mcs/mcs/typespec.cs

   1 //
   2 // typespec.cs: Type specification
   3 //
   4 // Authors: Marek Safar (marek.safar@gmail.com)
   5 //
   6 // Dual licensed under the terms of the MIT X11 or GNU GPL
   7 //
   8 // Copyright 2010 Novell, Inc
   9 // Copyright 2011 Xamarin, Inc (http://www.xamarin.com)
  10 //
  11
  12 using System;
  13 using System.Collections.Generic;
  14 using System.Text;
  15 using System.Linq;
  16
  17 #if STATIC
  18 using MetaType = IKVM.Reflection.Type;
  19 using IKVM.Reflection;
  20 #else
  21 using MetaType = System.Type;
  22 using System.Reflection;
  23 #endif
  24
  25 namespace Mono.CSharp
  26 {
  27         //
  28         // Inflated or non-inflated representation of any type.
  29         //
  30         public class TypeSpec : MemberSpec
  31         {
  32                 protected MetaType info;
  33                 protected MemberCache cache;
  34                 protected IList<TypeSpec> ifaces;
  35                 TypeSpec base_type;
  36
  37                 Dictionary<TypeSpec[], InflatedTypeSpec> inflated_instances;
  38
  39                 public static readonly TypeSpec[] EmptyTypes = new TypeSpec[0];
  40
  41 #if !STATIC
  42                 // Reflection Emit hacking
  43                 static readonly Type TypeBuilder;
  44                 static readonly Type GenericTypeBuilder;
  45
  46                 static TypeSpec ()
  47                 {
  48                         var assembly = typeof (object).Assembly;
  49                         TypeBuilder = assembly.GetType ("System.Reflection.Emit.TypeBuilder");
  50                         GenericTypeBuilder = assembly.GetType ("System.Reflection.MonoGenericClass");
  51                         if (GenericTypeBuilder == null)
  52                                 GenericTypeBuilder = assembly.GetType ("System.Reflection.Emit.TypeBuilderInstantiation");
  53                 }
  54 #endif
  55
  56                 public TypeSpec (MemberKind kind, TypeSpec declaringType, ITypeDefinition definition, MetaType info, Modifiers modifiers)
  57                         : base (kind, declaringType, definition, modifiers)
  58                 {
  59                         this.declaringType = declaringType;
  60                         this.info = info;
  61
  62                         if (definition != null && definition.TypeParametersCount > 0)
  63                                 state |= StateFlags.IsGeneric;
  64                 }
  65
  66                 #region Properties
  67
  68                 public override int Arity {
  69                         get {
  70                                 return MemberDefinition.TypeParametersCount;
  71                         }
  72                 }
  73
  74                 public virtual TypeSpec BaseType {
  75                         get {
  76                                 return base_type;
  77                         }
  78                         set {
  79                                 base_type = value;
  80                         }
  81                 }
  82
  83                 public virtual BuiltinTypeSpec.Type BuiltinType {
  84                         get {
  85                                 return BuiltinTypeSpec.Type.None;
  86                         }
  87                 }
  88
  89                 public bool HasDynamicElement {
  90                         get {
  91                                 return (state & StateFlags.HasDynamicElement) != 0;
  92                         }
  93                 }
  94
  95                 //
  96                 // Returns a list of all interfaces including
  97                 // interfaces from base type or base interfaces
  98                 //
  99                 public virtual IList<TypeSpec> Interfaces {
 100                         get {
 101                                 if ((state & StateFlags.InterfacesImported) == 0) {
 102                                         state |= StateFlags.InterfacesImported;
 103
 104                                         //
 105                                         // Delay interfaces expansion to save memory and once all
 106                                         // base types has been imported to avoid problems where
 107                                         // interface references type before its base was imported
 108                                         //
 109                                         var imported = MemberDefinition as ImportedTypeDefinition;
 110                                         if (imported != null && Kind != MemberKind.MissingType)
 111                                                 imported.DefineInterfaces (this);
 112
 113                                 }
 114
 115                                 return ifaces;
 116                         }
 117                         set {
 118                                 ifaces = value;
 119                         }
 120                 }
 121
 122                 public bool IsArray {
 123                         get {
 124                                 return Kind == MemberKind.ArrayType;
 125                         }
 126                 }
 127
 128                 public bool IsAttribute {
 129                         get {
 130                                 if (!IsClass)
 131                                         return false;
 132
 133                                 var type = this;
 134                                 do {
 135                                         if (type.BuiltinType == BuiltinTypeSpec.Type.Attribute)
 136                                                 return true;
 137
 138                                         if (type.IsGeneric)
 139                                                 return false;
 140
 141                                         type = type.base_type;
 142                                 } while (type != null);
 143
 144                                 return false;
 145                         }
 146                 }
 147
 148                 public bool IsInterface {
 149                         get {
 150                                 return Kind == MemberKind.Interface;
 151                         }
 152                 }
 153
 154                 public bool IsClass {
 155                         get {
 156                                 return Kind == MemberKind.Class;
 157                         }
 158                 }
 159
 160                 public bool IsConstantCompatible {
 161                         get {
 162                                 if ((Kind & (MemberKind.Enum | MemberKind.Class | MemberKind.Interface | MemberKind.Delegate | MemberKind.ArrayType)) != 0)
 163                                         return true;
 164
 165                                 switch (BuiltinType) {
 166                                 case BuiltinTypeSpec.Type.Int:
 167                                 case BuiltinTypeSpec.Type.UInt:
 168                                 case BuiltinTypeSpec.Type.Long:
 169                                 case BuiltinTypeSpec.Type.ULong:
 170                                 case BuiltinTypeSpec.Type.Float:
 171                                 case BuiltinTypeSpec.Type.Double:
 172                                 case BuiltinTypeSpec.Type.Char:
 173                                 case BuiltinTypeSpec.Type.Short:
 174                                 case BuiltinTypeSpec.Type.Decimal:
 175                                 case BuiltinTypeSpec.Type.Bool:
 176                                 case BuiltinTypeSpec.Type.SByte:
 177                                 case BuiltinTypeSpec.Type.Byte:
 178                                 case BuiltinTypeSpec.Type.UShort:
 179                                 case BuiltinTypeSpec.Type.Dynamic:
 180                                         return true;
 181                                 }
 182
 183                                 return false;
 184                         }
 185                 }
 186
 187                 public bool IsDelegate {
 188                         get {
 189                                 return Kind == MemberKind.Delegate;
 190                         }
 191                 }
 192
 193                 //
 194                 // Returns true for instances of Expression<T>
 195                 //
 196                 public virtual bool IsExpressionTreeType {
 197                         get {
 198                                 return false;
 199                         }
 200                         set {
 201                                 state = value ? state | StateFlags.InflatedExpressionType : state & ~StateFlags.InflatedExpressionType;
 202                         }
 203                 }
 204
 205                 public bool IsEnum {
 206                         get {
 207                                 return Kind == MemberKind.Enum;
 208                         }
 209                 }
 210
 211                 //
 212                 // Returns true for instances of IList<T>, IEnumerable<T>, ICollection<T>
 213                 //
 214                 public virtual bool IsGenericIterateInterface {
 215                         get {
 216                                 return false;
 217                         }
 218                         set {
 219                                 state = value ? state | StateFlags.GenericIterateInterface : state & ~StateFlags.GenericIterateInterface;
 220                         }
 221                 }
 222
 223                 //
 224                 // Returns true for instances of System.Threading.Tasks.Task<T>
 225                 //
 226                 public virtual bool IsGenericTask {
 227                         get {
 228                                 return false;
 229                         }
 230                         set {
 231                                 state = value ? state | StateFlags.GenericTask : state & ~StateFlags.GenericTask;
 232                         }
 233                 }
 234
 235                 // TODO: Should probably do
 236                 // IsGenericType -- recursive
 237                 // HasTypeParameter -- non-recursive
 238                 public bool IsGenericOrParentIsGeneric {
 239                         get {
 240                                 var ts = this;
 241                                 do {
 242                                         if (ts.IsGeneric)
 243                                                 return true;
 244                                         ts = ts.declaringType;
 245                                 } while (ts != null);
 246
 247                                 return false;
 248                         }
 249                 }
 250
 251                 public bool IsGenericParameter {
 252                         get {
 253                                 return Kind == MemberKind.TypeParameter;
 254                         }
 255                 }
 256
 257                 //
 258                 // Returns true for instances of Nullable<T>
 259                 //
 260                 public virtual bool IsNullableType {
 261                         get {
 262                                 return false;
 263                         }
 264                         set {
 265                                 state = value ? state | StateFlags.InflatedNullableType : state & ~StateFlags.InflatedNullableType;
 266                         }
 267                 }
 268
 269                 public bool IsNested {
 270                         get { return declaringType != null && Kind != MemberKind.TypeParameter; }
 271                 }
 272
 273                 public bool IsPointer {
 274                         get {
 275                                 return Kind == MemberKind.PointerType;
 276                         }
 277                 }
 278
 279                 public bool IsSealed {
 280                         get { return (Modifiers & Modifiers.SEALED) != 0; }
 281                 }
 282
 283                 public bool IsSpecialRuntimeType {
 284                         get {
 285                                 return (state & StateFlags.SpecialRuntimeType) != 0;
 286                         }
 287                         set {
 288                                 state = value ? state | StateFlags.SpecialRuntimeType : state & ~StateFlags.SpecialRuntimeType;
 289                         }
 290                 }
 291
 292                 public bool IsStruct {
 293                         get {
 294                                 return Kind == MemberKind.Struct;
 295                         }
 296                 }
 297
 298                 public bool IsTypeBuilder {
 299                         get {
 300 #if STATIC
 301                                 return true;
 302 #else
 303                                 var meta = GetMetaInfo().GetType ();
 304                                 return meta == TypeBuilder || meta == GenericTypeBuilder;
 305 #endif
 306                         }
 307                 }
 308
 309                 //
 310                 // Whether a type is unmanaged. This is used by the unsafe code
 311                 //
 312                 public bool IsUnmanaged {
 313                         get {
 314                                 if (IsPointer)
 315                                         return ((ElementTypeSpec) this).Element.IsUnmanaged;
 316
 317                                 var ds = MemberDefinition as TypeDefinition;
 318                                 if (ds != null)
 319                                         return ds.IsUnmanagedType ();
 320
 321                                 if (Kind == MemberKind.Void)
 322                                         return true;
 323
 324                                 if (IsNested && DeclaringType.IsGenericOrParentIsGeneric)
 325                                         return false;
 326
 327                                 return IsValueType (this);
 328                         }
 329                 }
 330
 331                 //
 332                 // A cache of all type members (including nested types)
 333                 //
 334                 public MemberCache MemberCache {
 335                         get {
 336                                 if (cache == null || (state & StateFlags.PendingMemberCacheMembers) != 0)
 337                                         InitializeMemberCache (false);
 338
 339                                 return cache;
 340                         }
 341                         set {
 342                                 if (cache != null)
 343                                         throw new InternalErrorException ("Membercache reset");
 344
 345                                 cache = value;
 346                         }
 347                 }
 348
 349                 public MemberCache MemberCacheTypes {
 350                         get {
 351                                 if (cache == null)
 352                                         InitializeMemberCache (true);
 353
 354                                 return cache;
 355                         }
 356                 }
 357
 358                 public new ITypeDefinition MemberDefinition {
 359                         get {
 360                                 return (ITypeDefinition) definition;
 361                         }
 362                 }
 363
 364                 // TODO: Wouldn't be better to rely on cast to InflatedTypeSpec and
 365                 // remove the property, YES IT WOULD !!!
 366                 public virtual TypeSpec[] TypeArguments {
 367                         get { return TypeSpec.EmptyTypes; }
 368                 }
 369
 370                 #endregion
 371
 372                 public virtual bool AddInterface (TypeSpec iface)
 373                 {
 374                         if ((state & StateFlags.InterfacesExpanded) != 0)
 375                                 throw new InternalErrorException ("Modifying expanded interface list");
 376
 377                         if (ifaces == null) {
 378                                 ifaces = new List<TypeSpec> () { iface };
 379                                 return true;
 380                         }
 381
 382                         if (!ifaces.Contains (iface)) {
 383                                 ifaces.Add (iface);
 384                                 return true;
 385                         }
 386
 387                         return false;
 388                 }
 389
 390                 //
 391                 // Special version used during type definition
 392                 //
 393                 public bool AddInterfaceDefined (TypeSpec iface)
 394                 {
 395                         if (!AddInterface (iface))
 396                                 return false;
 397
 398                         //
 399                         // We can get into a situation where a type is inflated before
 400                         // its interfaces are resoved. Consider this situation
 401                         //
 402                         // class A<T> : X<A<int>>, IFoo {}
 403                         //
 404                         // When resolving base class of X`1 we inflate context type A`1
 405                         // All this happens before we even hit IFoo resolve. Without
 406                         // additional expansion any inside usage of A<T> would miss IFoo
 407                         // interface because it comes from early inflated A`1 definition.
 408                         //
 409                         if (inflated_instances != null) {
 410                                 //
 411                                 // Inflate only existing instances not any new instances added
 412                                 // during AddInterface
 413                                 //
 414                                 var inflated_existing = inflated_instances.Values.ToArray ();
 415                                 foreach (var inflated in inflated_existing) {
 416                                         inflated.AddInterface (iface);
 417                                 }
 418                         }
 419
 420                         return true;
 421                 }
 422
 423                 //
 424                 // Returns all type arguments, usefull for nested types
 425                 //
 426                 public static TypeSpec[] GetAllTypeArguments (TypeSpec type)
 427                 {
 428                         IList<TypeSpec> targs = TypeSpec.EmptyTypes;
 429
 430                         do {
 431                                 if (type.Arity > 0) {
 432                                         if (targs.Count == 0) {
 433                                                 targs = type.TypeArguments;
 434                                         } else {
 435                                                 var list = targs as List<TypeSpec> ?? new List<TypeSpec> (targs);
 436                                                 list.AddRange (type.TypeArguments);
 437                                                 targs = list;
 438                                         }
 439                                 }
 440
 441                                 type = type.declaringType;
 442                         } while (type != null);
 443
 444                         return targs as TypeSpec[] ?? ((List<TypeSpec>) targs).ToArray ();
 445                 }
 446
 447                 public AttributeUsageAttribute GetAttributeUsage (PredefinedAttribute pa)
 448                 {
 449                         if (Kind != MemberKind.Class)
 450                                 throw new InternalErrorException ();
 451
 452                         if (!pa.IsDefined)
 453                                 return Attribute.DefaultUsageAttribute;
 454
 455                         AttributeUsageAttribute aua = null;
 456                         var type = this;
 457                         while (type != null) {
 458                                 aua = type.MemberDefinition.GetAttributeUsage (pa);
 459                                 if (aua != null)
 460                                         break;
 461
 462                                 type = type.BaseType;
 463                         }
 464
 465                         return aua;
 466                 }
 467
 468                 //
 469                 // Return metadata information used during emit to describe the type
 470                 //
 471                 public virtual MetaType GetMetaInfo ()
 472                 {
 473                         return info;
 474                 }
 475
 476                 public virtual TypeSpec GetDefinition ()
 477                 {
 478                         return this;
 479                 }
 480
 481                 //
 482                 // Text representation of type used by documentation writer
 483                 //
 484                 public override string GetSignatureForDocumentation ()
 485                 {
 486                         StringBuilder sb = new StringBuilder ();
 487                         if (IsNested) {
 488                                 sb.Append (DeclaringType.GetSignatureForDocumentation ());
 489                         } else {
 490                                 sb.Append (MemberDefinition.Namespace);
 491                         }
 492
 493                         if (sb.Length != 0)
 494                                 sb.Append (".");
 495
 496                         sb.Append (Name);
 497                         if (Arity > 0) {
 498                                 if (this is InflatedTypeSpec) {
 499                                     sb.Append ("{");
 500                                     for (int i = 0; i < Arity; ++i) {
 501                                         if (i > 0)
 502                                             sb.Append (",");
 503
 504                                         sb.Append (TypeArguments[i].GetSignatureForDocumentation ());
 505                                     }
 506                                     sb.Append ("}");
 507                                 } else {
 508                                         sb.Append ("`");
 509                                         sb.Append (Arity.ToString ());
 510                                 }
 511                         }
 512
 513                         return sb.ToString ();
 514                 }
 515
 516                 public string GetExplicitNameSignatureForDocumentation ()
 517                 {
 518                         StringBuilder sb = new StringBuilder ();
 519                         if (IsNested) {
 520                                 sb.Append (DeclaringType.GetExplicitNameSignatureForDocumentation ());
 521                         } else if (MemberDefinition.Namespace != null) {
 522                                 sb.Append (MemberDefinition.Namespace.Replace ('.', '#'));
 523                         }
 524
 525                         if (sb.Length != 0)
 526                                 sb.Append ("#");
 527
 528                         sb.Append (Name);
 529                         if (Arity > 0) {
 530                                 sb.Append ("{");
 531                                 for (int i = 0; i < Arity; ++i) {
 532                                         if (i > 0)
 533                                                 sb.Append (",");
 534
 535                                         sb.Append (TypeArguments[i].GetExplicitNameSignatureForDocumentation ());
 536                                 }
 537                                 sb.Append ("}");
 538                         }
 539
 540                         return sb.ToString ();
 541                 }
 542
 543                 public override string GetSignatureForError ()
 544                 {
 545                         string s;
 546
 547                         if (IsNested) {
 548                                 s = DeclaringType.GetSignatureForError ();
 549                         } else if (MemberDefinition is AnonymousTypeClass) {
 550                                 return ((AnonymousTypeClass) MemberDefinition).GetSignatureForError ();
 551                         } else {
 552                                 s = MemberDefinition.Namespace;
 553                         }
 554
 555                         if (!string.IsNullOrEmpty (s))
 556                                 s += ".";
 557
 558                         return s + Name + GetTypeNameSignature ();
 559                 }
 560
 561                 public string GetSignatureForErrorIncludingAssemblyName ()
 562                 {
 563                         return string.Format ("{0} [{1}]", GetSignatureForError (), MemberDefinition.DeclaringAssembly.FullName);
 564                 }
 565
 566                 protected virtual string GetTypeNameSignature ()
 567                 {
 568                         if (!IsGeneric)
 569                                 return null;
 570
 571                         return "<" + TypeManager.CSharpName (MemberDefinition.TypeParameters) + ">";
 572                 }
 573
 574                 public bool ImplementsInterface (TypeSpec iface, bool variantly)
 575                 {
 576                         var ifaces = Interfaces;
 577                         if (ifaces != null) {
 578                                 for (int i = 0; i < ifaces.Count; ++i) {
 579                                         if (TypeSpecComparer.IsEqual (ifaces[i], iface))
 580                                                 return true;
 581
 582                                         if (variantly && TypeSpecComparer.Variant.IsEqual (ifaces[i], iface))
 583                                                 return true;
 584                                 }
 585                         }
 586
 587                         return false;
 588                 }
 589
 590                 protected virtual void InitializeMemberCache (bool onlyTypes)
 591                 {
 592                         try {
 593                                 MemberDefinition.LoadMembers (this, onlyTypes, ref cache);
 594                         } catch (Exception e) {
 595                                 throw new InternalErrorException (e, "Unexpected error when loading type `{0}'", GetSignatureForError ());
 596                         }
 597
 598                         if (onlyTypes)
 599                                 state |= StateFlags.PendingMemberCacheMembers;
 600                         else
 601                                 state &= ~StateFlags.PendingMemberCacheMembers;
 602                 }
 603
 604                 //
 605                 // Is @baseClass base implementation of @type. With enabled @dynamicIsEqual the slower
 606                 // comparison is used to hide differences between `object' and `dynamic' for generic
 607                 // types. Should not be used for comparisons where G<object> != G<dynamic>
 608                 //
 609                 public static bool IsBaseClass (TypeSpec type, TypeSpec baseClass, bool dynamicIsObject)
 610                 {
 611                         if (dynamicIsObject && baseClass.IsGeneric) {
 612                                 //
 613                                 // Returns true for a hierarchies like this when passing baseClass of A<dynamic>
 614                                 //
 615                                 // class B : A<object> {}
 616                                 //
 617                                 type = type.BaseType;
 618                                 while (type != null) {
 619                                         if (TypeSpecComparer.IsEqual (type, baseClass))
 620                                                 return true;
 621
 622                                         type = type.BaseType;
 623                                 }
 624
 625                                 return false;
 626                         }
 627
 628                         while (type != null) {
 629                                 type = type.BaseType;
 630                                 if (type == baseClass)
 631                                         return true;
 632                         }
 633
 634                         return false;
 635                 }
 636
 637                 public static bool IsReferenceType (TypeSpec t)
 638                 {
 639                         switch (t.Kind) {
 640                         case MemberKind.TypeParameter:
 641                                 return ((TypeParameterSpec) t).IsReferenceType;
 642                         case MemberKind.Struct:
 643                         case MemberKind.Enum:
 644                         case MemberKind.Void:
 645                                 return false;
 646                         case MemberKind.InternalCompilerType:
 647                                 //
 648                                 // Null is considered to be a reference type
 649                                 //
 650                                 return t == InternalType.NullLiteral || t.BuiltinType == BuiltinTypeSpec.Type.Dynamic;
 651                         default:
 652                                 return true;
 653                         }
 654                 }
 655
 656                 public static bool IsValueType (TypeSpec t)
 657                 {
 658                         switch (t.Kind) {
 659                         case MemberKind.TypeParameter:
 660                                 return ((TypeParameterSpec) t).IsValueType;
 661                         case MemberKind.Struct:
 662                         case MemberKind.Enum:
 663                                 return true;
 664                         default:
 665                                 return false;
 666                         }
 667                 }
 668
 669                 public override MemberSpec InflateMember (TypeParameterInflator inflator)
 670                 {
 671                         var targs = IsGeneric ? MemberDefinition.TypeParameters : TypeSpec.EmptyTypes;
 672
 673                         //
 674                         // When inflating nested type from inside the type instance will be same
 675                         // because type parameters are same for all nested types
 676                         //
 677                         if (DeclaringType == inflator.TypeInstance) {
 678                                 return MakeGenericType (inflator.Context, targs);
 679                         }
 680
 681                         return new InflatedTypeSpec (inflator.Context, this, inflator.TypeInstance, targs);
 682                 }
 683
 684                 //
 685                 // Inflates current type using specific type arguments
 686                 //
 687                 public InflatedTypeSpec MakeGenericType (IModuleContext context, TypeSpec[] targs)
 688                 {
 689                         if (targs.Length == 0 && !IsNested)
 690                                 throw new ArgumentException ("Empty type arguments for type " + GetSignatureForError ());
 691
 692                         InflatedTypeSpec instance;
 693
 694                         if (inflated_instances == null) {
 695                                 inflated_instances = new Dictionary<TypeSpec[], InflatedTypeSpec> (TypeSpecComparer.Default);
 696
 697                                 if (IsNested) {
 698                                         instance = this as InflatedTypeSpec;
 699                                         if (instance != null) {
 700                                                 //
 701                                                 // Nested types could be inflated on already inflated instances
 702                                                 // Caching this type ensured we are using same instance for
 703                                                 // inside/outside inflation using local type parameters
 704                                                 //
 705                                                 inflated_instances.Add (TypeArguments, instance);
 706                                         }
 707                                 }
 708                         }
 709
 710                         if (!inflated_instances.TryGetValue (targs, out instance)) {
 711                                 if (GetDefinition () != this && !IsNested)
 712                                         throw new InternalErrorException ("`{0}' must be type definition or nested non-inflated type to MakeGenericType",
 713                                                 GetSignatureForError ());
 714
 715                                 instance = new InflatedTypeSpec (context, this, declaringType, targs);
 716                                 inflated_instances.Add (targs, instance);
 717                         }
 718
 719                         return instance;
 720                 }
 721
 722                 public virtual TypeSpec Mutate (TypeParameterMutator mutator)
 723                 {
 724                         return this;
 725                 }
 726
 727                 public override List<TypeSpec> ResolveMissingDependencies ()
 728                 {
 729                         List<TypeSpec> missing = null;
 730
 731                         if (Kind == MemberKind.MissingType) {
 732                                 missing = new List<TypeSpec> ();
 733                                 missing.Add (this);
 734                                 return missing;
 735                         }
 736
 737                         foreach (var targ in TypeArguments) {
 738                                 if (targ.Kind == MemberKind.MissingType) {
 739                                         if (missing == null)
 740                                                 missing = new List<TypeSpec> ();
 741
 742                                         missing.Add (targ);
 743                                 }
 744                         }
 745
 746                         if (Interfaces != null) {
 747                                 foreach (var iface in Interfaces) {
 748                                         if (iface.Kind == MemberKind.MissingType) {
 749                                                 if (missing == null)
 750                                                         missing = new List<TypeSpec> ();
 751
 752                                                 missing.Add (iface);
 753                                         }
 754                                 }
 755                         }
 756
 757                         if (MemberDefinition.TypeParametersCount > 0) {
 758                                 foreach (var tp in MemberDefinition.TypeParameters) {
 759                                         var tp_missing = tp.GetMissingDependencies ();
 760                                         if (tp_missing != null) {
 761                                                 if (missing == null)
 762                                                         missing = new List<TypeSpec> ();
 763
 764                                                 missing.AddRange (tp_missing);
 765                                         }
 766                                 }
 767                         }
 768
 769                         if (missing != null || BaseType == null)
 770                                 return missing;
 771
 772                         return BaseType.ResolveMissingDependencies ();
 773                 }
 774
 775                 public void SetMetaInfo (MetaType info)
 776                 {
 777                         if (this.info != null)
 778                                 throw new InternalErrorException ("MetaInfo reset");
 779
 780                         this.info = info;
 781                 }
 782
 783                 public void SetExtensionMethodContainer ()
 784                 {
 785                         modifiers |= Modifiers.METHOD_EXTENSION;
 786                 }
 787         }
 788
 789         //
 790         // Special version used for types which must exist in corlib or
 791         // the compiler cannot work
 792         //
 793         public sealed class BuiltinTypeSpec : TypeSpec
 794         {
 795                 public enum Type
 796                 {
 797                         None = 0,
 798
 799                         // Ordered carefully for fast compares
 800                         FirstPrimitive = 1,
 801                         Bool = 1,
 802                         Byte = 2,
 803                         SByte = 3,
 804                         Char = 4,
 805                         Short = 5,
 806                         UShort = 6,
 807                         Int = 7,
 808                         UInt = 8,
 809                         Long = 9,
 810                         ULong = 10,
 811                         Float = 11,
 812                         Double = 12,
 813                         LastPrimitive = 12,
 814                         Decimal = 13,
 815
 816                         IntPtr = 14,
 817                         UIntPtr = 15,
 818
 819                         Object = 16,
 820                         Dynamic = 17,
 821                         String = 18,
 822                         Type = 19,
 823
 824                         ValueType = 20,
 825                         Enum = 21,
 826                         Delegate = 22,
 827                         MulticastDelegate = 23,
 828                         Array = 24,
 829
 830                         IEnumerator,
 831                         IEnumerable,
 832                         IDisposable,
 833                         Exception,
 834                         Attribute,
 835                         Other,
 836                 }
 837
 838                 readonly Type type;
 839                 readonly string ns;
 840                 readonly string name;
 841
 842                 public BuiltinTypeSpec (MemberKind kind, string ns, string name, Type builtinKind)
 843                         : base (kind, null, null, null, Modifiers.PUBLIC)
 844                 {
 845                         this.type = builtinKind;
 846                         this.ns = ns;
 847                         this.name = name;
 848                 }
 849
 850                 public BuiltinTypeSpec (string name, Type builtinKind)
 851                         : this (MemberKind.InternalCompilerType, "", name, builtinKind)
 852                 {
 853                         // Make all internal types CLS-compliant, non-obsolete, compact
 854                         state = (state & ~(StateFlags.CLSCompliant_Undetected | StateFlags.Obsolete_Undetected | StateFlags.MissingDependency_Undetected)) | StateFlags.CLSCompliant;
 855                 }
 856
 857                 #region Properties
 858
 859                 public override int Arity {
 860                         get {
 861                                 return 0;
 862                         }
 863                 }
 864
 865                 public override BuiltinTypeSpec.Type BuiltinType {
 866                         get {
 867                                 return type;
 868                         }
 869                 }
 870
 871                 public string FullName {
 872                         get {
 873                                 return ns + '.' + name;
 874                         }
 875                 }
 876
 877                 public override string Name {
 878                         get {
 879                                 return name;
 880                         }
 881                 }
 882
 883                 public string Namespace {
 884                         get {
 885                                 return ns;
 886                         }
 887                 }
 888
 889                 #endregion
 890
 891                 public static bool IsPrimitiveType (TypeSpec type)
 892                 {
 893                         return type.BuiltinType >= Type.FirstPrimitive && type.BuiltinType <= Type.LastPrimitive;
 894                 }
 895
 896                 public static bool IsPrimitiveTypeOrDecimal (TypeSpec type)
 897                 {
 898                         return type.BuiltinType >= Type.FirstPrimitive && type.BuiltinType <= Type.Decimal;
 899                 }
 900
 901                 public override string GetSignatureForError ()
 902                 {
 903                         switch (Name) {
 904                         case "Int32": return "int";
 905                         case "Int64": return "long";
 906                         case "String": return "string";
 907                         case "Boolean": return "bool";
 908                         case "Void": return "void";
 909                         case "Object": return "object";
 910                         case "UInt32": return "uint";
 911                         case "Int16": return "short";
 912                         case "UInt16": return "ushort";
 913                         case "UInt64": return "ulong";
 914                         case "Single": return "float";
 915                         case "Double": return "double";
 916                         case "Decimal": return "decimal";
 917                         case "Char": return "char";
 918                         case "Byte": return "byte";
 919                         case "SByte": return "sbyte";
 920                         }
 921
 922                         if (ns.Length == 0)
 923                                 return name;
 924
 925                         return FullName;
 926                 }
 927
 928                 //
 929                 // Returns the size of type if known, otherwise, 0
 930                 //
 931                 public static int GetSize (TypeSpec type)
 932                 {
 933                         switch (type.BuiltinType) {
 934                         case Type.Int:
 935                         case Type.UInt:
 936                         case Type.Float:
 937                                 return 4;
 938                         case Type.Long:
 939                         case Type.ULong:
 940                         case Type.Double:
 941                                 return 8;
 942                         case Type.Byte:
 943                         case Type.SByte:
 944                         case Type.Bool:
 945                                 return 1;
 946                         case Type.Short:
 947                         case Type.Char:
 948                         case Type.UShort:
 949                                 return 2;
 950                         case Type.Decimal:
 951                                 return 16;
 952                         default:
 953                                 return 0;
 954                         }
 955                 }
 956
 957                 public void SetDefinition (ITypeDefinition td, MetaType type, Modifiers mod)
 958                 {
 959                         this.definition = td;
 960                         this.info = type;
 961                         this.modifiers |= (mod & ~Modifiers.AccessibilityMask);
 962                 }
 963
 964                 public void SetDefinition (TypeSpec ts)
 965                 {
 966                         this.definition = ts.MemberDefinition;
 967                         this.info = ts.GetMetaInfo ();
 968                         this.BaseType = ts.BaseType;
 969                         this.Interfaces = ts.Interfaces;
 970                         this.modifiers = ts.Modifiers;
 971                 }
 972         }
 973
 974         //
 975         // Various type comparers used by compiler
 976         //
 977         static class TypeSpecComparer
 978         {
 979                 //
 980                 // Does strict reference comparion only
 981                 //
 982                 public static readonly DefaultImpl Default = new DefaultImpl ();
 983
 984                 public class DefaultImpl : IEqualityComparer<TypeSpec[]>
 985                 {
 986                         #region IEqualityComparer<TypeSpec[]> Members
 987
 988                         bool IEqualityComparer<TypeSpec[]>.Equals (TypeSpec[] x, TypeSpec[] y)
 989                         {
 990                                 if (x == y)
 991                                         return true;
 992
 993                                 if (x.Length != y.Length)
 994                                         return false;
 995
 996                                 for (int i = 0; i < x.Length; ++i)
 997                                         if (x[i] != y[i])
 998                                                 return false;
 999
1000                                 return true;
1001                         }
1002
1003                         int IEqualityComparer<TypeSpec[]>.GetHashCode (TypeSpec[] obj)
1004                         {
1005                                 int hash = 0;
1006                                 for (int i = 0; i < obj.Length; ++i)
1007                                         hash = (hash << 5) - hash + obj[i].GetHashCode ();
1008
1009                                 return hash;
1010                         }
1011
1012                         #endregion
1013                 }
1014
1015                 //
1016                 // When comparing type signature of overrides or overloads
1017                 // this version tolerates different MVARs at same position
1018                 //
1019                 public static class Override
1020                 {
1021                         public static bool IsEqual (TypeSpec a, TypeSpec b)
1022                         {
1023                                 if (a == b)
1024                                         return true;
1025
1026                                 //
1027                                 // Consider the following example:
1028                                 //
1029                                 //     public abstract class A
1030                                 //     {
1031                                 //        public abstract T Foo<T>();
1032                                 //     }
1033                                 //
1034                                 //     public class B : A
1035                                 //     {
1036                                 //        public override U Foo<T>() { return default (U); }
1037                                 //     }
1038                                 //
1039                                 // Here, `T' and `U' are method type parameters from different methods
1040                                 // (A.Foo and B.Foo), so both `==' and Equals() will fail.
1041                                 //
1042                                 // However, since we're determining whether B.Foo() overrides A.Foo(),
1043                                 // we need to do a signature based comparision and consider them equal.
1044                                 //
1045
1046                                 var tp_a = a as TypeParameterSpec;
1047                                 if (tp_a != null) {
1048                                         var tp_b = b as TypeParameterSpec;
1049                                         return tp_b != null && tp_a.IsMethodOwned == tp_b.IsMethodOwned && tp_a.DeclaredPosition == tp_b.DeclaredPosition;
1050                                 }
1051
1052                                 var ac_a = a as ArrayContainer;
1053                                 if (ac_a != null) {
1054                                         var ac_b = b as ArrayContainer;
1055                                         return ac_b != null && ac_a.Rank == ac_b.Rank && IsEqual (ac_a.Element, ac_b.Element);
1056                                 }
1057
1058                                 if (a.BuiltinType == BuiltinTypeSpec.Type.Dynamic || b.BuiltinType == BuiltinTypeSpec.Type.Dynamic)
1059                                         return b.BuiltinType == BuiltinTypeSpec.Type.Object || a.BuiltinType == BuiltinTypeSpec.Type.Object;
1060
1061                                 if (a.MemberDefinition != b.MemberDefinition)
1062                                         return false;
1063
1064                                 do {
1065                                         for (int i = 0; i < a.TypeArguments.Length; ++i) {
1066                                                 if (!IsEqual (a.TypeArguments[i], b.TypeArguments[i]))
1067                                                         return false;
1068                                         }
1069
1070                                         a = a.DeclaringType;
1071                                         b = b.DeclaringType;
1072                                 } while (a != null);
1073
1074                                 return true;
1075                         }
1076
1077                         public static bool IsEqual (TypeSpec[] a, TypeSpec[] b)
1078                         {
1079                                 if (a == b)
1080                                         return true;
1081
1082                                 if (a.Length != b.Length)
1083                                         return false;
1084
1085                                 for (int i = 0; i < a.Length; ++i) {
1086                                         if (!IsEqual (a[i], b[i]))
1087                                                 return false;
1088                                 }
1089
1090                                 return true;
1091                         }
1092
1093
1094                         //
1095                         // Compares unordered arrays
1096                         //
1097                         public static bool IsSame (TypeSpec[] a, TypeSpec[] b)
1098                         {
1099                                 if (a == b)
1100                                         return true;
1101
1102                                 if (a == null || b == null || a.Length != b.Length)
1103                                         return false;
1104
1105                                 for (int ai = 0; ai < a.Length; ++ai) {
1106                                         bool found = false;
1107                                         for (int bi = 0; bi < b.Length; ++bi) {
1108                                                 if (IsEqual (a[ai], b[bi])) {
1109                                                         found = true;
1110                                                         break;
1111                                                 }
1112                                         }
1113
1114                                         if (!found)
1115                                                 return false;
1116                                 }
1117
1118                                 return true;
1119                         }
1120
1121                         public static bool IsEqual (AParametersCollection a, AParametersCollection b)
1122                         {
1123                                 if (a == b)
1124                                         return true;
1125
1126                                 if (a.Count != b.Count)
1127                                         return false;
1128
1129                                 for (int i = 0; i < a.Count; ++i) {
1130                                         if (!IsEqual (a.Types[i], b.Types[i]))
1131                                                 return false;
1132
1133                                         if ((a.FixedParameters[i].ModFlags & Parameter.Modifier.RefOutMask) != (b.FixedParameters[i].ModFlags & Parameter.Modifier.RefOutMask))
1134                                                 return false;
1135                                 }
1136
1137                                 return true;
1138                         }
1139                 }
1140
1141                 //
1142                 // Type variance equality comparison
1143                 //
1144                 public static class Variant
1145                 {
1146                         public static bool IsEqual (TypeSpec type1, TypeSpec type2)
1147                         {
1148                                 if (!type1.IsGeneric || !type2.IsGeneric)
1149                                         return false;
1150
1151                                 var target_type_def = type2.MemberDefinition;
1152                                 if (type1.MemberDefinition != target_type_def)
1153                                         return false;
1154
1155                                 var t1_targs = type1.TypeArguments;
1156                                 var t2_targs = type2.TypeArguments;
1157                                 var targs_definition = target_type_def.TypeParameters;
1158
1159                                 if (!type1.IsInterface && !type1.IsDelegate) {
1160                                         return false;
1161                                 }
1162
1163                                 for (int i = 0; i < targs_definition.Length; ++i) {
1164                                         if (TypeSpecComparer.IsEqual (t1_targs[i], t2_targs[i]))
1165                                                 continue;
1166
1167                                         Variance v = targs_definition[i].Variance;
1168                                         if (v == Variance.None) {
1169                                                 return false;
1170                                         }
1171
1172                                         if (v == Variance.Covariant) {
1173                                                 if (!Convert.ImplicitReferenceConversionExists (t1_targs[i], t2_targs[i]))
1174                                                         return false;
1175                                         } else if (!Convert.ImplicitReferenceConversionExists (t2_targs[i], t1_targs[i])) {
1176                                                 return false;
1177                                         }
1178                                 }
1179
1180                                 return true;
1181                         }
1182                 }
1183
1184                 //
1185                 // Checks whether two generic instances may become equal for some
1186                 // particular instantiation (26.3.1).
1187                 //
1188                 public static class Unify
1189                 {
1190                         //
1191                         // Either @a or @b must be generic type
1192                         //
1193                         public static bool IsEqual (TypeSpec a, TypeSpec b)
1194                         {
1195                                 if (a.MemberDefinition != b.MemberDefinition) {
1196                                         var base_ifaces = a.Interfaces;
1197                                         if (base_ifaces != null) {
1198                                                 foreach (var base_iface in base_ifaces) {
1199                                                         if (base_iface.Arity > 0 && IsEqual (base_iface, b))
1200                                                                 return true;
1201                                                 }
1202                                         }
1203
1204                                         return false;
1205                                 }
1206
1207                                 var ta = a.TypeArguments;
1208                                 var tb = b.TypeArguments;
1209                                 for (int i = 0; i < ta.Length; i++) {
1210                                         if (!MayBecomeEqualGenericTypes (ta[i], tb[i]))
1211                                                 return false;
1212                                 }
1213
1214                                 return true;
1215                         }
1216
1217                         static bool ContainsTypeParameter (TypeSpec tparam, TypeSpec type)
1218                         {
1219                                 TypeSpec[] targs = type.TypeArguments;
1220                                 for (int i = 0; i < targs.Length; i++) {
1221                                         if (tparam == targs[i])
1222                                                 return true;
1223
1224                                         if (ContainsTypeParameter (tparam, targs[i]))
1225                                                 return true;
1226                                 }
1227
1228                                 return false;
1229                         }
1230
1231                         /// <summary>
1232                         ///   Check whether `a' and `b' may become equal generic types.
1233                         ///   The algorithm to do that is a little bit complicated.
1234                         /// </summary>
1235                         static bool MayBecomeEqualGenericTypes (TypeSpec a, TypeSpec b)
1236                         {
1237                                 if (a.IsGenericParameter) {
1238                                         //
1239                                         // If a is an array of a's type, they may never
1240                                         // become equal.
1241                                         //
1242                                         if (b.IsArray)
1243                                                 return false;
1244
1245                                         //
1246                                         // If b is a generic parameter or an actual type,
1247                                         // they may become equal:
1248                                         //
1249                                         //    class X<T,U> : I<T>, I<U>
1250                                         //    class X<T> : I<T>, I<float>
1251                                         //
1252                                         if (b.IsGenericParameter)
1253                                                 return a != b && a.DeclaringType == b.DeclaringType;
1254
1255                                         //
1256                                         // We're now comparing a type parameter with a
1257                                         // generic instance.  They may become equal unless
1258                                         // the type parameter appears anywhere in the
1259                                         // generic instance:
1260                                         //
1261                                         //    class X<T,U> : I<T>, I<X<U>>
1262                                         //        -> error because you could instanciate it as
1263                                         //           X<X<int>,int>
1264                                         //
1265                                         //    class X<T> : I<T>, I<X<T>> -> ok
1266                                         //
1267
1268                                         return !ContainsTypeParameter (a, b);
1269                                 }
1270
1271                                 if (b.IsGenericParameter)
1272                                         return MayBecomeEqualGenericTypes (b, a);
1273
1274                                 //
1275                                 // At this point, neither a nor b are a type parameter.
1276                                 //
1277                                 // If one of them is a generic instance, compare them (if the
1278                                 // other one is not a generic instance, they can never
1279                                 // become equal).
1280                                 //
1281                                 if (TypeManager.IsGenericType (a) || TypeManager.IsGenericType (b))
1282                                         return IsEqual (a, b);
1283
1284                                 //
1285                                 // If both of them are arrays.
1286                                 //
1287                                 var a_ac = a as ArrayContainer;
1288                                 if (a_ac != null) {
1289                                         var b_ac = b as ArrayContainer;
1290                                         if (b_ac == null || a_ac.Rank != b_ac.Rank)
1291                                                 return false;
1292
1293                                         return MayBecomeEqualGenericTypes (a_ac.Element, b_ac.Element);
1294                                 }
1295
1296                                 //
1297                                 // Ok, two ordinary types.
1298                                 //
1299                                 return false;
1300                         }
1301                 }
1302
1303                 public static bool Equals (TypeSpec[] x, TypeSpec[] y)
1304                 {
1305                         if (x == y)
1306                                 return true;
1307
1308                         if (x.Length != y.Length)
1309                                 return false;
1310
1311                         for (int i = 0; i < x.Length; ++i)
1312                                 if (!IsEqual (x[i], y[i]))
1313                                         return false;
1314
1315                         return true;
1316                 }
1317
1318                 //
1319                 // Identity type conversion
1320                 //
1321                 // Default reference comparison, it has to be used when comparing
1322                 // two possible dynamic/internal types
1323                 //
1324                 public static bool IsEqual (TypeSpec a, TypeSpec b)
1325                 {
1326                         if (a == b) {
1327                                 // This also rejects dynamic == dynamic
1328                                 return a.Kind != MemberKind.InternalCompilerType || a.BuiltinType == BuiltinTypeSpec.Type.Dynamic;
1329                         }
1330
1331                         if (a == null || b == null)
1332                                 return false;
1333
1334                         if (a.IsArray) {
1335                                 var a_a = (ArrayContainer) a;
1336                                 var b_a = b as ArrayContainer;
1337                                 if (b_a == null)
1338                                         return false;
1339
1340                                 return a_a.Rank == b_a.Rank && IsEqual (a_a.Element, b_a.Element);
1341                         }
1342
1343                         if (!a.IsGeneric || !b.IsGeneric) {
1344                                 //
1345                                 // object and dynamic are considered equivalent there is an identity conversion
1346                                 // between object and dynamic, and between constructed types that are the same
1347                                 // when replacing all occurences of dynamic with object.
1348                                 //
1349                                 if (a.BuiltinType == BuiltinTypeSpec.Type.Dynamic || b.BuiltinType == BuiltinTypeSpec.Type.Dynamic)
1350                                         return b.BuiltinType == BuiltinTypeSpec.Type.Object || a.BuiltinType == BuiltinTypeSpec.Type.Object;
1351
1352                                 return false;
1353                         }
1354
1355                         if (a.MemberDefinition != b.MemberDefinition)
1356                                 return false;
1357
1358                         do {
1359                                 if (!Equals (a.TypeArguments, b.TypeArguments))
1360                                         return false;
1361
1362                                 a = a.DeclaringType;
1363                                 b = b.DeclaringType;
1364                         } while (a != null);
1365
1366                         return true;
1367                 }
1368         }
1369
1370         public interface ITypeDefinition : IMemberDefinition
1371         {
1372                 IAssemblyDefinition DeclaringAssembly { get; }
1373                 string Namespace { get; }
1374                 bool IsPartial { get; }
1375                 bool IsComImport { get; }
1376                 bool IsTypeForwarder { get; }
1377                 int TypeParametersCount { get; }
1378                 TypeParameterSpec[] TypeParameters { get; }
1379
1380                 TypeSpec GetAttributeCoClass ();
1381                 string GetAttributeDefaultMember ();
1382                 AttributeUsageAttribute GetAttributeUsage (PredefinedAttribute pa);
1383                 bool IsInternalAsPublic (IAssemblyDefinition assembly);
1384                 void LoadMembers (TypeSpec declaringType, bool onlyTypes, ref MemberCache cache);
1385         }
1386
1387         class InternalType : TypeSpec, ITypeDefinition
1388         {
1389                 public static readonly InternalType AnonymousMethod = new InternalType ("anonymous method");
1390                 public static readonly InternalType Arglist = new InternalType ("__arglist");
1391                 public static readonly InternalType MethodGroup = new InternalType ("method group");
1392                 public static readonly InternalType NullLiteral = new InternalType ("null");
1393                 public static readonly InternalType FakeInternalType = new InternalType ("<fake$type>");
1394                 public static readonly InternalType Namespace = new InternalType ("<namespace>");
1395                 public static readonly InternalType ErrorType = new InternalType ("<error>");
1396
1397                 readonly string name;
1398
1399                 InternalType (string name)
1400                         : base (MemberKind.InternalCompilerType, null, null, null, Modifiers.PUBLIC)
1401                 {
1402                         this.name = name;
1403                         this.definition = this;
1404                         cache = MemberCache.Empty;
1405
1406                         // Make all internal types CLS-compliant, non-obsolete
1407                         state = (state & ~(StateFlags.CLSCompliant_Undetected | StateFlags.Obsolete_Undetected | StateFlags.MissingDependency_Undetected)) | StateFlags.CLSCompliant;
1408                 }
1409
1410                 #region Properties
1411
1412                 public override int Arity {
1413                         get {
1414                                 return 0;
1415                         }
1416                 }
1417
1418                 IAssemblyDefinition ITypeDefinition.DeclaringAssembly {
1419                         get {
1420                                 throw new NotImplementedException ();
1421                         }
1422                 }
1423
1424                 bool ITypeDefinition.IsComImport {
1425                         get {
1426                                 return false;
1427                         }
1428                 }
1429
1430                 bool IMemberDefinition.IsImported {
1431                         get {
1432                                 return false;
1433                         }
1434                 }
1435
1436                 bool ITypeDefinition.IsPartial {
1437                         get {
1438                                 return false;
1439                         }
1440                 }
1441
1442                 bool ITypeDefinition.IsTypeForwarder {
1443                         get {
1444                                 return false;
1445                         }
1446                 }
1447
1448                 public override string Name {
1449                         get {
1450                                 return name;
1451                         }
1452                 }
1453
1454                 string ITypeDefinition.Namespace {
1455                         get {
1456                                 return null;
1457                         }
1458                 }
1459
1460                 int ITypeDefinition.TypeParametersCount {
1461                         get {
1462                                 return 0;
1463                         }
1464                 }
1465
1466                 TypeParameterSpec[] ITypeDefinition.TypeParameters {
1467                         get {
1468                                 return null;
1469                         }
1470                 }
1471
1472                 #endregion
1473
1474                 public override string GetSignatureForError ()
1475                 {
1476                         return name;
1477                 }
1478
1479                 #region ITypeDefinition Members
1480
1481                 TypeSpec ITypeDefinition.GetAttributeCoClass ()
1482                 {
1483                         return null;
1484                 }
1485
1486                 string ITypeDefinition.GetAttributeDefaultMember ()
1487                 {
1488                         return null;
1489                 }
1490
1491                 AttributeUsageAttribute ITypeDefinition.GetAttributeUsage (PredefinedAttribute pa)
1492                 {
1493                         return null;
1494                 }
1495
1496                 bool ITypeDefinition.IsInternalAsPublic (IAssemblyDefinition assembly)
1497                 {
1498                         throw new NotImplementedException ();
1499                 }
1500
1501                 void ITypeDefinition.LoadMembers (TypeSpec declaringType, bool onlyTypes, ref MemberCache cache)
1502                 {
1503                         throw new NotImplementedException ();
1504                 }
1505
1506                 string[] IMemberDefinition.ConditionalConditions ()
1507                 {
1508                         return null;
1509                 }
1510
1511                 ObsoleteAttribute IMemberDefinition.GetAttributeObsolete ()
1512                 {
1513                         return null;
1514                 }
1515
1516                 bool? IMemberDefinition.CLSAttributeValue {
1517                         get {
1518                                 return null;
1519                         }
1520                 }
1521
1522                 void IMemberDefinition.SetIsAssigned ()
1523                 {
1524                 }
1525
1526                 void IMemberDefinition.SetIsUsed ()
1527                 {
1528                 }
1529
1530                 #endregion
1531         }
1532
1533         //
1534         // Common base class for composite types
1535         //
1536         public abstract class ElementTypeSpec : TypeSpec, ITypeDefinition
1537         {
1538                 protected ElementTypeSpec (MemberKind kind, TypeSpec element, MetaType info)
1539                         : base (kind, element.DeclaringType, null, info, element.Modifiers)
1540                 {
1541                         this.Element = element;
1542
1543                         state &= ~SharedStateFlags;
1544                         state |= (element.state & SharedStateFlags);
1545
1546                         if (element.BuiltinType == BuiltinTypeSpec.Type.Dynamic)
1547                                 state |= StateFlags.HasDynamicElement;
1548
1549                         // Has to use its own type definition instead of just element definition to
1550                         // correctly identify itself for cases like x.MemberDefininition == predefined.MemberDefinition
1551                         this.definition = this;
1552
1553                         cache = MemberCache.Empty;
1554                 }
1555
1556                 #region Properties
1557
1558                 public TypeSpec Element { get; private set; }
1559
1560                 bool ITypeDefinition.IsComImport {
1561                         get {
1562                                 return false;
1563                         }
1564                 }
1565
1566                 bool ITypeDefinition.IsPartial {
1567                         get {
1568                                 return false;
1569                         }
1570                 }
1571
1572                 bool ITypeDefinition.IsTypeForwarder {
1573                         get {
1574                                 return false;
1575                         }
1576                 }
1577
1578                 public override string Name {
1579                         get {
1580                                 throw new NotSupportedException ();
1581                         }
1582                 }
1583
1584                 #endregion
1585
1586                 public override ObsoleteAttribute GetAttributeObsolete ()
1587                 {
1588                         return Element.GetAttributeObsolete ();
1589                 }
1590
1591                 protected virtual string GetPostfixSignature ()
1592                 {
1593                         return null;
1594                 }
1595
1596                 public override string GetSignatureForDocumentation ()
1597                 {
1598                         return Element.GetSignatureForDocumentation () + GetPostfixSignature ();
1599                 }
1600
1601                 public override string GetSignatureForError ()
1602                 {
1603                         return Element.GetSignatureForError () + GetPostfixSignature ();
1604                 }
1605
1606                 public override TypeSpec Mutate (TypeParameterMutator mutator)
1607                 {
1608                         var me = Element.Mutate (mutator);
1609                         if (me == Element)
1610                                 return this;
1611
1612                         var mutated = (ElementTypeSpec) MemberwiseClone ();
1613                         mutated.Element = me;
1614                         mutated.info = null;
1615                         return mutated;
1616                 }
1617
1618                 #region ITypeDefinition Members
1619
1620                 IAssemblyDefinition ITypeDefinition.DeclaringAssembly {
1621                         get {
1622                                 return Element.MemberDefinition.DeclaringAssembly;
1623                         }
1624                 }
1625
1626                 bool ITypeDefinition.IsInternalAsPublic (IAssemblyDefinition assembly)
1627                 {
1628                         return Element.MemberDefinition.IsInternalAsPublic (assembly);
1629                 }
1630
1631                 public string Namespace {
1632                         get { throw new NotImplementedException (); }
1633                 }
1634
1635                 public int TypeParametersCount {
1636                         get {
1637                                 return 0;
1638                         }
1639                 }
1640
1641                 public TypeParameterSpec[] TypeParameters {
1642                         get {
1643                                 throw new NotSupportedException ();
1644                         }
1645                 }
1646
1647                 public TypeSpec GetAttributeCoClass ()
1648                 {
1649                         return Element.MemberDefinition.GetAttributeCoClass ();
1650                 }
1651
1652                 public string GetAttributeDefaultMember ()
1653                 {
1654                         return Element.MemberDefinition.GetAttributeDefaultMember ();
1655                 }
1656
1657                 public void LoadMembers (TypeSpec declaringType, bool onlyTypes, ref MemberCache cache)
1658                 {
1659                         Element.MemberDefinition.LoadMembers (declaringType, onlyTypes, ref cache);
1660                 }
1661
1662                 public bool IsImported {
1663                         get {
1664                                 return Element.MemberDefinition.IsImported;
1665                         }
1666                 }
1667
1668                 public string[] ConditionalConditions ()
1669                 {
1670                         return Element.MemberDefinition.ConditionalConditions ();
1671                 }
1672
1673                 bool? IMemberDefinition.CLSAttributeValue {
1674                         get {
1675                                 return Element.MemberDefinition.CLSAttributeValue;
1676                         }
1677                 }
1678
1679                 public void SetIsAssigned ()
1680                 {
1681                         Element.MemberDefinition.SetIsAssigned ();
1682                 }
1683
1684                 public void SetIsUsed ()
1685                 {
1686                         Element.MemberDefinition.SetIsUsed ();
1687                 }
1688
1689                 #endregion
1690         }
1691
1692         public class ArrayContainer : ElementTypeSpec
1693         {
1694                 public struct TypeRankPair : IEquatable<TypeRankPair>
1695                 {
1696                         TypeSpec ts;
1697                         int rank;
1698
1699                         public TypeRankPair (TypeSpec ts, int rank)
1700                         {
1701                                 this.ts = ts;
1702                                 this.rank = rank;
1703                         }
1704
1705                         public override int GetHashCode ()
1706                         {
1707                                 return ts.GetHashCode () ^ rank.GetHashCode ();
1708                         }
1709
1710                         #region IEquatable<Tuple<T1,T2>> Members
1711
1712                         public bool Equals (TypeRankPair other)
1713                         {
1714                                 return other.ts == ts && other.rank == rank;
1715                         }
1716
1717                         #endregion
1718                 }
1719
1720                 readonly int rank;
1721                 readonly ModuleContainer module;
1722
1723                 private ArrayContainer (ModuleContainer module, TypeSpec element, int rank)
1724                         : base (MemberKind.ArrayType, element, null)
1725                 {
1726                         this.module = module;
1727                         this.rank = rank;
1728                 }
1729
1730                 public int Rank {
1731                         get {
1732                                 return rank;
1733                         }
1734                 }
1735
1736                 public MethodInfo GetConstructor ()
1737                 {
1738                         var mb = module.Builder;
1739
1740                         var arg_types = new MetaType[rank];
1741                         for (int i = 0; i < rank; i++)
1742                                 arg_types[i] = module.Compiler.BuiltinTypes.Int.GetMetaInfo ();
1743
1744                         var ctor = mb.GetArrayMethod (
1745                                 GetMetaInfo (), Constructor.ConstructorName,
1746                                 CallingConventions.HasThis,
1747                                 null, arg_types);
1748
1749                         return ctor;
1750                 }
1751
1752                 public MethodInfo GetAddressMethod ()
1753                 {
1754                         var mb = module.Builder;
1755
1756                         var arg_types = new MetaType[rank];
1757                         for (int i = 0; i < rank; i++)
1758                                 arg_types[i] = module.Compiler.BuiltinTypes.Int.GetMetaInfo ();
1759
1760                         var address = mb.GetArrayMethod (
1761                                 GetMetaInfo (), "Address",
1762                                 CallingConventions.HasThis | CallingConventions.Standard,
1763                                 ReferenceContainer.MakeType (module, Element).GetMetaInfo (), arg_types);
1764
1765                         return address;
1766                 }
1767
1768                 public MethodInfo GetGetMethod ()
1769                 {
1770                         var mb = module.Builder;
1771
1772                         var arg_types = new MetaType[rank];
1773                         for (int i = 0; i < rank; i++)
1774                                 arg_types[i] = module.Compiler.BuiltinTypes.Int.GetMetaInfo ();
1775
1776                         var get = mb.GetArrayMethod (
1777                                 GetMetaInfo (), "Get",
1778                                 CallingConventions.HasThis | CallingConventions.Standard,
1779                                 Element.GetMetaInfo (), arg_types);
1780
1781                         return get;
1782                 }
1783
1784                 public MethodInfo GetSetMethod ()
1785                 {
1786                         var mb = module.Builder;
1787
1788                         var arg_types = new MetaType[rank + 1];
1789                         for (int i = 0; i < rank; i++)
1790                                 arg_types[i] = module.Compiler.BuiltinTypes.Int.GetMetaInfo ();
1791
1792                         arg_types[rank] = Element.GetMetaInfo ();
1793
1794                         var set = mb.GetArrayMethod (
1795                                 GetMetaInfo (), "Set",
1796                                 CallingConventions.HasThis | CallingConventions.Standard,
1797                                 module.Compiler.BuiltinTypes.Void.GetMetaInfo (), arg_types);
1798
1799                         return set;
1800                 }
1801
1802                 public override MetaType GetMetaInfo ()
1803                 {
1804                         if (info == null) {
1805                                 if (rank == 1)
1806                                         info = Element.GetMetaInfo ().MakeArrayType ();
1807                                 else
1808                                         info = Element.GetMetaInfo ().MakeArrayType (rank);
1809                         }
1810
1811                         return info;
1812                 }
1813
1814                 protected override string GetPostfixSignature()
1815                 {
1816                         return GetPostfixSignature (rank);
1817                 }
1818
1819                 public static string GetPostfixSignature (int rank)
1820                 {
1821                         StringBuilder sb = new StringBuilder ();
1822                         sb.Append ("[");
1823                         for (int i = 1; i < rank; i++) {
1824                                 sb.Append (",");
1825                         }
1826                         sb.Append ("]");
1827
1828                         return sb.ToString ();
1829                 }
1830
1831                 public override string GetSignatureForDocumentation ()
1832                 {
1833                         StringBuilder sb = new StringBuilder ();
1834                         GetElementSignatureForDocumentation (sb);
1835                         return sb.ToString ();
1836                 }
1837
1838                 void GetElementSignatureForDocumentation (StringBuilder sb)
1839                 {
1840                         var ac = Element as ArrayContainer;
1841                         if (ac == null)
1842                                 sb.Append (Element.GetSignatureForDocumentation ());
1843                         else
1844                                 ac.GetElementSignatureForDocumentation (sb);
1845
1846                         sb.Append ("[");
1847                         for (int i = 1; i < rank; i++) {
1848                                 if (i == 1)
1849                                         sb.Append ("0:");
1850
1851                                 sb.Append (",0:");
1852                         }
1853                         sb.Append ("]");
1854                 }
1855
1856                 public static ArrayContainer MakeType (ModuleContainer module, TypeSpec element)
1857                 {
1858                         return MakeType (module, element, 1);
1859                 }
1860
1861                 public static ArrayContainer MakeType (ModuleContainer module, TypeSpec element, int rank)
1862                 {
1863                         ArrayContainer ac;
1864                         var key = new TypeRankPair (element, rank);
1865                         if (!module.ArrayTypesCache.TryGetValue (key, out ac)) {
1866                                 ac = new ArrayContainer (module, element, rank);
1867                                 ac.BaseType = module.Compiler.BuiltinTypes.Array;
1868                                 ac.Interfaces = ac.BaseType.Interfaces;
1869
1870                                 module.ArrayTypesCache.Add (key, ac);
1871                         }
1872
1873                         return ac;
1874                 }
1875         }
1876
1877         class ReferenceContainer : ElementTypeSpec
1878         {
1879                 private ReferenceContainer (TypeSpec element)
1880                         : base (MemberKind.Class, element, null)        // TODO: Kind.Class is most likely wrong
1881                 {
1882                 }
1883
1884                 public override MetaType GetMetaInfo ()
1885                 {
1886                         if (info == null) {
1887                                 info = Element.GetMetaInfo ().MakeByRefType ();
1888                         }
1889
1890                         return info;
1891                 }
1892
1893                 public static ReferenceContainer MakeType (ModuleContainer module, TypeSpec element)
1894                 {
1895                         ReferenceContainer pc;
1896                         if (!module.ReferenceTypesCache.TryGetValue (element, out pc)) {
1897                                 pc = new ReferenceContainer (element);
1898                                 module.ReferenceTypesCache.Add (element, pc);
1899                         }
1900
1901                         return pc;
1902                 }
1903         }
1904
1905         class PointerContainer : ElementTypeSpec
1906         {
1907                 private PointerContainer (TypeSpec element)
1908                         : base (MemberKind.PointerType, element, null)
1909                 {
1910                         // It's never CLS-Compliant
1911                         state &= ~StateFlags.CLSCompliant_Undetected;
1912                 }
1913
1914                 public override MetaType GetMetaInfo ()
1915                 {
1916                         if (info == null) {
1917                                 info = Element.GetMetaInfo ().MakePointerType ();
1918                         }
1919
1920                         return info;
1921                 }
1922
1923                 protected override string GetPostfixSignature()
1924                 {
1925                         return "*";
1926                 }
1927
1928                 public static PointerContainer MakeType (ModuleContainer module, TypeSpec element)
1929                 {
1930                         PointerContainer pc;
1931                         if (!module.PointerTypesCache.TryGetValue (element, out pc)) {
1932                                 pc = new PointerContainer (element);
1933                                 module.PointerTypesCache.Add (element, pc);
1934                         }
1935
1936                         return pc;
1937                 }
1938         }
1939 }