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 TypeName {
  22                 public readonly string Name;
  23                 public readonly TypeArguments TypeArguments;
  24
  25                 public readonly TypeName Left;
  26
  27                 public static readonly TypeName Null = new TypeName ("");
  28
  29                 public TypeName (string name)
  30                 {
  31                         this.Name = name;
  32                 }
  33
  34                 public TypeName (string name, TypeArguments args)
  35                         : this (name)
  36                 {
  37                         this.TypeArguments = args;
  38                 }
  39
  40                 public TypeName (TypeName left, string name, TypeArguments args)
  41                         : this (name, args)
  42                 {
  43                         this.Left = left;
  44                 }
  45
  46                 public string GetName ()
  47                 {
  48                         if (Left != null)
  49                                 return Left.GetName () + "." + Name;
  50                         else
  51                                 return Name;
  52                 }
  53
  54                 public int CountTypeArguments {
  55                         get {
  56                                 if (TypeArguments == null)
  57                                         return 0;
  58                                 else
  59                                         return TypeArguments.Count;
  60                         }
  61                 }
  62
  63                 public string GetFullName ()
  64                 {
  65                         string full_name;
  66                         if (TypeArguments != null)
  67                                 full_name = Name + "<" + TypeArguments + ">";
  68                         else
  69                                 full_name = Name;
  70                         if (Left != null)
  71                                 return Left.GetFullName () + "." + full_name;
  72                         else
  73                                 return full_name;
  74                 }
  75
  76                 public string GetTypeName ()
  77                 {
  78                         string full_name;
  79                         if (Left != null)
  80                                 return Left.GetFullName () + "." + Name;
  81                         else
  82                                 return Name;
  83                 }
  84
  85                 public Expression GetTypeExpression (Location loc)
  86                 {
  87                         if (Left != null) {
  88                                 Expression lexpr = Left.GetTypeExpression (loc);
  89
  90                                 if (TypeArguments != null)
  91                                         return new GenericMemberAccess (lexpr, Name, TypeArguments, loc);
  92                                 else
  93                                         return new MemberAccess (lexpr, Name, loc);
  94                         } else {
  95                                 if (TypeArguments != null)
  96                                         return new ConstructedType (Name, TypeArguments, loc);
  97                                 else
  98                                         return new SimpleName (Name, loc);
  99                         }
 100                 }
 101
 102                 public MemberName GetMemberName ()
 103                 {
 104                         if (TypeArguments != null) {
 105                                 string[] type_params = TypeArguments.GetDeclarations ();
 106                                 return new MemberName (Left, Name, type_params);
 107                         } else
 108                                 return new MemberName (Left, Name);
 109                 }
 110
 111                 public override string ToString ()
 112                 {
 113                         string full_name;
 114                         if (TypeArguments != null)
 115                                 full_name = Name + "<" + TypeArguments + ">";
 116                         else
 117                                 full_name = Name;
 118
 119                         if (Left != null)
 120                                 return Left + "." + full_name;
 121                         else
 122                                 return full_name;
 123                 }
 124         }
 125
 126         public class MemberName {
 127                 public readonly TypeName TypeName;
 128                 public readonly string Name;
 129                 public readonly string[] TypeParameters;
 130
 131                 public MemberName (string name)
 132                 {
 133                         this.Name = name;
 134                 }
 135
 136                 public MemberName (TypeName type, string name)
 137                 {
 138                         this.TypeName = type;
 139                         this.Name = name;
 140                 }
 141
 142                 public MemberName (string type, MemberName name)
 143                 {
 144                         this.TypeName = new TypeName (type);
 145                         this.Name = name.Name;
 146                         this.TypeParameters = name.TypeParameters;
 147                 }
 148
 149                 public MemberName (TypeName type, string name, ArrayList type_params)
 150                         : this (type, name)
 151                 {
 152                         if (type_params != null) {
 153                                 TypeParameters = new string [type_params.Count];
 154                                 type_params.CopyTo (TypeParameters, 0);
 155                         }
 156                 }
 157
 158                 public MemberName (TypeName type, string name, string[] type_params)
 159                         : this (type, name)
 160                 {
 161                         this.TypeParameters = type_params;
 162                 }
 163
 164                 public static readonly MemberName Null = new MemberName ("");
 165
 166                 public string GetMemberName ()
 167                 {
 168                         string full_name;
 169                         if (TypeName != null)
 170                                 return TypeName.GetFullName () + "." + Name;
 171                         else
 172                                 return Name;
 173                 }
 174
 175                 public static explicit operator string (MemberName name)
 176                 {
 177                         if (name.TypeName != null)
 178                                 return name.TypeName + "." + name.Name;
 179                         else
 180                                 return name.Name;
 181                 }
 182
 183                 public override string ToString ()
 184                 {
 185                         string full_name;
 186                         if (TypeParameters != null) {
 187                                 StringBuilder sb = new StringBuilder ();
 188                                 sb.Append (Name);
 189                                 sb.Append ("<");
 190                                 for (int i = 0; i < TypeParameters.Length; i++) {
 191                                         if (i > 0)
 192                                                 sb.Append (",");
 193                                         sb.Append (TypeParameters [i]);
 194                                 }
 195                                 sb.Append (">");
 196                                 full_name = sb.ToString ();
 197                         } else
 198                                 full_name = Name;
 199
 200                         if (TypeName != null)
 201                                 return TypeName + "." + full_name;
 202                         else
 203                                 return full_name;
 204                 }
 205         }
 206
 207         /// <summary>
 208         ///   Base representation for members.  This is only used to keep track
 209         ///   of Name, Location and Modifier flags.
 210         /// </summary>
 211         public abstract class MemberCore {
 212                 /// <summary>
 213                 ///   Public name
 214                 /// </summary>
 215                 public string Name;
 216
 217                 public readonly MemberName MemberName;
 218
 219                 /// <summary>
 220                 ///   Modifier flags that the user specified in the source code
 221                 /// </summary>
 222                 public int ModFlags;
 223
 224                 /// <summary>
 225                 ///   Location where this declaration happens
 226                 /// </summary>
 227                 public readonly Location Location;
 228
 229                 /// <summary>
 230                 ///   Attributes for this type
 231                 /// </summary>
 232                 Attributes attributes;
 233
 234                 public MemberCore (MemberName name, Attributes attrs, Location loc)
 235                 {
 236                         Name = (string) name;
 237                         MemberName = name;
 238                         Location = loc;
 239                         attributes = attrs;
 240                 }
 241
 242                 public abstract bool Define (TypeContainer parent);
 243
 244                 //
 245                 // Returns full member name for error message
 246                 //
 247                 public virtual string GetSignatureForError () {
 248                         return Name;
 249                 }
 250
 251                 public Attributes OptAttributes
 252                 {
 253                         get {
 254                                 return attributes;
 255                         }
 256                         set {
 257                                 attributes = value;
 258                         }
 259                 }
 260
 261                 //
 262                 // Whehter is it ok to use an unsafe pointer in this type container
 263                 //
 264                 public bool UnsafeOK (DeclSpace parent)
 265                 {
 266                         //
 267                         // First check if this MemberCore modifier flags has unsafe set
 268                         //
 269                         if ((ModFlags & Modifiers.UNSAFE) != 0)
 270                                 return true;
 271
 272                         if (parent.UnsafeContext)
 273                                 return true;
 274
 275                         Expression.UnsafeError (Location);
 276                         return false;
 277                 }
 278         }
 279
 280         /// <summary>
 281         ///   Base class for structs, classes, enumerations and interfaces.
 282         /// </summary>
 283         /// <remarks>
 284         ///   They all create new declaration spaces.  This
 285         ///   provides the common foundation for managing those name
 286         ///   spaces.
 287         /// </remarks>
 288         public abstract class DeclSpace : MemberCore, IAlias {
 289                 /// <summary>
 290                 ///   This points to the actual definition that is being
 291                 ///   created with System.Reflection.Emit
 292                 /// </summary>
 293                 public TypeBuilder TypeBuilder;
 294
 295                 /// <summary>
 296                 ///   If we are a generic type, this is the type we are
 297                 ///   currently defining.  We need to lookup members on this
 298                 ///   instead of the TypeBuilder.
 299                 /// </summary>
 300                 public TypeExpr CurrentType;
 301
 302                 /// <summary>
 303                 ///   This variable tracks whether we have Closed the type
 304                 /// </summary>
 305                 public bool Created = false;
 306
 307                 //
 308                 // This is the namespace in which this typecontainer
 309                 // was declared.  We use this to resolve names.
 310                 //
 311                 public NamespaceEntry NamespaceEntry;
 312
 313                 public Hashtable Cache = new Hashtable ();
 314
 315                 public string Basename;
 316
 317                 /// <summary>
 318                 ///   defined_names is used for toplevel objects
 319                 /// </summary>
 320                 protected Hashtable defined_names;
 321
 322                 readonly bool is_generic;
 323
 324                 //
 325                 // Whether we are Generic
 326                 //
 327                 public bool IsGeneric {
 328                         get {
 329                                 if (is_generic)
 330                                         return true;
 331                                 else if (parent != null)
 332                                         return parent.IsGeneric;
 333                                 else
 334                                         return false;
 335                         }
 336                 }
 337
 338                 TypeContainer parent;
 339
 340                 public DeclSpace (NamespaceEntry ns, TypeContainer parent, MemberName name,
 341                                   Attributes attrs, Location l)
 342                         : base (name, attrs, l)
 343                 {
 344                         NamespaceEntry = ns;
 345                         Basename = name.Name;
 346                         defined_names = new Hashtable ();
 347                         if (name.TypeParameters != null)
 348                                 is_generic = true;
 349                         this.parent = parent;
 350                 }
 351
 352                 public void RecordDecl ()
 353                 {
 354                         if ((NamespaceEntry != null) && (parent == RootContext.Tree.Types))
 355                                 NamespaceEntry.DefineName (Basename, this);
 356                 }
 357
 358                 /// <summary>
 359                 ///   The result value from adding an declaration into
 360                 ///   a struct or a class
 361                 /// </summary>
 362                 public enum AdditionResult {
 363                         /// <summary>
 364                         /// The declaration has been successfully
 365                         /// added to the declation space.
 366                         /// </summary>
 367                         Success,
 368
 369                         /// <summary>
 370                         ///   The symbol has already been defined.
 371                         /// </summary>
 372                         NameExists,
 373
 374                         /// <summary>
 375                         ///   Returned if the declation being added to the
 376                         ///   name space clashes with its container name.
 377                         ///
 378                         ///   The only exceptions for this are constructors
 379                         ///   and static constructors
 380                         /// </summary>
 381                         EnclosingClash,
 382
 383                         /// <summary>
 384                         ///   Returned if a constructor was created (because syntactically
 385                         ///   it looked like a constructor) but was not (because the name
 386                         ///   of the method is not the same as the container class
 387                         /// </summary>
 388                         NotAConstructor,
 389
 390                         /// <summary>
 391                         ///   This is only used by static constructors to emit the
 392                         ///   error 111, but this error for other things really
 393                         ///   happens at another level for other functions.
 394                         /// </summary>
 395                         MethodExists,
 396
 397                         /// <summary>
 398                         ///   Some other error.
 399                         /// </summary>
 400                         Error
 401                 }
 402
 403                 /// <summary>
 404                 ///   Returns a status code based purely on the name
 405                 ///   of the member being added
 406                 /// </summary>
 407                 protected AdditionResult IsValid (string basename, string name)
 408                 {
 409                         if (basename == Basename)
 410                                 return AdditionResult.EnclosingClash;
 411
 412                         if (defined_names.Contains (name))
 413                                 return AdditionResult.NameExists;
 414
 415                         return AdditionResult.Success;
 416                 }
 417
 418                 public static int length;
 419                 public static int small;
 420
 421                 /// <summary>
 422                 ///   Introduce @name into this declaration space and
 423                 ///   associates it with the object @o.  Note that for
 424                 ///   methods this will just point to the first method. o
 425                 /// </summary>
 426                 public void DefineName (string name, object o)
 427                 {
 428                         defined_names.Add (name, o);
 429
 430 #if DEBUGME
 431                         int p = name.LastIndexOf ('.');
 432                         int l = name.Length;
 433                         length += l;
 434                         small += l -p;
 435 #endif
 436                 }
 437
 438                 /// <summary>
 439                 ///   Returns the object associated with a given name in the declaration
 440                 ///   space.  This is the inverse operation of `DefineName'
 441                 /// </summary>
 442                 public object GetDefinition (string name)
 443                 {
 444                         return defined_names [name];
 445                 }
 446
 447                 bool in_transit = false;
 448
 449                 /// <summary>
 450                 ///   This function is used to catch recursive definitions
 451                 ///   in declarations.
 452                 /// </summary>
 453                 public bool InTransit {
 454                         get {
 455                                 return in_transit;
 456                         }
 457
 458                         set {
 459                                 in_transit = value;
 460                         }
 461                 }
 462
 463                 public TypeContainer Parent {
 464                         get {
 465                                 return parent;
 466                         }
 467                 }
 468
 469                 /// <summary>
 470                 ///   Looks up the alias for the name
 471                 /// </summary>
 472                 public IAlias LookupAlias (string name)
 473                 {
 474                         if (NamespaceEntry != null)
 475                                 return NamespaceEntry.LookupAlias (name);
 476                         else
 477                                 return null;
 478                 }
 479
 480                 //
 481                 // root_types contains all the types.  All TopLevel types
 482                 // hence have a parent that points to `root_types', that is
 483                 // why there is a non-obvious test down here.
 484                 //
 485                 public bool IsTopLevel {
 486                         get {
 487                                 if (parent != null){
 488                                         if (parent.parent == null)
 489                                                 return true;
 490                                 }
 491                                 return false;
 492                         }
 493                 }
 494
 495                 public virtual void CloseType ()
 496                 {
 497                         if (!Created){
 498                                 try {
 499                                         TypeBuilder.CreateType ();
 500                                 } catch {
 501                                         //
 502                                         // The try/catch is needed because
 503                                         // nested enumerations fail to load when they
 504                                         // are defined.
 505                                         //
 506                                         // Even if this is the right order (enumerations
 507                                         // declared after types).
 508                                         //
 509                                         // Note that this still creates the type and
 510                                         // it is possible to save it
 511                                 }
 512                                 Created = true;
 513                         }
 514                 }
 515
 516                 /// <remarks>
 517                 ///  Should be overriten by the appropriate declaration space
 518                 /// </remarks>
 519                 public abstract TypeBuilder DefineType ();
 520
 521                 /// <summary>
 522                 ///   Define all members, but don't apply any attributes or do anything which may
 523                 ///   access not-yet-defined classes.  This method also creates the MemberCache.
 524                 /// </summary>
 525                 public abstract bool DefineMembers (TypeContainer parent);
 526
 527                 //
 528                 // Whether this is an `unsafe context'
 529                 //
 530                 public bool UnsafeContext {
 531                         get {
 532                                 if ((ModFlags & Modifiers.UNSAFE) != 0)
 533                                         return true;
 534                                 if (parent != null)
 535                                         return parent.UnsafeContext;
 536                                 return false;
 537                         }
 538                 }
 539
 540                 public static string MakeFQN (string nsn, string name)
 541                 {
 542                         if (nsn == "")
 543                                 return name;
 544                         return String.Concat (nsn, ".", name);
 545                 }
 546
 547                 EmitContext type_resolve_ec;
 548                 EmitContext GetTypeResolveEmitContext (TypeContainer parent, Location loc)
 549                 {
 550                         type_resolve_ec = new EmitContext (parent, this, loc, null, null, ModFlags, false);
 551                         type_resolve_ec.ResolvingTypeTree = true;
 552
 553                         return type_resolve_ec;
 554                 }
 555
 556                 // <summary>
 557                 //    Looks up the type, as parsed into the expression `e'
 558                 // </summary>
 559                 public Type ResolveType (Expression e, bool silent, Location loc)
 560                 {
 561                         TypeExpr d = ResolveTypeExpr (e, silent, loc);
 562                         if (d == null)
 563                                 return null;
 564
 565                         return ResolveType (d, loc);
 566                 }
 567
 568                 public Type ResolveType (TypeExpr d, Location loc)
 569                 {
 570                         if (!d.CheckAccessLevel (this)) {
 571                                 Report. Error (122, loc,  "`" + d.Name + "' " +
 572                                        "is inaccessible because of its protection level");
 573                                 return null;
 574                         }
 575
 576                         Type t = d.ResolveType (type_resolve_ec);
 577                         if (t == null)
 578                                 return null;
 579
 580                         TypeContainer tc = TypeManager.LookupTypeContainer (t);
 581                         if ((tc != null) && tc.IsGeneric) {
 582                                 if (!IsGeneric) {
 583                                         int tnum = TypeManager.GetNumberOfTypeArguments (t);
 584                                         Report.Error (305, loc,
 585                                                       "Using the generic type `{0}' " +
 586                                                       "requires {1} type arguments",
 587                                                       TypeManager.GetFullName (t), tnum);
 588                                         return null;
 589                                 }
 590
 591                                 ConstructedType ctype = new ConstructedType (
 592                                         t, TypeParameters, loc);
 593
 594                                 t = ctype.ResolveType (type_resolve_ec);
 595                         }
 596
 597                         return t;
 598                 }
 599
 600                 // <summary>
 601                 //    Resolves the expression `e' for a type, and will recursively define
 602                 //    types.
 603                 // </summary>
 604                 public TypeExpr ResolveTypeExpr (Expression e, bool silent, Location loc)
 605                 {
 606                         if (type_resolve_ec == null)
 607                                 type_resolve_ec = GetTypeResolveEmitContext (parent, loc);
 608                         type_resolve_ec.loc = loc;
 609                         if (this is GenericMethod)
 610                                 type_resolve_ec.ContainerType = Parent.TypeBuilder;
 611                         else
 612                                 type_resolve_ec.ContainerType = TypeBuilder;
 613
 614                         int errors = Report.Errors;
 615
 616                         TypeExpr d = e.ResolveAsTypeTerminal (type_resolve_ec);
 617
 618                         if ((d != null) && (d.eclass == ExprClass.Type))
 619                                 return d;
 620
 621                         if (silent || (Report.Errors != errors))
 622                                 return null;
 623
 624                         if (e is SimpleName){
 625                                 SimpleName s = new SimpleName (((SimpleName) e).Name, -1, loc);
 626                                 d = s.ResolveAsTypeTerminal (type_resolve_ec);
 627
 628                                 if ((d == null) || (d.Type == null)) {
 629                                         Report.Error (246, loc, "Cannot find type `{0}'", e);
 630                                         return null;
 631                                 }
 632
 633                                 int num_args = TypeManager.GetNumberOfTypeArguments (d.Type);
 634
 635                                 if (num_args == 0) {
 636                                         Report.Error (308, loc,
 637                                                       "The non-generic type `{0}' cannot " +
 638                                                       "be used with type arguments.",
 639                                                       TypeManager.CSharpName (d.Type));
 640                                         return null;
 641                                 }
 642
 643                                 Report.Error (305, loc,
 644                                               "Using the generic type `{0}' " +
 645                                               "requires {1} type arguments",
 646                                               TypeManager.GetFullName (d.Type), num_args);
 647                                 return null;
 648                         }
 649
 650                         Report.Error (246, loc, "Cannot find type `{0}'", e);
 651                         return null;
 652                 }
 653
 654                 public bool CheckAccessLevel (Type check_type)
 655                 {
 656                         TypeBuilder tb;
 657                         if (this is GenericMethod)
 658                                 tb = Parent.TypeBuilder;
 659                         else
 660                                 tb = TypeBuilder;
 661
 662                         if (check_type.IsGenericInstance)
 663                                 check_type = check_type.GetGenericTypeDefinition ();
 664
 665                         if (check_type == tb)
 666                                 return true;
 667
 668                         if (check_type.IsGenericParameter)
 669                                 return true; // FIXME
 670
 671                         TypeAttributes check_attr = check_type.Attributes & TypeAttributes.VisibilityMask;
 672
 673                         //
 674                         // Broken Microsoft runtime, return public for arrays, no matter what
 675                         // the accessibility is for their underlying class, and they return
 676                         // NonPublic visibility for pointers
 677                         //
 678                         if (check_type.IsArray || check_type.IsPointer)
 679                                 return CheckAccessLevel (TypeManager.GetElementType (check_type));
 680
 681                         switch (check_attr){
 682                         case TypeAttributes.Public:
 683                                 return true;
 684
 685                         case TypeAttributes.NotPublic:
 686                                 //
 687                                 // This test should probably use the declaringtype.
 688                                 //
 689                                 if (check_type.Assembly == tb.Assembly){
 690                                         return true;
 691                                 }
 692                                 return false;
 693
 694                         case TypeAttributes.NestedPublic:
 695                                 return true;
 696
 697                         case TypeAttributes.NestedPrivate:
 698                                 string check_type_name = check_type.FullName;
 699                                 string type_name = CurrentType != null ?
 700                                         CurrentType.Name : tb.FullName;
 701
 702                                 int cio = check_type_name.LastIndexOf ('+');
 703                                 string container = check_type_name.Substring (0, cio);
 704
 705                                 //
 706                                 // Check if the check_type is a nested class of the current type
 707                                 //
 708                                 if (check_type_name.StartsWith (type_name + "+")){
 709                                         return true;
 710                                 }
 711
 712                                 if (type_name.StartsWith (container)){
 713                                         return true;
 714                                 }
 715
 716                                 return false;
 717
 718                         case TypeAttributes.NestedFamily:
 719                                 //
 720                                 // Only accessible to methods in current type or any subtypes
 721                                 //
 722                                 return FamilyAccessible (tb, check_type);
 723
 724                         case TypeAttributes.NestedFamANDAssem:
 725                                 return (check_type.Assembly == tb.Assembly) &&
 726                                         FamilyAccessible (tb, check_type);
 727
 728                         case TypeAttributes.NestedFamORAssem:
 729                                 return (check_type.Assembly == tb.Assembly) ||
 730                                         FamilyAccessible (tb, check_type);
 731
 732                         case TypeAttributes.NestedAssembly:
 733                                 return check_type.Assembly == tb.Assembly;
 734                         }
 735
 736                         Console.WriteLine ("HERE: " + check_attr);
 737                         return false;
 738
 739                 }
 740
 741                 protected bool FamilyAccessible (TypeBuilder tb, Type check_type)
 742                 {
 743                         Type declaring = check_type.DeclaringType;
 744                         if (tb.IsSubclassOf (declaring))
 745                                 return true;
 746
 747                         string check_type_name = check_type.FullName;
 748
 749                         int cio = check_type_name.LastIndexOf ('+');
 750                         string container = check_type_name.Substring (0, cio);
 751
 752                         //
 753                         // Check if the check_type is a nested class of the current type
 754                         //
 755                         if (check_type_name.StartsWith (container + "+"))
 756                                 return true;
 757
 758                         return false;
 759                 }
 760
 761                 // Access level of a type.
 762                 const int X = 1;
 763                 enum AccessLevel { // Each column represents `is this scope larger or equal to Blah scope'
 764                         // Public    Assembly   Protected
 765                         Protected           = (0 << 0) | (0 << 1) | (X << 2),
 766                         Public              = (X << 0) | (X << 1) | (X << 2),
 767                         Private             = (0 << 0) | (0 << 1) | (0 << 2),
 768                         Internal            = (0 << 0) | (X << 1) | (0 << 2),
 769                         ProtectedOrInternal = (0 << 0) | (X << 1) | (X << 2),
 770                 }
 771
 772                 static AccessLevel GetAccessLevelFromModifiers (int flags)
 773                 {
 774                         if ((flags & Modifiers.INTERNAL) != 0) {
 775
 776                                 if ((flags & Modifiers.PROTECTED) != 0)
 777                                         return AccessLevel.ProtectedOrInternal;
 778                                 else
 779                                         return AccessLevel.Internal;
 780
 781                         } else if ((flags & Modifiers.PROTECTED) != 0)
 782                                 return AccessLevel.Protected;
 783                         else if ((flags & Modifiers.PRIVATE) != 0)
 784                                 return AccessLevel.Private;
 785                         else
 786                                 return AccessLevel.Public;
 787                 }
 788
 789                 // What is the effective access level of this?
 790                 // TODO: Cache this?
 791                 AccessLevel EffectiveAccessLevel {
 792                         get {
 793                                 AccessLevel myAccess = GetAccessLevelFromModifiers (ModFlags);
 794                                 if (!IsTopLevel && (Parent != null))
 795                                         return myAccess & Parent.EffectiveAccessLevel;
 796                                 return myAccess;
 797                         }
 798                 }
 799
 800                 // Return the access level for type `t'
 801                 static AccessLevel TypeEffectiveAccessLevel (Type t)
 802                 {
 803                         if (t.IsPublic)
 804                                 return AccessLevel.Public;
 805                         if (t.IsNestedPrivate)
 806                                 return AccessLevel.Private;
 807                         if (t.IsNotPublic)
 808                                 return AccessLevel.Internal;
 809
 810                         // By now, it must be nested
 811                         AccessLevel parentLevel = TypeEffectiveAccessLevel (t.DeclaringType);
 812
 813                         if (t.IsNestedPublic)
 814                                 return parentLevel;
 815                         if (t.IsNestedAssembly)
 816                                 return parentLevel & AccessLevel.Internal;
 817                         if (t.IsNestedFamily)
 818                                 return parentLevel & AccessLevel.Protected;
 819                         if (t.IsNestedFamORAssem)
 820                                 return parentLevel & AccessLevel.ProtectedOrInternal;
 821                         if (t.IsNestedFamANDAssem)
 822                                 throw new NotImplementedException ("NestedFamANDAssem not implemented, cant make this kind of type from c# anyways");
 823
 824                         // nested private is taken care of
 825
 826                         throw new Exception ("I give up, what are you?");
 827                 }
 828
 829                 //
 830                 // This answers `is the type P, as accessible as a member M which has the
 831                 // accessability @flags which is declared as a nested member of the type T, this declspace'
 832                 //
 833                 public bool AsAccessible (Type p, int flags)
 834                 {
 835                         if (p.IsGenericParameter)
 836                                 return true; // FIXME
 837
 838                         //
 839                         // 1) if M is private, its accessability is the same as this declspace.
 840                         // we already know that P is accessible to T before this method, so we
 841                         // may return true.
 842                         //
 843
 844                         if ((flags & Modifiers.PRIVATE) != 0)
 845                                 return true;
 846
 847                         while (p.IsArray || p.IsPointer || p.IsByRef)
 848                                 p = TypeManager.GetElementType (p);
 849
 850                         AccessLevel pAccess = TypeEffectiveAccessLevel (p);
 851                         AccessLevel mAccess = this.EffectiveAccessLevel &
 852                                 GetAccessLevelFromModifiers (flags);
 853
 854                         // for every place from which we can access M, we must
 855                         // be able to access P as well. So, we want
 856                         // For every bit in M and P, M_i -> P_1 == true
 857                         // or, ~ (M -> P) == 0 <-> ~ ( ~M | P) == 0
 858
 859                         return ~ (~ mAccess | pAccess) == 0;
 860                 }
 861
 862                 static DoubleHash dh = new DoubleHash (1000);
 863
 864                 Type DefineTypeAndParents (DeclSpace tc)
 865                 {
 866                         DeclSpace container = tc.Parent;
 867
 868                         if (container.TypeBuilder == null && container.Name != "")
 869                                 DefineTypeAndParents (container);
 870
 871                         return tc.DefineType ();
 872                 }
 873
 874                 Type LookupInterfaceOrClass (string ns, string name, out bool error)
 875                 {
 876                         DeclSpace parent;
 877                         Type t;
 878                         object r;
 879
 880                         error = false;
 881
 882                         if (dh.Lookup (ns, name, out r))
 883                                 return (Type) r;
 884                         else {
 885                                 if (ns != ""){
 886                                         if (Namespace.IsNamespace (ns)){
 887                                                 string fullname = (ns != "") ? ns + "." + name : name;
 888                                                 t = TypeManager.LookupType (fullname);
 889                                         } else
 890                                                 t = null;
 891                                 } else
 892                                         t = TypeManager.LookupType (name);
 893                         }
 894
 895                         if (t != null) {
 896                                 dh.Insert (ns, name, t);
 897                                 return t;
 898                         }
 899
 900                         //
 901                         // In case we are fed a composite name, normalize it.
 902                         //
 903                         int p = name.LastIndexOf ('.');
 904                         if (p != -1){
 905                                 ns = MakeFQN (ns, name.Substring (0, p));
 906                                 name = name.Substring (p+1);
 907                         }
 908
 909                         parent = RootContext.Tree.LookupByNamespace (ns, name);
 910                         if (parent == null) {
 911                                 dh.Insert (ns, name, null);
 912                                 return null;
 913                         }
 914
 915                         t = DefineTypeAndParents (parent);
 916                         if (t == null){
 917                                 error = true;
 918                                 return null;
 919                         }
 920
 921                         dh.Insert (ns, name, t);
 922                         return t;
 923                 }
 924
 925                 public static void Error_AmbiguousTypeReference (Location loc, string name, string t1, string t2)
 926                 {
 927                         Report.Error (104, loc,
 928                                       "`{0}' is an ambiguous reference ({1} or {2})",
 929                                       name, t1, t2);
 930                 }
 931
 932                 public Type FindNestedType (Location loc, string name,
 933                                             out DeclSpace containing_ds)
 934                 {
 935                         Type t;
 936                         bool error;
 937
 938                         containing_ds = this;
 939                         while (containing_ds != null){
 940                                 Type container_type = containing_ds.TypeBuilder;
 941                                 Type current_type = container_type;
 942
 943                                 while (current_type != null && current_type != TypeManager.object_type) {
 944                                         string pre = current_type.FullName;
 945
 946                                         t = LookupInterfaceOrClass (pre, name, out error);
 947                                         if (error)
 948                                                 return null;
 949
 950                                         if ((t != null) && containing_ds.CheckAccessLevel (t))
 951                                                 return t;
 952
 953                                         current_type = current_type.BaseType;
 954                                 }
 955                                 containing_ds = containing_ds.Parent;
 956                         }
 957
 958                         return null;
 959                 }
 960
 961                 /// <summary>
 962                 ///   GetType is used to resolve type names at the DeclSpace level.
 963                 ///   Use this to lookup class/struct bases, interface bases or
 964                 ///   delegate type references
 965                 /// </summary>
 966                 ///
 967                 /// <remarks>
 968                 ///   Contrast this to LookupType which is used inside method bodies to
 969                 ///   lookup types that have already been defined.  GetType is used
 970                 ///   during the tree resolution process and potentially define
 971                 ///   recursively the type
 972                 /// </remarks>
 973                 public Type FindType (Location loc, string name, int num_type_args)
 974                 {
 975                         Type t;
 976                         bool error;
 977
 978                         //
 979                         // For the case the type we are looking for is nested within this one
 980                         // or is in any base class
 981                         //
 982                         DeclSpace containing_ds = this;
 983
 984                         while (containing_ds != null){
 985                                 Type container_type = containing_ds.TypeBuilder;
 986                                 Type current_type = container_type;
 987
 988                                 while (current_type != null && current_type != TypeManager.object_type) {
 989                                         string pre = current_type.FullName;
 990
 991                                         t = LookupInterfaceOrClass (pre, name, out error);
 992                                         if (error)
 993                                                 return null;
 994
 995                                         if ((t != null) &&
 996                                             containing_ds.CheckAccessLevel (t) &&
 997                                             TypeManager.CheckGeneric (t, num_type_args))
 998                                                 return t;
 999
1000                                         current_type = current_type.BaseType;
1001                                 }
1002                                 containing_ds = containing_ds.Parent;
1003                         }
1004
1005                         //
1006                         // Attempt to lookup the class on our namespace and all it's implicit parents
1007                         //
1008                         for (NamespaceEntry ns = NamespaceEntry; ns != null; ns = ns.ImplicitParent) {
1009                                 t = LookupInterfaceOrClass (ns.FullName, name, out error);
1010                                 if (error)
1011                                         return null;
1012
1013                                 if ((t != null) && TypeManager.CheckGeneric (t, num_type_args))
1014                                         return t;
1015                         }
1016
1017                         //
1018                         // Attempt to do a direct unqualified lookup
1019                         //
1020                         t = LookupInterfaceOrClass ("", name, out error);
1021                         if (error)
1022                                 return null;
1023
1024                         if ((t != null) && TypeManager.CheckGeneric (t, num_type_args))
1025                                 return t;
1026
1027                         //
1028                         // Attempt to lookup the class on any of the `using'
1029                         // namespaces
1030                         //
1031
1032                         for (NamespaceEntry ns = NamespaceEntry; ns != null; ns = ns.Parent){
1033
1034                                 t = LookupInterfaceOrClass (ns.FullName, name, out error);
1035                                 if (error)
1036                                         return null;
1037
1038                                 if ((t != null) && TypeManager.CheckGeneric (t, num_type_args))
1039                                         return t;
1040
1041                                 //
1042                                 // Now check the using clause list
1043                                 //
1044                                 Type match = null;
1045                                 foreach (Namespace using_ns in ns.GetUsingTable ()) {
1046                                         match = LookupInterfaceOrClass (using_ns.Name, name, out error);
1047                                         if (error)
1048                                                 return null;
1049
1050                                         if ((match != null) &&
1051                                             TypeManager.CheckGeneric (match, num_type_args)) {
1052                                                 if (t != null){
1053                                                         if (CheckAccessLevel (match)) {
1054                                                                 Error_AmbiguousTypeReference (loc, name, t.FullName, match.FullName);
1055                                                                 return null;
1056                                                         }
1057                                                         continue;
1058                                                 }
1059
1060                                                 t = match;
1061                                         }
1062                                 }
1063                                 if ((t != null) && TypeManager.CheckGeneric (t, num_type_args))
1064                                         return t;
1065                         }
1066
1067                         //Report.Error (246, Location, "Can not find type `"+name+"'");
1068                         return null;
1069                 }
1070
1071                 /// <remarks>
1072                 ///   This function is broken and not what you're looking for.  It should only
1073                 ///   be used while the type is still being created since it doesn't use the cache
1074                 ///   and relies on the filter doing the member name check.
1075                 /// </remarks>
1076                 public abstract MemberList FindMembers (MemberTypes mt, BindingFlags bf,
1077                                                         MemberFilter filter, object criteria);
1078
1079                 /// <remarks>
1080                 ///   If we have a MemberCache, return it.  This property may return null if the
1081                 ///   class doesn't have a member cache or while it's still being created.
1082                 /// </remarks>
1083                 public abstract MemberCache MemberCache {
1084                         get;
1085                 }
1086
1087                 //
1088                 // Extensions for generics
1089                 //
1090                 TypeParameter[] type_params;
1091                 TypeParameter[] type_param_list;
1092
1093                 protected string GetInstantiationName ()
1094                 {
1095                         StringBuilder sb = new StringBuilder (Name);
1096                         sb.Append ("<");
1097                         for (int i = 0; i < type_param_list.Length; i++) {
1098                                 if (i > 0)
1099                                         sb.Append (",");
1100                                 sb.Append (type_param_list [i].Name);
1101                         }
1102                         sb.Append (">");
1103                         return sb.ToString ();
1104                 }
1105
1106                 bool check_type_parameter (ArrayList list, int start, string name)
1107                 {
1108                         for (int i = 0; i < start; i++) {
1109                                 TypeParameter param = (TypeParameter) list [i];
1110
1111                                 if (param.Name != name)
1112                                         continue;
1113
1114                                 if (RootContext.WarningLevel >= 3)
1115                                         Report.Warning (
1116                                                 693, Location,
1117                                                 "Type parameter `{0}' has same name " +
1118                                                 "as type parameter from outer type `{1}'",
1119                                                 name, parent.GetInstantiationName ());
1120
1121                                 return false;
1122                         }
1123
1124                         return true;
1125                 }
1126
1127                 TypeParameter[] initialize_type_params ()
1128                 {
1129                         if (type_param_list != null)
1130                                 return type_param_list;
1131
1132                         DeclSpace the_parent = parent;
1133                         if (this is GenericMethod)
1134                                 the_parent = the_parent.Parent;
1135
1136                         int start = 0;
1137                         TypeParameter[] parent_params = null;
1138                         if ((the_parent != null) && the_parent.IsGeneric) {
1139                                 parent_params = the_parent.initialize_type_params ();
1140                                 start = parent_params != null ? parent_params.Length : 0;
1141                         }
1142
1143                         ArrayList list = new ArrayList ();
1144                         if (parent_params != null)
1145                                 list.AddRange (parent_params);
1146
1147                         int count = type_params != null ? type_params.Length : 0;
1148                         for (int i = 0; i < count; i++) {
1149                                 TypeParameter param = type_params [i];
1150                                 check_type_parameter (list, start, param.Name);
1151                                 list.Add (param);
1152                         }
1153
1154                         type_param_list = new TypeParameter [list.Count];
1155                         list.CopyTo (type_param_list, 0);
1156                         return type_param_list;
1157                 }
1158
1159                 public AdditionResult SetParameterInfo (ArrayList constraints_list)
1160                 {
1161                         if (!is_generic) {
1162                                 if (constraints_list != null) {
1163                                         Report.Error (
1164                                                 80, Location, "Contraints are not allowed " +
1165                                                 "on non-generic declarations");
1166                                         return AdditionResult.Error;
1167                                 }
1168
1169                                 return AdditionResult.Success;
1170                         }
1171
1172                         type_params = new TypeParameter [MemberName.TypeParameters.Length];
1173
1174                         //
1175                         // Register all the names
1176                         //
1177                         for (int i = 0; i < MemberName.TypeParameters.Length; i++) {
1178                                 string name = MemberName.TypeParameters [i];
1179
1180                                 AdditionResult res = IsValid (name, name);
1181
1182                                 if (res != AdditionResult.Success)
1183                                         return res;
1184
1185                                 Constraints constraints = null;
1186                                 if (constraints_list != null) {
1187                                         foreach (Constraints constraint in constraints_list) {
1188                                                 if (constraint.TypeParameter == name) {
1189                                                         constraints = constraint;
1190                                                         break;
1191                                                 }
1192                                         }
1193                                 }
1194
1195                                 type_params [i] = new TypeParameter (name, constraints, Location);
1196
1197                                 DefineName (name, type_params [i]);
1198                         }
1199
1200                         return AdditionResult.Success;
1201                 }
1202
1203                 public TypeParameter[] TypeParameters {
1204                         get {
1205                                 if (!IsGeneric)
1206                                         throw new InvalidOperationException ();
1207                                 if (type_param_list == null)
1208                                         initialize_type_params ();
1209
1210                                 return type_param_list;
1211                         }
1212                 }
1213
1214                 protected TypeParameter[] CurrentTypeParameters {
1215                         get {
1216                                 if (!IsGeneric)
1217                                         throw new InvalidOperationException ();
1218                                 if (type_params != null)
1219                                         return type_params;
1220                                 else
1221                                         return new TypeParameter [0];
1222                         }
1223                 }
1224
1225                 public int CountTypeParameters {
1226                         get {
1227                                 if (!IsGeneric)
1228                                         return 0;
1229                                 if (type_param_list == null)
1230                                         initialize_type_params ();
1231
1232                                 return type_param_list.Length;
1233                         }
1234                 }
1235
1236                 public TypeParameterExpr LookupGeneric (string name, Location loc)
1237                 {
1238                         if (!IsGeneric)
1239                                 return null;
1240
1241                         foreach (TypeParameter type_param in CurrentTypeParameters) {
1242                                 if (type_param.Name != name)
1243                                         continue;
1244
1245                                 return new TypeParameterExpr (type_param, loc);
1246                         }
1247
1248                         if (parent != null)
1249                                 return parent.LookupGeneric (name, loc);
1250
1251                         return null;
1252                 }
1253
1254                 bool IAlias.IsType {
1255                         get { return true; }
1256                 }
1257
1258                 string IAlias.Name {
1259                         get { return Name; }
1260                 }
1261
1262                 TypeExpr IAlias.Type
1263                 {
1264                         get {
1265                                 if (TypeBuilder == null)
1266                                         throw new InvalidOperationException ();
1267
1268                                 if (CurrentType != null)
1269                                         return CurrentType;
1270
1271                                 return new TypeExpression (TypeBuilder, Location);
1272                         }
1273                 }
1274         }
1275
1276         /// <summary>
1277         ///   This is a readonly list of MemberInfo's.
1278         /// </summary>
1279         public class MemberList : IList {
1280                 public readonly IList List;
1281                 int count;
1282
1283                 /// <summary>
1284                 ///   Create a new MemberList from the given IList.
1285                 /// </summary>
1286                 public MemberList (IList list)
1287                 {
1288                         if (list != null)
1289                                 this.List = list;
1290                         else
1291                                 this.List = new ArrayList ();
1292                         count = List.Count;
1293                 }
1294
1295                 /// <summary>
1296                 ///   Concatenate the ILists `first' and `second' to a new MemberList.
1297                 /// </summary>
1298                 public MemberList (IList first, IList second)
1299                 {
1300                         ArrayList list = new ArrayList ();
1301                         list.AddRange (first);
1302                         list.AddRange (second);
1303                         count = list.Count;
1304                         List = list;
1305                 }
1306
1307                 public static readonly MemberList Empty = new MemberList (new ArrayList ());
1308
1309                 /// <summary>
1310                 ///   Cast the MemberList into a MemberInfo[] array.
1311                 /// </summary>
1312                 /// <remarks>
1313                 ///   This is an expensive operation, only use it if it's really necessary.
1314                 /// </remarks>
1315                 public static explicit operator MemberInfo [] (MemberList list)
1316                 {
1317                         Timer.StartTimer (TimerType.MiscTimer);
1318                         MemberInfo [] result = new MemberInfo [list.Count];
1319                         list.CopyTo (result, 0);
1320                         Timer.StopTimer (TimerType.MiscTimer);
1321                         return result;
1322                 }
1323
1324                 // ICollection
1325
1326                 public int Count {
1327                         get {
1328                                 return count;
1329                         }
1330                 }
1331
1332                 public bool IsSynchronized {
1333                         get {
1334                                 return List.IsSynchronized;
1335                         }
1336                 }
1337
1338                 public object SyncRoot {
1339                         get {
1340                                 return List.SyncRoot;
1341                         }
1342                 }
1343
1344                 public void CopyTo (Array array, int index)
1345                 {
1346                         List.CopyTo (array, index);
1347                 }
1348
1349                 // IEnumerable
1350
1351                 public IEnumerator GetEnumerator ()
1352                 {
1353                         return List.GetEnumerator ();
1354                 }
1355
1356                 // IList
1357
1358                 public bool IsFixedSize {
1359                         get {
1360                                 return true;
1361                         }
1362                 }
1363
1364                 public bool IsReadOnly {
1365                         get {
1366                                 return true;
1367                         }
1368                 }
1369
1370                 object IList.this [int index] {
1371                         get {
1372                                 return List [index];
1373                         }
1374
1375                         set {
1376                                 throw new NotSupportedException ();
1377                         }
1378                 }
1379
1380                 // FIXME: try to find out whether we can avoid the cast in this indexer.
1381                 public MemberInfo this [int index] {
1382                         get {
1383                                 return (MemberInfo) List [index];
1384                         }
1385                 }
1386
1387                 public int Add (object value)
1388                 {
1389                         throw new NotSupportedException ();
1390                 }
1391
1392                 public void Clear ()
1393                 {
1394                         throw new NotSupportedException ();
1395                 }
1396
1397                 public bool Contains (object value)
1398                 {
1399                         return List.Contains (value);
1400                 }
1401
1402                 public int IndexOf (object value)
1403                 {
1404                         return List.IndexOf (value);
1405                 }
1406
1407                 public void Insert (int index, object value)
1408                 {
1409                         throw new NotSupportedException ();
1410                 }
1411
1412                 public void Remove (object value)
1413                 {
1414                         throw new NotSupportedException ();
1415                 }
1416
1417                 public void RemoveAt (int index)
1418                 {
1419                         throw new NotSupportedException ();
1420                 }
1421         }
1422
1423         /// <summary>
1424         ///   This interface is used to get all members of a class when creating the
1425         ///   member cache.  It must be implemented by all DeclSpace derivatives which
1426         ///   want to support the member cache and by TypeHandle to get caching of
1427         ///   non-dynamic types.
1428         /// </summary>
1429         public interface IMemberContainer {
1430                 /// <summary>
1431                 ///   The name of the IMemberContainer.  This is only used for
1432                 ///   debugging purposes.
1433                 /// </summary>
1434                 string Name {
1435                         get;
1436                 }
1437
1438                 /// <summary>
1439                 ///   The type of this IMemberContainer.
1440                 /// </summary>
1441                 Type Type {
1442                         get;
1443                 }
1444
1445                 /// <summary>
1446                 ///   Returns the IMemberContainer of the parent class or null if this
1447                 ///   is an interface or TypeManger.object_type.
1448                 ///   This is used when creating the member cache for a class to get all
1449                 ///   members from the parent class.
1450                 /// </summary>
1451                 IMemberContainer Parent {
1452                         get;
1453                 }
1454
1455                 /// <summary>
1456                 ///   Whether this is an interface.
1457                 /// </summary>
1458                 bool IsInterface {
1459                         get;
1460                 }
1461
1462                 /// <summary>
1463                 ///   Returns all members of this class with the corresponding MemberTypes
1464                 ///   and BindingFlags.
1465                 /// </summary>
1466                 /// <remarks>
1467                 ///   When implementing this method, make sure not to return any inherited
1468                 ///   members and check the MemberTypes and BindingFlags properly.
1469                 ///   Unfortunately, System.Reflection is lame and doesn't provide a way to
1470                 ///   get the BindingFlags (static/non-static,public/non-public) in the
1471                 ///   MemberInfo class, but the cache needs this information.  That's why
1472                 ///   this method is called multiple times with different BindingFlags.
1473                 /// </remarks>
1474                 MemberList GetMembers (MemberTypes mt, BindingFlags bf);
1475
1476                 /// <summary>
1477                 ///   Return the container's member cache.
1478                 /// </summary>
1479                 MemberCache MemberCache {
1480                         get;
1481                 }
1482         }
1483
1484         /// <summary>
1485         ///   The MemberCache is used by dynamic and non-dynamic types to speed up
1486         ///   member lookups.  It has a member name based hash table; it maps each member
1487         ///   name to a list of CacheEntry objects.  Each CacheEntry contains a MemberInfo
1488         ///   and the BindingFlags that were initially used to get it.  The cache contains
1489         ///   all members of the current class and all inherited members.  If this cache is
1490         ///   for an interface types, it also contains all inherited members.
1491         ///
1492         ///   There are two ways to get a MemberCache:
1493         ///   * if this is a dynamic type, lookup the corresponding DeclSpace and then
1494         ///     use the DeclSpace.MemberCache property.
1495         ///   * if this not a dynamic type, call TypeHandle.GetTypeHandle() to get a
1496         ///     TypeHandle instance for the type and then use TypeHandle.MemberCache.
1497         /// </summary>
1498         public class MemberCache {
1499                 public readonly IMemberContainer Container;
1500                 protected Hashtable member_hash;
1501                 protected Hashtable method_hash;
1502
1503                 Hashtable interface_hash;
1504
1505                 /// <summary>
1506                 ///   Create a new MemberCache for the given IMemberContainer `container'.
1507                 /// </summary>
1508                 public MemberCache (IMemberContainer container)
1509                 {
1510                         this.Container = container;
1511
1512                         Timer.IncrementCounter (CounterType.MemberCache);
1513                         Timer.StartTimer (TimerType.CacheInit);
1514
1515
1516
1517                         // If we have a parent class (we have a parent class unless we're
1518                         // TypeManager.object_type), we deep-copy its MemberCache here.
1519                         if (Container.IsInterface) {
1520                                 MemberCache parent;
1521                                 interface_hash = new Hashtable ();
1522
1523                                 if (Container.Parent != null)
1524                                         parent = Container.Parent.MemberCache;
1525                                 else
1526                                         parent = TypeHandle.ObjectType.MemberCache;
1527                                 member_hash = SetupCacheForInterface (parent);
1528                         } else if (Container.Parent != null)
1529                                 member_hash = SetupCache (Container.Parent.MemberCache);
1530                         else
1531                                 member_hash = new Hashtable ();
1532
1533                         // If this is neither a dynamic type nor an interface, create a special
1534                         // method cache with all declared and inherited methods.
1535                         Type type = container.Type;
1536                         if (!(type is TypeBuilder) && !type.IsInterface && !type.IsGenericParameter) {
1537                                 method_hash = new Hashtable ();
1538                                 AddMethods (type);
1539                         }
1540
1541                         // Add all members from the current class.
1542                         AddMembers (Container);
1543
1544                         Timer.StopTimer (TimerType.CacheInit);
1545                 }
1546
1547                 /// <summary>
1548                 ///   Bootstrap this member cache by doing a deep-copy of our parent.
1549                 /// </summary>
1550                 Hashtable SetupCache (MemberCache parent)
1551                 {
1552                         Hashtable hash = new Hashtable ();
1553
1554                         IDictionaryEnumerator it = parent.member_hash.GetEnumerator ();
1555                         while (it.MoveNext ()) {
1556                                 hash [it.Key] = ((ArrayList) it.Value).Clone ();
1557                         }
1558
1559                         return hash;
1560                 }
1561
1562
1563                 /// <summary>
1564                 ///   Add the contents of `new_hash' to `hash'.
1565                 /// </summary>
1566                 void AddHashtable (Hashtable hash, Hashtable new_hash)
1567                 {
1568                         IDictionaryEnumerator it = new_hash.GetEnumerator ();
1569                         while (it.MoveNext ()) {
1570                                 ArrayList list = (ArrayList) hash [it.Key];
1571                                 if (list != null)
1572                                         list.AddRange ((ArrayList) it.Value);
1573                                 else
1574                                         hash [it.Key] = ((ArrayList) it.Value).Clone ();
1575                         }
1576                 }
1577
1578                 /// <summary>
1579                 ///   Bootstrap the member cache for an interface type.
1580                 ///   Type.GetMembers() won't return any inherited members for interface types,
1581                 ///   so we need to do this manually.  Interfaces also inherit from System.Object.
1582                 /// </summary>
1583                 Hashtable SetupCacheForInterface (MemberCache parent)
1584                 {
1585                         Hashtable hash = SetupCache (parent);
1586                         TypeExpr [] ifaces = TypeManager.GetInterfaces (Container.Type);
1587
1588                         foreach (TypeExpr iface in ifaces) {
1589                                 Type itype = iface.Type;
1590
1591                                 if (interface_hash.Contains (itype))
1592                                         continue;
1593
1594                                 interface_hash [itype] = null;
1595
1596                                 IMemberContainer iface_container =
1597                                         TypeManager.LookupMemberContainer (itype);
1598
1599                                 MemberCache iface_cache = iface_container.MemberCache;
1600
1601                                 AddHashtable (hash, iface_cache.member_hash);
1602
1603                                 if (iface_cache.interface_hash == null)
1604                                         continue;
1605
1606                                 foreach (Type parent_contains in iface_cache.interface_hash.Keys)
1607                                         interface_hash [parent_contains] = null;
1608                         }
1609
1610                         return hash;
1611                 }
1612
1613                 /// <summary>
1614                 ///   Add all members from class `container' to the cache.
1615                 /// </summary>
1616                 void AddMembers (IMemberContainer container)
1617                 {
1618                         // We need to call AddMembers() with a single member type at a time
1619                         // to get the member type part of CacheEntry.EntryType right.
1620                         AddMembers (MemberTypes.Constructor, container);
1621                         AddMembers (MemberTypes.Field, container);
1622                         AddMembers (MemberTypes.Method, container);
1623                         AddMembers (MemberTypes.Property, container);
1624                         AddMembers (MemberTypes.Event, container);
1625                         // Nested types are returned by both Static and Instance searches.
1626                         AddMembers (MemberTypes.NestedType,
1627                                     BindingFlags.Static | BindingFlags.Public, container);
1628                         AddMembers (MemberTypes.NestedType,
1629                                     BindingFlags.Static | BindingFlags.NonPublic, container);
1630                 }
1631
1632                 void AddMembers (MemberTypes mt, IMemberContainer container)
1633                 {
1634                         AddMembers (mt, BindingFlags.Static | BindingFlags.Public, container);
1635                         AddMembers (mt, BindingFlags.Static | BindingFlags.NonPublic, container);
1636                         AddMembers (mt, BindingFlags.Instance | BindingFlags.Public, container);
1637                         AddMembers (mt, BindingFlags.Instance | BindingFlags.NonPublic, container);
1638                 }
1639
1640                 /// <summary>
1641                 ///   Add all members from class `container' with the requested MemberTypes and
1642                 ///   BindingFlags to the cache.  This method is called multiple times with different
1643                 ///   MemberTypes and BindingFlags.
1644                 /// </summary>
1645                 void AddMembers (MemberTypes mt, BindingFlags bf, IMemberContainer container)
1646                 {
1647                         MemberList members = container.GetMembers (mt, bf);
1648
1649                         foreach (MemberInfo member in members) {
1650                                 string name = member.Name;
1651
1652                                 int pos = name.IndexOf ('<');
1653                                 if (pos > 0)
1654                                         name = name.Substring (0, pos);
1655
1656                                 // We use a name-based hash table of ArrayList's.
1657                                 ArrayList list = (ArrayList) member_hash [name];
1658                                 if (list == null) {
1659                                         list = new ArrayList ();
1660                                         member_hash.Add (name, list);
1661                                 }
1662
1663                                 // When this method is called for the current class, the list will
1664                                 // already contain all inherited members from our parent classes.
1665                                 // We cannot add new members in front of the list since this'd be an
1666                                 // expensive operation, that's why the list is sorted in reverse order
1667                                 // (ie. members from the current class are coming last).
1668                                 list.Add (new CacheEntry (container, member, mt, bf));
1669                         }
1670                 }
1671
1672                 /// <summary>
1673                 ///   Add all declared and inherited methods from class `type' to the method cache.
1674                 /// </summary>
1675                 void AddMethods (Type type)
1676                 {
1677                         AddMethods (BindingFlags.Static | BindingFlags.Public |
1678                                     BindingFlags.FlattenHierarchy, type);
1679                         AddMethods (BindingFlags.Static | BindingFlags.NonPublic |
1680                                     BindingFlags.FlattenHierarchy, type);
1681                         AddMethods (BindingFlags.Instance | BindingFlags.Public, type);
1682                         AddMethods (BindingFlags.Instance | BindingFlags.NonPublic, type);
1683                 }
1684
1685                 void AddMethods (BindingFlags bf, Type type)
1686                 {
1687                         MemberInfo [] members = type.GetMethods (bf);
1688
1689                         Array.Reverse (members);
1690
1691                         foreach (MethodBase member in members) {
1692                                 string name = member.Name;
1693
1694                                 // Varargs methods aren't allowed in C# code.
1695                                 if ((member.CallingConvention & CallingConventions.VarArgs) != 0)
1696                                         continue;
1697
1698                                 // We use a name-based hash table of ArrayList's.
1699                                 ArrayList list = (ArrayList) method_hash [name];
1700                                 if (list == null) {
1701                                         list = new ArrayList ();
1702                                         method_hash.Add (name, list);
1703                                 }
1704
1705                                 // Unfortunately, the elements returned by Type.GetMethods() aren't
1706                                 // sorted so we need to do this check for every member.
1707                                 BindingFlags new_bf = bf;
1708                                 if (member.DeclaringType == type)
1709                                         new_bf |= BindingFlags.DeclaredOnly;
1710
1711                                 list.Add (new CacheEntry (Container, member, MemberTypes.Method, new_bf));
1712                         }
1713                 }
1714
1715                 /// <summary>
1716                 ///   Compute and return a appropriate `EntryType' magic number for the given
1717                 ///   MemberTypes and BindingFlags.
1718                 /// </summary>
1719                 protected static EntryType GetEntryType (MemberTypes mt, BindingFlags bf)
1720                 {
1721                         EntryType type = EntryType.None;
1722
1723                         if ((mt & MemberTypes.Constructor) != 0)
1724                                 type |= EntryType.Constructor;
1725                         if ((mt & MemberTypes.Event) != 0)
1726                                 type |= EntryType.Event;
1727                         if ((mt & MemberTypes.Field) != 0)
1728                                 type |= EntryType.Field;
1729                         if ((mt & MemberTypes.Method) != 0)
1730                                 type |= EntryType.Method;
1731                         if ((mt & MemberTypes.Property) != 0)
1732                                 type |= EntryType.Property;
1733                         // Nested types are returned by static and instance searches.
1734                         if ((mt & MemberTypes.NestedType) != 0)
1735                                 type |= EntryType.NestedType | EntryType.Static | EntryType.Instance;
1736
1737                         if ((bf & BindingFlags.Instance) != 0)
1738                                 type |= EntryType.Instance;
1739                         if ((bf & BindingFlags.Static) != 0)
1740                                 type |= EntryType.Static;
1741                         if ((bf & BindingFlags.Public) != 0)
1742                                 type |= EntryType.Public;
1743                         if ((bf & BindingFlags.NonPublic) != 0)
1744                                 type |= EntryType.NonPublic;
1745                         if ((bf & BindingFlags.DeclaredOnly) != 0)
1746                                 type |= EntryType.Declared;
1747
1748                         return type;
1749                 }
1750
1751                 /// <summary>
1752                 ///   The `MemberTypes' enumeration type is a [Flags] type which means that it may
1753                 ///   denote multiple member types.  Returns true if the given flags value denotes a
1754                 ///   single member types.
1755                 /// </summary>
1756                 public static bool IsSingleMemberType (MemberTypes mt)
1757                 {
1758                         switch (mt) {
1759                         case MemberTypes.Constructor:
1760                         case MemberTypes.Event:
1761                         case MemberTypes.Field:
1762                         case MemberTypes.Method:
1763                         case MemberTypes.Property:
1764                         case MemberTypes.NestedType:
1765                                 return true;
1766
1767                         default:
1768                                 return false;
1769                         }
1770                 }
1771
1772                 /// <summary>
1773                 ///   We encode the MemberTypes and BindingFlags of each members in a "magic"
1774                 ///   number to speed up the searching process.
1775                 /// </summary>
1776                 [Flags]
1777                 protected enum EntryType {
1778                         None            = 0x000,
1779
1780                         Instance        = 0x001,
1781                         Static          = 0x002,
1782                         MaskStatic      = Instance|Static,
1783
1784                         Public          = 0x004,
1785                         NonPublic       = 0x008,
1786                         MaskProtection  = Public|NonPublic,
1787
1788                         Declared        = 0x010,
1789
1790                         Constructor     = 0x020,
1791                         Event           = 0x040,
1792                         Field           = 0x080,
1793                         Method          = 0x100,
1794                         Property        = 0x200,
1795                         NestedType      = 0x400,
1796
1797                         MaskType        = Constructor|Event|Field|Method|Property|NestedType
1798                 }
1799
1800                 protected struct CacheEntry {
1801                         public readonly IMemberContainer Container;
1802                         public readonly EntryType EntryType;
1803                         public readonly MemberInfo Member;
1804
1805                         public CacheEntry (IMemberContainer container, MemberInfo member,
1806                                            MemberTypes mt, BindingFlags bf)
1807                         {
1808                                 this.Container = container;
1809                                 this.Member = member;
1810                                 this.EntryType = GetEntryType (mt, bf);
1811                         }
1812                 }
1813
1814                 /// <summary>
1815                 ///   This is called each time we're walking up one level in the class hierarchy
1816                 ///   and checks whether we can abort the search since we've already found what
1817                 ///   we were looking for.
1818                 /// </summary>
1819                 protected bool DoneSearching (ArrayList list)
1820                 {
1821                         //
1822                         // We've found exactly one member in the current class and it's not
1823                         // a method or constructor.
1824                         //
1825                         if (list.Count == 1 && !(list [0] is MethodBase))
1826                                 return true;
1827
1828                         //
1829                         // Multiple properties: we query those just to find out the indexer
1830                         // name
1831                         //
1832                         if ((list.Count > 0) && (list [0] is PropertyInfo))
1833                                 return true;
1834
1835                         return false;
1836                 }
1837
1838                 /// <summary>
1839                 ///   Looks up members with name `name'.  If you provide an optional
1840                 ///   filter function, it'll only be called with members matching the
1841                 ///   requested member name.
1842                 ///
1843                 ///   This method will try to use the cache to do the lookup if possible.
1844                 ///
1845                 ///   Unlike other FindMembers implementations, this method will always
1846                 ///   check all inherited members - even when called on an interface type.
1847                 ///
1848                 ///   If you know that you're only looking for methods, you should use
1849                 ///   MemberTypes.Method alone since this speeds up the lookup a bit.
1850                 ///   When doing a method-only search, it'll try to use a special method
1851                 ///   cache (unless it's a dynamic type or an interface) and the returned
1852                 ///   MemberInfo's will have the correct ReflectedType for inherited methods.
1853                 ///   The lookup process will automatically restart itself in method-only
1854                 ///   search mode if it discovers that it's about to return methods.
1855                 /// </summary>
1856                 ArrayList global = new ArrayList ();
1857                 bool using_global = false;
1858
1859                 public MemberList FindMembers (MemberTypes mt, BindingFlags bf, string name,
1860                                                MemberFilter filter, object criteria)
1861                 {
1862                         if (using_global)
1863                                 throw new Exception ();
1864
1865                         bool declared_only = (bf & BindingFlags.DeclaredOnly) != 0;
1866                         bool method_search = mt == MemberTypes.Method;
1867                         // If we have a method cache and we aren't already doing a method-only search,
1868                         // then we restart a method search if the first match is a method.
1869                         bool do_method_search = !method_search && (method_hash != null);
1870
1871                         ArrayList applicable;
1872
1873                         // If this is a method-only search, we try to use the method cache if
1874                         // possible; a lookup in the method cache will return a MemberInfo with
1875                         // the correct ReflectedType for inherited methods.
1876
1877                         if (method_search && (method_hash != null))
1878                                 applicable = (ArrayList) method_hash [name];
1879                         else
1880                                 applicable = (ArrayList) member_hash [name];
1881
1882                         if (applicable == null)
1883                                 return MemberList.Empty;
1884
1885                         //
1886                         // 32  slots gives 53 rss/54 size
1887                         // 2/4 slots gives 55 rss
1888                         //
1889                         // Strange: from 25,000 calls, only 1,800
1890                         // are above 2.  Why does this impact it?
1891                         //
1892                         global.Clear ();
1893                         using_global = true;
1894
1895                         Timer.StartTimer (TimerType.CachedLookup);
1896
1897                         EntryType type = GetEntryType (mt, bf);
1898
1899                         IMemberContainer current = Container;
1900
1901                         // `applicable' is a list of all members with the given member name `name'
1902                         // in the current class and all its parent classes.  The list is sorted in
1903                         // reverse order due to the way how the cache is initialy created (to speed
1904                         // things up, we're doing a deep-copy of our parent).
1905
1906                         for (int i = applicable.Count-1; i >= 0; i--) {
1907                                 CacheEntry entry = (CacheEntry) applicable [i];
1908
1909                                 // This happens each time we're walking one level up in the class
1910                                 // hierarchy.  If we're doing a DeclaredOnly search, we must abort
1911                                 // the first time this happens (this may already happen in the first
1912                                 // iteration of this loop if there are no members with the name we're
1913                                 // looking for in the current class).
1914                                 if (entry.Container != current) {
1915                                         if (declared_only || DoneSearching (global))
1916                                                 break;
1917
1918                                         current = entry.Container;
1919                                 }
1920
1921                                 // Is the member of the correct type ?
1922                                 if ((entry.EntryType & type & EntryType.MaskType) == 0)
1923                                         continue;
1924
1925                                 // Is the member static/non-static ?
1926                                 if ((entry.EntryType & type & EntryType.MaskStatic) == 0)
1927                                         continue;
1928
1929                                 // Apply the filter to it.
1930                                 if (filter (entry.Member, criteria)) {
1931                                         if ((entry.EntryType & EntryType.MaskType) != EntryType.Method)
1932                                                 do_method_search = false;
1933                                         global.Add (entry.Member);
1934                                 }
1935                         }
1936
1937                         Timer.StopTimer (TimerType.CachedLookup);
1938
1939                         // If we have a method cache and we aren't already doing a method-only
1940                         // search, we restart in method-only search mode if the first match is
1941                         // a method.  This ensures that we return a MemberInfo with the correct
1942                         // ReflectedType for inherited methods.
1943                         if (do_method_search && (global.Count > 0)){
1944                                 using_global = false;
1945
1946                                 return FindMembers (MemberTypes.Method, bf, name, filter, criteria);
1947                         }
1948
1949                         using_global = false;
1950                         MemberInfo [] copy = new MemberInfo [global.Count];
1951                         global.CopyTo (copy);
1952                         return new MemberList (copy);
1953                 }
1954
1955                 //
1956                 // This finds the method or property for us to override. invocationType is the type where
1957                 // the override is going to be declared, name is the name of the method/property, and
1958                 // paramTypes is the parameters, if any to the method or property
1959                 //
1960                 // Because the MemberCache holds members from this class and all the base classes,
1961                 // we can avoid tons of reflection stuff.
1962                 //
1963                 public MemberInfo FindMemberToOverride (Type invocationType, string name, Type [] paramTypes, bool is_property)
1964                 {
1965                         ArrayList applicable;
1966                         if (method_hash != null && !is_property)
1967                                 applicable = (ArrayList) method_hash [name];
1968                         else
1969                                 applicable = (ArrayList) member_hash [name];
1970
1971                         if (applicable == null)
1972                                 return null;
1973                         //
1974                         // Walk the chain of methods, starting from the top.
1975                         //
1976                         for (int i = applicable.Count - 1; i >= 0; i--) {
1977                                 CacheEntry entry = (CacheEntry) applicable [i];
1978
1979                                 if ((entry.EntryType & (is_property ? EntryType.Property : EntryType.Method)) == 0)
1980                                         continue;
1981
1982                                 PropertyInfo pi = null;
1983                                 MethodInfo mi = null;
1984                                 Type [] cmpAttrs;
1985
1986                                 if (is_property) {
1987                                         pi = (PropertyInfo) entry.Member;
1988                                         cmpAttrs = TypeManager.GetArgumentTypes (pi);
1989                                 } else {
1990                                         mi = (MethodInfo) entry.Member;
1991                                         cmpAttrs = TypeManager.GetArgumentTypes (mi);
1992                                 }
1993
1994                                 //
1995                                 // Check the arguments
1996                                 //
1997                                 if (cmpAttrs.Length != paramTypes.Length)
1998                                         continue;
1999
2000                                 for (int j = cmpAttrs.Length - 1; j >= 0; j --) {
2001                                         if (!paramTypes [j].Equals (cmpAttrs [j]))
2002                                                 goto next;
2003                                 }
2004
2005                                 //
2006                                 // get one of the methods because this has the visibility info.
2007                                 //
2008                                 if (is_property) {
2009                                         mi = pi.GetGetMethod (true);
2010                                         if (mi == null)
2011                                                 mi = pi.GetSetMethod (true);
2012                                 }
2013
2014                                 //
2015                                 // Check visibility
2016                                 //
2017                                 switch (mi.Attributes & MethodAttributes.MemberAccessMask) {
2018                                 case MethodAttributes.Private:
2019                                         //
2020                                         // A private method is Ok if we are a nested subtype.
2021                                         // The spec actually is not very clear about this, see bug 52458.
2022                                         //
2023                                         if (invocationType == entry.Container.Type ||
2024                                             TypeManager.IsNestedChildOf (invocationType, entry.Container.Type))
2025                                                 return entry.Member;
2026
2027                                         break;
2028                                 case MethodAttributes.FamANDAssem:
2029                                 case MethodAttributes.Assembly:
2030                                         //
2031                                         // Check for assembly methods
2032                                         //
2033                                         if (mi.DeclaringType.Assembly == CodeGen.Assembly.Builder)
2034                                                 return entry.Member;
2035
2036                                         break;
2037                                 default:
2038                                         //
2039                                         // A protected method is ok, because we are overriding.
2040                                         // public is always ok.
2041                                         //
2042                                         return entry.Member;
2043                                 }
2044                         next:
2045                                 ;
2046                         }
2047
2048                         return null;
2049                 }
2050         }
2051 }