mcs/gmcs/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 //
   6 // Licensed under the terms of the GNU GPL
   7 //
   8 // (C) 2001 Ximian, Inc (http://www.ximian.com)
   9 //
  10 // TODO: Move the method verification stuff from the class.cs and interface.cs here
  11 //
  12
  13 using System;
  14 using System.Text;
  15 using System.Collections;
  16 using System.Reflection.Emit;
  17 using System.Reflection;
  18
  19 namespace Mono.CSharp {
  20
  21         public class MemberName {
  22                 public readonly string Name;
  23                 public readonly TypeArguments TypeArguments;
  24
  25                 public readonly MemberName Left;
  26
  27                 public static readonly MemberName Null = new MemberName ("");
  28
  29                 public MemberName (string name)
  30                 {
  31                         this.Name = name;
  32                 }
  33
  34                 public MemberName (string name, TypeArguments args)
  35                         : this (name)
  36                 {
  37                         this.TypeArguments = args;
  38                 }
  39
  40                 public MemberName (MemberName left, string name, TypeArguments args)
  41                         : this (name, args)
  42                 {
  43                         this.Left = left;
  44                 }
  45
  46                 public string GetName ()
  47                 {
  48                         if (Left != null)
  49                                 return Left.GetName () + "." + Name;
  50                         else
  51                                 return Name;
  52                 }
  53
  54                 public int CountTypeArguments {
  55                         get {
  56                                 if (TypeArguments == null)
  57                                         return 0;
  58                                 else
  59                                         return TypeArguments.Count;
  60                         }
  61                 }
  62
  63                 public string GetFullName ()
  64                 {
  65                         string full_name;
  66                         if (TypeArguments != null)
  67                                 full_name = Name + "<" + TypeArguments + ">";
  68                         else
  69                                 full_name = Name;
  70                         if (Left != null)
  71                                 return Left.GetFullName () + "." + full_name;
  72                         else
  73                                 return full_name;
  74                 }
  75
  76                 public string GetMemberName ()
  77                 {
  78                         string full_name;
  79                         if (Left != null)
  80                                 return Left.GetFullName () + "." + Name;
  81                         else
  82                                 return Name;
  83                 }
  84
  85                 public Expression GetTypeExpression (Location loc)
  86                 {
  87                         if (Left != null) {
  88                                 Expression lexpr = Left.GetTypeExpression (loc);
  89
  90                                 if (TypeArguments != null)
  91                                         return new GenericMemberAccess (lexpr, Name, TypeArguments, loc);
  92                                 else
  93                                         return new MemberAccess (lexpr, Name, loc);
  94                         } else {
  95                                 if (TypeArguments != null)
  96                                         return new ConstructedType (Name, TypeArguments, loc);
  97                                 else
  98                                         return new SimpleName (Name, loc);
  99                         }
 100                 }
 101
 102                 public override string ToString ()
 103                 {
 104                         string full_name;
 105                         if (TypeArguments != null)
 106                                 full_name = Name + "<" + TypeArguments + ">";
 107                         else
 108                                 full_name = Name;
 109
 110                         if (Left != null)
 111                                 return Left + "." + full_name;
 112                         else
 113                                 return full_name;
 114                 }
 115         }
 116
 117         /// <summary>
 118         ///   Base representation for members.  This is only used to keep track
 119         ///   of Name, Location and Modifier flags.
 120         /// </summary>
 121         public abstract class MemberCore {
 122                 /// <summary>
 123                 ///   Public name
 124                 /// </summary>
 125                 public string Name;
 126
 127                 /// <summary>
 128                 ///   Modifier flags that the user specified in the source code
 129                 /// </summary>
 130                 public int ModFlags;
 131
 132                 /// <summary>
 133                 ///   Location where this declaration happens
 134                 /// </summary>
 135                 public readonly Location Location;
 136
 137                 /// <summary>
 138                 ///   Attributes for this type
 139                 /// </summary>
 140                 Attributes attributes;
 141
 142                 public MemberCore (string name, Attributes attrs, Location loc)
 143                 {
 144                         Name = name;
 145                         Location = loc;
 146                         attributes = attrs;
 147                 }
 148
 149                 public abstract bool Define (TypeContainer parent);
 150
 151                 //
 152                 // Returns full member name for error message
 153                 //
 154                 public virtual string GetSignatureForError () {
 155                         return Name;
 156                 }
 157
 158                 public Attributes OptAttributes
 159                 {
 160                         get {
 161                                 return attributes;
 162                         }
 163                         set {
 164                                 attributes = value;
 165                         }
 166                 }
 167
 168                 //
 169                 // Whehter is it ok to use an unsafe pointer in this type container
 170                 //
 171                 public bool UnsafeOK (DeclSpace parent)
 172                 {
 173                         //
 174                         // First check if this MemberCore modifier flags has unsafe set
 175                         //
 176                         if ((ModFlags & Modifiers.UNSAFE) != 0)
 177                                 return true;
 178
 179                         if (parent.UnsafeContext)
 180                                 return true;
 181
 182                         Expression.UnsafeError (Location);
 183                         return false;
 184                 }
 185         }
 186
 187         /// <summary>
 188         ///   Base class for structs, classes, enumerations and interfaces.
 189         /// </summary>
 190         /// <remarks>
 191         ///   They all create new declaration spaces.  This
 192         ///   provides the common foundation for managing those name
 193         ///   spaces.
 194         /// </remarks>
 195         public abstract class DeclSpace : MemberCore, IAlias {
 196                 /// <summary>
 197                 ///   This points to the actual definition that is being
 198                 ///   created with System.Reflection.Emit
 199                 /// </summary>
 200                 public TypeBuilder TypeBuilder;
 201
 202                 /// <summary>
 203                 ///   If we are a generic type, this is the type we are
 204                 ///   currently defining.  We need to lookup members on this
 205                 ///   instead of the TypeBuilder.
 206                 /// </summary>
 207                 public TypeExpr CurrentType;
 208
 209                 /// <summary>
 210                 ///   This variable tracks whether we have Closed the type
 211                 /// </summary>
 212                 public bool Created = false;
 213
 214                 //
 215                 // This is the namespace in which this typecontainer
 216                 // was declared.  We use this to resolve names.
 217                 //
 218                 public NamespaceEntry NamespaceEntry;
 219
 220                 public Hashtable Cache = new Hashtable ();
 221
 222                 public string Basename;
 223
 224                 /// <summary>
 225                 ///   defined_names is used for toplevel objects
 226                 /// </summary>
 227                 protected Hashtable defined_names;
 228
 229                 bool is_generic;
 230
 231                 //
 232                 // Whether we are Generic
 233                 //
 234                 public bool IsGeneric {
 235                         get {
 236                                 if (is_generic)
 237                                         return true;
 238                                 else if (parent != null)
 239                                         return parent.IsGeneric;
 240                                 else
 241                                         return false;
 242                         }
 243                 }
 244
 245                 TypeContainer parent;
 246
 247                 public DeclSpace (NamespaceEntry ns, TypeContainer parent, string name, Attributes attrs, Location l)
 248                         : base (name, attrs, l)
 249                 {
 250                         NamespaceEntry = ns;
 251                         Basename = name.Substring (1 + name.LastIndexOf ('.'));
 252                         defined_names = new Hashtable ();
 253                         this.parent = parent;
 254                 }
 255
 256                 public void RecordDecl ()
 257                 {
 258                         if ((NamespaceEntry != null) && (parent == RootContext.Tree.Types))
 259                                 NamespaceEntry.DefineName (Basename, this);
 260                 }
 261
 262                 /// <summary>
 263                 ///   The result value from adding an declaration into
 264                 ///   a struct or a class
 265                 /// </summary>
 266                 public enum AdditionResult {
 267                         /// <summary>
 268                         /// The declaration has been successfully
 269                         /// added to the declation space.
 270                         /// </summary>
 271                         Success,
 272
 273                         /// <summary>
 274                         ///   The symbol has already been defined.
 275                         /// </summary>
 276                         NameExists,
 277
 278                         /// <summary>
 279                         ///   Returned if the declation being added to the
 280                         ///   name space clashes with its container name.
 281                         ///
 282                         ///   The only exceptions for this are constructors
 283                         ///   and static constructors
 284                         /// </summary>
 285                         EnclosingClash,
 286
 287                         /// <summary>
 288                         ///   Returned if a constructor was created (because syntactically
 289                         ///   it looked like a constructor) but was not (because the name
 290                         ///   of the method is not the same as the container class
 291                         /// </summary>
 292                         NotAConstructor,
 293
 294                         /// <summary>
 295                         ///   This is only used by static constructors to emit the
 296                         ///   error 111, but this error for other things really
 297                         ///   happens at another level for other functions.
 298                         /// </summary>
 299                         MethodExists,
 300
 301                         /// <summary>
 302                         ///   Some other error.
 303                         /// </summary>
 304                         Error
 305                 }
 306
 307                 /// <summary>
 308                 ///   Returns a status code based purely on the name
 309                 ///   of the member being added
 310                 /// </summary>
 311                 protected AdditionResult IsValid (string basename, string name)
 312                 {
 313                         if (basename == Basename)
 314                                 return AdditionResult.EnclosingClash;
 315
 316                         if (defined_names.Contains (name))
 317                                 return AdditionResult.NameExists;
 318
 319                         return AdditionResult.Success;
 320                 }
 321
 322                 public static int length;
 323                 public static int small;
 324
 325                 /// <summary>
 326                 ///   Introduce @name into this declaration space and
 327                 ///   associates it with the object @o.  Note that for
 328                 ///   methods this will just point to the first method. o
 329                 /// </summary>
 330                 public void DefineName (string name, object o)
 331                 {
 332                         defined_names.Add (name, o);
 333
 334 #if DEBUGME
 335                         int p = name.LastIndexOf ('.');
 336                         int l = name.Length;
 337                         length += l;
 338                         small += l -p;
 339 #endif
 340                 }
 341
 342                 /// <summary>
 343                 ///   Returns the object associated with a given name in the declaration
 344                 ///   space.  This is the inverse operation of `DefineName'
 345                 /// </summary>
 346                 public object GetDefinition (string name)
 347                 {
 348                         return defined_names [name];
 349                 }
 350
 351                 bool in_transit = false;
 352
 353                 /// <summary>
 354                 ///   This function is used to catch recursive definitions
 355                 ///   in declarations.
 356                 /// </summary>
 357                 public bool InTransit {
 358                         get {
 359                                 return in_transit;
 360                         }
 361
 362                         set {
 363                                 in_transit = value;
 364                         }
 365                 }
 366
 367                 public TypeContainer Parent {
 368                         get {
 369                                 return parent;
 370                         }
 371                 }
 372
 373                 /// <summary>
 374                 ///   Looks up the alias for the name
 375                 /// </summary>
 376                 public IAlias LookupAlias (string name)
 377                 {
 378                         if (NamespaceEntry != null)
 379                                 return NamespaceEntry.LookupAlias (name);
 380                         else
 381                                 return null;
 382                 }
 383
 384                 //
 385                 // root_types contains all the types.  All TopLevel types
 386                 // hence have a parent that points to `root_types', that is
 387                 // why there is a non-obvious test down here.
 388                 //
 389                 public bool IsTopLevel {
 390                         get {
 391                                 if (parent != null){
 392                                         if (parent.parent == null)
 393                                                 return true;
 394                                 }
 395                                 return false;
 396                         }
 397                 }
 398
 399                 public virtual void CloseType ()
 400                 {
 401                         if (!Created){
 402                                 try {
 403                                         TypeBuilder.CreateType ();
 404                                 } catch {
 405                                         //
 406                                         // The try/catch is needed because
 407                                         // nested enumerations fail to load when they
 408                                         // are defined.
 409                                         //
 410                                         // Even if this is the right order (enumerations
 411                                         // declared after types).
 412                                         //
 413                                         // Note that this still creates the type and
 414                                         // it is possible to save it
 415                                 }
 416                                 Created = true;
 417                         }
 418                 }
 419
 420                 /// <remarks>
 421                 ///  Should be overriten by the appropriate declaration space
 422                 /// </remarks>
 423                 public abstract TypeBuilder DefineType ();
 424
 425                 /// <summary>
 426                 ///   Define all members, but don't apply any attributes or do anything which may
 427                 ///   access not-yet-defined classes.  This method also creates the MemberCache.
 428                 /// </summary>
 429                 public abstract bool DefineMembers (TypeContainer parent);
 430
 431                 //
 432                 // Whether this is an `unsafe context'
 433                 //
 434                 public bool UnsafeContext {
 435                         get {
 436                                 if ((ModFlags & Modifiers.UNSAFE) != 0)
 437                                         return true;
 438                                 if (parent != null)
 439                                         return parent.UnsafeContext;
 440                                 return false;
 441                         }
 442                 }
 443
 444                 public static string MakeFQN (string nsn, string name)
 445                 {
 446                         if (nsn == "")
 447                                 return name;
 448                         return String.Concat (nsn, ".", name);
 449                 }
 450
 451                 EmitContext type_resolve_ec;
 452                 EmitContext GetTypeResolveEmitContext (TypeContainer parent, Location loc)
 453                 {
 454                         type_resolve_ec = new EmitContext (parent, this, loc, null, null, ModFlags, false);
 455                         type_resolve_ec.ResolvingTypeTree = true;
 456
 457                         return type_resolve_ec;
 458                 }
 459
 460                 // <summary>
 461                 //    Looks up the type, as parsed into the expression `e'
 462                 // </summary>
 463                 public Type ResolveType (Expression e, bool silent, Location loc)
 464                 {
 465                         TypeExpr d = ResolveTypeExpr (e, silent, loc);
 466                         if (d == null)
 467                                 return null;
 468
 469                         return ResolveType (d, loc);
 470                 }
 471
 472                 public Type ResolveType (TypeExpr d, Location loc)
 473                 {
 474                         if (!d.CheckAccessLevel (this)) {
 475                                 Report. Error (122, loc,  "`" + d.Name + "' " +
 476                                        "is inaccessible because of its protection level");
 477                                 return null;
 478                         }
 479
 480                         Type t = d.ResolveType (type_resolve_ec);
 481                         if (t == null)
 482                                 return null;
 483
 484                         TypeContainer tc = TypeManager.LookupTypeContainer (t);
 485                         if ((tc != null) && tc.IsGeneric) {
 486                                 if (!IsGeneric) {
 487                                         int tnum = TypeManager.GetNumberOfTypeArguments (t);
 488                                         Report.Error (305, loc,
 489                                                       "Using the generic type `{0}' " +
 490                                                       "requires {1} type arguments",
 491                                                       TypeManager.GetFullName (t), tnum);
 492                                         return null;
 493                                 }
 494
 495                                 ConstructedType ctype = new ConstructedType (
 496                                         t, TypeParameters, loc);
 497
 498                                 t = ctype.ResolveType (type_resolve_ec);
 499                         }
 500
 501                         return t;
 502                 }
 503
 504                 // <summary>
 505                 //    Resolves the expression `e' for a type, and will recursively define
 506                 //    types.
 507                 // </summary>
 508                 public TypeExpr ResolveTypeExpr (Expression e, bool silent, Location loc)
 509                 {
 510                         if (type_resolve_ec == null)
 511                                 type_resolve_ec = GetTypeResolveEmitContext (parent, loc);
 512                         type_resolve_ec.loc = loc;
 513                         if (this is GenericMethod)
 514                                 type_resolve_ec.ContainerType = Parent.TypeBuilder;
 515                         else
 516                                 type_resolve_ec.ContainerType = TypeBuilder;
 517
 518                         int errors = Report.Errors;
 519
 520                         TypeExpr d = e.ResolveAsTypeTerminal (type_resolve_ec);
 521
 522                         if ((d != null) && (d.eclass == ExprClass.Type))
 523                                 return d;
 524
 525                         if (silent || (Report.Errors != errors))
 526                                 return null;
 527
 528                         if (e is SimpleName){
 529                                 SimpleName s = new SimpleName (((SimpleName) e).Name, -1, loc);
 530                                 d = s.ResolveAsTypeTerminal (type_resolve_ec);
 531
 532                                 if ((d == null) || (d.Type == null)) {
 533                                         Report.Error (246, loc, "Cannot find type `{0}'", e);
 534                                         return null;
 535                                 }
 536
 537                                 int num_args = TypeManager.GetNumberOfTypeArguments (d.Type);
 538
 539                                 if (num_args == 0) {
 540                                         Report.Error (308, loc,
 541                                                       "The non-generic type `{0}' cannot " +
 542                                                       "be used with type arguments.",
 543                                                       TypeManager.CSharpName (d.Type));
 544                                         return null;
 545                                 }
 546
 547                                 Report.Error (305, loc,
 548                                               "Using the generic type `{0}' " +
 549                                               "requires {1} type arguments",
 550                                               TypeManager.GetFullName (d.Type), num_args);
 551                                 return null;
 552                         }
 553
 554                         Report.Error (246, loc, "Cannot find type `{0}'", e);
 555                         return null;
 556                 }
 557
 558                 public bool CheckAccessLevel (Type check_type)
 559                 {
 560                         TypeBuilder tb;
 561                         if (this is GenericMethod)
 562                                 tb = Parent.TypeBuilder;
 563                         else
 564                                 tb = TypeBuilder;
 565
 566                         if (check_type.IsGenericInstance)
 567                                 check_type = check_type.GetGenericTypeDefinition ();
 568
 569                         if (check_type == tb)
 570                                 return true;
 571
 572                         if (check_type.IsGenericParameter)
 573                                 return true; // FIXME
 574
 575                         TypeAttributes check_attr = check_type.Attributes & TypeAttributes.VisibilityMask;
 576
 577                         //
 578                         // Broken Microsoft runtime, return public for arrays, no matter what
 579                         // the accessibility is for their underlying class, and they return
 580                         // NonPublic visibility for pointers
 581                         //
 582                         if (check_type.IsArray || check_type.IsPointer)
 583                                 return CheckAccessLevel (TypeManager.GetElementType (check_type));
 584
 585                         switch (check_attr){
 586                         case TypeAttributes.Public:
 587                                 return true;
 588
 589                         case TypeAttributes.NotPublic:
 590                                 //
 591                                 // This test should probably use the declaringtype.
 592                                 //
 593                                 if (check_type.Assembly == tb.Assembly){
 594                                         return true;
 595                                 }
 596                                 return false;
 597
 598                         case TypeAttributes.NestedPublic:
 599                                 return true;
 600
 601                         case TypeAttributes.NestedPrivate:
 602                                 string check_type_name = check_type.FullName;
 603                                 string type_name = CurrentType != null ?
 604                                         CurrentType.Name : tb.FullName;
 605
 606                                 int cio = check_type_name.LastIndexOf ('+');
 607                                 string container = check_type_name.Substring (0, cio);
 608
 609                                 //
 610                                 // Check if the check_type is a nested class of the current type
 611                                 //
 612                                 if (check_type_name.StartsWith (type_name + "+")){
 613                                         return true;
 614                                 }
 615
 616                                 if (type_name.StartsWith (container)){
 617                                         return true;
 618                                 }
 619
 620                                 return false;
 621
 622                         case TypeAttributes.NestedFamily:
 623                                 //
 624                                 // Only accessible to methods in current type or any subtypes
 625                                 //
 626                                 return FamilyAccessible (tb, check_type);
 627
 628                         case TypeAttributes.NestedFamANDAssem:
 629                                 return (check_type.Assembly == tb.Assembly) &&
 630                                         FamilyAccessible (tb, check_type);
 631
 632                         case TypeAttributes.NestedFamORAssem:
 633                                 return (check_type.Assembly == tb.Assembly) ||
 634                                         FamilyAccessible (tb, check_type);
 635
 636                         case TypeAttributes.NestedAssembly:
 637                                 return check_type.Assembly == tb.Assembly;
 638                         }
 639
 640                         Console.WriteLine ("HERE: " + check_attr);
 641                         return false;
 642
 643                 }
 644
 645                 protected bool FamilyAccessible (TypeBuilder tb, Type check_type)
 646                 {
 647                         Type declaring = check_type.DeclaringType;
 648                         if (tb.IsSubclassOf (declaring))
 649                                 return true;
 650
 651                         string check_type_name = check_type.FullName;
 652
 653                         int cio = check_type_name.LastIndexOf ('+');
 654                         string container = check_type_name.Substring (0, cio);
 655
 656                         //
 657                         // Check if the check_type is a nested class of the current type
 658                         //
 659                         if (check_type_name.StartsWith (container + "+"))
 660                                 return true;
 661
 662                         return false;
 663                 }
 664
 665                 // Access level of a type.
 666                 const int X = 1;
 667                 enum AccessLevel { // Each column represents `is this scope larger or equal to Blah scope'
 668                         // Public    Assembly   Protected
 669                         Protected           = (0 << 0) | (0 << 1) | (X << 2),
 670                         Public              = (X << 0) | (X << 1) | (X << 2),
 671                         Private             = (0 << 0) | (0 << 1) | (0 << 2),
 672                         Internal            = (0 << 0) | (X << 1) | (0 << 2),
 673                         ProtectedOrInternal = (0 << 0) | (X << 1) | (X << 2),
 674                 }
 675
 676                 static AccessLevel GetAccessLevelFromModifiers (int flags)
 677                 {
 678                         if ((flags & Modifiers.INTERNAL) != 0) {
 679
 680                                 if ((flags & Modifiers.PROTECTED) != 0)
 681                                         return AccessLevel.ProtectedOrInternal;
 682                                 else
 683                                         return AccessLevel.Internal;
 684
 685                         } else if ((flags & Modifiers.PROTECTED) != 0)
 686                                 return AccessLevel.Protected;
 687                         else if ((flags & Modifiers.PRIVATE) != 0)
 688                                 return AccessLevel.Private;
 689                         else
 690                                 return AccessLevel.Public;
 691                 }
 692
 693                 // What is the effective access level of this?
 694                 // TODO: Cache this?
 695                 AccessLevel EffectiveAccessLevel {
 696                         get {
 697                                 AccessLevel myAccess = GetAccessLevelFromModifiers (ModFlags);
 698                                 if (!IsTopLevel && (Parent != null))
 699                                         return myAccess & Parent.EffectiveAccessLevel;
 700                                 return myAccess;
 701                         }
 702                 }
 703
 704                 // Return the access level for type `t'
 705                 static AccessLevel TypeEffectiveAccessLevel (Type t)
 706                 {
 707                         if (t.IsPublic)
 708                                 return AccessLevel.Public;
 709                         if (t.IsNestedPrivate)
 710                                 return AccessLevel.Private;
 711                         if (t.IsNotPublic)
 712                                 return AccessLevel.Internal;
 713
 714                         // By now, it must be nested
 715                         AccessLevel parentLevel = TypeEffectiveAccessLevel (t.DeclaringType);
 716
 717                         if (t.IsNestedPublic)
 718                                 return parentLevel;
 719                         if (t.IsNestedAssembly)
 720                                 return parentLevel & AccessLevel.Internal;
 721                         if (t.IsNestedFamily)
 722                                 return parentLevel & AccessLevel.Protected;
 723                         if (t.IsNestedFamORAssem)
 724                                 return parentLevel & AccessLevel.ProtectedOrInternal;
 725                         if (t.IsNestedFamANDAssem)
 726                                 throw new NotImplementedException ("NestedFamANDAssem not implemented, cant make this kind of type from c# anyways");
 727
 728                         // nested private is taken care of
 729
 730                         throw new Exception ("I give up, what are you?");
 731                 }
 732
 733                 //
 734                 // This answers `is the type P, as accessible as a member M which has the
 735                 // accessability @flags which is declared as a nested member of the type T, this declspace'
 736                 //
 737                 public bool AsAccessible (Type p, int flags)
 738                 {
 739                         if (p.IsGenericParameter)
 740                                 return true; // FIXME
 741
 742                         //
 743                         // 1) if M is private, its accessability is the same as this declspace.
 744                         // we already know that P is accessible to T before this method, so we
 745                         // may return true.
 746                         //
 747
 748                         if ((flags & Modifiers.PRIVATE) != 0)
 749                                 return true;
 750
 751                         while (p.IsArray || p.IsPointer || p.IsByRef)
 752                                 p = TypeManager.GetElementType (p);
 753
 754                         AccessLevel pAccess = TypeEffectiveAccessLevel (p);
 755                         AccessLevel mAccess = this.EffectiveAccessLevel &
 756                                 GetAccessLevelFromModifiers (flags);
 757
 758                         // for every place from which we can access M, we must
 759                         // be able to access P as well. So, we want
 760                         // For every bit in M and P, M_i -> P_1 == true
 761                         // or, ~ (M -> P) == 0 <-> ~ ( ~M | P) == 0
 762
 763                         return ~ (~ mAccess | pAccess) == 0;
 764                 }
 765
 766                 static DoubleHash dh = new DoubleHash (1000);
 767
 768                 Type DefineTypeAndParents (DeclSpace tc)
 769                 {
 770                         DeclSpace container = tc.Parent;
 771
 772                         if (container.TypeBuilder == null && container.Name != "")
 773                                 DefineTypeAndParents (container);
 774
 775                         return tc.DefineType ();
 776                 }
 777
 778                 Type LookupInterfaceOrClass (string ns, string name, out bool error)
 779                 {
 780                         DeclSpace parent;
 781                         Type t;
 782                         object r;
 783
 784                         error = false;
 785
 786                         if (dh.Lookup (ns, name, out r))
 787                                 return (Type) r;
 788                         else {
 789                                 if (ns != ""){
 790                                         if (Namespace.IsNamespace (ns)){
 791                                                 string fullname = (ns != "") ? ns + "." + name : name;
 792                                                 t = TypeManager.LookupType (fullname);
 793                                         } else
 794                                                 t = null;
 795                                 } else
 796                                         t = TypeManager.LookupType (name);
 797                         }
 798
 799                         if (t != null) {
 800                                 dh.Insert (ns, name, t);
 801                                 return t;
 802                         }
 803
 804                         //
 805                         // In case we are fed a composite name, normalize it.
 806                         //
 807                         int p = name.LastIndexOf ('.');
 808                         if (p != -1){
 809                                 ns = MakeFQN (ns, name.Substring (0, p));
 810                                 name = name.Substring (p+1);
 811                         }
 812
 813                         parent = RootContext.Tree.LookupByNamespace (ns, name);
 814                         if (parent == null) {
 815                                 dh.Insert (ns, name, null);
 816                                 return null;
 817                         }
 818
 819                         t = DefineTypeAndParents (parent);
 820                         if (t == null){
 821                                 error = true;
 822                                 return null;
 823                         }
 824
 825                         dh.Insert (ns, name, t);
 826                         return t;
 827                 }
 828
 829                 public static void Error_AmbiguousTypeReference (Location loc, string name, string t1, string t2)
 830                 {
 831                         Report.Error (104, loc,
 832                                       "`{0}' is an ambiguous reference ({1} or {2})",
 833                                       name, t1, t2);
 834                 }
 835
 836                 public Type FindNestedType (Location loc, string name,
 837                                             out DeclSpace containing_ds)
 838                 {
 839                         Type t;
 840                         bool error;
 841
 842                         containing_ds = this;
 843                         while (containing_ds != null){
 844                                 Type container_type = containing_ds.TypeBuilder;
 845                                 Type current_type = container_type;
 846
 847                                 while (current_type != null && current_type != TypeManager.object_type) {
 848                                         string pre = current_type.FullName;
 849
 850                                         t = LookupInterfaceOrClass (pre, name, out error);
 851                                         if (error)
 852                                                 return null;
 853
 854                                         if ((t != null) && containing_ds.CheckAccessLevel (t))
 855                                                 return t;
 856
 857                                         current_type = current_type.BaseType;
 858                                 }
 859                                 containing_ds = containing_ds.Parent;
 860                         }
 861
 862                         return null;
 863                 }
 864
 865                 /// <summary>
 866                 ///   GetType is used to resolve type names at the DeclSpace level.
 867                 ///   Use this to lookup class/struct bases, interface bases or
 868                 ///   delegate type references
 869                 /// </summary>
 870                 ///
 871                 /// <remarks>
 872                 ///   Contrast this to LookupType which is used inside method bodies to
 873                 ///   lookup types that have already been defined.  GetType is used
 874                 ///   during the tree resolution process and potentially define
 875                 ///   recursively the type
 876                 /// </remarks>
 877                 public Type FindType (Location loc, string name, int num_type_args)
 878                 {
 879                         Type t;
 880                         bool error;
 881
 882                         //
 883                         // For the case the type we are looking for is nested within this one
 884                         // or is in any base class
 885                         //
 886                         DeclSpace containing_ds = this;
 887
 888                         while (containing_ds != null){
 889                                 Type container_type = containing_ds.TypeBuilder;
 890                                 Type current_type = container_type;
 891
 892                                 while (current_type != null && current_type != TypeManager.object_type) {
 893                                         string pre = current_type.FullName;
 894
 895                                         t = LookupInterfaceOrClass (pre, name, out error);
 896                                         if (error)
 897                                                 return null;
 898
 899                                         if ((t != null) &&
 900                                             containing_ds.CheckAccessLevel (t) &&
 901                                             TypeManager.CheckGeneric (t, num_type_args))
 902                                                 return t;
 903
 904                                         current_type = current_type.BaseType;
 905                                 }
 906                                 containing_ds = containing_ds.Parent;
 907                         }
 908
 909                         //
 910                         // Attempt to lookup the class on our namespace and all it's implicit parents
 911                         //
 912                         for (NamespaceEntry ns = NamespaceEntry; ns != null; ns = ns.ImplicitParent) {
 913                                 t = LookupInterfaceOrClass (ns.FullName, name, out error);
 914                                 if (error)
 915                                         return null;
 916
 917                                 if ((t != null) && TypeManager.CheckGeneric (t, num_type_args))
 918                                         return t;
 919                         }
 920
 921                         //
 922                         // Attempt to do a direct unqualified lookup
 923                         //
 924                         t = LookupInterfaceOrClass ("", name, out error);
 925                         if (error)
 926                                 return null;
 927
 928                         if ((t != null) && TypeManager.CheckGeneric (t, num_type_args))
 929                                 return t;
 930
 931                         //
 932                         // Attempt to lookup the class on any of the `using'
 933                         // namespaces
 934                         //
 935
 936                         for (NamespaceEntry ns = NamespaceEntry; ns != null; ns = ns.Parent){
 937
 938                                 t = LookupInterfaceOrClass (ns.FullName, name, out error);
 939                                 if (error)
 940                                         return null;
 941
 942                                 if ((t != null) && TypeManager.CheckGeneric (t, num_type_args))
 943                                         return t;
 944
 945                                 //
 946                                 // Now check the using clause list
 947                                 //
 948                                 Type match = null;
 949                                 foreach (Namespace using_ns in ns.GetUsingTable ()) {
 950                                         match = LookupInterfaceOrClass (using_ns.Name, name, out error);
 951                                         if (error)
 952                                                 return null;
 953
 954                                         if ((match != null) &&
 955                                             TypeManager.CheckGeneric (match, num_type_args)) {
 956                                                 if (t != null){
 957                                                         if (CheckAccessLevel (match)) {
 958                                                                 Error_AmbiguousTypeReference (loc, name, t.FullName, match.FullName);
 959                                                                 return null;
 960                                                         }
 961                                                         continue;
 962                                                 }
 963
 964                                                 t = match;
 965                                         }
 966                                 }
 967                                 if ((t != null) && TypeManager.CheckGeneric (t, num_type_args))
 968                                         return t;
 969                         }
 970
 971                         //Report.Error (246, Location, "Can not find type `"+name+"'");
 972                         return null;
 973                 }
 974
 975                 /// <remarks>
 976                 ///   This function is broken and not what you're looking for.  It should only
 977                 ///   be used while the type is still being created since it doesn't use the cache
 978                 ///   and relies on the filter doing the member name check.
 979                 /// </remarks>
 980                 public abstract MemberList FindMembers (MemberTypes mt, BindingFlags bf,
 981                                                         MemberFilter filter, object criteria);
 982
 983                 /// <remarks>
 984                 ///   If we have a MemberCache, return it.  This property may return null if the
 985                 ///   class doesn't have a member cache or while it's still being created.
 986                 /// </remarks>
 987                 public abstract MemberCache MemberCache {
 988                         get;
 989                 }
 990
 991                 //
 992                 // Extensions for generics
 993                 //
 994                 TypeParameter[] type_params;
 995                 TypeParameter[] type_param_list;
 996
 997                 protected string GetInstantiationName ()
 998                 {
 999                         StringBuilder sb = new StringBuilder (Name);
1000                         sb.Append ("<");
1001                         for (int i = 0; i < type_param_list.Length; i++) {
1002                                 if (i > 0)
1003                                         sb.Append (",");
1004                                 sb.Append (type_param_list [i].Name);
1005                         }
1006                         sb.Append (">");
1007                         return sb.ToString ();
1008                 }
1009
1010                 bool check_type_parameter (ArrayList list, int start, string name)
1011                 {
1012                         for (int i = 0; i < start; i++) {
1013                                 TypeParameter param = (TypeParameter) list [i];
1014
1015                                 if (param.Name != name)
1016                                         continue;
1017
1018                                 if (RootContext.WarningLevel >= 3)
1019                                         Report.Warning (
1020                                                 693, Location,
1021                                                 "Type parameter `{0}' has same name " +
1022                                                 "as type parameter from outer type `{1}'",
1023                                                 name, parent.GetInstantiationName ());
1024
1025                                 return false;
1026                         }
1027
1028                         return true;
1029                 }
1030
1031                 TypeParameter[] initialize_type_params ()
1032                 {
1033                         if (type_param_list != null)
1034                                 return type_param_list;
1035
1036                         DeclSpace the_parent = parent;
1037                         if (this is GenericMethod)
1038                                 the_parent = the_parent.Parent;
1039
1040                         int start = 0;
1041                         TypeParameter[] parent_params = null;
1042                         if ((the_parent != null) && the_parent.IsGeneric) {
1043                                 parent_params = the_parent.initialize_type_params ();
1044                                 start = parent_params != null ? parent_params.Length : 0;
1045                         }
1046
1047                         ArrayList list = new ArrayList ();
1048                         if (parent_params != null)
1049                                 list.AddRange (parent_params);
1050
1051                         int count = type_params != null ? type_params.Length : 0;
1052                         for (int i = 0; i < count; i++) {
1053                                 TypeParameter param = type_params [i];
1054                                 check_type_parameter (list, start, param.Name);
1055                                 list.Add (param);
1056                         }
1057
1058                         type_param_list = new TypeParameter [list.Count];
1059                         list.CopyTo (type_param_list, 0);
1060                         return type_param_list;
1061                 }
1062
1063                 ///
1064                 /// Called by the parser to configure the type_parameter_list for this
1065                 /// declaration space
1066                 ///
1067                 public AdditionResult SetParameterInfo (TypeArguments args,
1068                                                         ArrayList constraints_list)
1069                 {
1070                         string[] type_parameter_list = args.GetDeclarations ();
1071                         if (type_parameter_list == null)
1072                                 return AdditionResult.Error;
1073
1074                         return SetParameterInfo (type_parameter_list, constraints_list);
1075                 }
1076
1077                 public AdditionResult SetParameterInfo (IList type_parameter_list,
1078                                                         ArrayList constraints_list)
1079                 {
1080                         type_params = new TypeParameter [type_parameter_list.Count];
1081
1082                         //
1083                         // Mark this type as Generic
1084                         //
1085                         is_generic = true;
1086
1087                         //
1088                         // Register all the names
1089                         //
1090                         for (int i = 0; i < type_parameter_list.Count; i++) {
1091                                 string name = (string) type_parameter_list [i];
1092
1093                                 AdditionResult res = IsValid (name, name);
1094
1095                                 if (res != AdditionResult.Success)
1096                                         return res;
1097
1098                                 Constraints constraints = null;
1099                                 if (constraints_list != null) {
1100                                         foreach (Constraints constraint in constraints_list) {
1101                                                 if (constraint.TypeParameter == name) {
1102                                                         constraints = constraint;
1103                                                         break;
1104                                                 }
1105                                         }
1106                                 }
1107
1108                                 type_params [i] = new TypeParameter (name, constraints, Location);
1109
1110                                 DefineName (name, type_params [i]);
1111                         }
1112
1113                         return AdditionResult.Success;
1114                 }
1115
1116                 public TypeParameter[] TypeParameters {
1117                         get {
1118                                 if (!IsGeneric)
1119                                         throw new InvalidOperationException ();
1120                                 if (type_param_list == null)
1121                                         initialize_type_params ();
1122
1123                                 return type_param_list;
1124                         }
1125                 }
1126
1127                 protected TypeParameter[] CurrentTypeParameters {
1128                         get {
1129                                 if (!IsGeneric)
1130                                         throw new InvalidOperationException ();
1131                                 if (type_params != null)
1132                                         return type_params;
1133                                 else
1134                                         return new TypeParameter [0];
1135                         }
1136                 }
1137
1138                 public int CountTypeParameters {
1139                         get {
1140                                 if (!IsGeneric)
1141                                         return 0;
1142                                 if (type_param_list == null)
1143                                         initialize_type_params ();
1144
1145                                 return type_param_list.Length;
1146                         }
1147                 }
1148
1149                 public TypeParameterExpr LookupGeneric (string name, Location loc)
1150                 {
1151                         if (!IsGeneric)
1152                                 return null;
1153
1154                         foreach (TypeParameter type_param in CurrentTypeParameters) {
1155                                 if (type_param.Name != name)
1156                                         continue;
1157
1158                                 return new TypeParameterExpr (type_param, loc);
1159                         }
1160
1161                         if (parent != null)
1162                                 return parent.LookupGeneric (name, loc);
1163
1164                         return null;
1165                 }
1166
1167                 bool IAlias.IsType {
1168                         get { return true; }
1169                 }
1170
1171                 string IAlias.Name {
1172                         get { return Name; }
1173                 }
1174
1175                 TypeExpr IAlias.Type
1176                 {
1177                         get {
1178                                 if (TypeBuilder == null)
1179                                         throw new InvalidOperationException ();
1180
1181                                 if (CurrentType != null)
1182                                         return CurrentType;
1183
1184                                 return new TypeExpression (TypeBuilder, Location);
1185                         }
1186                 }
1187         }
1188
1189         /// <summary>
1190         ///   This is a readonly list of MemberInfo's.
1191         /// </summary>
1192         public class MemberList : IList {
1193                 public readonly IList List;
1194                 int count;
1195
1196                 /// <summary>
1197                 ///   Create a new MemberList from the given IList.
1198                 /// </summary>
1199                 public MemberList (IList list)
1200                 {
1201                         if (list != null)
1202                                 this.List = list;
1203                         else
1204                                 this.List = new ArrayList ();
1205                         count = List.Count;
1206                 }
1207
1208                 /// <summary>
1209                 ///   Concatenate the ILists `first' and `second' to a new MemberList.
1210                 /// </summary>
1211                 public MemberList (IList first, IList second)
1212                 {
1213                         ArrayList list = new ArrayList ();
1214                         list.AddRange (first);
1215                         list.AddRange (second);
1216                         count = list.Count;
1217                         List = list;
1218                 }
1219
1220                 public static readonly MemberList Empty = new MemberList (new ArrayList ());
1221
1222                 /// <summary>
1223                 ///   Cast the MemberList into a MemberInfo[] array.
1224                 /// </summary>
1225                 /// <remarks>
1226                 ///   This is an expensive operation, only use it if it's really necessary.
1227                 /// </remarks>
1228                 public static explicit operator MemberInfo [] (MemberList list)
1229                 {
1230                         Timer.StartTimer (TimerType.MiscTimer);
1231                         MemberInfo [] result = new MemberInfo [list.Count];
1232                         list.CopyTo (result, 0);
1233                         Timer.StopTimer (TimerType.MiscTimer);
1234                         return result;
1235                 }
1236
1237                 // ICollection
1238
1239                 public int Count {
1240                         get {
1241                                 return count;
1242                         }
1243                 }
1244
1245                 public bool IsSynchronized {
1246                         get {
1247                                 return List.IsSynchronized;
1248                         }
1249                 }
1250
1251                 public object SyncRoot {
1252                         get {
1253                                 return List.SyncRoot;
1254                         }
1255                 }
1256
1257                 public void CopyTo (Array array, int index)
1258                 {
1259                         List.CopyTo (array, index);
1260                 }
1261
1262                 // IEnumerable
1263
1264                 public IEnumerator GetEnumerator ()
1265                 {
1266                         return List.GetEnumerator ();
1267                 }
1268
1269                 // IList
1270
1271                 public bool IsFixedSize {
1272                         get {
1273                                 return true;
1274                         }
1275                 }
1276
1277                 public bool IsReadOnly {
1278                         get {
1279                                 return true;
1280                         }
1281                 }
1282
1283                 object IList.this [int index] {
1284                         get {
1285                                 return List [index];
1286                         }
1287
1288                         set {
1289                                 throw new NotSupportedException ();
1290                         }
1291                 }
1292
1293                 // FIXME: try to find out whether we can avoid the cast in this indexer.
1294                 public MemberInfo this [int index] {
1295                         get {
1296                                 return (MemberInfo) List [index];
1297                         }
1298                 }
1299
1300                 public int Add (object value)
1301                 {
1302                         throw new NotSupportedException ();
1303                 }
1304
1305                 public void Clear ()
1306                 {
1307                         throw new NotSupportedException ();
1308                 }
1309
1310                 public bool Contains (object value)
1311                 {
1312                         return List.Contains (value);
1313                 }
1314
1315                 public int IndexOf (object value)
1316                 {
1317                         return List.IndexOf (value);
1318                 }
1319
1320                 public void Insert (int index, object value)
1321                 {
1322                         throw new NotSupportedException ();
1323                 }
1324
1325                 public void Remove (object value)
1326                 {
1327                         throw new NotSupportedException ();
1328                 }
1329
1330                 public void RemoveAt (int index)
1331                 {
1332                         throw new NotSupportedException ();
1333                 }
1334         }
1335
1336         /// <summary>
1337         ///   This interface is used to get all members of a class when creating the
1338         ///   member cache.  It must be implemented by all DeclSpace derivatives which
1339         ///   want to support the member cache and by TypeHandle to get caching of
1340         ///   non-dynamic types.
1341         /// </summary>
1342         public interface IMemberContainer {
1343                 /// <summary>
1344                 ///   The name of the IMemberContainer.  This is only used for
1345                 ///   debugging purposes.
1346                 /// </summary>
1347                 string Name {
1348                         get;
1349                 }
1350
1351                 /// <summary>
1352                 ///   The type of this IMemberContainer.
1353                 /// </summary>
1354                 Type Type {
1355                         get;
1356                 }
1357
1358                 /// <summary>
1359                 ///   Returns the IMemberContainer of the parent class or null if this
1360                 ///   is an interface or TypeManger.object_type.
1361                 ///   This is used when creating the member cache for a class to get all
1362                 ///   members from the parent class.
1363                 /// </summary>
1364                 IMemberContainer Parent {
1365                         get;
1366                 }
1367
1368                 /// <summary>
1369                 ///   Whether this is an interface.
1370                 /// </summary>
1371                 bool IsInterface {
1372                         get;
1373                 }
1374
1375                 /// <summary>
1376                 ///   Returns all members of this class with the corresponding MemberTypes
1377                 ///   and BindingFlags.
1378                 /// </summary>
1379                 /// <remarks>
1380                 ///   When implementing this method, make sure not to return any inherited
1381                 ///   members and check the MemberTypes and BindingFlags properly.
1382                 ///   Unfortunately, System.Reflection is lame and doesn't provide a way to
1383                 ///   get the BindingFlags (static/non-static,public/non-public) in the
1384                 ///   MemberInfo class, but the cache needs this information.  That's why
1385                 ///   this method is called multiple times with different BindingFlags.
1386                 /// </remarks>
1387                 MemberList GetMembers (MemberTypes mt, BindingFlags bf);
1388
1389                 /// <summary>
1390                 ///   Return the container's member cache.
1391                 /// </summary>
1392                 MemberCache MemberCache {
1393                         get;
1394                 }
1395         }
1396
1397         /// <summary>
1398         ///   The MemberCache is used by dynamic and non-dynamic types to speed up
1399         ///   member lookups.  It has a member name based hash table; it maps each member
1400         ///   name to a list of CacheEntry objects.  Each CacheEntry contains a MemberInfo
1401         ///   and the BindingFlags that were initially used to get it.  The cache contains
1402         ///   all members of the current class and all inherited members.  If this cache is
1403         ///   for an interface types, it also contains all inherited members.
1404         ///
1405         ///   There are two ways to get a MemberCache:
1406         ///   * if this is a dynamic type, lookup the corresponding DeclSpace and then
1407         ///     use the DeclSpace.MemberCache property.
1408         ///   * if this not a dynamic type, call TypeHandle.GetTypeHandle() to get a
1409         ///     TypeHandle instance for the type and then use TypeHandle.MemberCache.
1410         /// </summary>
1411         public class MemberCache {
1412                 public readonly IMemberContainer Container;
1413                 protected Hashtable member_hash;
1414                 protected Hashtable method_hash;
1415
1416                 Hashtable interface_hash;
1417
1418                 /// <summary>
1419                 ///   Create a new MemberCache for the given IMemberContainer `container'.
1420                 /// </summary>
1421                 public MemberCache (IMemberContainer container)
1422                 {
1423                         this.Container = container;
1424
1425                         Timer.IncrementCounter (CounterType.MemberCache);
1426                         Timer.StartTimer (TimerType.CacheInit);
1427
1428
1429
1430                         // If we have a parent class (we have a parent class unless we're
1431                         // TypeManager.object_type), we deep-copy its MemberCache here.
1432                         if (Container.IsInterface) {
1433                                 MemberCache parent;
1434                                 interface_hash = new Hashtable ();
1435
1436                                 if (Container.Parent != null)
1437                                         parent = Container.Parent.MemberCache;
1438                                 else
1439                                         parent = TypeHandle.ObjectType.MemberCache;
1440                                 member_hash = SetupCacheForInterface (parent);
1441                         } else if (Container.Parent != null)
1442                                 member_hash = SetupCache (Container.Parent.MemberCache);
1443                         else
1444                                 member_hash = new Hashtable ();
1445
1446                         // If this is neither a dynamic type nor an interface, create a special
1447                         // method cache with all declared and inherited methods.
1448                         Type type = container.Type;
1449                         if (!(type is TypeBuilder) && !type.IsInterface && !type.IsGenericParameter) {
1450                                 method_hash = new Hashtable ();
1451                                 AddMethods (type);
1452                         }
1453
1454                         // Add all members from the current class.
1455                         AddMembers (Container);
1456
1457                         Timer.StopTimer (TimerType.CacheInit);
1458                 }
1459
1460                 /// <summary>
1461                 ///   Bootstrap this member cache by doing a deep-copy of our parent.
1462                 /// </summary>
1463                 Hashtable SetupCache (MemberCache parent)
1464                 {
1465                         Hashtable hash = new Hashtable ();
1466
1467                         IDictionaryEnumerator it = parent.member_hash.GetEnumerator ();
1468                         while (it.MoveNext ()) {
1469                                 hash [it.Key] = ((ArrayList) it.Value).Clone ();
1470                         }
1471
1472                         return hash;
1473                 }
1474
1475
1476                 /// <summary>
1477                 ///   Add the contents of `new_hash' to `hash'.
1478                 /// </summary>
1479                 void AddHashtable (Hashtable hash, Hashtable new_hash)
1480                 {
1481                         IDictionaryEnumerator it = new_hash.GetEnumerator ();
1482                         while (it.MoveNext ()) {
1483                                 ArrayList list = (ArrayList) hash [it.Key];
1484                                 if (list != null)
1485                                         list.AddRange ((ArrayList) it.Value);
1486                                 else
1487                                         hash [it.Key] = ((ArrayList) it.Value).Clone ();
1488                         }
1489                 }
1490
1491                 /// <summary>
1492                 ///   Bootstrap the member cache for an interface type.
1493                 ///   Type.GetMembers() won't return any inherited members for interface types,
1494                 ///   so we need to do this manually.  Interfaces also inherit from System.Object.
1495                 /// </summary>
1496                 Hashtable SetupCacheForInterface (MemberCache parent)
1497                 {
1498                         Hashtable hash = SetupCache (parent);
1499                         TypeExpr [] ifaces = TypeManager.GetInterfaces (Container.Type);
1500
1501                         foreach (TypeExpr iface in ifaces) {
1502                                 Type itype = iface.Type;
1503
1504                                 if (interface_hash.Contains (itype))
1505                                         continue;
1506
1507                                 interface_hash [itype] = null;
1508
1509                                 IMemberContainer iface_container =
1510                                         TypeManager.LookupMemberContainer (itype);
1511
1512                                 MemberCache iface_cache = iface_container.MemberCache;
1513
1514                                 AddHashtable (hash, iface_cache.member_hash);
1515
1516                                 if (iface_cache.interface_hash == null)
1517                                         continue;
1518
1519                                 foreach (Type parent_contains in iface_cache.interface_hash.Keys)
1520                                         interface_hash [parent_contains] = null;
1521                         }
1522
1523                         return hash;
1524                 }
1525
1526                 /// <summary>
1527                 ///   Add all members from class `container' to the cache.
1528                 /// </summary>
1529                 void AddMembers (IMemberContainer container)
1530                 {
1531                         // We need to call AddMembers() with a single member type at a time
1532                         // to get the member type part of CacheEntry.EntryType right.
1533                         AddMembers (MemberTypes.Constructor, container);
1534                         AddMembers (MemberTypes.Field, container);
1535                         AddMembers (MemberTypes.Method, container);
1536                         AddMembers (MemberTypes.Property, container);
1537                         AddMembers (MemberTypes.Event, container);
1538                         // Nested types are returned by both Static and Instance searches.
1539                         AddMembers (MemberTypes.NestedType,
1540                                     BindingFlags.Static | BindingFlags.Public, container);
1541                         AddMembers (MemberTypes.NestedType,
1542                                     BindingFlags.Static | BindingFlags.NonPublic, container);
1543                 }
1544
1545                 void AddMembers (MemberTypes mt, IMemberContainer container)
1546                 {
1547                         AddMembers (mt, BindingFlags.Static | BindingFlags.Public, container);
1548                         AddMembers (mt, BindingFlags.Static | BindingFlags.NonPublic, container);
1549                         AddMembers (mt, BindingFlags.Instance | BindingFlags.Public, container);
1550                         AddMembers (mt, BindingFlags.Instance | BindingFlags.NonPublic, container);
1551                 }
1552
1553                 /// <summary>
1554                 ///   Add all members from class `container' with the requested MemberTypes and
1555                 ///   BindingFlags to the cache.  This method is called multiple times with different
1556                 ///   MemberTypes and BindingFlags.
1557                 /// </summary>
1558                 void AddMembers (MemberTypes mt, BindingFlags bf, IMemberContainer container)
1559                 {
1560                         MemberList members = container.GetMembers (mt, bf);
1561
1562                         foreach (MemberInfo member in members) {
1563                                 string name = member.Name;
1564
1565                                 int pos = name.IndexOf ('<');
1566                                 if (pos > 0)
1567                                         name = name.Substring (0, pos);
1568
1569                                 // We use a name-based hash table of ArrayList's.
1570                                 ArrayList list = (ArrayList) member_hash [name];
1571                                 if (list == null) {
1572                                         list = new ArrayList ();
1573                                         member_hash.Add (name, list);
1574                                 }
1575
1576                                 // When this method is called for the current class, the list will
1577                                 // already contain all inherited members from our parent classes.
1578                                 // We cannot add new members in front of the list since this'd be an
1579                                 // expensive operation, that's why the list is sorted in reverse order
1580                                 // (ie. members from the current class are coming last).
1581                                 list.Add (new CacheEntry (container, member, mt, bf));
1582                         }
1583                 }
1584
1585                 /// <summary>
1586                 ///   Add all declared and inherited methods from class `type' to the method cache.
1587                 /// </summary>
1588                 void AddMethods (Type type)
1589                 {
1590                         AddMethods (BindingFlags.Static | BindingFlags.Public |
1591                                     BindingFlags.FlattenHierarchy, type);
1592                         AddMethods (BindingFlags.Static | BindingFlags.NonPublic |
1593                                     BindingFlags.FlattenHierarchy, type);
1594                         AddMethods (BindingFlags.Instance | BindingFlags.Public, type);
1595                         AddMethods (BindingFlags.Instance | BindingFlags.NonPublic, type);
1596                 }
1597
1598                 void AddMethods (BindingFlags bf, Type type)
1599                 {
1600                         MemberInfo [] members = type.GetMethods (bf);
1601
1602                         Array.Reverse (members);
1603
1604                         foreach (MethodBase member in members) {
1605                                 string name = member.Name;
1606
1607                                 // Varargs methods aren't allowed in C# code.
1608                                 if ((member.CallingConvention & CallingConventions.VarArgs) != 0)
1609                                         continue;
1610
1611                                 // We use a name-based hash table of ArrayList's.
1612                                 ArrayList list = (ArrayList) method_hash [name];
1613                                 if (list == null) {
1614                                         list = new ArrayList ();
1615                                         method_hash.Add (name, list);
1616                                 }
1617
1618                                 // Unfortunately, the elements returned by Type.GetMethods() aren't
1619                                 // sorted so we need to do this check for every member.
1620                                 BindingFlags new_bf = bf;
1621                                 if (member.DeclaringType == type)
1622                                         new_bf |= BindingFlags.DeclaredOnly;
1623
1624                                 list.Add (new CacheEntry (Container, member, MemberTypes.Method, new_bf));
1625                         }
1626                 }
1627
1628                 /// <summary>
1629                 ///   Compute and return a appropriate `EntryType' magic number for the given
1630                 ///   MemberTypes and BindingFlags.
1631                 /// </summary>
1632                 protected static EntryType GetEntryType (MemberTypes mt, BindingFlags bf)
1633                 {
1634                         EntryType type = EntryType.None;
1635
1636                         if ((mt & MemberTypes.Constructor) != 0)
1637                                 type |= EntryType.Constructor;
1638                         if ((mt & MemberTypes.Event) != 0)
1639                                 type |= EntryType.Event;
1640                         if ((mt & MemberTypes.Field) != 0)
1641                                 type |= EntryType.Field;
1642                         if ((mt & MemberTypes.Method) != 0)
1643                                 type |= EntryType.Method;
1644                         if ((mt & MemberTypes.Property) != 0)
1645                                 type |= EntryType.Property;
1646                         // Nested types are returned by static and instance searches.
1647                         if ((mt & MemberTypes.NestedType) != 0)
1648                                 type |= EntryType.NestedType | EntryType.Static | EntryType.Instance;
1649
1650                         if ((bf & BindingFlags.Instance) != 0)
1651                                 type |= EntryType.Instance;
1652                         if ((bf & BindingFlags.Static) != 0)
1653                                 type |= EntryType.Static;
1654                         if ((bf & BindingFlags.Public) != 0)
1655                                 type |= EntryType.Public;
1656                         if ((bf & BindingFlags.NonPublic) != 0)
1657                                 type |= EntryType.NonPublic;
1658                         if ((bf & BindingFlags.DeclaredOnly) != 0)
1659                                 type |= EntryType.Declared;
1660
1661                         return type;
1662                 }
1663
1664                 /// <summary>
1665                 ///   The `MemberTypes' enumeration type is a [Flags] type which means that it may
1666                 ///   denote multiple member types.  Returns true if the given flags value denotes a
1667                 ///   single member types.
1668                 /// </summary>
1669                 public static bool IsSingleMemberType (MemberTypes mt)
1670                 {
1671                         switch (mt) {
1672                         case MemberTypes.Constructor:
1673                         case MemberTypes.Event:
1674                         case MemberTypes.Field:
1675                         case MemberTypes.Method:
1676                         case MemberTypes.Property:
1677                         case MemberTypes.NestedType:
1678                                 return true;
1679
1680                         default:
1681                                 return false;
1682                         }
1683                 }
1684
1685                 /// <summary>
1686                 ///   We encode the MemberTypes and BindingFlags of each members in a "magic"
1687                 ///   number to speed up the searching process.
1688                 /// </summary>
1689                 [Flags]
1690                 protected enum EntryType {
1691                         None            = 0x000,
1692
1693                         Instance        = 0x001,
1694                         Static          = 0x002,
1695                         MaskStatic      = Instance|Static,
1696
1697                         Public          = 0x004,
1698                         NonPublic       = 0x008,
1699                         MaskProtection  = Public|NonPublic,
1700
1701                         Declared        = 0x010,
1702
1703                         Constructor     = 0x020,
1704                         Event           = 0x040,
1705                         Field           = 0x080,
1706                         Method          = 0x100,
1707                         Property        = 0x200,
1708                         NestedType      = 0x400,
1709
1710                         MaskType        = Constructor|Event|Field|Method|Property|NestedType
1711                 }
1712
1713                 protected struct CacheEntry {
1714                         public readonly IMemberContainer Container;
1715                         public readonly EntryType EntryType;
1716                         public readonly MemberInfo Member;
1717
1718                         public CacheEntry (IMemberContainer container, MemberInfo member,
1719                                            MemberTypes mt, BindingFlags bf)
1720                         {
1721                                 this.Container = container;
1722                                 this.Member = member;
1723                                 this.EntryType = GetEntryType (mt, bf);
1724                         }
1725                 }
1726
1727                 /// <summary>
1728                 ///   This is called each time we're walking up one level in the class hierarchy
1729                 ///   and checks whether we can abort the search since we've already found what
1730                 ///   we were looking for.
1731                 /// </summary>
1732                 protected bool DoneSearching (ArrayList list)
1733                 {
1734                         //
1735                         // We've found exactly one member in the current class and it's not
1736                         // a method or constructor.
1737                         //
1738                         if (list.Count == 1 && !(list [0] is MethodBase))
1739                                 return true;
1740
1741                         //
1742                         // Multiple properties: we query those just to find out the indexer
1743                         // name
1744                         //
1745                         if ((list.Count > 0) && (list [0] is PropertyInfo))
1746                                 return true;
1747
1748                         return false;
1749                 }
1750
1751                 /// <summary>
1752                 ///   Looks up members with name `name'.  If you provide an optional
1753                 ///   filter function, it'll only be called with members matching the
1754                 ///   requested member name.
1755                 ///
1756                 ///   This method will try to use the cache to do the lookup if possible.
1757                 ///
1758                 ///   Unlike other FindMembers implementations, this method will always
1759                 ///   check all inherited members - even when called on an interface type.
1760                 ///
1761                 ///   If you know that you're only looking for methods, you should use
1762                 ///   MemberTypes.Method alone since this speeds up the lookup a bit.
1763                 ///   When doing a method-only search, it'll try to use a special method
1764                 ///   cache (unless it's a dynamic type or an interface) and the returned
1765                 ///   MemberInfo's will have the correct ReflectedType for inherited methods.
1766                 ///   The lookup process will automatically restart itself in method-only
1767                 ///   search mode if it discovers that it's about to return methods.
1768                 /// </summary>
1769                 ArrayList global = new ArrayList ();
1770                 bool using_global = false;
1771
1772                 public MemberList FindMembers (MemberTypes mt, BindingFlags bf, string name,
1773                                                MemberFilter filter, object criteria)
1774                 {
1775                         if (using_global)
1776                                 throw new Exception ();
1777
1778                         bool declared_only = (bf & BindingFlags.DeclaredOnly) != 0;
1779                         bool method_search = mt == MemberTypes.Method;
1780                         // If we have a method cache and we aren't already doing a method-only search,
1781                         // then we restart a method search if the first match is a method.
1782                         bool do_method_search = !method_search && (method_hash != null);
1783
1784                         ArrayList applicable;
1785
1786                         // If this is a method-only search, we try to use the method cache if
1787                         // possible; a lookup in the method cache will return a MemberInfo with
1788                         // the correct ReflectedType for inherited methods.
1789
1790                         if (method_search && (method_hash != null))
1791                                 applicable = (ArrayList) method_hash [name];
1792                         else
1793                                 applicable = (ArrayList) member_hash [name];
1794
1795                         if (applicable == null)
1796                                 return MemberList.Empty;
1797
1798                         //
1799                         // 32  slots gives 53 rss/54 size
1800                         // 2/4 slots gives 55 rss
1801                         //
1802                         // Strange: from 25,000 calls, only 1,800
1803                         // are above 2.  Why does this impact it?
1804                         //
1805                         global.Clear ();
1806                         using_global = true;
1807
1808                         Timer.StartTimer (TimerType.CachedLookup);
1809
1810                         EntryType type = GetEntryType (mt, bf);
1811
1812                         IMemberContainer current = Container;
1813
1814                         // `applicable' is a list of all members with the given member name `name'
1815                         // in the current class and all its parent classes.  The list is sorted in
1816                         // reverse order due to the way how the cache is initialy created (to speed
1817                         // things up, we're doing a deep-copy of our parent).
1818
1819                         for (int i = applicable.Count-1; i >= 0; i--) {
1820                                 CacheEntry entry = (CacheEntry) applicable [i];
1821
1822                                 // This happens each time we're walking one level up in the class
1823                                 // hierarchy.  If we're doing a DeclaredOnly search, we must abort
1824                                 // the first time this happens (this may already happen in the first
1825                                 // iteration of this loop if there are no members with the name we're
1826                                 // looking for in the current class).
1827                                 if (entry.Container != current) {
1828                                         if (declared_only || DoneSearching (global))
1829                                                 break;
1830
1831                                         current = entry.Container;
1832                                 }
1833
1834                                 // Is the member of the correct type ?
1835                                 if ((entry.EntryType & type & EntryType.MaskType) == 0)
1836                                         continue;
1837
1838                                 // Is the member static/non-static ?
1839                                 if ((entry.EntryType & type & EntryType.MaskStatic) == 0)
1840                                         continue;
1841
1842                                 // Apply the filter to it.
1843                                 if (filter (entry.Member, criteria)) {
1844                                         if ((entry.EntryType & EntryType.MaskType) != EntryType.Method)
1845                                                 do_method_search = false;
1846                                         global.Add (entry.Member);
1847                                 }
1848                         }
1849
1850                         Timer.StopTimer (TimerType.CachedLookup);
1851
1852                         // If we have a method cache and we aren't already doing a method-only
1853                         // search, we restart in method-only search mode if the first match is
1854                         // a method.  This ensures that we return a MemberInfo with the correct
1855                         // ReflectedType for inherited methods.
1856                         if (do_method_search && (global.Count > 0)){
1857                                 using_global = false;
1858
1859                                 return FindMembers (MemberTypes.Method, bf, name, filter, criteria);
1860                         }
1861
1862                         using_global = false;
1863                         MemberInfo [] copy = new MemberInfo [global.Count];
1864                         global.CopyTo (copy);
1865                         return new MemberList (copy);
1866                 }
1867
1868                 //
1869                 // This finds the method or property for us to override. invocationType is the type where
1870                 // the override is going to be declared, name is the name of the method/property, and
1871                 // paramTypes is the parameters, if any to the method or property
1872                 //
1873                 // Because the MemberCache holds members from this class and all the base classes,
1874                 // we can avoid tons of reflection stuff.
1875                 //
1876                 public MemberInfo FindMemberToOverride (Type invocationType, string name, Type [] paramTypes, bool is_property)
1877                 {
1878                         ArrayList applicable;
1879                         if (method_hash != null && !is_property)
1880                                 applicable = (ArrayList) method_hash [name];
1881                         else
1882                                 applicable = (ArrayList) member_hash [name];
1883
1884                         if (applicable == null)
1885                                 return null;
1886                         //
1887                         // Walk the chain of methods, starting from the top.
1888                         //
1889                         for (int i = applicable.Count - 1; i >= 0; i--) {
1890                                 CacheEntry entry = (CacheEntry) applicable [i];
1891
1892                                 if ((entry.EntryType & (is_property ? EntryType.Property : EntryType.Method)) == 0)
1893                                         continue;
1894
1895                                 PropertyInfo pi = null;
1896                                 MethodInfo mi = null;
1897                                 Type [] cmpAttrs;
1898
1899                                 if (is_property) {
1900                                         pi = (PropertyInfo) entry.Member;
1901                                         cmpAttrs = TypeManager.GetArgumentTypes (pi);
1902                                 } else {
1903                                         mi = (MethodInfo) entry.Member;
1904                                         cmpAttrs = TypeManager.GetArgumentTypes (mi);
1905                                 }
1906
1907                                 //
1908                                 // Check the arguments
1909                                 //
1910                                 if (cmpAttrs.Length != paramTypes.Length)
1911                                         continue;
1912
1913                                 for (int j = cmpAttrs.Length - 1; j >= 0; j --) {
1914                                         if (!paramTypes [j].Equals (cmpAttrs [j]))
1915                                                 goto next;
1916                                 }
1917
1918                                 //
1919                                 // get one of the methods because this has the visibility info.
1920                                 //
1921                                 if (is_property) {
1922                                         mi = pi.GetGetMethod (true);
1923                                         if (mi == null)
1924                                                 mi = pi.GetSetMethod (true);
1925                                 }
1926
1927                                 //
1928                                 // Check visibility
1929                                 //
1930                                 switch (mi.Attributes & MethodAttributes.MemberAccessMask) {
1931                                 case MethodAttributes.Private:
1932                                         //
1933                                         // A private method is Ok if we are a nested subtype.
1934                                         // The spec actually is not very clear about this, see bug 52458.
1935                                         //
1936                                         if (invocationType == entry.Container.Type ||
1937                                             TypeManager.IsNestedChildOf (invocationType, entry.Container.Type))
1938                                                 return entry.Member;
1939
1940                                         break;
1941                                 case MethodAttributes.FamANDAssem:
1942                                 case MethodAttributes.Assembly:
1943                                         //
1944                                         // Check for assembly methods
1945                                         //
1946                                         if (mi.DeclaringType.Assembly == CodeGen.Assembly.Builder)
1947                                                 return entry.Member;
1948
1949                                         break;
1950                                 default:
1951                                         //
1952                                         // A protected method is ok, because we are overriding.
1953                                         // public is always ok.
1954                                         //
1955                                         return entry.Member;
1956                                 }
1957                         next:
1958                                 ;
1959                         }
1960
1961                         return null;
1962                 }
1963         }
1964 }