mcs/mbas/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.Collections;
  15 using System.Reflection.Emit;
  16 using System.Reflection;
  17
  18 namespace Mono.MonoBASIC {
  19
  20         /// <summary>
  21         ///   Base representation for members.  This is only used to keep track
  22         ///   of Name, Location and Modifier flags.
  23         /// </summary>
  24         public abstract class MemberCore : Attributable
  25         {
  26                 /// <summary>
  27                 ///   Public name
  28                 /// </summary>
  29                 public string Name;
  30
  31                 /// <summary>
  32                 ///   Modifier flags that the user specified in the source code
  33                 /// </summary>
  34                 public int ModFlags;
  35
  36                 /// <summary>
  37                 ///   Location where this declaration happens
  38                 /// </summary>
  39                 public readonly Location Location;
  40
  41                 public MemberCore (string name, Attributes attrs, Location loc)
  42                         : base (attrs)
  43                 {
  44                         Name = name;
  45                         Location = loc;
  46                 }
  47
  48                 protected void WarningNotHiding (TypeContainer parent)
  49                 {
  50                         /*Report.Warning (
  51                                 109, Location,
  52                                 "The member " + parent.MakeName (Name) + " does not hide an " +
  53                                 "inherited member.  The keyword new is not required");
  54                         */
  55                 }
  56
  57                 void Error_CannotChangeAccessModifiers (TypeContainer parent, MethodInfo parent_method,
  58                                                         string name)
  59                 {
  60                         //
  61                         // FIXME: report the old/new permissions?
  62                         //
  63                         Report.Error (
  64                                 31048, Location, parent.MakeName (Name) +
  65                                 ": can't change the access modifiers when overriding inherited " +
  66                                 "member `" + name + "'");
  67                 }
  68
  69                 //
  70                 // Performs various checks on the MethodInfo `mb' regarding the modifier flags
  71                 // that have been defined.
  72                 //
  73                 // `name' is the user visible name for reporting errors (this is used to
  74                 // provide the right name regarding method names and properties)
  75                 //
  76                 protected bool CheckMethodAgainstBase (TypeContainer parent, MethodAttributes my_attrs,
  77                                                        MethodInfo mb, string name)
  78                 {
  79                         bool ok = true;
  80
  81                         if ((ModFlags & Modifiers.OVERRIDE) != 0){
  82                                 // Now we check that the overriden method is not final
  83                                 if (mb.IsFinal)
  84                                 {
  85                                         Report.Error (30267, Location, parent.MakeName (Name) + " : cannot " +
  86                                                 "override inherited member `" + name +
  87                                                 "' because it is NotOverridable.");
  88                                         ok = false;
  89                                 }
  90                                 else if (!(mb.IsAbstract || mb.IsVirtual)){
  91                                         Report.Error (
  92                                                 31086, Location, parent.MakeName (Name) +
  93                                                 ": Cannot override inherited member `" +
  94                                                 name + "' because it is not " +
  95                                                 "declared as Overridable");
  96                                         ok = false;
  97                                 }
  98
  99                                 //
 100                                 // Check that the permissions are not being changed
 101                                 //
 102                                 MethodAttributes thisp = my_attrs & MethodAttributes.MemberAccessMask;
 103                                 MethodAttributes parentp = mb.Attributes & MethodAttributes.MemberAccessMask;
 104
 105                                 if (thisp != parentp){
 106                                         Error_CannotChangeAccessModifiers (parent, mb, name);
 107                                         ok = false;
 108                                 }
 109                         }
 110
 111                         if ((ModFlags & ( Modifiers.NEW | Modifiers.SHADOWS | Modifiers.OVERRIDE )) == 0) {
 112                                 if ((ModFlags & Modifiers.NONVIRTUAL) != 0)     {
 113                                         Report.Error (31088, Location,
 114                                                 parent.MakeName (Name) + " cannot " +
 115                                                 "be declared NotOverridable since this method is " +
 116                                                 "not marked as Overrides");
 117                                 }
 118                         }
 119
 120                         if (mb.IsAbstract) {
 121                                 if ((ModFlags & (Modifiers.OVERRIDE)) == 0)     {
 122                                         if (Name != "Finalize") {
 123                                                 Report.Error (
 124                                                         31404, Location,
 125                                                         name + " cannot Shadows the method " +
 126                                                         parent.MakeName (Name) + " since it is declared " +
 127                                                         "'MustOverride' in base class");
 128                                         }
 129                                 }
 130                         }
 131                         else if (mb.IsVirtual){
 132                                 if ((ModFlags & (Modifiers.NEW | Modifiers.OVERRIDE | Modifiers.SHADOWS)) == 0){
 133                                         if (Name != "Finalize"){
 134                                                 Report.Warning (
 135                                                         40005, 2, Location, parent.MakeName (Name) +
 136                                                         " shadows overridable member `" + name +
 137                                                         "'.  To make the current member override that " +
 138                                                         "implementation, add the overrides keyword." );
 139                                                 ModFlags |= Modifiers.SHADOWS;
 140                                         }
 141                                 }
 142                         }
 143                         else {
 144                                 if ((ModFlags & (Modifiers.NEW | Modifiers.OVERRIDE |
 145                                         Modifiers.SHADOWS)) == 0){
 146                                         if (Name != "Finalize"){
 147                                                 Report.Warning (
 148                                                         40004, 1, Location, "The keyword Shadows is required on " +
 149                                                         parent.MakeName (Name) + " because it hides " +
 150                                                         "inherited member `" + name + "'");
 151                                                 ModFlags |= Modifiers.SHADOWS;
 152                                         }
 153                                 }
 154                         }
 155
 156                         return ok;
 157                 }
 158
 159                 public abstract bool Define (TypeContainer parent);
 160
 161                 //
 162                 // Whehter is it ok to use an unsafe pointer in this type container
 163                 //
 164                 public bool UnsafeOK (DeclSpace parent)
 165                 {
 166                         //
 167                         // First check if this MemberCore modifier flags has unsafe set
 168                         //
 169                         if ((ModFlags & Modifiers.UNSAFE) != 0)
 170                                 return true;
 171
 172                         if (parent.UnsafeContext)
 173                                 return true;
 174
 175                         Expression.UnsafeError (Location);
 176                         return false;
 177                 }
 178         }
 179
 180         //
 181         // FIXME: This is temporary outside DeclSpace, because I have to fix a bug
 182         // in MCS that makes it fail the lookup for the enum
 183         //
 184
 185                 /// <summary>
 186                 ///   The result value from adding an declaration into
 187                 ///   a struct or a class
 188                 /// </summary>
 189                 public enum AdditionResult {
 190                         /// <summary>
 191                         /// The declaration has been successfully
 192                         /// added to the declation space.
 193                         /// </summary>
 194                         Success,
 195
 196                         /// <summary>
 197                         ///   The symbol has already been defined.
 198                         /// </summary>
 199                         NameExists,
 200
 201                         /// <summary>
 202                         ///   Returned if the declation being added to the
 203                         ///   name space clashes with its container name.
 204                         ///
 205                         ///   The only exceptions for this are constructors
 206                         ///   and static constructors
 207                         /// </summary>
 208                         EnclosingClash,
 209
 210                         /// <summary>
 211                         ///   Returned if a constructor was created (because syntactically
 212                         ///   it looked like a constructor) but was not (because the name
 213                         ///   of the method is not the same as the container class
 214                         /// </summary>
 215                         NotAConstructor,
 216
 217                         /// <summary>
 218                         ///   This is only used by static constructors to emit the
 219                         ///   error 111, but this error for other things really
 220                         ///   happens at another level for other functions.
 221                         /// </summary>
 222                         MethodExists
 223                 }
 224
 225         /// <summary>
 226         ///   Base class for structs, classes, enumerations and interfaces.
 227         /// </summary>
 228         /// <remarks>
 229         ///   They all create new declaration spaces.  This
 230         ///   provides the common foundation for managing those name
 231         ///   spaces.
 232         /// </remarks>
 233         public abstract class DeclSpace : MemberCore {
 234                 /// <summary>
 235                 ///   this points to the actual definition that is being
 236                 ///   created with System.Reflection.Emit
 237                 /// </summary>
 238                 public TypeBuilder TypeBuilder;
 239
 240                 /// <summary>
 241                 ///   This variable tracks whether we have Closed the type
 242                 /// </summary>
 243                 public bool Created = false;
 244
 245                 //
 246                 // This is the namespace in which this typecontainer
 247                 // was declared.  We use this to resolve names.
 248                 //
 249                 public Namespace Namespace;
 250
 251                 public Hashtable Cache = new Hashtable ();
 252
 253                 public string Basename;
 254
 255                 /// <summary>
 256                 ///   defined_names is used for toplevel objects
 257                 /// </summary>
 258                 protected Hashtable defined_names;
 259
 260                 TypeContainer parent;
 261
 262                 public DeclSpace (TypeContainer parent, string name, Attributes attrs, Location l)
 263                         : base (name, attrs, l)
 264                 {
 265                         Basename = name.Substring (1 + name.LastIndexOf ('.'));
 266                         defined_names = new Hashtable ();
 267                         this.parent = parent;
 268                 }
 269
 270                 /// <summary>
 271                 ///   Returns a status code based purely on the name
 272                 ///   of the member being added
 273                 /// </summary>
 274                 protected AdditionResult IsValid (string name)
 275                 {
 276                         if (name == Basename)
 277                                 return AdditionResult.EnclosingClash;
 278
 279                         if (defined_names.Contains (name))
 280                                 return AdditionResult.NameExists;
 281
 282                         return AdditionResult.Success;
 283                 }
 284
 285                 /// <summary>
 286                 ///   Introduce @name into this declaration space and
 287                 ///   associates it with the object @o.  Note that for
 288                 ///   methods this will just point to the first method. o
 289                 /// </summary>
 290                 protected void DefineName (string name, object o)
 291                 {
 292                         try {
 293                                 defined_names.Add (name, o);
 294                         }
 295                         catch (ArgumentException exp) {
 296                                 Report.Error (30260, /*Location,*/
 297                                         "More than one defination with same name '" + name +
 298                                         "' is found in the container '" + Name + "'");
 299                     }
 300
 301                 }
 302
 303                 /// <summary>
 304                 ///   Returns the object associated with a given name in the declaration
 305                 ///   space.  This is the inverse operation of `DefineName'
 306                 /// </summary>
 307                 public object GetDefinition (string name)
 308                 {
 309                         return defined_names [name];
 310                 }
 311
 312                 bool in_transit = false;
 313
 314                 /// <summary>
 315                 ///   This function is used to catch recursive definitions
 316                 ///   in declarations.
 317                 /// </summary>
 318                 public bool InTransit {
 319                         get {
 320                                 return in_transit;
 321                         }
 322
 323                         set {
 324                                 in_transit = value;
 325                         }
 326                 }
 327
 328                 public TypeContainer Parent {
 329                         get {
 330                                 return parent;
 331                         }
 332                 }
 333
 334                 /// <summary>
 335                 ///   Looks up the alias for the name
 336                 /// </summary>
 337                 public string LookupAlias (string name)
 338                 {
 339                         return RootContext.SourceBeingCompiled.LookupAlias (name);
 340                 }
 341
 342                 //
 343                 // root_types contains all the types.  All TopLevel types
 344                 // hence have a parent that points to `root_types', that is
 345                 // why there is a non-obvious test down here.
 346                 //
 347                 public bool IsTopLevel {
 348                         get {
 349                                 if (parent != null){
 350                                         if (parent.parent == null)
 351                                                 return true;
 352                                 }
 353                                 return false;
 354                         }
 355                 }
 356
 357                 public virtual void CloseType ()
 358                 {
 359                         if (!Created){
 360                                 try {
 361                                         TypeBuilder.CreateType ();
 362                                 } catch {
 363                                         //
 364                                         // The try/catch is needed because
 365                                         // nested enumerations fail to load when they
 366                                         // are defined.
 367                                         //
 368                                         // Even if this is the right order (enumerations
 369                                         // declared after types).
 370                                         //
 371                                         // Note that this still creates the type and
 372                                         // it is possible to save it
 373                                 }
 374                                 Created = true;
 375                         }
 376                 }
 377
 378                 /// <remarks>
 379                 ///  Should be overriten by the appropriate declaration space
 380                 /// <remarks>
 381                 public abstract TypeBuilder DefineType ();
 382
 383                 /// <summary>
 384                 ///   Define all members, but don't apply any attributes or do anything which may
 385                 ///   access not-yet-defined classes.  This method also creates the MemberCache.
 386                 /// </summary>
 387                 public abstract bool DefineMembers (TypeContainer parent);
 388
 389                 //
 390                 // Whether this is an `unsafe context'
 391                 //
 392                 public bool UnsafeContext {
 393                         get {
 394                                 if ((ModFlags & Modifiers.UNSAFE) != 0)
 395                                         return true;
 396                                 if (parent != null)
 397                                         return parent.UnsafeContext;
 398                                 return false;
 399                         }
 400                 }
 401
 402                 public static string MakeFQN (string nsn, string name)
 403                 {
 404                         string prefix = (nsn == "" ? "" : nsn + ".");
 405
 406                         return prefix + name;
 407                 }
 408
 409                 EmitContext type_resolve_ec;
 410                 EmitContext GetTypeResolveEmitContext (TypeContainer parent, Location loc)
 411                 {
 412                         type_resolve_ec = new EmitContext (parent, this, loc, null, null, ModFlags, false);
 413                         type_resolve_ec.ResolvingTypeTree = true;
 414
 415                         return type_resolve_ec;
 416                 }
 417
 418                 // <summary>
 419                 //    Looks up the type, as parsed into the expression `e'
 420                 // </summary>
 421                 public Type ResolveType (Expression e, bool silent, Location loc)
 422                 {
 423                         if (type_resolve_ec == null)
 424                                 type_resolve_ec = GetTypeResolveEmitContext (parent, loc);
 425                         type_resolve_ec.loc = loc;
 426
 427                         int errors = Report.Errors;
 428                         Expression d = e.Resolve (type_resolve_ec, ResolveFlags.Type);
 429                         if (d == null || d.eclass != ExprClass.Type){
 430                                 if (!silent && errors == Report.Errors){
 431                                         Report.Error (30002, loc, "Cannot find type `"+ e.ToString () +"'");
 432                                 }
 433                                 return null;
 434                         }
 435
 436                         return d.Type;
 437                 }
 438
 439                 // <summary>
 440                 //    Resolves the expression `e' for a type, and will recursively define
 441                 //    types.
 442                 // </summary>
 443                 public Expression ResolveTypeExpr (Expression e, bool silent, Location loc)
 444                 {
 445                         if (type_resolve_ec == null)
 446                                 type_resolve_ec = GetTypeResolveEmitContext (parent, loc);
 447
 448                         Expression d = e.Resolve (type_resolve_ec, ResolveFlags.Type);
 449                         if (d == null || d.eclass != ExprClass.Type){
 450                                 if (!silent){
 451                                         Report.Error (30002, loc, "Cannot find type `"+ e +"'");
 452                                 }
 453                                 return null;
 454                         }
 455
 456                         return d;
 457                 }
 458
 459                 Type LookupInterfaceOrClass (string ns, string name, out bool error)
 460                 {
 461                         DeclSpace parent;
 462                         Type t;
 463
 464                         error = false;
 465                         name = MakeFQN (ns, name);
 466
 467                         t  = TypeManager.LookupType (name);
 468                         if (t != null)
 469                                 return t;
 470
 471                         parent = (DeclSpace) RootContext.Tree.Decls [name];
 472                         if (parent == null)
 473                                 return null;
 474
 475                         t = parent.DefineType ();
 476                         if (t == null){
 477                                 Report.Error (30256, Location, "Class definition is circular: `"+name+"'");
 478                                 error = true;
 479                                 return null;
 480                         }
 481                         return t;
 482                 }
 483
 484                 public static void Error_AmbiguousTypeReference (Location loc, string name, Type t1, Type t2)
 485                 {
 486                         Report.Error (104, loc,
 487                                       String.Format ("`{0}' is an ambiguous reference ({1} or {2}) ", name,
 488                                                      t1.FullName, t2.FullName));
 489                 }
 490
 491                 /// <summary>
 492                 ///   GetType is used to resolve type names at the DeclSpace level.
 493                 ///   Use this to lookup class/struct bases, interface bases or
 494                 ///   delegate type references
 495                 /// </summary>
 496                 ///
 497                 /// <remarks>
 498                 ///   Contrast this to LookupType which is used inside method bodies to
 499                 ///   lookup types that have already been defined.  GetType is used
 500                 ///   during the tree resolution process and potentially define
 501                 ///   recursively the type
 502                 /// </remarks>
 503                 public Type FindType (Location loc, string name)
 504                 {
 505                         Type t;
 506                         bool error;
 507
 508                         //
 509                         // For the case the type we are looking for is nested within this one
 510                         // or is in any base class
 511                         //
 512                         DeclSpace containing_ds = this;
 513
 514                         while (containing_ds != null){
 515                                 Type current_type = containing_ds.TypeBuilder;
 516
 517                                 while (current_type != null) {
 518                                         string pre = current_type.FullName;
 519
 520                                         t = LookupInterfaceOrClass (pre, name, out error);
 521                                         if (error)
 522                                                 return null;
 523
 524                                         if (t != null)
 525                                                 return t;
 526
 527                                         current_type = current_type.BaseType;
 528                                 }
 529                                 containing_ds = containing_ds.Parent;
 530                         }
 531
 532                         //
 533                         // Attempt to lookup the class on our namespace and all it's implicit parents
 534                         //
 535                         for (string ns = Namespace.Name; ns != null; ns = RootContext.ImplicitParent (ns)) {
 536
 537                                 t = LookupInterfaceOrClass (ns, name, out error);
 538                                 if (error)
 539                                         return null;
 540
 541                                 if (t != null)
 542                                         return t;
 543                         }
 544
 545                         //
 546                         // Attempt to do a direct unqualified lookup
 547                         //
 548                         t = LookupInterfaceOrClass ("", name, out error);
 549                         if (error)
 550                                 return null;
 551
 552                         if (t != null)
 553                                 return t;
 554
 555                         //
 556                         // Attempt to lookup the class on any of the `using'
 557                         // namespaces
 558                         //
 559
 560                         for (Namespace ns = Namespace; ns != null; ns = ns.Parent){
 561
 562                                 t = LookupInterfaceOrClass (ns.Name, name, out error);
 563                                 if (error)
 564                                         return null;
 565
 566                                 if (t != null)
 567                                         return t;
 568
 569                                 //
 570                                 // Now check the using clause list
 571                                 //
 572                                 ICollection imports_list = RootContext.SourceBeingCompiled.ImportsTable;
 573
 574                                 if (imports_list == null)
 575                                         continue;
 576
 577                                 Type match = null;
 578                                 foreach (SourceBeingCompiled.ImportsEntry ue in imports_list){
 579                                         match = LookupInterfaceOrClass (ue.Name, name, out error);
 580                                         if (error)
 581                                                 return null;
 582
 583                                         if (match != null){
 584                                                 if (t != null){
 585                                                         Error_AmbiguousTypeReference (loc, name, t, match);
 586                                                         return null;
 587                                                 }
 588
 589                                                 t = match;
 590                                                 ue.Used = true;
 591                                         }
 592                                 }
 593                                 if (t != null)
 594                                         return t;
 595                         }
 596
 597                         //Report.Error (246, Location, "Can not find type `"+name+"'");
 598                         return null;
 599                 }
 600
 601                 /// <remarks>
 602                 ///   This function is broken and not what you're looking for.  It should only
 603                 ///   be used while the type is still being created since it doesn't use the cache
 604                 ///   and relies on the filter doing the member name check.
 605                 /// </remarks>
 606                 public abstract MemberList FindMembers (MemberTypes mt, BindingFlags bf,
 607                                                         MemberFilter filter, object criteria);
 608
 609                 /// <remarks>
 610                 ///   If we have a MemberCache, return it.  This property may return null if the
 611                 ///   class doesn't have a member cache or while it's still being created.
 612                 /// </remarks>
 613                 public abstract MemberCache MemberCache {
 614                         get;
 615                 }
 616
 617                 public override void ApplyAttributeBuilder (Attribute a, CustomAttributeBuilder cb)
 618                 {
 619                         try {
 620                                 TypeBuilder.SetCustomAttribute (cb);
 621                         } catch (System.ArgumentException e) {
 622                                 Report.Warning (-21, a.Location,
 623                                                 "The CharSet named property on StructLayout\n"+
 624                                                 "\tdoes not work correctly on Microsoft.NET\n"+
 625                                                 "\tYou might want to remove the CharSet declaration\n"+
 626                                                 "\tor compile using the Mono runtime instead of the\n"+
 627                                                 "\tMicrosoft .NET runtime\n"+
 628                                                 "\tThe runtime gave the error: " + e);
 629                         }
 630                 }
 631         }
 632
 633
 634         /// <summary>
 635         ///   This is a readonly list of MemberInfo's.
 636         /// </summary>
 637         public class MemberList : IList {
 638                 public readonly IList List;
 639                 int count;
 640
 641                 /// <summary>
 642                 ///   Create a new MemberList from the given IList.
 643                 /// </summary>
 644                 public MemberList (IList list)
 645                 {
 646                         if (list != null)
 647                                 this.List = list;
 648                         else
 649                                 this.List = new ArrayList ();
 650                         count = List.Count;
 651                 }
 652
 653                 /// <summary>
 654                 ///   Concatenate the ILists `first' and `second' to a new MemberList.
 655                 /// </summary>
 656                 public MemberList (IList first, IList second)
 657                 {
 658                         ArrayList list = new ArrayList ();
 659                         list.AddRange (first);
 660                         list.AddRange (second);
 661                         count = list.Count;
 662                         List = list;
 663                 }
 664
 665                 public static readonly MemberList Empty = new MemberList (new ArrayList ());
 666
 667                 /// <summary>
 668                 ///   Cast the MemberList into a MemberInfo[] array.
 669                 /// </summary>
 670                 /// <remarks>
 671                 ///   This is an expensive operation, only use it if it's really necessary.
 672                 /// </remarks>
 673                 public static explicit operator MemberInfo [] (MemberList list)
 674                 {
 675                         Timer.StartTimer (TimerType.MiscTimer);
 676                         MemberInfo [] result = new MemberInfo [list.Count];
 677                         list.CopyTo (result, 0);
 678                         Timer.StopTimer (TimerType.MiscTimer);
 679                         return result;
 680                 }
 681
 682                 // ICollection
 683
 684                 public int Count {
 685                         get {
 686                                 return count;
 687                         }
 688                 }
 689
 690                 public bool IsSynchronized {
 691                         get {
 692                                 return List.IsSynchronized;
 693                         }
 694                 }
 695
 696                 public object SyncRoot {
 697                         get {
 698                                 return List.SyncRoot;
 699                         }
 700                 }
 701
 702                 public void CopyTo (Array array, int index)
 703                 {
 704                         List.CopyTo (array, index);
 705                 }
 706
 707                 // IEnumerable
 708
 709                 public IEnumerator GetEnumerator ()
 710                 {
 711                         return List.GetEnumerator ();
 712                 }
 713
 714                 // IList
 715
 716                 public bool IsFixedSize {
 717                         get {
 718                                 return true;
 719                         }
 720                 }
 721
 722                 public bool IsReadOnly {
 723                         get {
 724                                 return true;
 725                         }
 726                 }
 727
 728                 object IList.this [int index] {
 729                         get {
 730                                 return List [index];
 731                         }
 732
 733                         set {
 734                                 throw new NotSupportedException ();
 735                         }
 736                 }
 737
 738                 // FIXME: try to find out whether we can avoid the cast in this indexer.
 739                 public MemberInfo this [int index] {
 740                         get {
 741                                 return (MemberInfo) List [index];
 742                         }
 743                 }
 744
 745                 public int Add (object value)
 746                 {
 747                         throw new NotSupportedException ();
 748                 }
 749
 750                 public void Clear ()
 751                 {
 752                         throw new NotSupportedException ();
 753                 }
 754
 755                 public bool Contains (object value)
 756                 {
 757                         return List.Contains (value);
 758                 }
 759
 760                 public int IndexOf (object value)
 761                 {
 762                         return List.IndexOf (value);
 763                 }
 764
 765                 public void Insert (int index, object value)
 766                 {
 767                         throw new NotSupportedException ();
 768                 }
 769
 770                 public void Remove (object value)
 771                 {
 772                         throw new NotSupportedException ();
 773                 }
 774
 775                 public void RemoveAt (int index)
 776                 {
 777                         throw new NotSupportedException ();
 778                 }
 779         }
 780
 781         /// <summary>
 782         ///   This interface is used to get all members of a class when creating the
 783         ///   member cache.  It must be implemented by all DeclSpace derivatives which
 784         ///   want to support the member cache and by TypeHandle to get caching of
 785         ///   non-dynamic types.
 786         /// </summary>
 787         public interface IMemberContainer {
 788                 /// <summary>
 789                 ///   The name of the IMemberContainer.  This is only used for
 790                 ///   debugging purposes.
 791                 /// </summary>
 792                 string Name {
 793                         get;
 794                 }
 795
 796                 /// <summary>
 797                 ///   The type of this IMemberContainer.
 798                 /// </summary>
 799                 Type Type {
 800                         get;
 801                 }
 802
 803                 /// <summary>
 804                 ///   Returns the IMemberContainer of the parent class or null if this
 805                 ///   is an interface or TypeManger.object_type.
 806                 ///   This is used when creating the member cache for a class to get all
 807                 ///   members from the parent class.
 808                 /// </summary>
 809                 IMemberContainer Parent {
 810                         get;
 811                 }
 812
 813                 /// <summary>
 814                 ///   Whether this is an interface.
 815                 /// </summary>
 816                 bool IsInterface {
 817                         get;
 818                 }
 819
 820                 /// <summary>
 821                 ///   Returns all members of this class with the corresponding MemberTypes
 822                 ///   and BindingFlags.
 823                 /// </summary>
 824                 /// <remarks>
 825                 ///   When implementing this method, make sure not to return any inherited
 826                 ///   members and check the MemberTypes and BindingFlags properly.
 827                 ///   Unfortunately, System.Reflection is lame and doesn't provide a way to
 828                 ///   get the BindingFlags (static/non-static,public/non-public) in the
 829                 ///   MemberInfo class, but the cache needs this information.  That's why
 830                 ///   this method is called multiple times with different BindingFlags.
 831                 /// </remarks>
 832                 MemberList GetMembers (MemberTypes mt, BindingFlags bf);
 833
 834                 /// <summary>
 835                 ///   Return the container's member cache.
 836                 /// </summary>
 837                 MemberCache MemberCache {
 838                         get;
 839                 }
 840         }
 841
 842         /// <summary>
 843         ///   The MemberCache is used by dynamic and non-dynamic types to speed up
 844         ///   member lookups.  It has a member name based hash table; it maps each member
 845         ///   name to a list of CacheEntry objects.  Each CacheEntry contains a MemberInfo
 846         ///   and the BindingFlags that were initially used to get it.  The cache contains
 847         ///   all members of the current class and all inherited members.  If this cache is
 848         ///   for an interface types, it also contains all inherited members.
 849         ///
 850         ///   There are two ways to get a MemberCache:
 851         ///   * if this is a dynamic type, lookup the corresponding DeclSpace and then
 852         ///     use the DeclSpace.MemberCache property.
 853         ///   * if this not a dynamic type, call TypeHandle.GetTypeHandle() to get a
 854         ///     TypeHandle instance for the type and then use TypeHandle.MemberCache.
 855         /// </summary>
 856         public class MemberCache {
 857                 public readonly IMemberContainer Container;
 858                 protected CaseInsensitiveHashtable member_hash;
 859                 protected CaseInsensitiveHashtable method_hash;
 860                 protected CaseInsensitiveHashtable interface_hash;
 861
 862                 /// <summary>
 863                 ///   Create a new MemberCache for the given IMemberContainer `container'.
 864                 /// </summary>
 865                 public MemberCache (IMemberContainer container)
 866                 {
 867                         this.Container = container;
 868
 869                         Timer.IncrementCounter (CounterType.MemberCache);
 870                         Timer.StartTimer (TimerType.CacheInit);
 871
 872                         interface_hash = new CaseInsensitiveHashtable ();
 873
 874                         // If we have a parent class (we have a parent class unless we're
 875                         // TypeManager.object_type), we deep-copy its MemberCache here.
 876                         if (Container.Parent != null)
 877                                 member_hash = SetupCache (Container.Parent.MemberCache);
 878                         else if (Container.IsInterface)
 879                                 member_hash = SetupCacheForInterface ();
 880                         else
 881                                 member_hash = new CaseInsensitiveHashtable ();
 882
 883                         // If this is neither a dynamic type nor an interface, create a special
 884                         // method cache with all declared and inherited methods.
 885                         Type type = container.Type;
 886                         if (!(type is TypeBuilder) && !type.IsInterface) {
 887                                 method_hash = new CaseInsensitiveHashtable ();
 888                                 AddMethods (type);
 889                         }
 890
 891                         // Add all members from the current class.
 892                         AddMembers (Container);
 893
 894                         Timer.StopTimer (TimerType.CacheInit);
 895                 }
 896
 897                 /// <summary>
 898                 ///   Bootstrap this member cache by doing a deep-copy of our parent.
 899                 /// </summary>
 900                 CaseInsensitiveHashtable SetupCache (MemberCache parent)
 901                 {
 902                         CaseInsensitiveHashtable hash = new CaseInsensitiveHashtable ();
 903
 904                         IDictionaryEnumerator it = parent.member_hash.GetEnumerator ();
 905                         while (it.MoveNext ()) {
 906                                 ArrayList al = (ArrayList) it.Value;
 907                                 // Constructors are never inherited and all have the same key
 908                                 if ((((CacheEntry)al [0]).EntryType & EntryType.Constructor) == 0)
 909                                         hash [it.Key] = ((ArrayList) it.Value).Clone ();
 910                         }
 911
 912                         return hash;
 913                 }
 914
 915                 void AddInterfaces (MemberCache parent)
 916                 {
 917                         foreach (Type iface in parent.interface_hash.Keys) {
 918                                 if (!interface_hash.Contains (iface))
 919                                         interface_hash.Add (iface, true);
 920                         }
 921                 }
 922
 923                 /// <summary>
 924                 ///   Add the contents of `new_hash' to `hash'.
 925                 /// </summary>
 926                 void AddHashtable (Hashtable hash, Hashtable new_hash)
 927                 {
 928                         IDictionaryEnumerator it = new_hash.GetEnumerator ();
 929                         while (it.MoveNext ()) {
 930                                 ArrayList list = (ArrayList) hash [it.Key];
 931                                 if (list != null)
 932                                         list.AddRange ((ArrayList) it.Value);
 933                                 else
 934                                         hash [it.Key] = ((ArrayList) it.Value).Clone ();
 935                         }
 936                 }
 937
 938                 /// <summary>
 939                 ///   Bootstrap the member cache for an interface type.
 940                 ///   Type.GetMembers() won't return any inherited members for interface types,
 941                 ///   so we need to do this manually.  Interfaces also inherit from System.Object.
 942                 /// </summary>
 943                 CaseInsensitiveHashtable SetupCacheForInterface ()
 944                 {
 945                         CaseInsensitiveHashtable hash = SetupCache (TypeHandle.ObjectType.MemberCache);
 946                         Type [] ifaces = TypeManager.GetInterfaces (Container.Type);
 947
 948                         foreach (Type iface in ifaces) {
 949                                 if (interface_hash.Contains (iface))
 950                                         continue;
 951                                 interface_hash.Add (iface, true);
 952
 953                                 IMemberContainer iface_container =
 954                                         TypeManager.LookupMemberContainer (iface);
 955
 956                                 MemberCache iface_cache = iface_container.MemberCache;
 957                                 AddHashtable (hash, iface_cache.member_hash);
 958                                 AddInterfaces (iface_cache);
 959                         }
 960
 961                         return hash;
 962                 }
 963
 964                 /// <summary>
 965                 ///   Add all members from class `container' to the cache.
 966                 /// </summary>
 967                 void AddMembers (IMemberContainer container)
 968                 {
 969                         // We need to call AddMembers() with a single member type at a time
 970                         // to get the member type part of CacheEntry.EntryType right.
 971                         AddMembers (MemberTypes.Constructor, container);
 972                         AddMembers (MemberTypes.Field, container);
 973                         AddMembers (MemberTypes.Method, container);
 974                         AddMembers (MemberTypes.Property, container);
 975                         AddMembers (MemberTypes.Event, container);
 976                         // Nested types are returned by both Static and Instance searches.
 977                         AddMembers (MemberTypes.NestedType,
 978                                     BindingFlags.Static | BindingFlags.Public, container);
 979                         AddMembers (MemberTypes.NestedType,
 980                                     BindingFlags.Static | BindingFlags.NonPublic, container);
 981                 }
 982
 983                 void AddMembers (MemberTypes mt, IMemberContainer container)
 984                 {
 985                         AddMembers (mt, BindingFlags.Static | BindingFlags.Public, container);
 986                         AddMembers (mt, BindingFlags.Static | BindingFlags.NonPublic, container);
 987                         AddMembers (mt, BindingFlags.Instance | BindingFlags.Public, container);
 988                         AddMembers (mt, BindingFlags.Instance | BindingFlags.NonPublic, container);
 989                 }
 990
 991                 /// <summary>
 992                 ///   Add all members from class `container' with the requested MemberTypes and
 993                 ///   BindingFlags to the cache.  This method is called multiple times with different
 994                 ///   MemberTypes and BindingFlags.
 995                 /// </summary>
 996                 void AddMembers (MemberTypes mt, BindingFlags bf, IMemberContainer container)
 997                 {
 998                         MemberList members = container.GetMembers (mt, bf);
 999                         /*BindingFlags new_bf = (container == Container) ?
1000                                 bf | BindingFlags.DeclaredOnly : bf;
1001                         */
1002                         foreach (MemberInfo member in members) {
1003                                 string name = member.Name;
1004
1005                                 // We use a name-based hash table of ArrayList's.
1006                                 ArrayList list = (ArrayList) member_hash [name];
1007                                 if (list == null) {
1008                                         list = new ArrayList ();
1009                                         member_hash.Add (name, list);
1010                                 }
1011
1012                                 // When this method is called for the current class, the list will
1013                                 // already contain all inherited members from our parent classes.
1014                                 // We cannot add new members in front of the list since this'd be an
1015                                 // expensive operation, that's why the list is sorted in reverse order
1016                                 // (ie. members from the current class are coming last).
1017                                 list.Add (new CacheEntry (container, member, mt, bf));
1018                         }
1019                 }
1020
1021                 /// <summary>
1022                 ///   Add all declared and inherited methods from class `type' to the method cache.
1023                 /// </summary>
1024                 void AddMethods (Type type)
1025                 {
1026                         AddMethods (BindingFlags.Static | BindingFlags.Public, type);
1027                         AddMethods (BindingFlags.Static | BindingFlags.NonPublic, type);
1028                         AddMethods (BindingFlags.Instance | BindingFlags.Public, type);
1029                         AddMethods (BindingFlags.Instance | BindingFlags.NonPublic, type);
1030                 }
1031
1032                 void AddMethods (BindingFlags bf, Type type)
1033                 {
1034                         MemberInfo [] members = type.GetMethods (bf);
1035
1036                         foreach (MethodBase member in members) {
1037                                 string name = member.Name;
1038
1039                                 // Varargs methods aren't allowed in C# code.
1040                                 if ((member.CallingConvention & CallingConventions.VarArgs) != 0)
1041                                         continue;
1042
1043                                 // We use a name-based hash table of ArrayList's.
1044                                 ArrayList list = (ArrayList) method_hash [name];
1045                                 if (list == null) {
1046                                         list = new ArrayList ();
1047                                         method_hash.Add (name, list);
1048                                 }
1049
1050                                 // Unfortunately, the elements returned by Type.GetMethods() aren't
1051                                 // sorted so we need to do this check for every member.
1052                                 BindingFlags new_bf = bf;
1053                                 if (member.DeclaringType == type)
1054                                         new_bf |= BindingFlags.DeclaredOnly;
1055
1056                                 list.Add (new CacheEntry (Container, member, MemberTypes.Method, new_bf));
1057                         }
1058                 }
1059
1060                 /// <summary>
1061                 ///   Compute and return a appropriate `EntryType' magic number for the given
1062                 ///   MemberTypes and BindingFlags.
1063                 /// </summary>
1064                 protected static EntryType GetEntryType (MemberTypes mt, BindingFlags bf)
1065                 {
1066                         EntryType type = EntryType.None;
1067
1068                         if ((mt & MemberTypes.Constructor) != 0)
1069                                 type |= EntryType.Constructor;
1070                         if ((mt & MemberTypes.Event) != 0)
1071                                 type |= EntryType.Event;
1072                         if ((mt & MemberTypes.Field) != 0)
1073                                 type |= EntryType.Field;
1074                         if ((mt & MemberTypes.Method) != 0)
1075                                 type |= EntryType.Method;
1076                         if ((mt & MemberTypes.Property) != 0)
1077                                 type |= EntryType.Property;
1078                         // Nested types are returned by static and instance searches.
1079                         if ((mt & MemberTypes.NestedType) != 0)
1080                                 type |= EntryType.NestedType | EntryType.Static | EntryType.Instance;
1081
1082                         if ((bf & BindingFlags.Instance) != 0)
1083                                 type |= EntryType.Instance;
1084                         if ((bf & BindingFlags.Static) != 0)
1085                                 type |= EntryType.Static;
1086                         if ((bf & BindingFlags.Public) != 0)
1087                                 type |= EntryType.Public;
1088                         if ((bf & BindingFlags.NonPublic) != 0)
1089                                 type |= EntryType.NonPublic;
1090                         if ((bf & BindingFlags.DeclaredOnly) != 0)
1091                                 type |= EntryType.Declared;
1092
1093                         return type;
1094                 }
1095
1096                 /// <summary>
1097                 ///   The `MemberTypes' enumeration type is a [Flags] type which means that it may
1098                 ///   denote multiple member types.  Returns true if the given flags value denotes a
1099                 ///   single member types.
1100                 /// </summary>
1101                 public static bool IsSingleMemberType (MemberTypes mt)
1102                 {
1103                         switch (mt) {
1104                         case MemberTypes.Constructor:
1105                         case MemberTypes.Event:
1106                         case MemberTypes.Field:
1107                         case MemberTypes.Method:
1108                         case MemberTypes.Property:
1109                         case MemberTypes.NestedType:
1110                                 return true;
1111
1112                         default:
1113                                 return false;
1114                         }
1115                 }
1116
1117                 /// <summary>
1118                 ///   We encode the MemberTypes and BindingFlags of each members in a "magic"
1119                 ///   number to speed up the searching process.
1120                 /// </summary>
1121                 [Flags]
1122                 protected enum EntryType {
1123                         None            = 0x000,
1124
1125                         Instance        = 0x001,
1126                         Static          = 0x002,
1127                         MaskStatic      = Instance|Static,
1128
1129                         Public          = 0x004,
1130                         NonPublic       = 0x008,
1131                         MaskProtection  = Public|NonPublic,
1132
1133                         Declared        = 0x010,
1134
1135                         Constructor     = 0x020,
1136                         Event           = 0x040,
1137                         Field           = 0x080,
1138                         Method          = 0x100,
1139                         Property        = 0x200,
1140                         NestedType      = 0x400,
1141
1142                         MaskType        = Constructor|Event|Field|Method|Property|NestedType
1143                 }
1144
1145                 protected struct CacheEntry {
1146                         public readonly IMemberContainer Container;
1147                         public readonly EntryType EntryType;
1148                         public readonly MemberInfo Member;
1149
1150                         public CacheEntry (IMemberContainer container, MemberInfo member,
1151                                            MemberTypes mt, BindingFlags bf)
1152                         {
1153                                 this.Container = container;
1154                                 this.Member = member;
1155                                 this.EntryType = GetEntryType (mt, bf);
1156                         }
1157                 }
1158
1159                 /// <summary>
1160                 ///   This is called each time we're walking up one level in the class hierarchy
1161                 ///   and checks whether we can abort the search since we've already found what
1162                 ///   we were looking for.
1163                 /// </summary>
1164                 protected bool DoneSearching (ArrayList list)
1165                 {
1166                         //
1167                         // We've found exactly one member in the current class and it's not
1168                         // a method or constructor.
1169                         //
1170                         if (list.Count == 1 && !(list [0] is MethodBase))
1171                                 return true;
1172
1173                         //
1174                         // Multiple properties: we query those just to find out the indexer
1175                         // name
1176                         //
1177                         if ((list.Count > 0) && (list [0] is PropertyInfo))
1178                                 return true;
1179
1180                         return false;
1181                 }
1182
1183                 /// <summary>
1184                 ///   Looks up members with name `name'.  If you provide an optional
1185                 ///   filter function, it'll only be called with members matching the
1186                 ///   requested member name.
1187                 ///
1188                 ///   This method will try to use the cache to do the lookup if possible.
1189                 ///
1190                 ///   Unlike other FindMembers implementations, this method will always
1191                 ///   check all inherited members - even when called on an interface type.
1192                 ///
1193                 ///   If you know that you're only looking for methods, you should use
1194                 ///   MemberTypes.Method alone since this speeds up the lookup a bit.
1195                 ///   When doing a method-only search, it'll try to use a special method
1196                 ///   cache (unless it's a dynamic type or an interface) and the returned
1197                 ///   MemberInfo's will have the correct ReflectedType for inherited methods.
1198                 ///   The lookup process will automatically restart itself in method-only
1199                 ///   search mode if it discovers that it's about to return methods.
1200                 /// </summary>
1201                 public MemberList FindMembers (MemberTypes mt, BindingFlags bf, string name,
1202                                                MemberFilter filter, object criteria)
1203                 {
1204                         bool declared_only = (bf & BindingFlags.DeclaredOnly) != 0;
1205                         bool method_search = mt == MemberTypes.Method;
1206                         // If we have a method cache and we aren't already doing a method-only search,
1207                         // then we restart a method search if the first match is a method.
1208                         bool do_method_search = !method_search && (method_hash != null);
1209 bf |= BindingFlags.IgnoreCase;
1210                         ArrayList applicable;
1211
1212                         // If this is a method-only search, we try to use the method cache if
1213                         // possible; a lookup in the method cache will return a MemberInfo with
1214                         // the correct ReflectedType for inherited methods.
1215                         if (method_search && (method_hash != null))
1216                                 applicable = (ArrayList) method_hash [name];
1217                         else
1218                                 applicable = (ArrayList) member_hash [name];
1219
1220                         if (applicable == null)
1221                                 return MemberList.Empty;
1222
1223                         ArrayList list = new ArrayList ();
1224
1225                         Timer.StartTimer (TimerType.CachedLookup);
1226
1227                         EntryType type = GetEntryType (mt, bf);
1228
1229                         IMemberContainer current = Container;
1230
1231                         // `applicable' is a list of all members with the given member name `name'
1232                         // in the current class and all its parent classes.  The list is sorted in
1233                         // reverse order due to the way how the cache is initialy created (to speed
1234                         // things up, we're doing a deep-copy of our parent).
1235
1236                         for (int i = applicable.Count-1; i >= 0; i--) {
1237                                 CacheEntry entry = (CacheEntry) applicable [i];
1238
1239                                 // This happens each time we're walking one level up in the class
1240                                 // hierarchy.  If we're doing a DeclaredOnly search, we must abort
1241                                 // the first time this happens (this may already happen in the first
1242                                 // iteration of this loop if there are no members with the name we're
1243                                 // looking for in the current class).
1244                                 if (entry.Container != current) {
1245                                         if (declared_only || DoneSearching (list))
1246                                                 break;
1247
1248                                         current = entry.Container;
1249                                 }
1250
1251                                 // Is the member of the correct type ?
1252                                 if ((entry.EntryType & type & EntryType.MaskType) == 0)
1253                                         continue;
1254
1255                                 // Is the member static/non-static ?
1256                                 if ((entry.EntryType & type & EntryType.MaskStatic) == 0)
1257                                         continue;
1258
1259                                 // Apply the filter to it.
1260                                 if (filter (entry.Member, criteria)) {
1261                                         if ((entry.EntryType & EntryType.MaskType) != EntryType.Method)
1262                                                 do_method_search = false;
1263                                         list.Add (entry.Member);
1264                                 }
1265                         }
1266
1267                         Timer.StopTimer (TimerType.CachedLookup);
1268
1269                         // If we have a method cache and we aren't already doing a method-only
1270                         // search, we restart in method-only search mode if the first match is
1271                         // a method.  This ensures that we return a MemberInfo with the correct
1272                         // ReflectedType for inherited methods.
1273                         if (do_method_search && (list.Count > 0))
1274                                 return FindMembers (MemberTypes.Method, bf, name, filter, criteria);
1275
1276                         return new MemberList (list);
1277                 }
1278         }
1279 }