mcs/mcs/decl.cs

   1 //
   2 // decl.cs: Declaration base class for structs, classes, enums and interfaces.
   3 //
   4 // Author: Miguel de Icaza (miguel@gnu.org)
   5 //         Marek Safar (marek.safar@seznam.cz)
   6 //
   7 // Dual licensed under the terms of the MIT X11 or GNU GPL
   8 //
   9 // Copyright 2001 Ximian, Inc (http://www.ximian.com)
  10 // Copyright 2004-2008 Novell, Inc
  11 //
  12 //
  13
  14 using System;
  15 using System.Text;
  16 using System.Collections.Generic;
  17 using System.Globalization;
  18 using System.Reflection.Emit;
  19 using System.Reflection;
  20
  21 #if NET_2_1
  22 using XmlElement = System.Object;
  23 #else
  24 using System.Xml;
  25 #endif
  26
  27 namespace Mono.CSharp {
  28
  29         //
  30         // Better name would be DottenName
  31         //
  32         public class MemberName {
  33                 public readonly string Name;
  34                 public TypeArguments TypeArguments;
  35
  36                 public readonly MemberName Left;
  37                 public readonly Location Location;
  38
  39                 public static readonly MemberName Null = new MemberName ("");
  40
  41                 bool is_double_colon;
  42
  43                 private MemberName (MemberName left, string name, bool is_double_colon,
  44                                     Location loc)
  45                 {
  46                         this.Name = name;
  47                         this.Location = loc;
  48                         this.is_double_colon = is_double_colon;
  49                         this.Left = left;
  50                 }
  51
  52                 private MemberName (MemberName left, string name, bool is_double_colon,
  53                                     TypeArguments args, Location loc)
  54                         : this (left, name, is_double_colon, loc)
  55                 {
  56                         if (args != null && args.Count > 0)
  57                                 this.TypeArguments = args;
  58                 }
  59
  60                 public MemberName (string name)
  61                         : this (name, Location.Null)
  62                 { }
  63
  64                 public MemberName (string name, Location loc)
  65                         : this (null, name, false, loc)
  66                 { }
  67
  68                 public MemberName (string name, TypeArguments args, Location loc)
  69                         : this (null, name, false, args, loc)
  70                 { }
  71
  72                 public MemberName (MemberName left, string name)
  73                         : this (left, name, left != null ? left.Location : Location.Null)
  74                 { }
  75
  76                 public MemberName (MemberName left, string name, Location loc)
  77                         : this (left, name, false, loc)
  78                 { }
  79
  80                 public MemberName (MemberName left, string name, TypeArguments args, Location loc)
  81                         : this (left, name, false, args, loc)
  82                 { }
  83
  84                 public MemberName (string alias, string name, TypeArguments args, Location loc)
  85                         : this (new MemberName (alias, loc), name, true, args, loc)
  86                 { }
  87
  88                 public MemberName (MemberName left, MemberName right)
  89                         : this (left, right, right.Location)
  90                 { }
  91
  92                 public MemberName (MemberName left, MemberName right, Location loc)
  93                         : this (null, right.Name, false, right.TypeArguments, loc)
  94                 {
  95                         if (right.is_double_colon)
  96                                 throw new InternalErrorException ("Cannot append double_colon member name");
  97                         this.Left = (right.Left == null) ? left : new MemberName (left, right.Left);
  98                 }
  99
 100                 // TODO: Remove
 101                 public string GetName ()
 102                 {
 103                         return GetName (false);
 104                 }
 105
 106                 public int Arity {
 107                         get {
 108                                 return TypeArguments == null ? 0 : TypeArguments.Count;
 109                         }
 110                 }
 111
 112                 public bool IsGeneric {
 113                         get {
 114                                 if (TypeArguments != null)
 115                                         return true;
 116                                 else if (Left != null)
 117                                         return Left.IsGeneric;
 118                                 else
 119                                         return false;
 120                         }
 121                 }
 122
 123                 public string GetName (bool is_generic)
 124                 {
 125                         string name = is_generic ? Basename : Name;
 126                         if (Left != null)
 127                                 return Left.GetName (is_generic) + (is_double_colon ? "::" : ".") + name;
 128
 129                         return name;
 130                 }
 131
 132                 public ATypeNameExpression GetTypeExpression ()
 133                 {
 134                         if (Left == null) {
 135                                 if (TypeArguments != null)
 136                                         return new SimpleName (Name, TypeArguments, Location);
 137
 138                                 return new SimpleName (Name, Location);
 139                         }
 140
 141                         if (is_double_colon) {
 142                                 if (Left.Left != null)
 143                                         throw new InternalErrorException ("The left side of a :: should be an identifier");
 144                                 return new QualifiedAliasMember (Left.Name, Name, TypeArguments, Location);
 145                         }
 146
 147                         Expression lexpr = Left.GetTypeExpression ();
 148                         return new MemberAccess (lexpr, Name, TypeArguments, Location);
 149                 }
 150
 151                 public MemberName Clone ()
 152                 {
 153                         MemberName left_clone = Left == null ? null : Left.Clone ();
 154                         return new MemberName (left_clone, Name, is_double_colon, TypeArguments, Location);
 155                 }
 156
 157                 public string Basename {
 158                         get {
 159                                 if (TypeArguments != null)
 160                                         return MakeName (Name, TypeArguments);
 161                                 return Name;
 162                         }
 163                 }
 164
 165                 public string GetSignatureForError ()
 166                 {
 167                         string append = TypeArguments == null ? "" : "<" + TypeArguments.GetSignatureForError () + ">";
 168                         if (Left == null)
 169                                 return Name + append;
 170                         string connect = is_double_colon ? "::" : ".";
 171                         return Left.GetSignatureForError () + connect + Name + append;
 172                 }
 173
 174                 public override bool Equals (object other)
 175                 {
 176                         return Equals (other as MemberName);
 177                 }
 178
 179                 public bool Equals (MemberName other)
 180                 {
 181                         if (this == other)
 182                                 return true;
 183                         if (other == null || Name != other.Name)
 184                                 return false;
 185                         if (is_double_colon != other.is_double_colon)
 186                                 return false;
 187
 188                         if ((TypeArguments != null) &&
 189                             (other.TypeArguments == null || TypeArguments.Count != other.TypeArguments.Count))
 190                                 return false;
 191
 192                         if ((TypeArguments == null) && (other.TypeArguments != null))
 193                                 return false;
 194
 195                         if (Left == null)
 196                                 return other.Left == null;
 197
 198                         return Left.Equals (other.Left);
 199                 }
 200
 201                 public override int GetHashCode ()
 202                 {
 203                         int hash = Name.GetHashCode ();
 204                         for (MemberName n = Left; n != null; n = n.Left)
 205                                 hash ^= n.Name.GetHashCode ();
 206                         if (is_double_colon)
 207                                 hash ^= 0xbadc01d;
 208
 209                         if (TypeArguments != null)
 210                                 hash ^= TypeArguments.Count << 5;
 211
 212                         return hash & 0x7FFFFFFF;
 213                 }
 214
 215                 public int CountTypeArguments {
 216                         get {
 217                                 if (TypeArguments != null)
 218                                         return TypeArguments.Count;
 219                                 else if (Left != null)
 220                                         return Left.CountTypeArguments;
 221                                 else
 222                                         return 0;
 223                         }
 224                 }
 225
 226                 public static string MakeName (string name, TypeArguments args)
 227                 {
 228                         if (args == null)
 229                                 return name;
 230
 231                         return name + "`" + args.Count;
 232                 }
 233
 234                 public static string MakeName (string name, int count)
 235                 {
 236                         return name + "`" + count;
 237                 }
 238         }
 239
 240         public class SimpleMemberName
 241         {
 242                 public string Value;
 243                 public Location Location;
 244
 245                 public SimpleMemberName (string name, Location loc)
 246                 {
 247                         this.Value = name;
 248                         this.Location = loc;
 249                 }
 250         }
 251
 252         /// <summary>
 253         ///   Base representation for members.  This is used to keep track
 254         ///   of Name, Location and Modifier flags, and handling Attributes.
 255         /// </summary>
 256         [System.Diagnostics.DebuggerDisplay ("{GetSignatureForError()}")]
 257         public abstract class MemberCore : Attributable, IMemberContext, IMemberDefinition
 258         {
 259                 /// <summary>
 260                 ///   Public name
 261                 /// </summary>
 262
 263                 protected string cached_name;
 264                 // TODO: Remove in favor of MemberName
 265                 public string Name {
 266                         get {
 267                                 if (cached_name == null)
 268                                         cached_name = MemberName.GetName (!(this is GenericMethod) && !(this is Method));
 269                                 return cached_name;
 270                         }
 271                 }
 272
 273                 string IMemberDefinition.Name {
 274                         get {
 275                                 return member_name.Name;
 276                         }
 277                 }
 278
 279                 // Is not readonly because of IndexerName attribute
 280                 private MemberName member_name;
 281                 public MemberName MemberName {
 282                         get { return member_name; }
 283                 }
 284
 285                 /// <summary>
 286                 ///   Modifier flags that the user specified in the source code
 287                 /// </summary>
 288                 private Modifiers mod_flags;
 289                 public Modifiers ModFlags {
 290                         set {
 291                                 mod_flags = value;
 292                                 if ((value & Modifiers.COMPILER_GENERATED) != 0)
 293                                         caching_flags = Flags.IsUsed | Flags.IsAssigned;
 294                         }
 295                         get {
 296                                 return mod_flags;
 297                         }
 298                 }
 299
 300                 public /*readonly*/ TypeContainer Parent;
 301
 302                 /// <summary>
 303                 ///   Location where this declaration happens
 304                 /// </summary>
 305                 public Location Location {
 306                         get { return member_name.Location; }
 307                 }
 308
 309                 /// <summary>
 310                 ///   XML documentation comment
 311                 /// </summary>
 312                 protected string comment;
 313
 314                 /// <summary>
 315                 ///   Represents header string for documentation comment
 316                 ///   for each member types.
 317                 /// </summary>
 318                 public abstract string DocCommentHeader { get; }
 319
 320                 [Flags]
 321                 public enum Flags {
 322                         Obsolete_Undetected = 1,                // Obsolete attribute has not been detected yet
 323                         Obsolete = 1 << 1,                      // Type has obsolete attribute
 324                         ClsCompliance_Undetected = 1 << 2,      // CLS Compliance has not been detected yet
 325                         ClsCompliant = 1 << 3,                  // Type is CLS Compliant
 326                         CloseTypeCreated = 1 << 4,              // Tracks whether we have Closed the type
 327                         HasCompliantAttribute_Undetected = 1 << 5,      // Presence of CLSCompliantAttribute has not been detected
 328                         HasClsCompliantAttribute = 1 << 6,                      // Type has CLSCompliantAttribute
 329                         ClsCompliantAttributeFalse = 1 << 7,                    // Member has CLSCompliant(false)
 330                         Excluded_Undetected = 1 << 8,           // Conditional attribute has not been detected yet
 331                         Excluded = 1 << 9,                                      // Method is conditional
 332                         MethodOverloadsExist = 1 << 10,         // Test for duplication must be performed
 333                         IsUsed = 1 << 11,
 334                         IsAssigned = 1 << 12,                           // Field is assigned
 335                         HasExplicitLayout       = 1 << 13,
 336                         PartialDefinitionExists = 1 << 14,      // Set when corresponding partial method definition exists
 337                         HasStructLayout         = 1 << 15                       // Has StructLayoutAttribute
 338                 }
 339
 340                 /// <summary>
 341                 ///   MemberCore flags at first detected then cached
 342                 /// </summary>
 343                 internal Flags caching_flags;
 344
 345                 public MemberCore (DeclSpace parent, MemberName name, Attributes attrs)
 346                 {
 347                         this.Parent = parent as TypeContainer;
 348                         member_name = name;
 349                         caching_flags = Flags.Obsolete_Undetected | Flags.ClsCompliance_Undetected | Flags.HasCompliantAttribute_Undetected | Flags.Excluded_Undetected;
 350                         AddAttributes (attrs, this);
 351                 }
 352
 353                 public virtual Assembly Assembly {
 354                         get { return Parent.Module.Assembly; }
 355                 }
 356
 357                 protected virtual void SetMemberName (MemberName new_name)
 358                 {
 359                         member_name = new_name;
 360                         cached_name = null;
 361                 }
 362
 363                 protected bool CheckAbstractAndExtern (bool has_block)
 364                 {
 365                         if (Parent.PartialContainer.Kind == MemberKind.Interface)
 366                                 return true;
 367
 368                         if (has_block) {
 369                                 if ((ModFlags & Modifiers.EXTERN) != 0) {
 370                                         Report.Error (179, Location, "`{0}' cannot declare a body because it is marked extern",
 371                                                 GetSignatureForError ());
 372                                         return false;
 373                                 }
 374
 375                                 if ((ModFlags & Modifiers.ABSTRACT) != 0) {
 376                                         Report.Error (500, Location, "`{0}' cannot declare a body because it is marked abstract",
 377                                                 GetSignatureForError ());
 378                                         return false;
 379                                 }
 380                         } else {
 381                                 if ((ModFlags & (Modifiers.ABSTRACT | Modifiers.EXTERN | Modifiers.PARTIAL)) == 0 && !(Parent is Delegate)) {
 382                                         if (RootContext.Version >= LanguageVersion.V_3) {
 383                                                 Property.PropertyMethod pm = this as Property.PropertyMethod;
 384                                                 if (pm is Indexer.GetIndexerMethod || pm is Indexer.SetIndexerMethod)
 385                                                         pm = null;
 386
 387                                                 if (pm != null && pm.Property.AccessorSecond == null) {
 388                                                         Report.Error (840, Location,
 389                                                                 "`{0}' must have a body because it is not marked abstract or extern. The property can be automatically implemented when you define both accessors",
 390                                                                 GetSignatureForError ());
 391                                                         return false;
 392                                                 }
 393                                         }
 394
 395                                         Report.Error (501, Location, "`{0}' must have a body because it is not marked abstract, extern, or partial",
 396                                                       GetSignatureForError ());
 397                                         return false;
 398                                 }
 399                         }
 400
 401                         return true;
 402                 }
 403
 404                 protected void CheckProtectedModifier ()
 405                 {
 406                         if ((ModFlags & Modifiers.PROTECTED) == 0)
 407                                 return;
 408
 409                         if (Parent.PartialContainer.Kind == MemberKind.Struct) {
 410                                 Report.Error (666, Location, "`{0}': Structs cannot contain protected members",
 411                                         GetSignatureForError ());
 412                                 return;
 413                         }
 414
 415                         if ((Parent.ModFlags & Modifiers.STATIC) != 0) {
 416                                 Report.Error (1057, Location, "`{0}': Static classes cannot contain protected members",
 417                                         GetSignatureForError ());
 418                                 return;
 419                         }
 420
 421                         if ((Parent.ModFlags & Modifiers.SEALED) != 0 && (ModFlags & Modifiers.OVERRIDE) == 0 &&
 422                                 !(this is Destructor)) {
 423                                 Report.Warning (628, 4, Location, "`{0}': new protected member declared in sealed class",
 424                                         GetSignatureForError ());
 425                                 return;
 426                         }
 427                 }
 428
 429                 public abstract bool Define ();
 430
 431                 public virtual string DocComment {
 432                         get {
 433                                 return comment;
 434                         }
 435                         set {
 436                                 comment = value;
 437                         }
 438                 }
 439
 440                 //
 441                 // Returns full member name for error message
 442                 //
 443                 public virtual string GetSignatureForError ()
 444                 {
 445                         if (Parent == null || Parent.Parent == null)
 446                                 return member_name.GetSignatureForError ();
 447
 448                         return Parent.GetSignatureForError () + "." + member_name.GetSignatureForError ();
 449                 }
 450
 451                 /// <summary>
 452                 /// Base Emit method. This is also entry point for CLS-Compliant verification.
 453                 /// </summary>
 454                 public virtual void Emit ()
 455                 {
 456                         if (!RootContext.VerifyClsCompliance)
 457                                 return;
 458
 459                         VerifyClsCompliance ();
 460                 }
 461
 462                 public bool IsCompilerGenerated {
 463                         get     {
 464                                 if ((mod_flags & Modifiers.COMPILER_GENERATED) != 0)
 465                                         return true;
 466
 467                                 return Parent == null ? false : Parent.IsCompilerGenerated;
 468                         }
 469                 }
 470
 471                 public bool IsImported {
 472                         get {
 473                                 return false;
 474                         }
 475                 }
 476
 477                 public virtual bool IsUsed {
 478                         get {
 479                                 return (caching_flags & Flags.IsUsed) != 0;
 480                         }
 481                 }
 482
 483                 protected Report Report {
 484                         get {
 485                                 return Compiler.Report;
 486                         }
 487                 }
 488
 489                 public void SetIsUsed ()
 490                 {
 491                         caching_flags |= Flags.IsUsed;
 492                 }
 493
 494                 public void SetIsAssigned ()
 495                 {
 496                         caching_flags |= Flags.IsAssigned;
 497                 }
 498
 499                 /// <summary>
 500                 /// Returns instance of ObsoleteAttribute for this MemberCore
 501                 /// </summary>
 502                 public virtual ObsoleteAttribute GetAttributeObsolete ()
 503                 {
 504                         if ((caching_flags & (Flags.Obsolete_Undetected | Flags.Obsolete)) == 0)
 505                                 return null;
 506
 507                         caching_flags &= ~Flags.Obsolete_Undetected;
 508
 509                         if (OptAttributes == null)
 510                                 return null;
 511
 512                         Attribute obsolete_attr = OptAttributes.Search (PredefinedAttributes.Get.Obsolete);
 513                         if (obsolete_attr == null)
 514                                 return null;
 515
 516                         caching_flags |= Flags.Obsolete;
 517
 518                         ObsoleteAttribute obsolete = obsolete_attr.GetObsoleteAttribute ();
 519                         if (obsolete == null)
 520                                 return null;
 521
 522                         return obsolete;
 523                 }
 524
 525                 /// <summary>
 526                 /// Checks for ObsoleteAttribute presence. It's used for testing of all non-types elements
 527                 /// </summary>
 528                 public virtual void CheckObsoleteness (Location loc)
 529                 {
 530                         ObsoleteAttribute oa = GetAttributeObsolete ();
 531                         if (oa != null)
 532                                 AttributeTester.Report_ObsoleteMessage (oa, GetSignatureForError (), loc, Report);
 533                 }
 534
 535                 //
 536                 // Checks whether the type P is as accessible as this member
 537                 //
 538                 public bool IsAccessibleAs (TypeSpec p)
 539                 {
 540                         //
 541                         // if M is private, its accessibility is the same as this declspace.
 542                         // we already know that P is accessible to T before this method, so we
 543                         // may return true.
 544                         //
 545                         if ((mod_flags & Modifiers.PRIVATE) != 0)
 546                                 return true;
 547
 548                         while (TypeManager.HasElementType (p))
 549                                 p = TypeManager.GetElementType (p);
 550
 551                         if (p.IsGenericParameter)
 552                                 return true;
 553
 554                         for (TypeSpec p_parent; p != null; p = p_parent) {
 555                                 p_parent = p.DeclaringType;
 556
 557                                 if (p.IsGeneric) {
 558                                         foreach (TypeSpec t in p.TypeArguments) {
 559                                                 if (!IsAccessibleAs (t))
 560                                                         return false;
 561                                         }
 562                                 }
 563
 564                                 var pAccess = p.Modifiers & Modifiers.AccessibilityMask;
 565                                 if (pAccess == Modifiers.PUBLIC)
 566                                         continue;
 567
 568                                 bool same_access_restrictions = false;
 569                                 for (MemberCore mc = this; !same_access_restrictions && mc != null && mc.Parent != null; mc = mc.Parent) {
 570                                         var al = mc.ModFlags & Modifiers.AccessibilityMask;
 571                                         switch (pAccess) {
 572                                         case Modifiers.INTERNAL:
 573                                                 if (al == Modifiers.PRIVATE || al == Modifiers.INTERNAL)
 574                                                         same_access_restrictions = TypeManager.IsThisOrFriendAssembly (Parent.Module.Assembly, p.Assembly);
 575
 576                                                 break;
 577
 578                                         case Modifiers.PROTECTED:
 579                                                 if (al == Modifiers.PROTECTED) {
 580                                                         same_access_restrictions = mc.Parent.IsBaseTypeDefinition (p_parent);
 581                                                         break;
 582                                                 }
 583
 584                                                 if (al == Modifiers.PRIVATE) {
 585                                                         //
 586                                                         // When type is private and any of its parents derives from
 587                                                         // protected type then the type is accessible
 588                                                         //
 589                                                         while (mc.Parent != null) {
 590                                                                 if (mc.Parent.IsBaseTypeDefinition (p_parent))
 591                                                                         same_access_restrictions = true;
 592                                                                 mc = mc.Parent;
 593                                                         }
 594                                                 }
 595
 596                                                 break;
 597
 598                                         case Modifiers.PROTECTED | Modifiers.INTERNAL:
 599                                                 if (al == Modifiers.INTERNAL)
 600                                                         same_access_restrictions = TypeManager.IsThisOrFriendAssembly (Parent.Module.Assembly, p.Assembly);
 601                                                 else if (al == Modifiers.PROTECTED)
 602                                                         same_access_restrictions = mc.Parent.IsBaseTypeDefinition (p_parent);
 603                                                 else if (al == (Modifiers.PROTECTED | Modifiers.INTERNAL))
 604                                                         same_access_restrictions = mc.Parent.IsBaseTypeDefinition (p_parent) &&
 605                                                                 TypeManager.IsThisOrFriendAssembly (Parent.Module.Assembly, p.Assembly);
 606                                                 break;
 607
 608                                         case Modifiers.PRIVATE:
 609                                                 //
 610                                                 // Both are private and share same parent
 611                                                 //
 612                                                 if (al == Modifiers.PRIVATE) {
 613                                                         var decl = mc.Parent;
 614                                                         do {
 615                                                                 same_access_restrictions = decl.CurrentType == p_parent;
 616                                                         } while (!same_access_restrictions && !decl.IsTopLevel && (decl = decl.Parent) != null);
 617                                                 }
 618
 619                                                 break;
 620
 621                                         default:
 622                                                 throw new InternalErrorException (al.ToString ());
 623                                         }
 624                                 }
 625
 626                                 if (!same_access_restrictions)
 627                                         return false;
 628                         }
 629
 630                         return true;
 631                 }
 632
 633                 /// <summary>
 634                 /// Analyze whether CLS-Compliant verification must be execute for this MemberCore.
 635                 /// </summary>
 636                 public override bool IsClsComplianceRequired ()
 637                 {
 638                         if ((caching_flags & Flags.ClsCompliance_Undetected) == 0)
 639                                 return (caching_flags & Flags.ClsCompliant) != 0;
 640
 641                         caching_flags &= ~Flags.ClsCompliance_Undetected;
 642
 643                         if (HasClsCompliantAttribute) {
 644                                 if ((caching_flags & Flags.ClsCompliantAttributeFalse) != 0)
 645                                         return false;
 646
 647                                 caching_flags |= Flags.ClsCompliant;
 648                                 return true;
 649                         }
 650
 651                         if (Parent.PartialContainer.IsClsComplianceRequired ()) {
 652                                 caching_flags |= Flags.ClsCompliant;
 653                                 return true;
 654                         }
 655
 656                         return false;
 657                 }
 658
 659                 public virtual string[] ConditionalConditions ()
 660                 {
 661                         return null;
 662                 }
 663
 664                 /// <summary>
 665                 /// Returns true when MemberCore is exposed from assembly.
 666                 /// </summary>
 667                 public bool IsExposedFromAssembly ()
 668                 {
 669                         if ((ModFlags & (Modifiers.PUBLIC | Modifiers.PROTECTED)) == 0)
 670                                 return false;
 671
 672                         DeclSpace parentContainer = Parent.PartialContainer;
 673                         while (parentContainer != null && parentContainer.ModFlags != 0) {
 674                                 if ((parentContainer.ModFlags & (Modifiers.PUBLIC | Modifiers.PROTECTED)) == 0)
 675                                         return false;
 676                                 parentContainer = parentContainer.Parent;
 677                         }
 678                         return true;
 679                 }
 680
 681                 public virtual ExtensionMethodGroupExpr LookupExtensionMethod (TypeSpec extensionType, string name, int arity, Location loc)
 682                 {
 683                         return Parent.LookupExtensionMethod (extensionType, name, arity, loc);
 684                 }
 685
 686                 public virtual FullNamedExpression LookupNamespaceAlias (string name)
 687                 {
 688                         return Parent.NamespaceEntry.LookupNamespaceAlias (name);
 689                 }
 690
 691                 public virtual FullNamedExpression LookupNamespaceOrType (string name, int arity, Location loc, bool ignore_cs0104)
 692                 {
 693                         return Parent.LookupNamespaceOrType (name, arity, loc, ignore_cs0104);
 694                 }
 695
 696                 /// <summary>
 697                 /// Goes through class hierarchy and gets value of first found CLSCompliantAttribute.
 698                 /// If no is attribute exists then assembly CLSCompliantAttribute is returned.
 699                 /// </summary>
 700                 public bool IsNotCLSCompliant ()
 701                 {
 702                         if ((caching_flags & Flags.HasCompliantAttribute_Undetected) == 0)
 703                                 return (caching_flags & Flags.ClsCompliantAttributeFalse) != 0;
 704
 705                         caching_flags &= ~Flags.HasCompliantAttribute_Undetected;
 706
 707                         if (OptAttributes != null) {
 708                                 Attribute cls_attribute = OptAttributes.Search (PredefinedAttributes.Get.CLSCompliant);
 709                                 if (cls_attribute != null) {
 710                                         caching_flags |= Flags.HasClsCompliantAttribute;
 711                                         if (cls_attribute.GetClsCompliantAttributeValue ())
 712                                                 return false;
 713
 714                                         caching_flags |= Flags.ClsCompliantAttributeFalse;
 715                                         return true;
 716                                 }
 717                         }
 718
 719                         return false;
 720                 }
 721
 722                 /// <summary>
 723                 /// Returns true if MemberCore is explicitly marked with CLSCompliantAttribute
 724                 /// </summary>
 725                 protected bool HasClsCompliantAttribute {
 726                         get {
 727                                 if ((caching_flags & Flags.HasCompliantAttribute_Undetected) != 0)
 728                                         IsNotCLSCompliant ();
 729
 730                                 return (caching_flags & Flags.HasClsCompliantAttribute) != 0;
 731                         }
 732                 }
 733
 734                 /// <summary>
 735                 /// Returns true when a member supports multiple overloads (methods, indexers, etc)
 736                 /// </summary>
 737                 public virtual bool EnableOverloadChecks (MemberCore overload)
 738                 {
 739                         return false;
 740                 }
 741
 742                 /// <summary>
 743                 /// The main virtual method for CLS-Compliant verifications.
 744                 /// The method returns true if member is CLS-Compliant and false if member is not
 745                 /// CLS-Compliant which means that CLS-Compliant tests are not necessary. A descendants override it
 746                 /// and add their extra verifications.
 747                 /// </summary>
 748                 protected virtual bool VerifyClsCompliance ()
 749                 {
 750                         if (HasClsCompliantAttribute) {
 751                                 if (CodeGen.Assembly.ClsCompliantAttribute == null) {
 752                                         Attribute a = OptAttributes.Search (PredefinedAttributes.Get.CLSCompliant);
 753                                         if ((caching_flags & Flags.ClsCompliantAttributeFalse) != 0) {
 754                                                 Report.Warning (3021, 2, a.Location,
 755                                                         "`{0}' does not need a CLSCompliant attribute because the assembly is not marked as CLS-compliant",
 756                                                         GetSignatureForError ());
 757                                         } else {
 758                                                 Report.Warning (3014, 1, a.Location,
 759                                                         "`{0}' cannot be marked as CLS-compliant because the assembly is not marked as CLS-compliant",
 760                                                         GetSignatureForError ());
 761                                         }
 762                                         return false;
 763                                 }
 764
 765                                 if (!IsExposedFromAssembly ()) {
 766                                         Attribute a = OptAttributes.Search (PredefinedAttributes.Get.CLSCompliant);
 767                                         Report.Warning (3019, 2, a.Location, "CLS compliance checking will not be performed on `{0}' because it is not visible from outside this assembly", GetSignatureForError ());
 768                                         return false;
 769                                 }
 770
 771                                 if ((caching_flags & Flags.ClsCompliantAttributeFalse) != 0) {
 772                                         if (Parent.Kind == MemberKind.Interface && Parent.IsClsComplianceRequired ()) {
 773                                                 Report.Warning (3010, 1, Location, "`{0}': CLS-compliant interfaces must have only CLS-compliant members", GetSignatureForError ());
 774                                         } else if (Parent.Kind == MemberKind.Class && (ModFlags & Modifiers.ABSTRACT) != 0 && Parent.IsClsComplianceRequired ()) {
 775                                                 Report.Warning (3011, 1, Location, "`{0}': only CLS-compliant members can be abstract", GetSignatureForError ());
 776                                         }
 777
 778                                         return false;
 779                                 }
 780
 781                                 if (Parent.Parent != null && !Parent.IsClsComplianceRequired ()) {
 782                                         Attribute a = OptAttributes.Search (PredefinedAttributes.Get.CLSCompliant);
 783                                         Report.Warning (3018, 1, a.Location, "`{0}' cannot be marked as CLS-compliant because it is a member of non CLS-compliant type `{1}'",
 784                                                 GetSignatureForError (), Parent.GetSignatureForError ());
 785                                         return false;
 786                                 }
 787                         } else {
 788                                 if (!IsExposedFromAssembly ())
 789                                         return false;
 790
 791                                 if (!Parent.PartialContainer.IsClsComplianceRequired ())
 792                                         return false;
 793                         }
 794
 795                         if (member_name.Name [0] == '_') {
 796                                 Report.Warning (3008, 1, Location, "Identifier `{0}' is not CLS-compliant", GetSignatureForError () );
 797                         }
 798
 799                         return true;
 800                 }
 801
 802                 //
 803                 // Raised (and passed an XmlElement that contains the comment)
 804                 // when GenerateDocComment is writing documentation expectedly.
 805                 //
 806                 internal virtual void OnGenerateDocComment (XmlElement intermediateNode)
 807                 {
 808                 }
 809
 810                 //
 811                 // Returns a string that represents the signature for this
 812                 // member which should be used in XML documentation.
 813                 //
 814                 public virtual string GetDocCommentName (DeclSpace ds)
 815                 {
 816                         if (ds == null || this is DeclSpace)
 817                                 return DocCommentHeader + Name;
 818                         else
 819                                 return String.Concat (DocCommentHeader, ds.Name, ".", Name);
 820                 }
 821
 822                 //
 823                 // Generates xml doc comments (if any), and if required,
 824                 // handle warning report.
 825                 //
 826                 internal virtual void GenerateDocComment (DeclSpace ds)
 827                 {
 828                         try {
 829                                 DocUtil.GenerateDocComment (this, ds, Report);
 830                         } catch (Exception e) {
 831                                 throw new InternalErrorException (this, e);
 832                         }
 833                 }
 834
 835                 #region IMemberContext Members
 836
 837                 public virtual CompilerContext Compiler {
 838                         get { return Parent.Compiler; }
 839                 }
 840
 841                 public virtual TypeSpec CurrentType {
 842                         get { return Parent.CurrentType; }
 843                 }
 844
 845                 public MemberCore CurrentMemberDefinition {
 846                         get { return this; }
 847                 }
 848
 849                 public virtual TypeParameter[] CurrentTypeParameters {
 850                         get { return null; }
 851                 }
 852
 853                 public virtual bool HasUnresolvedConstraints {
 854                         get { return false; }
 855                 }
 856
 857                 public bool IsObsolete {
 858                         get {
 859                                 if (GetAttributeObsolete () != null)
 860                                         return true;
 861
 862                                 return Parent == null ? false : Parent.IsObsolete;
 863                         }
 864                 }
 865
 866                 public bool IsUnsafe {
 867                         get {
 868                                 if ((ModFlags & Modifiers.UNSAFE) != 0)
 869                                         return true;
 870
 871                                 return Parent == null ? false : Parent.IsUnsafe;
 872                         }
 873                 }
 874
 875                 public bool IsStatic {
 876                         get {
 877                                 return (ModFlags & Modifiers.STATIC) != 0;
 878                         }
 879                 }
 880
 881                 #endregion
 882         }
 883
 884         //
 885         // Base member specification. A member specification contains
 886         // member details which can alter in the context (e.g. generic instances)
 887         //
 888         public abstract class MemberSpec
 889         {
 890                 [Flags]
 891                 protected enum StateFlags
 892                 {
 893                         Obsolete_Undetected = 1,        // Obsolete attribute has not been detected yet
 894                         Obsolete = 1 << 1,                      // Member has obsolete attribute
 895                         CLSCompliant_Undetected = 1 << 3,       // CLSCompliant attribute has not been detected yet
 896                         CLSCompliant = 1 << 4,          // Member is CLS Compliant
 897
 898                         IsAccessor = 1 << 9,            // Method is an accessor
 899                         IsGeneric = 1 << 10,            // Member contains type arguments
 900
 901                         PendingMetaInflate = 1 << 12,
 902                         PendingMakeMethod = 1 << 13,
 903                         PendingMemberCacheMembers = 1 << 14,
 904                         PendingBaseTypeInflate = 1 << 15,
 905                         InterfacesExpanded = 1 << 16,
 906                         IsNotRealProperty = 1 << 17,
 907                 }
 908
 909                 protected Modifiers modifiers;
 910                 protected StateFlags state;
 911                 protected IMemberDefinition definition;
 912                 public readonly MemberKind Kind;
 913                 protected TypeSpec declaringType;
 914
 915 #if DEBUG
 916                 static int counter;
 917                 public int ID = counter++;
 918 #endif
 919
 920                 protected MemberSpec (MemberKind kind, TypeSpec declaringType, IMemberDefinition definition, Modifiers modifiers)
 921                 {
 922                         this.Kind = kind;
 923                         this.declaringType = declaringType;
 924                         this.definition = definition;
 925                         this.modifiers = modifiers;
 926
 927                         state = StateFlags.Obsolete_Undetected | StateFlags.CLSCompliant_Undetected;
 928                 }
 929
 930                 #region Properties
 931
 932                 public Assembly Assembly {
 933                         get {
 934                                 return definition.Assembly;
 935                         }
 936                 }
 937
 938                 public virtual int Arity {
 939                         get {
 940                                 return 0;
 941                         }
 942                 }
 943
 944                 public TypeSpec DeclaringType {
 945                         get {
 946                                 return declaringType;
 947                         }
 948                         set {
 949                                 declaringType = value;
 950                         }
 951                 }
 952
 953                 public IMemberDefinition MemberDefinition {
 954                         get {
 955                                 return definition;
 956                         }
 957                 }
 958
 959                 public Modifiers Modifiers {
 960                         get {
 961                                 return modifiers;
 962                         }
 963                         set {
 964                                 modifiers = value;
 965                         }
 966                 }
 967
 968                 public virtual string Name {
 969                         get {
 970                                 return definition.Name;
 971                         }
 972                 }
 973
 974                 public bool IsAbstract {
 975                         get { return (modifiers & Modifiers.ABSTRACT) != 0; }
 976                 }
 977
 978                 public bool IsAccessor {
 979                         get {
 980                                 return (state & StateFlags.IsAccessor) != 0;
 981                         }
 982                         set {
 983                                 state = value ? state | StateFlags.IsAccessor : state & ~StateFlags.IsAccessor;
 984                         }
 985                 }
 986
 987                 //
 988                 // Return true when this member is a generic in C# terms
 989                 // A nested non-generic type of generic type will return false
 990                 //
 991                 public bool IsGeneric {
 992                         get {
 993                                 return (state & StateFlags.IsGeneric) != 0;
 994                         }
 995                         set {
 996                                 state = value ? state | StateFlags.IsGeneric : state & ~StateFlags.IsGeneric;
 997                         }
 998                 }
 999
1000                 public bool IsPrivate {
1001                         get { return (modifiers & Modifiers.PRIVATE) != 0; }
1002                 }
1003
1004                 public bool IsPublic {
1005                         get { return (modifiers & Modifiers.PUBLIC) != 0; }
1006                 }
1007
1008                 public bool IsStatic {
1009                         get {
1010                                 return (modifiers & Modifiers.STATIC) != 0;
1011                         }
1012                 }
1013
1014                 #endregion
1015
1016                 public virtual ObsoleteAttribute GetAttributeObsolete ()
1017                 {
1018                         if ((state & (StateFlags.Obsolete | StateFlags.Obsolete_Undetected)) == 0)
1019                                 return null;
1020
1021                         state &= ~StateFlags.Obsolete_Undetected;
1022
1023                         var oa = definition.GetAttributeObsolete ();
1024                         if (oa != null)
1025                                 state |= StateFlags.Obsolete;
1026
1027                         return oa;
1028                 }
1029
1030                 protected virtual bool IsNotCLSCompliant ()
1031                 {
1032                         return MemberDefinition.IsNotCLSCompliant ();
1033                 }
1034
1035                 public virtual string GetSignatureForError ()
1036                 {
1037                         var bf = MemberDefinition as Property.BackingField;
1038                         var name = bf == null ? Name : bf.OriginalName;
1039                         return DeclaringType.GetSignatureForError () + "." + name;
1040                 }
1041
1042                 public virtual MemberSpec InflateMember (TypeParameterInflator inflator)
1043                 {
1044                         var inflated = (MemberSpec) MemberwiseClone ();
1045                         inflated.declaringType = inflator.TypeInstance;
1046                         inflated.state |= StateFlags.PendingMetaInflate;
1047 #if DEBUG
1048                         if (inflated.ID > 0)
1049                                 inflated.ID = -inflated.ID;
1050 #endif
1051                         return inflated;
1052                 }
1053
1054                 //
1055                 // Is this member accessible from invocationType
1056                 //
1057                 public bool IsAccessible (TypeSpec invocationType)
1058                 {
1059                         var ma = Modifiers & Modifiers.AccessibilityMask;
1060                         if (ma == Modifiers.PUBLIC)
1061                                 return true;
1062
1063                         var parentType = /* this as TypeSpec ?? */ DeclaringType;
1064
1065                         //
1066                         // If only accessible to the current class or children
1067                         //
1068                         if (ma == Modifiers.PRIVATE)
1069                                 return invocationType.MemberDefinition == parentType.MemberDefinition ||
1070                                         TypeManager.IsNestedChildOf (invocationType, parentType);
1071
1072                         if ((ma & Modifiers.INTERNAL) != 0) {
1073                                 var b = TypeManager.IsThisOrFriendAssembly (invocationType == InternalType.FakeInternalType ?
1074                                          CodeGen.Assembly.Builder : invocationType.Assembly, parentType.Assembly);
1075                                 if (b || ma == Modifiers.INTERNAL)
1076                                         return b;
1077                         }
1078
1079                         // PROTECTED
1080                         if (!TypeManager.IsNestedFamilyAccessible (invocationType, parentType))
1081                                 return false;
1082
1083                         return true;
1084                 }
1085
1086                 //
1087                 // Returns member CLS compliance based on full member hierarchy
1088                 //
1089                 public bool IsCLSCompliant ()
1090                 {
1091                         if ((state & StateFlags.CLSCompliant_Undetected) != 0) {
1092                                 state &= ~StateFlags.CLSCompliant_Undetected;
1093
1094                                 if (IsNotCLSCompliant ())
1095                                         return false;
1096
1097                                 bool compliant;
1098                                 if (DeclaringType != null) {
1099                                         compliant = DeclaringType.IsCLSCompliant ();
1100                                 } else {
1101                                         // TODO: NEED AssemblySpec
1102                                         if (MemberDefinition.IsImported) {
1103                                                 var attr = MemberDefinition.Assembly.GetCustomAttributes (typeof (CLSCompliantAttribute), false);
1104                                                 compliant = attr.Length > 0 && ((CLSCompliantAttribute) attr[0]).IsCompliant;
1105                                         } else {
1106                                                 compliant = CodeGen.Assembly.IsClsCompliant;
1107                                         }
1108                                 }
1109
1110                                 if (compliant)
1111                                         state |= StateFlags.CLSCompliant;
1112                         }
1113
1114                         return (state & StateFlags.CLSCompliant) != 0;
1115                 }
1116
1117                 public bool IsConditionallyExcluded (Location loc)
1118                 {
1119                         if ((Kind & (MemberKind.Class | MemberKind.Method)) == 0)
1120                                 return false;
1121
1122                         var conditions = MemberDefinition.ConditionalConditions ();
1123                         if (conditions == null)
1124                                 return false;
1125
1126                         foreach (var condition in conditions) {
1127                                 if (loc.CompilationUnit.IsConditionalDefined (condition))
1128                                         return false;
1129                         }
1130
1131                         return true;
1132                 }
1133
1134                 public override string ToString ()
1135                 {
1136                         return GetSignatureForError ();
1137                 }
1138         }
1139
1140         //
1141         // Member details which are same between all member
1142         // specifications
1143         //
1144         public interface IMemberDefinition
1145         {
1146                 Assembly Assembly { get; }
1147                 string Name { get; }
1148                 bool IsImported { get; }
1149
1150                 string[] ConditionalConditions ();
1151                 ObsoleteAttribute GetAttributeObsolete ();
1152                 bool IsNotCLSCompliant ();
1153                 void SetIsAssigned ();
1154                 void SetIsUsed ();
1155         }
1156
1157         public interface IParametersMember : IInterfaceMemberSpec
1158         {
1159                 AParametersCollection Parameters { get; }
1160         }
1161
1162         public interface IInterfaceMemberSpec
1163         {
1164                 TypeSpec MemberType { get; }
1165         }
1166
1167         //
1168         // Base type container declaration. It exists to handle partial types
1169         // which share same definition (PartialContainer) but have different
1170         // resolve scopes
1171         //
1172         public abstract class DeclSpace : MemberCore {
1173                 /// <summary>
1174                 ///   This points to the actual definition that is being
1175                 ///   created with System.Reflection.Emit
1176                 /// </summary>
1177                 public TypeBuilder TypeBuilder;
1178
1179                 //
1180                 // This is the namespace in which this typecontainer
1181                 // was declared.  We use this to resolve names.
1182                 //
1183                 public NamespaceEntry NamespaceEntry;
1184
1185                 private Dictionary<string, FullNamedExpression> Cache = new Dictionary<string, FullNamedExpression> ();
1186
1187                 public readonly string Basename;
1188
1189                 protected Dictionary<string, MemberCore> defined_names;
1190
1191                 public TypeContainer PartialContainer;
1192
1193                 protected readonly bool is_generic;
1194                 readonly int count_type_params;
1195                 protected TypeParameter[] type_params;
1196                 TypeParameter[] type_param_list;
1197
1198                 //
1199                 // Whether we are Generic
1200                 //
1201                 public bool IsGeneric {
1202                         get {
1203                                 if (is_generic)
1204                                         return true;
1205                                 else if (Parent != null)
1206                                         return Parent.IsGeneric;
1207                                 else
1208                                         return false;
1209                         }
1210                 }
1211
1212                 static string[] attribute_targets = new string [] { "type" };
1213
1214                 public DeclSpace (NamespaceEntry ns, DeclSpace parent, MemberName name,
1215                                   Attributes attrs)
1216                         : base (parent, name, attrs)
1217                 {
1218                         NamespaceEntry = ns;
1219                         Basename = name.Basename;
1220                         defined_names = new Dictionary<string, MemberCore> ();
1221                         PartialContainer = null;
1222                         if (name.TypeArguments != null) {
1223                                 is_generic = true;
1224                                 count_type_params = name.TypeArguments.Count;
1225                         }
1226                         if (parent != null)
1227                                 count_type_params += parent.count_type_params;
1228                 }
1229
1230                 /// <summary>
1231                 /// Adds the member to defined_names table. It tests for duplications and enclosing name conflicts
1232                 /// </summary>
1233                 protected virtual bool AddToContainer (MemberCore symbol, string name)
1234                 {
1235                         MemberCore mc;
1236                         if (!defined_names.TryGetValue (name, out mc)) {
1237                                 defined_names.Add (name, symbol);
1238                                 return true;
1239                         }
1240
1241                         if (((mc.ModFlags | symbol.ModFlags) & Modifiers.COMPILER_GENERATED) != 0)
1242                                 return true;
1243
1244                         if (symbol.EnableOverloadChecks (mc))
1245                                 return true;
1246
1247                         InterfaceMemberBase im = mc as InterfaceMemberBase;
1248                         if (im != null && im.IsExplicitImpl)
1249                                 return true;
1250
1251                         Report.SymbolRelatedToPreviousError (mc);
1252                         if ((mc.ModFlags & Modifiers.PARTIAL) != 0 && (symbol is ClassOrStruct || symbol is Interface)) {
1253                                 Error_MissingPartialModifier (symbol);
1254                                 return false;
1255                         }
1256
1257                         if (this is ModuleContainer) {
1258                                 Report.Error (101, symbol.Location,
1259                                         "The namespace `{0}' already contains a definition for `{1}'",
1260                                         ((DeclSpace)symbol).NamespaceEntry.GetSignatureForError (), symbol.MemberName.Name);
1261                         } else if (symbol is TypeParameter) {
1262                                 Report.Error (692, symbol.Location,
1263                                         "Duplicate type parameter `{0}'", symbol.GetSignatureForError ());
1264                         } else {
1265                                 Report.Error (102, symbol.Location,
1266                                               "The type `{0}' already contains a definition for `{1}'",
1267                                               GetSignatureForError (), symbol.MemberName.Name);
1268                         }
1269
1270                         return false;
1271                 }
1272
1273                 protected void RemoveFromContainer (string name)
1274                 {
1275                         defined_names.Remove (name);
1276                 }
1277
1278                 /// <summary>
1279                 ///   Returns the MemberCore associated with a given name in the declaration
1280                 ///   space. It doesn't return method based symbols !!
1281                 /// </summary>
1282                 ///
1283                 public MemberCore GetDefinition (string name)
1284                 {
1285                         MemberCore mc = null;
1286                         defined_names.TryGetValue (name, out mc);
1287                         return mc;
1288                 }
1289
1290                 //
1291                 // root_types contains all the types.  All TopLevel types
1292                 // hence have a parent that points to `root_types', that is
1293                 // why there is a non-obvious test down here.
1294                 //
1295                 public bool IsTopLevel {
1296                         get { return (Parent != null && Parent.Parent == null); }
1297                 }
1298
1299                 public virtual bool IsUnmanagedType ()
1300                 {
1301                         return false;
1302                 }
1303
1304                 protected virtual TypeAttributes TypeAttr {
1305                         get { return Module.DefaultCharSetType; }
1306                 }
1307
1308                 /// <remarks>
1309                 ///  Should be overriten by the appropriate declaration space
1310                 /// </remarks>
1311                 public abstract TypeBuilder DefineType ();
1312
1313                 protected void Error_MissingPartialModifier (MemberCore type)
1314                 {
1315                         Report.Error (260, type.Location,
1316                                 "Missing partial modifier on declaration of type `{0}'. Another partial declaration of this type exists",
1317                                 type.GetSignatureForError ());
1318                 }
1319
1320                 public override string GetSignatureForError ()
1321                 {
1322                         return MemberName.GetSignatureForError ();
1323                 }
1324
1325                 public bool CheckAccessLevel (TypeSpec check_type)
1326                 {
1327 // TODO: Use this instead
1328 //                      return PartialContainer.Definition.IsAccessible (check_type);
1329
1330                         TypeSpec tb = PartialContainer.Definition;
1331                         check_type = check_type.GetDefinition ();
1332
1333                         var check_attr = check_type.Modifiers & Modifiers.AccessibilityMask;
1334
1335                         switch (check_attr){
1336                         case Modifiers.PUBLIC:
1337                                 return true;
1338
1339                         case Modifiers.INTERNAL:
1340                                 return TypeManager.IsThisOrFriendAssembly (Assembly, check_type.Assembly);
1341
1342                         case Modifiers.PRIVATE:
1343                                 TypeSpec declaring = check_type.DeclaringType;
1344                                 return tb == declaring.GetDefinition () || TypeManager.IsNestedChildOf (tb, declaring);
1345
1346                         case Modifiers.PROTECTED:
1347                                 //
1348                                 // Only accessible to methods in current type or any subtypes
1349                                 //
1350                                 return TypeManager.IsNestedFamilyAccessible (tb, check_type.DeclaringType);
1351
1352                         case Modifiers.PROTECTED | Modifiers.INTERNAL:
1353                                 if (TypeManager.IsThisOrFriendAssembly (Assembly, check_type.Assembly))
1354                                         return true;
1355
1356                                 goto case Modifiers.PROTECTED;
1357                         }
1358
1359                         throw new NotImplementedException (check_attr.ToString ());
1360                 }
1361
1362                 private TypeSpec LookupNestedTypeInHierarchy (string name, int arity)
1363                 {
1364                         // TODO: GenericMethod only
1365                         if (PartialContainer == null)
1366                                 return null;
1367
1368                         // Has any nested type
1369                         // Does not work, because base type can have
1370                         //if (PartialContainer.Types == null)
1371                         //      return null;
1372
1373                         var container = PartialContainer.CurrentType;
1374
1375                         // Is not Root container
1376                         if (container == null)
1377                                 return null;
1378
1379                         var     t = MemberCache.FindNestedType (container, name, arity);
1380                         if (t == null)
1381                                 return null;
1382
1383                         // FIXME: Breaks error reporting
1384                         if (!t.IsAccessible (CurrentType))
1385                                 return null;
1386
1387                         return t;
1388                 }
1389
1390                 //
1391                 // Public function used to locate types.
1392                 //
1393                 // Set 'ignore_cs0104' to true if you want to ignore cs0104 errors.
1394                 //
1395                 // Returns: Type or null if they type can not be found.
1396                 //
1397                 public override FullNamedExpression LookupNamespaceOrType (string name, int arity, Location loc, bool ignore_cs0104)
1398                 {
1399                         FullNamedExpression e;
1400                         if (arity == 0 && Cache.TryGetValue (name, out e))
1401                                 return e;
1402
1403                         e = null;
1404                         int errors = Report.Errors;
1405
1406                         if (arity == 0) {
1407                                 TypeParameter[] tp = CurrentTypeParameters;
1408                                 if (tp != null) {
1409                                         TypeParameter tparam = TypeParameter.FindTypeParameter (tp, name);
1410                                         if (tparam != null)
1411                                                 e = new TypeParameterExpr (tparam, Location.Null);
1412                                 }
1413                         }
1414
1415                         if (e == null) {
1416                                 TypeSpec t = LookupNestedTypeInHierarchy (name, arity);
1417
1418                                 if (t != null)
1419                                         e = new TypeExpression (t, Location.Null);
1420                                 else if (Parent != null)
1421                                         e = Parent.LookupNamespaceOrType (name, arity, loc, ignore_cs0104);
1422                                 else
1423                                         e = NamespaceEntry.LookupNamespaceOrType (name, arity, loc, ignore_cs0104);
1424                         }
1425
1426                         // TODO MemberCache: How to cache arity stuff ?
1427                         if (errors == Report.Errors && arity == 0)
1428                                 Cache [name] = e;
1429
1430                         return e;
1431                 }
1432
1433                 public override Assembly Assembly {
1434                         get { return Module.Assembly; }
1435                 }
1436
1437                 public virtual ModuleContainer Module {
1438                         get { return Parent.Module; }
1439                 }
1440
1441                 TypeParameter[] initialize_type_params ()
1442                 {
1443                         if (type_param_list != null)
1444                                 return type_param_list;
1445
1446                         DeclSpace the_parent = Parent;
1447                         if (this is GenericMethod)
1448                                 the_parent = null;
1449
1450                         var list = new List<TypeParameter> ();
1451                         if (the_parent != null && the_parent.IsGeneric) {
1452                                 // FIXME: move generics info out of DeclSpace
1453                                 TypeParameter[] parent_params = the_parent.TypeParameters;
1454                                 list.AddRange (parent_params);
1455                         }
1456
1457                         int count = type_params != null ? type_params.Length : 0;
1458                         for (int i = 0; i < count; i++) {
1459                                 TypeParameter param = type_params [i];
1460                                 list.Add (param);
1461                                 if (Parent.CurrentTypeParameters != null) {
1462                                         foreach (TypeParameter tp in Parent.CurrentTypeParameters) {
1463                                                 if (tp.Name != param.Name)
1464                                                         continue;
1465
1466                                                 Report.SymbolRelatedToPreviousError (tp.Location, null);
1467                                                 Report.Warning (693, 3, param.Location,
1468                                                         "Type parameter `{0}' has the same name as the type parameter from outer type `{1}'",
1469                                                         param.Name, Parent.GetSignatureForError ());
1470                                         }
1471                                 }
1472                         }
1473
1474                         type_param_list = new TypeParameter [list.Count];
1475                         list.CopyTo (type_param_list, 0);
1476                         return type_param_list;
1477                 }
1478
1479                 public virtual void SetParameterInfo (List<Constraints> constraints_list)
1480                 {
1481                         if (!is_generic) {
1482                                 if (constraints_list != null) {
1483                                         Report.Error (
1484                                                 80, Location, "Constraints are not allowed " +
1485                                                 "on non-generic declarations");
1486                                 }
1487
1488                                 return;
1489                         }
1490
1491                         TypeParameterName[] names = MemberName.TypeArguments.GetDeclarations ();
1492                         type_params = new TypeParameter [names.Length];
1493
1494                         //
1495                         // Register all the names
1496                         //
1497                         for (int i = 0; i < type_params.Length; i++) {
1498                                 TypeParameterName name = names [i];
1499
1500                                 Constraints constraints = null;
1501                                 if (constraints_list != null) {
1502                                         int total = constraints_list.Count;
1503                                         for (int ii = 0; ii < total; ++ii) {
1504                                                 Constraints constraints_at = (Constraints)constraints_list[ii];
1505                                                 // TODO: it is used by iterators only
1506                                                 if (constraints_at == null) {
1507                                                         constraints_list.RemoveAt (ii);
1508                                                         --total;
1509                                                         continue;
1510                                                 }
1511                                                 if (constraints_at.TypeParameter.Value == name.Name) {
1512                                                         constraints = constraints_at;
1513                                                         constraints_list.RemoveAt(ii);
1514                                                         break;
1515                                                 }
1516                                         }
1517                                 }
1518
1519                                 Variance variance = name.Variance;
1520                                 if (name.Variance != Variance.None && !(this is Delegate || this is Interface)) {
1521                                         Report.Error (1960, name.Location, "Variant type parameters can only be used with interfaces and delegates");
1522                                         variance = Variance.None;
1523                                 }
1524
1525                                 type_params [i] = new TypeParameter (
1526                                         Parent, i, new MemberName (name.Name, Location), constraints, name.OptAttributes, variance);
1527
1528                                 AddToContainer (type_params [i], name.Name);
1529                         }
1530
1531                         if (constraints_list != null && constraints_list.Count > 0) {
1532                                 foreach (Constraints constraint in constraints_list) {
1533                                         Report.Error(699, constraint.Location, "`{0}': A constraint references nonexistent type parameter `{1}'",
1534                                                 GetSignatureForError (), constraint.TypeParameter.Value);
1535                                 }
1536                         }
1537                 }
1538
1539                 protected TypeParameter[] TypeParameters {
1540                         get {
1541                                 if (!IsGeneric)
1542                                         throw new InvalidOperationException ();
1543                                 if ((PartialContainer != null) && (PartialContainer != this))
1544                                         return PartialContainer.TypeParameters;
1545                                 if (type_param_list == null)
1546                                         initialize_type_params ();
1547
1548                                 return type_param_list;
1549                         }
1550                 }
1551
1552                 public int CountTypeParameters {
1553                         get {
1554                                 return count_type_params;
1555                         }
1556                 }
1557
1558                 public override string[] ValidAttributeTargets {
1559                         get { return attribute_targets; }
1560                 }
1561
1562                 protected override bool VerifyClsCompliance ()
1563                 {
1564                         if (!base.VerifyClsCompliance ()) {
1565                                 return false;
1566                         }
1567
1568                         if (type_params != null) {
1569                                 foreach (TypeParameter tp in type_params) {
1570                                         tp.VerifyClsCompliance ();
1571                                 }
1572                         }
1573
1574                         return true;
1575                 }
1576         }
1577 }