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