resolve (rc);
 401                         e.Emit (ec);
 402
 403                         Instance = new LocalTemporary (storey_type_expr.Type);
 404                         Instance.Store (ec);
 405
 406                         EmitHoistedFieldsInitialization (rc, ec);
 407
 408                         SymbolWriter.DefineScopeVariable (ID, Instance.Builder);
 409                         SymbolWriter.CloseCompilerGeneratedBlock (ec);
 410                 }
 411
 412                 void EmitHoistedFieldsInitialization (ResolveContext rc, EmitContext ec)
 413                 {
 414                         //
 415                         // Initialize all storey reference fields by using local or hoisted variables
 416                         //
 417                         if (used_parent_storeys != null) {
 418                                 foreach (StoreyFieldPair sf in used_parent_storeys) {
 419                                         //
 420                                         // Get instance expression of storey field
 421                                         //
 422                                         Expression instace_expr = GetStoreyInstanceExpression (ec);
 423                                         var fs = sf.Field.Spec;
 424                                         if (TypeManager.IsGenericType (instace_expr.Type))
 425                                                 fs = MemberCache.GetMember (instace_expr.Type, fs);
 426
 427                                         FieldExpr f_set_expr = new FieldExpr (fs, Location);
 428                                         f_set_expr.InstanceExpression = instace_expr;
 429
 430                                         SimpleAssign a = new SimpleAssign (f_set_expr, sf.Storey.GetStoreyInstanceExpression (ec));
 431                                         if (a.Resolve (rc) != null)
 432                                                 a.EmitStatement (ec);
 433                                 }
 434                         }
 435
 436                         //
 437                         // Define hoisted `this' in top-level storey only
 438                         //
 439                         if (OriginalSourceBlock.Explicit.HasCapturedThis && !(Parent is AnonymousMethodStorey)) {
 440                                 AddCapturedThisField (ec);
 441                                 rc.CurrentBlock.AddScopeStatement (new ThisInitializer (hoisted_this));
 442                         }
 443
 444                         //
 445                         // Setting currect anonymous method to null blocks any further variable hoisting
 446                         //
 447                         AnonymousExpression ae = ec.CurrentAnonymousMethod;
 448                         ec.CurrentAnonymousMethod = null;
 449
 450                         if (hoisted_params != null) {
 451                                 EmitHoistedParameters (ec, hoisted_params);
 452                         }
 453
 454                         ec.CurrentAnonymousMethod = ae;
 455                 }
 456
 457                 protected virtual void EmitHoistedParameters (EmitContext ec, IList<HoistedParameter> hoisted)
 458                 {
 459                         foreach (HoistedParameter hp in hoisted) {
 460                                 hp.EmitHoistingAssignment (ec);
 461                         }
 462                 }
 463
 464                 public override void EmitType ()
 465                 {
 466                         SymbolWriter.DefineAnonymousScope (ID);
 467
 468                         if (hoisted_this != null)
 469                                 hoisted_this.EmitSymbolInfo ();
 470
 471                         if (hoisted_locals != null) {
 472                                 foreach (HoistedVariable local in hoisted_locals)
 473                                         local.EmitSymbolInfo ();
 474                         }
 475
 476                         if (hoisted_params != null) {
 477                                 foreach (HoistedParameter param in hoisted_params)
 478                                         param.EmitSymbolInfo ();
 479                         }
 480
 481                         if (used_parent_storeys != null) {
 482                                 foreach (StoreyFieldPair sf in used_parent_storeys) {
 483                                         SymbolWriter.DefineCapturedScope (ID, sf.Storey.ID, sf.Field.Name);
 484                                 }
 485                         }
 486
 487                         base.EmitType ();
 488                 }
 489
 490                 //
 491                 // Returns a field which holds referenced storey instance
 492                 //
 493                 Field GetReferencedStoreyField (AnonymousMethodStorey storey)
 494                 {
 495                         if (used_parent_storeys == null)
 496                                 return null;
 497
 498                         foreach (StoreyFieldPair sf in used_parent_storeys) {
 499                                 if (sf.Storey == storey)
 500                                         return sf.Field;
 501                         }
 502
 503                         return null;
 504                 }
 505
 506                 //
 507                 // Creates storey instance expression regardless of currect IP
 508                 //
 509                 public Expression GetStoreyInstanceExpression (EmitContext ec)
 510                 {
 511                         AnonymousExpression am = ec.CurrentAnonymousMethod;
 512
 513                         //
 514                         // Access from original block -> storey
 515                         //
 516                         if (am == null)
 517                                 return Instance;
 518
 519                         //
 520                         // Access from anonymous method implemented as a static -> storey
 521                         //
 522                         if (am.Storey == null)
 523                                 return Instance;
 524
 525                         Field f = am.Storey.GetReferencedStoreyField (this);
 526                         if (f == null) {
 527                                 if (am.Storey == this) {
 528                                         //
 529                                         // Access inside of same storey (S -> S)
 530                                         //
 531                                         return new CompilerGeneratedThis (CurrentType, Location);
 532                                 }
 533                                 //
 534                                 // External field access
 535                                 //
 536                                 return Instance;
 537                         }
 538
 539                         //
 540                         // Storey was cached to local field
 541                         //
 542                         FieldExpr f_ind = new FieldExpr (f, Location);
 543                         f_ind.InstanceExpression = new CompilerGeneratedThis (CurrentType, Location);
 544                         return f_ind;
 545                 }
 546
 547                 protected virtual string GetVariableMangledName (LocalVariable local_info)
 548                 {
 549                         //
 550                         // No need to mangle anonymous method hoisted variables cause they
 551                         // are hoisted in their own scopes
 552                         //
 553                         return local_info.Name;
 554                 }
 555
 556                 public HoistedThis HoistedThis {
 557                         get { return hoisted_this; }
 558                 }
 559
 560                 public IList<ExplicitBlock> ReferencesFromChildrenBlock {
 561                         get { return children_references; }
 562                 }
 563
 564                 public static void Reset ()
 565                 {
 566                         unique_id = 0;
 567                 }
 568         }
 569
 570         public abstract class HoistedVariable
 571         {
 572                 //
 573                 // Hoisted version of variable references used in expression
 574                 // tree has to be delayed until we know its location. The variable
 575                 // doesn't know its location until all stories are calculated
 576                 //
 577                 class ExpressionTreeVariableReference : Expression
 578                 {
 579                         readonly HoistedVariable hv;
 580
 581                         public ExpressionTreeVariableReference (HoistedVariable hv)
 582                         {
 583                                 this.hv = hv;
 584                         }
 585
 586                         public override Expression CreateExpressionTree (ResolveContext ec)
 587                         {
 588                                 return hv.CreateExpressionTree ();
 589                         }
 590
 591                         protected override Expression DoResolve (ResolveContext ec)
 592                         {
 593                                 eclass = ExprClass.Value;
 594                                 type = ec.Module.PredefinedTypes.Expression.Resolve ();
 595                                 return this;
 596                         }
 597
 598                         public override void Emit (EmitContext ec)
 599                         {
 600                                 ResolveContext rc = new ResolveContext (ec.MemberContext);
 601                                 Expression e = hv.GetFieldExpression (ec).CreateExpressionTree (rc);
 602                                 // This should never fail
 603                                 e = e.Resolve (rc);
 604                                 if (e != null)
 605                                         e.Emit (ec);
 606                         }
 607                 }
 608
 609                 protected readonly AnonymousMethodStorey storey;
 610                 protected Field field;
 611                 Dictionary<AnonymousExpression, FieldExpr> cached_inner_access; // TODO: Hashtable is too heavyweight
 612                 FieldExpr cached_outer_access;
 613
 614                 protected HoistedVariable (AnonymousMethodStorey storey, string name, TypeSpec type)
 615                         : this (storey, storey.AddCapturedVariable (name, type))
 616                 {
 617                 }
 618
 619                 protected HoistedVariable (AnonymousMethodStorey storey, Field field)
 620                 {
 621                         this.storey = storey;
 622                         this.field = field;
 623                 }
 624
 625                 public void AddressOf (EmitContext ec, AddressOp mode)
 626                 {
 627                         GetFieldExpression (ec).AddressOf (ec, mode);
 628                 }
 629
 630                 public Expression CreateExpressionTree ()
 631                 {
 632                         return new ExpressionTreeVariableReference (this);
 633                 }
 634
 635                 public void Emit (EmitContext ec)
 636                 {
 637                         GetFieldExpression (ec).Emit (ec);
 638                 }
 639
 640                 //
 641                 // Creates field access expression for hoisted variable
 642                 //
 643                 protected virtual FieldExpr GetFieldExpression (EmitContext ec)
 644                 {
 645                         if (ec.CurrentAnonymousMethod == null || ec.CurrentAnonymousMethod.Storey == null) {
 646                                 if (cached_outer_access != null)
 647                                         return cached_outer_access;
 648
 649                                 //
 650                                 // When setting top-level hoisted variable in generic storey
 651                                 // change storey generic types to method generic types (VAR -> MVAR)
 652                                 //
 653                                 if (storey.Instance.Type.IsGenericOrParentIsGeneric) {
 654                                         var fs = MemberCache.GetMember (storey.Instance.Type, field.Spec);
 655                                         cached_outer_access = new FieldExpr (fs, field.Location);
 656                                 } else {
 657                                         cached_outer_access = new FieldExpr (field, field.Location);
 658                                 }
 659
 660                                 cached_outer_access.InstanceExpression = storey.GetStoreyInstanceExpression (ec);
 661                                 return cached_outer_access;
 662                         }
 663
 664                         FieldExpr inner_access;
 665                         if (cached_inner_access != null) {
 666                                 if (!cached_inner_access.TryGetValue (ec.CurrentAnonymousMethod, out inner_access))
 667                                         inner_access = null;
 668                         } else {
 669                                 inner_access = null;
 670                                 cached_inner_access = new Dictionary<AnonymousExpression, FieldExpr> (4);
 671                         }
 672
 673                         if (inner_access == null) {
 674                                 if (field.Parent.IsGeneric) {
 675                                         var fs = MemberCache.GetMember (field.Parent.CurrentType, field.Spec);
 676                                         inner_access = new FieldExpr (fs, field.Location);
 677                                 } else {
 678                                         inner_access = new FieldExpr (field, field.Location);
 679                                 }
 680
 681                                 inner_access.InstanceExpression = storey.GetStoreyInstanceExpression (ec);
 682                                 cached_inner_access.Add (ec.CurrentAnonymousMethod, inner_access);
 683                         }
 684
 685                         return inner_access;
 686                 }
 687
 688                 public abstract void EmitSymbolInfo ();
 689
 690                 public void Emit (EmitContext ec, bool leave_copy)
 691                 {
 692                         GetFieldExpression (ec).Emit (ec, leave_copy);
 693                 }
 694
 695                 public void EmitAssign (EmitContext ec, Expression source, bool leave_copy, bool prepare_for_load)
 696                 {
 697                         GetFieldExpression (ec).EmitAssign (ec, source, leave_copy, false);
 698                 }
 699         }
 700
 701         public class HoistedParameter : HoistedVariable
 702         {
 703                 sealed class HoistedFieldAssign : Assign
 704                 {
 705                         public HoistedFieldAssign (Expression target, Expression source)
 706                                 : base (target, source, source.Location)
 707                         {
 708                         }
 709
 710                         protected override Expression ResolveConversions (ResolveContext ec)
 711                         {
 712                                 //
 713                                 // Implicit conversion check fails for hoisted type arguments
 714                                 // as they are of different types (!!0 x !0)
 715                                 //
 716                                 return this;
 717                         }
 718                 }
 719
 720                 readonly ParameterReference parameter;
 721
 722                 public HoistedParameter (AnonymousMethodStorey scope, ParameterReference par)
 723                         : base (scope, par.Name, par.Type)
 724                 {
 725                         this.parameter = par;
 726                 }
 727
 728                 public HoistedParameter (HoistedParameter hp, string name)
 729                         : base (hp.storey, name, hp.parameter.Type)
 730                 {
 731                         this.parameter = hp.parameter;
 732                 }
 733
 734                 public void EmitHoistingAssignment (EmitContext ec)
 735                 {
 736                         //
 737                         // Remove hoisted redirection to emit assignment from original parameter
 738                         //
 739                         HoistedVariable temp = parameter.Parameter.HoistedVariant;
 740                         parameter.Parameter.HoistedVariant = null;
 741
 742                         Assign a = new HoistedFieldAssign (GetFieldExpression (ec), parameter);
 743                         if (a.Resolve (new ResolveContext (ec.MemberContext)) != null)
 744                                 a.EmitStatement (ec);
 745
 746                         parameter.Parameter.HoistedVariant = temp;
 747                 }
 748
 749                 public override void EmitSymbolInfo ()
 750                 {
 751                         SymbolWriter.DefineCapturedParameter (storey.ID, field.Name, field.Name);
 752                 }
 753
 754                 public Field Field {
 755                         get { return field; }
 756                 }
 757         }
 758
 759         class HoistedLocalVariable : HoistedVariable
 760         {
 761                 readonly string name;
 762
 763                 public HoistedLocalVariable (AnonymousMethodStorey scope, LocalVariable local, string name)
 764                         : base (scope, name, local.Type)
 765                 {
 766                         this.name = local.Name;
 767                 }
 768
 769                 public override void EmitSymbolInfo ()
 770                 {
 771                         SymbolWriter.DefineCapturedLocal (storey.ID, name, field.Name);
 772                 }
 773         }
 774
 775         public class HoistedThis : HoistedVariable
 776         {
 777                 public HoistedThis (AnonymousMethodStorey storey, Field field)
 778                         : base (storey, field)
 779                 {
 780                 }
 781
 782                 public void EmitHoistingAssignment (EmitContext ec)
 783                 {
 784                         SimpleAssign a = new SimpleAssign (GetFieldExpression (ec), new CompilerGeneratedThis (ec.CurrentType, field.Location));
 785                         if (a.Resolve (new ResolveContext (ec.MemberContext)) != null)
 786                                 a.EmitStatement (ec);
 787                 }
 788
 789                 public override void EmitSymbolInfo ()
 790                 {
 791                         SymbolWriter.DefineCapturedThis (storey.ID, field.Name);
 792                 }
 793
 794                 public Field Field {
 795                         get { return field; }
 796                 }
 797         }
 798
 799         //
 800         // Anonymous method expression as created by parser
 801         //
 802         public class AnonymousMethodExpression : Expression
 803         {
 804                 //
 805                 // Special conversion for nested expression tree lambdas
 806                 //
 807                 class Quote : ShimExpression
 808                 {
 809                         public Quote (Expression expr)
 810                                 : base (expr)
 811                         {
 812                         }
 813
 814                         public override Expression CreateExpressionTree (ResolveContext ec)
 815                         {
 816                                 var args = new Arguments (1);
 817                                 args.Add (new Argument (expr.CreateExpressionTree (ec)));
 818                                 return CreateExpressionFactoryCall (ec, "Quote", args);
 819                         }
 820
 821                         protected override Expression DoResolve (ResolveContext rc)
 822                         {
 823                                 expr = expr.Resolve (rc);
 824                                 if (expr == null)
 825                                         return null;
 826
 827                                 eclass = expr.eclass;
 828                                 type = expr.Type;
 829                                 return this;
 830                         }
 831                 }
 832
 833                 readonly Dictionary<TypeSpec, Expression> compatibles;
 834                 readonly bool is_async;
 835
 836                 public ParametersBlock Block;
 837
 838                 public AnonymousMethodExpression (bool isAsync, Location loc)
 839                 {
 840                         this.is_async = isAsync;
 841                         this.loc = loc;
 842                         this.compatibles = new Dictionary<TypeSpec, Expression> ();
 843                 }
 844
 845                 #region Properties
 846
 847                 public override string ExprClassName {
 848                         get {
 849                                 return "anonymous method";
 850                         }
 851                 }
 852
 853                 public virtual bool HasExplicitParameters {
 854                         get {
 855                                 return Parameters != ParametersCompiled.Undefined;
 856                         }
 857                 }
 858
 859                 public bool IsAsync {
 860                         get {
 861                                 return is_async;
 862                         }
 863                 }
 864
 865                 public ParametersCompiled Parameters {
 866                         get {
 867                                 return Block.Parameters;
 868                         }
 869                 }
 870
 871                 #endregion
 872
 873                 //
 874                 // Returns true if the body of lambda expression can be implicitly
 875                 // converted to the delegate of type `delegate_type'
 876                 //
 877                 public bool ImplicitStandardConversionExists (ResolveContext ec, TypeSpec delegate_type)
 878                 {
 879                         using (ec.With (ResolveContext.Options.InferReturnType, false)) {
 880                                 using (ec.Set (ResolveContext.Options.ProbingMode)) {
 881                                         return Compatible (ec, delegate_type) != null;
 882                                 }
 883                         }
 884                 }
 885
 886                 TypeSpec CompatibleChecks (ResolveContext ec, TypeSpec delegate_type)
 887                 {
 888                         if (delegate_type.IsDelegate)
 889                                 return delegate_type;
 890
 891                         if (delegate_type.IsExpressionTreeType) {
 892                                 delegate_type = delegate_type.TypeArguments [0];
 893                                 if (delegate_type.IsDelegate)
 894                                         return delegate_type;
 895
 896                                 ec.Report.Error (835, loc, "Cannot convert `{0}' to an expression tree of non-delegate type `{1}'",
 897                                         GetSignatureForError (), TypeManager.CSharpName (delegate_type));
 898                                 return null;
 899                         }
 900
 901                         ec.Report.Error (1660, loc, "Cannot convert `{0}' to non-delegate type `{1}'",
 902                                       GetSignatureForError (), TypeManager.CSharpName (delegate_type));
 903                         return null;
 904                 }
 905
 906                 protected bool VerifyExplicitParameters (ResolveContext ec, TypeSpec delegate_type, AParametersCollection parameters)
 907                 {
 908                         if (VerifyParameterCompatibility (ec, delegate_type, parameters, ec.IsInProbingMode))
 909                                 return true;
 910
 911                         if (!ec.IsInProbingMode)
 912                                 ec.Report.Error (1661, loc,
 913                                         "Cannot convert `{0}' to delegate type `{1}' since there is a parameter mismatch",
 914                                         GetSignatureForError (), TypeManager.CSharpName (delegate_type));
 915
 916                         return false;
 917                 }
 918
 919                 protected bool VerifyParameterCompatibility (ResolveContext ec, TypeSpec delegate_type, AParametersCollection invoke_pd, bool ignore_errors)
 920                 {
 921                         if (Parameters.Count != invoke_pd.Count) {
 922                                 if (ignore_errors)
 923                                         return false;
 924
 925                                 ec.Report.Error (1593, loc, "Delegate `{0}' does not take `{1}' arguments",
 926                                               TypeManager.CSharpName (delegate_type), Parameters.Count.ToString ());
 927                                 return false;
 928                         }
 929
 930                         bool has_implicit_parameters = !HasExplicitParameters;
 931                         bool error = false;
 932
 933                         for (int i = 0; i < Parameters.Count; ++i) {
 934                                 Parameter.Modifier p_mod = invoke_pd.FixedParameters [i].ModFlags;
 935                                 if (Parameters.FixedParameters [i].ModFlags != p_mod && p_mod != Parameter.Modifier.PARAMS) {
 936                                         if (ignore_errors)
 937                                                 return false;
 938
 939                                         if (p_mod == Parameter.Modifier.NONE)
 940                                                 ec.Report.Error (1677, loc, "Parameter `{0}' should not be declared with the `{1}' keyword",
 941                                                               (i + 1).ToString (), Parameter.GetModifierSignature (Parameters.FixedParameters [i].ModFlags));
 942                                         else
 943                                                 ec.Report.Error (1676, loc, "Parameter `{0}' must be declared with the `{1}' keyword",
 944                                                               (i+1).ToString (), Parameter.GetModifierSignature (p_mod));
 945                                         error = true;
 946                                 }
 947
 948                                 if (has_implicit_parameters)
 949                                         continue;
 950
 951                                 TypeSpec type = invoke_pd.Types [i];
 952
 953                                 // We assume that generic parameters are always inflated
 954                                 if (TypeManager.IsGenericParameter (type))
 955                                         continue;
 956
 957                                 if (TypeManager.HasElementType (type) && TypeManager.IsGenericParameter (TypeManager.GetElementType (type)))
 958                                         continue;
 959
 960                                 if (!TypeSpecComparer.IsEqual (invoke_pd.Types [i], Parameters.Types [i])) {
 961                                         if (ignore_errors)
 962                                                 return false;
 963
 964                                         ec.Report.Error (1678, loc, "Parameter `{0}' is declared as type `{1}' but should be `{2}'",
 965                                                       (i+1).ToString (),
 966                                                       TypeManager.CSharpName (Parameters.Types [i]),
 967                                                       TypeManager.CSharpName (invoke_pd.Types [i]));
 968                                         error = true;
 969                                 }
 970                         }
 971
 972                         return !error;
 973                 }
 974
 975                 //
 976                 // Infers type arguments based on explicit arguments
 977                 //
 978                 public bool ExplicitTypeInference (ResolveContext ec, TypeInferenceContext type_inference, TypeSpec delegate_type)
 979                 {
 980                         if (!HasExplicitParameters)
 981                                 return false;
 982
 983                         if (!delegate_type.IsDelegate) {
 984                                 if (!delegate_type.IsExpressionTreeType)
 985                                         return false;
 986
 987                                 delegate_type = TypeManager.GetTypeArguments (delegate_type) [0];
 988                                 if (!delegate_type.IsDelegate)
 989                                         return false;
 990                         }
 991
 992                         AParametersCollection d_params = Delegate.GetParameters (delegate_type);
 993                         if (d_params.Count != Parameters.Count)
 994                                 return false;
 995
 996                         for (int i = 0; i < Parameters.Count; ++i) {
 997                                 TypeSpec itype = d_params.Types [i];
 998                                 if (!TypeManager.IsGenericParameter (itype)) {
 999                                         if (!TypeManager.HasElementType (itype))
1000                                                 continue;
1001
1002                                         if (!TypeManager.IsGenericParameter (TypeManager.GetElementType (itype)))
1003                                             continue;
1004                                 }
1005                                 type_inference.ExactInference (Parameters.Types [i], itype);
1006                         }
1007                         return true;
1008                 }
1009
1010                 public TypeSpec InferReturnType (ResolveContext ec, TypeInferenceContext tic, TypeSpec delegate_type)
1011                 {
1012                         Expression expr;
1013                         AnonymousExpression am;
1014
1015                         if (compatibles.TryGetValue (delegate_type, out expr)) {
1016                                 am = expr as AnonymousExpression;
1017                                 return am == null ? null : am.ReturnType;
1018                         }
1019
1020                         using (ec.Set (ResolveContext.Options.ProbingMode | ResolveContext.Options.InferReturnType)) {
1021                                 var body = CompatibleMethodBody (ec, tic, InternalType.Arglist, delegate_type);
1022                                 if (body != null) {
1023                                         if (is_async) {
1024                                                 AsyncInitializer.Create (body.Block, body.Parameters, ec.CurrentMemberDefinition.Parent, null, loc);
1025                                         }
1026
1027                                         am = body.Compatible (ec, body, is_async);
1028                                 } else {
1029                                         am = null;
1030                                 }
1031                         }
1032
1033                         if (am == null)
1034                                 return null;
1035
1036 //                      compatibles.Add (delegate_type, am);
1037                         return am.ReturnType;
1038                 }
1039
1040                 //
1041                 // Returns AnonymousMethod container if this anonymous method
1042                 // expression can be implicitly converted to the delegate type `delegate_type'
1043                 //
1044                 public Expression Compatible (ResolveContext ec, TypeSpec type)
1045                 {
1046                         Expression am;
1047                         if (compatibles.TryGetValue (type, out am))
1048                                 return am;
1049
1050                         TypeSpec delegate_type = CompatibleChecks (ec, type);
1051                         if (delegate_type == null)
1052                                 return null;
1053
1054                         //
1055                         // At this point its the first time we know the return type that is
1056                         // needed for the anonymous method.  We create the method here.
1057                         //
1058
1059                         var invoke_mb = Delegate.GetInvokeMethod (delegate_type);
1060                         TypeSpec return_type = invoke_mb.ReturnType;
1061
1062                         //
1063                         // Second: the return type of the delegate must be compatible with
1064                         // the anonymous type.   Instead of doing a pass to examine the block
1065                         // we satisfy the rule by setting the return type on the EmitContext
1066                         // to be the delegate type return type.
1067                         //
1068
1069                         var body = CompatibleMethodBody (ec, null, return_type, delegate_type);
1070                         if (body == null)
1071                                 return null;
1072
1073                         bool etree_conversion = delegate_type != type;
1074
1075                         try {
1076                                 if (etree_conversion) {
1077                                         if (ec.HasSet (ResolveContext.Options.ExpressionTreeConversion)) {
1078                                                 //
1079                                                 // Nested expression tree lambda use same scope as parent
1080                                                 // lambda, this also means no variable capturing between this
1081                                                 // and parent scope
1082                                                 //
1083                                                 am = body.Compatible (ec, ec.CurrentAnonymousMethod, is_async);
1084
1085                                                 //
1086                                                 // Quote nested expression tree
1087                                                 //
1088                                                 if (am != null)
1089                                                         am = new Quote (am);
1090                                         } else {
1091                                                 int errors = ec.Report.Errors;
1092
1093                                                 using (ec.Set (ResolveContext.Options.ExpressionTreeConversion)) {
1094                                                         am = body.Compatible (ec);
1095                                                 }
1096
1097                                                 //
1098                                                 // Rewrite expressions into expression tree when targeting Expression<T>
1099                                                 //
1100                                                 if (am != null && errors == ec.Report.Errors)
1101                                                         am = CreateExpressionTree (ec, delegate_type);
1102                                         }
1103                                 } else {
1104                                         if (is_async) {
1105                                                 AsyncInitializer.Create (body.Block, body.Parameters, ec.CurrentMemberDefinition.Parent, body.ReturnType, loc);
1106                                         }
1107
1108                                         am = body.Compatible (ec);
1109                                 }
1110                         } catch (CompletionResult) {
1111                                 throw;
1112                         } catch (Exception e) {
1113                                 throw new InternalErrorException (e, loc);
1114                         }
1115
1116                         if (!ec.IsInProbingMode) {
1117                                 compatibles.Add (type, am ?? EmptyExpression.Null);
1118                         }
1119
1120                         return am;
1121                 }
1122
1123                 protected virtual Expression CreateExpressionTree (ResolveContext ec, TypeSpec delegate_type)
1124                 {
1125                         return CreateExpressionTree (ec);
1126                 }
1127
1128                 public override Expression CreateExpressionTree (ResolveContext ec)
1129                 {
1130                         ec.Report.Error (1946, loc, "An anonymous method cannot be converted to an expression tree");
1131                         return null;
1132                 }
1133
1134                 protected virtual ParametersCompiled ResolveParameters (ResolveContext ec, TypeInferenceContext tic, TypeSpec delegate_type)
1135                 {
1136                         var delegate_parameters = Delegate.GetParameters (delegate_type);
1137
1138                         if (Parameters == ParametersCompiled.Undefined) {
1139                                 //
1140                                 // We provide a set of inaccessible parameters
1141                                 //
1142                                 Parameter[] fixedpars = new Parameter[delegate_parameters.Count];
1143
1144                                 for (int i = 0; i < delegate_parameters.Count; i++) {
1145                                         Parameter.Modifier i_mod = delegate_parameters.FixedParameters [i].ModFlags;
1146                                         if (i_mod == Parameter.Modifier.OUT) {
1147                                                 if (!ec.IsInProbingMode) {
1148                                                         ec.Report.Error (1688, loc,
1149                                                                 "Cannot convert anonymous method block without a parameter list to delegate type `{0}' because it has one or more `out' parameters",
1150                                                                 delegate_type.GetSignatureForError ());
1151                                                 }
1152
1153                                                 return null;
1154                                         }
1155                                         fixedpars[i] = new Parameter (
1156                                                 new TypeExpression (delegate_parameters.Types [i], loc), null,
1157                                                 delegate_parameters.FixedParameters [i].ModFlags, null, loc);
1158                                 }
1159
1160                                 return ParametersCompiled.CreateFullyResolved (fixedpars, delegate_parameters.Types);
1161                         }
1162
1163                         if (!VerifyExplicitParameters (ec, delegate_type, delegate_parameters)) {
1164                                 return null;
1165                         }
1166
1167                         return Parameters;
1168                 }
1169
1170                 protected override Expression DoResolve (ResolveContext ec)
1171                 {
1172                         if (ec.HasSet (ResolveContext.Options.ConstantScope)) {
1173                                 ec.Report.Error (1706, loc, "Anonymous methods and lambda expressions cannot be used in the current context");
1174                                 return null;
1175                         }
1176
1177                         //
1178                         // Set class type, set type
1179                         //
1180
1181                         eclass = ExprClass.Value;
1182
1183                         //
1184                         // This hack means `The type is not accessible
1185                         // anywhere', we depend on special conversion
1186                         // rules.
1187                         //
1188                         type = InternalType.AnonymousMethod;
1189
1190                         if (!DoResolveParameters (ec))
1191                                 return null;
1192
1193                         // FIXME: The emitted code isn't very careful about reachability
1194                         // so, ensure we have a 'ret' at the end
1195                         BlockContext bc = ec as BlockContext;
1196                         if (bc != null && bc.CurrentBranching != null && bc.CurrentBranching.CurrentUsageVector.IsUnreachable)
1197                                 bc.NeedReturnLabel ();
1198
1199                         return this;
1200                 }
1201
1202                 protected virtual bool DoResolveParameters (ResolveContext rc)
1203                 {
1204                         return Parameters.Resolve (rc);
1205                 }
1206
1207                 public override void Emit (EmitContext ec)
1208                 {
1209                         // nothing, as we only exist to not do anything.
1210                 }
1211
1212                 public static void Error_AddressOfCapturedVar (ResolveContext ec, IVariableReference var, Location loc)
1213                 {
1214                         ec.Report.Error (1686, loc,
1215                                 "Local variable or parameter `{0}' cannot have their address taken and be used inside an anonymous method, lambda expression or query expression",
1216                                 var.Name);
1217                 }
1218
1219                 public override string GetSignatureForError ()
1220                 {
1221                         return ExprClassName;
1222                 }
1223
1224                 AnonymousMethodBody CompatibleMethodBody (ResolveContext ec, TypeInferenceContext tic, TypeSpec return_type, TypeSpec delegate_type)
1225                 {
1226                         ParametersCompiled p = ResolveParameters (ec, tic, delegate_type);
1227                         if (p == null)
1228                                 return null;
1229
1230                         ParametersBlock b = ec.IsInProbingMode ? (ParametersBlock) Block.PerformClone () : Block;
1231
1232                         return CompatibleMethodFactory (return_type, delegate_type, p, b);
1233                 }
1234
1235                 protected virtual AnonymousMethodBody CompatibleMethodFactory (TypeSpec return_type, TypeSpec delegate_type, ParametersCompiled p, ParametersBlock b)
1236                 {
1237                         return new AnonymousMethodBody (p, b, return_type, delegate_type, loc);
1238                 }
1239
1240                 protected override void CloneTo (CloneContext clonectx, Expression t)
1241                 {
1242                         AnonymousMethodExpression target = (AnonymousMethodExpression) t;
1243
1244                         target.Block = (ParametersBlock) clonectx.LookupBlock (Block);
1245                 }
1246         }
1247
1248         //
1249         // Abstract expression for any block which requires variables hoisting
1250         //
1251         public abstract class AnonymousExpression : ExpressionStatement
1252         {
1253                 protected class AnonymousMethodMethod : Method
1254                 {
1255                         public readonly AnonymousExpression AnonymousMethod;
1256                         public readonly AnonymousMethodStorey Storey;
1257                         readonly string RealName;
1258
1259                         public AnonymousMethodMethod (DeclSpace parent, AnonymousExpression am, AnonymousMethodStorey storey,
1260                                                           GenericMethod generic, TypeExpr return_type,
1261                                                           Modifiers mod, string real_name, MemberName name,
1262                                                           ParametersCompiled parameters)
1263                                 : base (parent, generic, return_type, mod | Modifiers.COMPILER_GENERATED,
1264                                                 name, parameters, null)
1265                         {
1266                                 this.AnonymousMethod = am;
1267                                 this.Storey = storey;
1268                                 this.RealName = real_name;
1269
1270                                 Parent.PartialContainer.AddMethod (this);
1271                                 Block = new ToplevelBlock (am.block, parameters);
1272                         }
1273
1274                         public override EmitContext CreateEmitContext (ILGenerator ig)
1275                         {
1276                                 EmitContext ec = new EmitContext (this, ig, ReturnType);
1277                                 ec.CurrentAnonymousMethod = AnonymousMethod;
1278                                 if (AnonymousMethod.return_label != null) {
1279                                         ec.HasReturnLabel = true;
1280                                         ec.ReturnLabel = (Label) AnonymousMethod.return_label;
1281                                 }
1282
1283                                 return ec;
1284                         }
1285
1286                         protected override void DefineTypeParameters ()
1287                         {
1288                                 // Type parameters were cloned
1289                         }
1290
1291                         protected override bool ResolveMemberType ()
1292                         {
1293                                 if (!base.ResolveMemberType ())
1294                                         return false;
1295
1296                                 if (Storey != null && Storey.Mutator != null) {
1297                                         if (!parameters.IsEmpty) {
1298                                                 var mutated = Storey.Mutator.Mutate (parameters.Types);
1299                                                 if (mutated != parameters.Types)
1300                                                         parameters = ParametersCompiled.CreateFullyResolved ((Parameter[]) parameters.FixedParameters, mutated);
1301                                         }
1302
1303                                         member_type = Storey.Mutator.Mutate (member_type);
1304                                 }
1305
1306                                 return true;
1307                         }
1308
1309                         public override void Emit ()
1310                         {
1311                                 if (MethodBuilder == null) {
1312                                         Define ();
1313                                 }
1314
1315                                 base.Emit ();
1316                         }
1317
1318                         public override void EmitExtraSymbolInfo (SourceMethod source)
1319                         {
1320                                 source.SetRealMethodName (RealName);
1321                         }
1322                 }
1323
1324                 protected ParametersBlock block;
1325
1326                 public TypeSpec ReturnType;
1327
1328                 object return_label;
1329
1330                 protected AnonymousExpression (ParametersBlock block, TypeSpec return_type, Location loc)
1331                 {
1332                         this.ReturnType = return_type;
1333                         this.block = block;
1334                         this.loc = loc;
1335                 }
1336
1337                 public abstract string ContainerType { get; }
1338                 public abstract bool IsIterator { get; }
1339                 public abstract AnonymousMethodStorey Storey { get; }
1340
1341                 public AnonymousExpression Compatible (ResolveContext ec)
1342                 {
1343                         return Compatible (ec, this, false);
1344                 }
1345
1346                 public AnonymousExpression Compatible (ResolveContext ec, AnonymousExpression ae, bool isAsync)
1347                 {
1348                         if (block.Resolved)
1349                                 return this;
1350
1351                         // TODO: Implement clone
1352                         BlockContext aec = new BlockContext (ec, block, ReturnType);
1353                         aec.CurrentAnonymousMethod = ae;
1354
1355                         ResolveContext.Options flags = 0;
1356
1357                         var am = this as AnonymousMethodBody;
1358
1359                         if (ec.HasSet (ResolveContext.Options.InferReturnType) && am != null) {
1360                                 am.ReturnTypeInference = new TypeInferenceContext ();
1361                         }
1362
1363                         if (ec.IsInProbingMode)
1364                                 flags |= ResolveContext.Options.ProbingMode;
1365
1366                         if (ec.HasSet (ResolveContext.Options.FieldInitializerScope))
1367                                 flags |= ResolveContext.Options.FieldInitializerScope;
1368
1369                         if (ec.HasSet (ResolveContext.Options.ExpressionTreeConversion))
1370                                 flags |= ResolveContext.Options.ExpressionTreeConversion;
1371
1372                         aec.Set (flags);
1373
1374                         var errors = ec.Report.Errors;
1375
1376                         bool res = Block.Resolve (ec.CurrentBranching, aec, null);
1377
1378                         if (aec.HasReturnLabel)
1379                                 return_label = aec.ReturnLabel;
1380
1381                         if (am != null && am.ReturnTypeInference != null) {
1382                                 am.ReturnTypeInference.FixAllTypes (ec);
1383                                 ReturnType = am.ReturnTypeInference.InferredTypeArguments [0];
1384                                 am.ReturnTypeInference = null;
1385
1386                                 //
1387                                 // If e is synchronous the inferred return type is T
1388                                 // If e is asynchronous the inferred return type is Task<T>
1389                                 //
1390                                 if (isAsync && ReturnType != null) {
1391                                         ReturnType = ec.Module.PredefinedTypes.TaskGeneric.TypeSpec.MakeGenericType (ec, new [] { ReturnType });
1392                                 }
1393                         }
1394
1395                         if (res && errors != ec.Report.Errors)
1396                                 return null;
1397
1398                         return res ? this : null;
1399                 }
1400
1401                 public void SetHasThisAccess ()
1402                 {
1403                         ExplicitBlock b = block;
1404                         do {
1405                                 if (b.HasCapturedThis)
1406                                         return;
1407
1408                                 b.HasCapturedThis = true;
1409                                 b = b.Parent == null ? null : b.Parent.Explicit;
1410                         } while (b != null);
1411                 }
1412
1413                 //
1414                 // The block that makes up the body for the anonymous method
1415                 //
1416                 public ParametersBlock Block {
1417                         get {
1418                                 return block;
1419                         }
1420                 }
1421
1422         }
1423
1424         public class AnonymousMethodBody : AnonymousExpression
1425         {
1426                 protected readonly ParametersCompiled parameters;
1427                 AnonymousMethodStorey storey;
1428
1429                 AnonymousMethodMethod method;
1430                 Field am_cache;
1431                 string block_name;
1432                 TypeInferenceContext return_inference;
1433
1434                 static int unique_id;
1435
1436                 public AnonymousMethodBody (ParametersCompiled parameters,
1437                                         ParametersBlock block, TypeSpec return_type, TypeSpec delegate_type,
1438                                         Location loc)
1439                         : base (block, return_type, loc)
1440                 {
1441                         this.type = delegate_type;
1442                         this.parameters = parameters;
1443                 }
1444
1445                 #region Properties
1446
1447                 public override string ContainerType {
1448                         get { return "anonymous method"; }
1449                 }
1450
1451                 public override bool IsIterator {
1452                         get {
1453                                 return false;
1454                         }
1455                 }
1456
1457                 public ParametersCompiled Parameters {
1458                         get {
1459                                 return parameters;
1460                         }
1461                 }
1462
1463                 public TypeInferenceContext ReturnTypeInference {
1464                         get {
1465                                 return return_inference;
1466                         }
1467                         set {
1468                                 return_inference = value;
1469                         }
1470                 }
1471
1472                 public override AnonymousMethodStorey Storey {
1473                         get { return storey; }
1474                 }
1475
1476                 #endregion
1477
1478                 public override Expression CreateExpressionTree (ResolveContext ec)
1479                 {
1480                         ec.Report.Error (1945, loc, "An expression tree cannot contain an anonymous method expression");
1481                         return null;
1482                 }
1483
1484                 bool Define (ResolveContext ec)
1485                 {
1486                         if (!Block.Resolved && Compatible (ec) == null)
1487                                 return false;
1488
1489                         if (block_name == null) {
1490                                 MemberCore mc = (MemberCore) ec.MemberContext;
1491                                 block_name = mc.MemberName.Basename;
1492                         }
1493
1494                         return true;
1495                 }
1496
1497                 //
1498                 // Creates a host for the anonymous method
1499                 //
1500                 AnonymousMethodMethod DoCreateMethodHost (EmitContext ec)
1501                 {
1502                         //
1503                         // Anonymous method body can be converted to
1504                         //
1505                         // 1, an instance method in current scope when only `this' is hoisted
1506                         // 2, a static method in current scope when neither `this' nor any variable is hoisted
1507                         // 3, an instance method in compiler generated storey when any hoisted variable exists
1508                         //
1509
1510                         Modifiers modifiers;
1511                         if (Block.HasCapturedVariable || Block.HasCapturedThis) {
1512                                 storey = FindBestMethodStorey ();
1513                                 modifiers = storey != null ? Modifiers.INTERNAL : Modifiers.PRIVATE;
1514                         } else {
1515                                 if (ec.CurrentAnonymousMethod != null)
1516                                         storey = ec.CurrentAnonymousMethod.Storey;
1517
1518                                 modifiers = Modifiers.STATIC | Modifiers.PRIVATE;
1519                         }
1520
1521                         TypeContainer parent = storey != null ? storey : ec.CurrentTypeDefinition.Parent.PartialContainer;
1522
1523                         MemberCore mc = ec.MemberContext as MemberCore;
1524                         string name = CompilerGeneratedClass.MakeName (parent != storey ? block_name : null,
1525                                 "m", null, unique_id++);
1526
1527                         MemberName member_name;
1528                         GenericMethod generic_method;
1529                         if (storey == null && mc.MemberName.TypeArguments != null) {
1530                                 member_name = new MemberName (name, mc.MemberName.TypeArguments.Clone (), Location);
1531
1532                                 var hoisted_tparams = ec.CurrentTypeParameters;
1533                                 var type_params = new TypeParameter[hoisted_tparams.Length];
1534                                 for (int i = 0; i < type_params.Length; ++i) {
1535                                         type_params[i] = hoisted_tparams[i].CreateHoistedCopy (parent, null);
1536                                 }
1537
1538                                 generic_method = new GenericMethod (parent.NamespaceEntry, parent, member_name, type_params,
1539                                         new TypeExpression (ReturnType, Location), parameters);
1540                         } else {
1541                                 member_name = new MemberName (name, Location);
1542                                 generic_method = null;
1543                         }
1544
1545                         string real_name = String.Format (
1546                                 "{0}~{1}{2}", mc.GetSignatureForError (), GetSignatureForError (),
1547                                 parameters.GetSignatureForError ());
1548
1549                         return new AnonymousMethodMethod (parent,
1550                                 this, storey, generic_method, new TypeExpression (ReturnType, Location), modifiers,
1551                                 real_name, member_name, parameters);
1552                 }
1553
1554                 protected override Expression DoResolve (ResolveContext ec)
1555                 {
1556                         if (!Define (ec))
1557                                 return null;
1558
1559                         eclass = ExprClass.Value;
1560                         return this;
1561                 }
1562
1563                 public override void Emit (EmitContext ec)
1564                 {
1565                         //
1566                         // Use same anonymous method implementation for scenarios where same
1567                         // code is used from multiple blocks, e.g. field initializers
1568                         //
1569                         if (method == null) {
1570                                 //
1571                                 // Delay an anonymous method definition to avoid emitting unused code
1572                                 // for unreachable blocks or expression trees
1573                                 //
1574                                 method = DoCreateMethodHost (ec);
1575                                 method.Define ();
1576                         }
1577
1578                         bool is_static = (method.ModFlags & Modifiers.STATIC) != 0;
1579                         if (is_static && am_cache == null) {
1580                                 //
1581                                 // Creates a field cache to store delegate instance if it's not generic
1582                                 //
1583                                 if (!method.MemberName.IsGeneric) {
1584                                         TypeContainer parent = method.Parent.PartialContainer;
1585                                         int id = parent.Fields == null ? 0 : parent.Fields.Count;
1586                                         var cache_type = storey != null && storey.Mutator != null ? storey.Mutator.Mutate (type) : type;
1587
1588                                         am_cache = new Field (parent, new TypeExpression (cache_type, loc),
1589                                                 Modifiers.STATIC | Modifiers.PRIVATE | Modifiers.COMPILER_GENERATED,
1590                                                 new MemberName (CompilerGeneratedClass.MakeName (null, "f", "am$cache", id), loc), null);
1591                                         am_cache.Define ();
1592                                         parent.AddField (am_cache);
1593                                 } else {
1594                                         // TODO: Implement caching of generated generic static methods
1595                                         //
1596                                         // Idea:
1597                                         //
1598                                         // Some extra class is needed to capture variable generic type
1599                                         // arguments. Maybe we could re-use anonymous types, with a unique
1600                                         // anonymous method id, but they are quite heavy.
1601                                         //
1602                                         // Consider : "() => typeof(T);"
1603                                         //
1604                                         // We need something like
1605                                         // static class Wrap<Tn, Tm, DelegateType> {
1606                                         //              public static DelegateType cache;
1607                                         // }
1608                                         //
1609                                         // We then specialize local variable to capture all generic parameters
1610                                         // and delegate type, e.g. "Wrap<Ta, Tb, DelegateTypeInst> cache;"
1611                                         //
1612                                 }
1613                         }
1614
1615                         Label l_initialized = ec.DefineLabel ();
1616
1617                         if (am_cache != null) {
1618                                 ec.Emit (OpCodes.Ldsfld, am_cache.Spec);
1619                                 ec.Emit (OpCodes.Brtrue_S, l_initialized);
1620                         }
1621
1622                         //
1623                         // Load method delegate implementation
1624                         //
1625
1626                         if (is_static) {
1627                                 ec.Emit (OpCodes.Ldnull);
1628                         } else if (storey != null) {
1629                                 Expression e = storey.GetStoreyInstanceExpression (ec).Resolve (new ResolveContext (ec.MemberContext));
1630                                 if (e != null)
1631                                         e.Emit (ec);
1632                         } else {
1633                                 ec.Emit (OpCodes.Ldarg_0);
1634                         }
1635
1636                         var delegate_method = method.Spec;
1637                         if (storey != null && storey.MemberName.IsGeneric) {
1638                                 TypeSpec t = storey.Instance.Type;
1639
1640                                 //
1641                                 // Mutate anonymous method instance type if we are in nested
1642                                 // hoisted generic anonymous method storey
1643                                 //
1644                                 if (ec.CurrentAnonymousMethod != null &&
1645                                         ec.CurrentAnonymousMethod.Storey != null &&
1646                                         ec.CurrentAnonymousMethod.Storey.Mutator != null) {
1647                                         t = storey.Mutator.Mutate (t);
1648                                 }
1649
1650                                 ec.Emit (OpCodes.Ldftn, TypeBuilder.GetMethod (t.GetMetaInfo (), (MethodInfo) delegate_method.GetMetaInfo ()));
1651                         } else {
1652                                 if (delegate_method.IsGeneric)
1653                                         delegate_method = delegate_method.MakeGenericMethod (ec.MemberContext, method.TypeParameters);
1654
1655                                 ec.Emit (OpCodes.Ldftn, delegate_method);
1656                         }
1657
1658                         var constructor_method = Delegate.GetConstructor (type);
1659                         ec.Emit (OpCodes.Newobj, constructor_method);
1660
1661                         if (am_cache != null) {
1662                                 ec.Emit (OpCodes.Stsfld, am_cache.Spec);
1663                                 ec.MarkLabel (l_initialized);
1664                                 ec.Emit (OpCodes.Ldsfld, am_cache.Spec);
1665                         }
1666                 }
1667
1668                 public override void EmitStatement (EmitContext ec)
1669                 {
1670                         throw new NotImplementedException ();
1671                 }
1672
1673                 //
1674                 // Look for the best storey for this anonymous method
1675                 //
1676                 AnonymousMethodStorey FindBestMethodStorey ()
1677                 {
1678                         //
1679                         // Use the nearest parent block which has a storey
1680                         //
1681                         for (Block b = Block.Parent; b != null; b = b.Parent) {
1682                                 AnonymousMethodStorey s = b.Explicit.AnonymousMethodStorey;
1683                                 if (s != null)
1684                                         return s;
1685                         }
1686
1687                         return null;
1688                 }
1689
1690                 public override string GetSignatureForError ()
1691                 {
1692                         return TypeManager.CSharpName (type);
1693                 }
1694
1695                 public static void Reset ()
1696                 {
1697                         unique_id = 0;
1698                 }
1699         }
1700
1701         //
1702         // Anonymous type container
1703         //
1704         public class AnonymousTypeClass : CompilerGeneratedClass
1705         {
1706                 static int types_counter;
1707                 public const string ClassNamePrefix = "<>__AnonType";
1708                 public const string SignatureForError = "anonymous type";
1709
1710                 readonly IList<AnonymousTypeParameter> parameters;
1711
1712                 private AnonymousTypeClass (TypeContainer parent, MemberName name, IList<AnonymousTypeParameter> parameters, Location loc)
1713                         : base (parent, name, (parent.Module.Evaluator != null ? Modifiers.PUBLIC : 0) | Modifiers.SEALED)
1714                 {
1715                         this.parameters = parameters;
1716                 }
1717
1718                 public static AnonymousTypeClass Create (TypeContainer parent, IList<AnonymousTypeParameter> parameters, Location loc)
1719                 {
1720                         string name = ClassNamePrefix + types_counter++;
1721
1722                         ParametersCompiled all_parameters;
1723                         TypeParameterName[] t_params;
1724                         SimpleName[] t_args;
1725
1726                         if (parameters.Count == 0) {
1727                                 all_parameters = ParametersCompiled.EmptyReadOnlyParameters;
1728                                 t_params = new TypeParameterName[0];
1729                                 t_args = null;
1730                         } else {
1731                                 t_args = new SimpleName[parameters.Count];
1732                                 t_params = new TypeParameterName[parameters.Count];
1733                                 Parameter[] ctor_params = new Parameter[parameters.Count];
1734                                 for (int i = 0; i < parameters.Count; ++i) {
1735                                         AnonymousTypeParameter p = parameters[i];
1736                                         for (int ii = 0; ii < i; ++ii) {
1737                                                 if (parameters[ii].Name == p.Name) {
1738                                                         parent.Compiler.Report.Error (833, parameters[ii].Location,
1739                                                                 "`{0}': An anonymous type cannot have multiple properties with the same name",
1740                                                                         p.Name);
1741
1742                                                         p = new AnonymousTypeParameter (null, "$" + i.ToString (), p.Location);
1743                                                         parameters[i] = p;
1744                                                         break;
1745                                                 }
1746                                         }
1747
1748                                         t_args[i] = new SimpleName ("<" + p.Name + ">__T", p.Location);
1749                                         t_params[i] = new TypeParameterName (t_args[i].Name, null, p.Location);
1750                                         ctor_params[i] = new Parameter (t_args[i], p.Name, Parameter.Modifier.NONE, null, p.Location);
1751                                 }
1752
1753                                 all_parameters = new ParametersCompiled (ctor_params);
1754                         }
1755
1756                         //
1757                         // Create generic anonymous type host with generic arguments
1758                         // named upon properties names
1759                         //
1760                         AnonymousTypeClass a_type = new AnonymousTypeClass (parent.NamespaceEntry.SlaveDeclSpace,
1761                                 new MemberName (name, new TypeArguments (t_params), loc), parameters, loc);
1762
1763                         if (parameters.Count > 0)
1764                                 a_type.SetParameterInfo (null);
1765
1766                         Constructor c = new Constructor (a_type, name, Modifiers.PUBLIC | Modifiers.DEBUGGER_HIDDEN,
1767                                 null, all_parameters, null, loc);
1768                         c.Block = new ToplevelBlock (parent.Module.Compiler, c.ParameterInfo, loc);
1769
1770                         //
1771                         // Create fields and contructor body with field initialization
1772                         //
1773                         bool error = false;
1774                         for (int i = 0; i < parameters.Count; ++i) {
1775                                 AnonymousTypeParameter p = parameters [i];
1776
1777                                 Field f = new Field (a_type, t_args [i], Modifiers.PRIVATE | Modifiers.READONLY,
1778                                         new MemberName ("<" + p.Name + ">", p.Location), null);
1779
1780                                 if (!a_type.AddField (f)) {
1781                                         error = true;
1782                                         continue;
1783                                 }
1784
1785                                 c.Block.AddStatement (new StatementExpression (
1786                                         new SimpleAssign (new MemberAccess (new This (p.Location), f.Name),
1787                                                 c.Block.GetParameterReference (i, p.Location))));
1788
1789                                 ToplevelBlock get_block = new ToplevelBlock (parent.Module.Compiler, p.Location);
1790                                 get_block.AddStatement (new Return (
1791                                         new MemberAccess (new This (p.Location), f.Name), p.Location));
1792
1793                                 Property prop = new Property (a_type, t_args [i], Modifiers.PUBLIC,
1794                                         new MemberName (p.Name, p.Location), null);
1795                                 prop.Get = new Property.GetMethod (prop, 0, null, p.Location);
1796                                 prop.Get.Block = get_block;
1797                                 a_type.AddProperty (prop);
1798                         }
1799
1800                         if (error)
1801                                 return null;
1802
1803                         a_type.AddConstructor (c);
1804                         return a_type;
1805                 }
1806
1807                 public static void Reset ()
1808                 {
1809                         types_counter = 0;
1810                 }
1811
1812                 protected override bool AddToContainer (MemberCore symbol, string name)
1813                 {
1814                         MemberCore mc = GetDefinition (name);
1815
1816                         if (mc == null) {
1817                                 defined_names.Add (name, symbol);
1818                                 return true;
1819                         }
1820
1821                         // A conflict between anonymous type members will be reported
1822                         if (symbol is TypeParameter) {
1823                                 Report.SymbolRelatedToPreviousError (symbol);
1824                                 return false;
1825                         }
1826
1827                         // Ignore other conflicts
1828                         return true;
1829                 }
1830
1831                 protected override bool DoDefineMembers ()
1832                 {
1833                         if (!base.DoDefineMembers ())
1834                                 return false;
1835
1836                         Location loc = Location;
1837
1838                         var equals_parameters = ParametersCompiled.CreateFullyResolved (
1839                                 new Parameter (new TypeExpression (Compiler.BuiltinTypes.Object, loc), "obj", 0, null, loc), Compiler.BuiltinTypes.Object);
1840
1841                         Method equals = new Method (this, null, new TypeExpression (Compiler.BuiltinTypes.Bool, loc),
1842                                 Modifiers.PUBLIC | Modifiers.OVERRIDE | Modifiers.DEBUGGER_HIDDEN, new MemberName ("Equals", loc),
1843                                 equals_parameters, null);
1844
1845                         equals_parameters[0].Resolve (equals, 0);
1846
1847                         Method tostring = new Method (this, null, new TypeExpression (Compiler.BuiltinTypes.String, loc),
1848                                 Modifiers.PUBLIC | Modifiers.OVERRIDE | Modifiers.DEBUGGER_HIDDEN, new MemberName ("ToString", loc),
1849                                 Mono.CSharp.ParametersCompiled.EmptyReadOnlyParameters, null);
1850
1851                         ToplevelBlock equals_block = new ToplevelBlock (Compiler, equals.ParameterInfo, loc);
1852
1853                         TypeExpr current_type;
1854                         if (type_params != null) {
1855                                 var targs = new TypeArguments ();
1856                                 foreach (var type_param in type_params)
1857                                         targs.Add (new TypeParameterExpr (type_param, type_param.Location));
1858
1859                                 current_type = new GenericTypeExpr (Definition, targs, loc);
1860                         } else {
1861                                 current_type = new TypeExpression (Definition, loc);
1862                         }
1863
1864                         var li_other = LocalVariable.CreateCompilerGenerated (CurrentType, equals_block, loc);
1865                         equals_block.AddStatement (new BlockVariableDeclaration (new TypeExpression (li_other.Type, loc), li_other));
1866                         var other_variable = new LocalVariableReference (li_other, loc);
1867
1868                         MemberAccess system_collections_generic = new MemberAccess (new MemberAccess (
1869                                 new QualifiedAliasMember ("global", "System", loc), "Collections", loc), "Generic", loc);
1870
1871                         Expression rs_equals = null;
1872                         Expression string_concat = new StringConstant (Compiler.BuiltinTypes, "{", loc);
1873                         Expression rs_hashcode = new IntConstant (Compiler.BuiltinTypes, -2128831035, loc);
1874                         for (int i = 0; i < parameters.Count; ++i) {
1875                                 var p = parameters [i];
1876                                 var f = Fields [i];
1877
1878                                 MemberAccess equality_comparer = new MemberAccess (new MemberAccess (
1879                                         system_collections_generic, "EqualityComparer",
1880                                                 new TypeArguments (new SimpleName (CurrentTypeParameters [i].Name, loc)), loc),
1881                                                 "Default", loc);
1882
1883                                 Arguments arguments_equal = new Arguments (2);
1884                                 arguments_equal.Add (new Argument (new MemberAccess (new This (f.Location), f.Name)));
1885                                 arguments_equal.Add (new Argument (new MemberAccess (other_variable, f.Name)));
1886
1887                                 Expression field_equal = new Invocation (new MemberAccess (equality_comparer,
1888                                         "Equals", loc), arguments_equal);
1889
1890                                 Arguments arguments_hashcode = new Arguments (1);
1891                                 arguments_hashcode.Add (new Argument (new MemberAccess (new This (f.Location), f.Name)));
1892                                 Expression field_hashcode = new Invocation (new MemberAccess (equality_comparer,
1893                                         "GetHashCode", loc), arguments_hashcode);
1894
1895                                 IntConstant FNV_prime = new IntConstant (Compiler.BuiltinTypes, 16777619, loc);
1896                                 rs_hashcode = new Binary (Binary.Operator.Multiply,
1897                                         new Binary (Binary.Operator.ExclusiveOr, rs_hashcode, field_hashcode, loc),
1898                                         FNV_prime, loc);
1899
1900                                 Expression field_to_string = new Conditional (new BooleanExpression (new Binary (Binary.Operator.Inequality,
1901                                         new MemberAccess (new This (f.Location), f.Name), new NullLiteral (loc), loc)),
1902                                         new Invocation (new MemberAccess (
1903                                                 new MemberAccess (new This (f.Location), f.Name), "ToString"), null),
1904                                         new StringConstant (Compiler.BuiltinTypes, string.Empty, loc), loc);
1905
1906                                 if (rs_equals == null) {
1907                                         rs_equals = field_equal;
1908                                         string_concat = new Binary (Binary.Operator.Addition,
1909                                                 string_concat,
1910                                                 new Binary (Binary.Operator.Addition,
1911                                                         new StringConstant (Compiler.BuiltinTypes, " " + p.Name + " = ", loc),
1912                                                         field_to_string,
1913                                                         loc),
1914                                                 loc);
1915                                         continue;
1916                                 }
1917
1918                                 //
1919                                 // Implementation of ToString () body using string concatenation
1920                                 //
1921                                 string_concat = new Binary (Binary.Operator.Addition,
1922                                         new Binary (Binary.Operator.Addition,
1923                                                 string_concat,
1924                                                 new StringConstant (Compiler.BuiltinTypes, ", " + p.Name + " = ", loc),
1925                                                 loc),
1926                                         field_to_string,
1927                                         loc);
1928
1929                                 rs_equals = new Binary (Binary.Operator.LogicalAnd, rs_equals, field_equal, loc);
1930                         }
1931
1932                         string_concat = new Binary (Binary.Operator.Addition,
1933                                 string_concat,
1934                                 new StringConstant (Compiler.BuiltinTypes, " }", loc),
1935                                 loc);
1936
1937                         //
1938                         // Equals (object obj) override
1939                         //
1940                         var other_variable_assign = new TemporaryVariableReference (li_other, loc);
1941                         equals_block.AddStatement (new StatementExpression (
1942                                 new SimpleAssign (other_variable_assign,
1943                                         new As (equals_block.GetParameterReference (0, loc),
1944                                                 current_type, loc), loc)));
1945
1946                         Expression equals_test = new Binary (Binary.Operator.Inequality, other_variable, new NullLiteral (loc), loc);
1947                         if (rs_equals != null)
1948                                 equals_test = new Binary (Binary.Operator.LogicalAnd, equals_test, rs_equals, loc);
1949                         equals_block.AddStatement (new Return (equals_test, loc));
1950
1951                         equals.Block = equals_block;
1952                         equals.Define ();
1953                         AddMethod (equals);
1954
1955                         //
1956                         // GetHashCode () override
1957                         //
1958                         Method hashcode = new Method (this, null, new TypeExpression (Compiler.BuiltinTypes.Int, loc),
1959                                 Modifiers.PUBLIC | Modifiers.OVERRIDE | Modifiers.DEBUGGER_HIDDEN,
1960                                 new MemberName ("GetHashCode", loc),
1961                                 Mono.CSharp.ParametersCompiled.EmptyReadOnlyParameters, null);
1962
1963                         //
1964                         // Modified FNV with good avalanche behavior and uniform
1965                         // distribution with larger hash sizes.
1966                         //
1967                         // const int FNV_prime = 16777619;
1968                         // int hash = (int) 2166136261;
1969                         // foreach (int d in data)
1970                         //     hash = (hash ^ d) * FNV_prime;
1971                         // hash += hash << 13;
1972                         // hash ^= hash >> 7;
1973                         // hash += hash << 3;
1974                         // hash ^= hash >> 17;
1975                         // hash += hash << 5;
1976
1977                         ToplevelBlock hashcode_top = new ToplevelBlock (Compiler, loc);
1978                         Block hashcode_block = new Block (hashcode_top, loc, loc);
1979                         hashcode_top.AddStatement (new Unchecked (hashcode_block, loc));
1980
1981                         var li_hash = LocalVariable.CreateCompilerGenerated (Compiler.BuiltinTypes.Int, hashcode_top, loc);
1982                         hashcode_block.AddStatement (new BlockVariableDeclaration (new TypeExpression (li_hash.Type, loc), li_hash));
1983                         LocalVariableReference hash_variable_assign = new LocalVariableReference (li_hash, loc);
1984                         hashcode_block.AddStatement (new StatementExpression (
1985                                 new SimpleAssign (hash_variable_assign, rs_hashcode)));
1986
1987                         var hash_variable = new LocalVariableReference (li_hash, loc);
1988                         hashcode_block.AddStatement (new StatementExpression (
1989                                 new CompoundAssign (Binary.Operator.Addition, hash_variable,
1990                                         new Binary (Binary.Operator.LeftShift, hash_variable, new IntConstant (Compiler.BuiltinTypes, 13, loc), loc), loc)));
1991                         hashcode_block.AddStatement (new StatementExpression (
1992                                 new CompoundAssign (Binary.Operator.ExclusiveOr, hash_variable,
1993                                         new Binary (Binary.Operator.RightShift, hash_variable, new IntConstant (Compiler.BuiltinTypes, 7, loc), loc), loc)));
1994                         hashcode_block.AddStatement (new StatementExpression (
1995                                 new CompoundAssign (Binary.Operator.Addition, hash_variable,
1996                                         new Binary (Binary.Operator.LeftShift, hash_variable, new IntConstant (Compiler.BuiltinTypes, 3, loc), loc), loc)));
1997                         hashcode_block.AddStatement (new StatementExpression (
1998                                 new CompoundAssign (Binary.Operator.ExclusiveOr, hash_variable,
1999                                         new Binary (Binary.Operator.RightShift, hash_variable, new IntConstant (Compiler.BuiltinTypes, 17, loc), loc), loc)));
2000                         hashcode_block.AddStatement (new StatementExpression (
2001                                 new CompoundAssign (Binary.Operator.Addition, hash_variable,
2002                                         new Binary (Binary.Operator.LeftShift, hash_variable, new IntConstant (Compiler.BuiltinTypes, 5, loc), loc), loc)));
2003
2004                         hashcode_block.AddStatement (new Return (hash_variable, loc));
2005                         hashcode.Block = hashcode_top;
2006                         hashcode.Define ();
2007                         AddMethod (hashcode);
2008
2009                         //
2010                         // ToString () override
2011                         //
2012
2013                         ToplevelBlock tostring_block = new ToplevelBlock (Compiler, loc);
2014                         tostring_block.AddStatement (new Return (string_concat, loc));
2015                         tostring.Block = tostring_block;
2016                         tostring.Define ();
2017                         AddMethod (tostring);
2018
2019                         return true;
2020                 }
2021
2022                 public override string GetSignatureForError ()
2023                 {
2024                         return SignatureForError;
2025                 }
2026
2027                 public IList<AnonymousTypeParameter> Parameters {
2028                         get {
2029                                 return parameters;
2030                         }
2031                 }
2032         }
2033 }