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