mcs/mcs/interface.cs

   1 //
   2 // interface.cs: Interface handler
   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 #define CACHE
  11 using System.Collections;
  12 using System;
  13 using System.IO;
  14 using System.Reflection;
  15 using System.Reflection.Emit;
  16
  17 namespace Mono.CSharp {
  18
  19         /// <summary>
  20         ///   Interfaces
  21         /// </summary>
  22         public class Interface : DeclSpace, IMemberContainer {
  23                 const MethodAttributes interface_method_attributes =
  24                         MethodAttributes.Public |
  25                         MethodAttributes.Abstract |
  26                         MethodAttributes.HideBySig |
  27                         MethodAttributes.NewSlot |
  28                         MethodAttributes.Virtual;
  29
  30                 const MethodAttributes property_attributes =
  31                         MethodAttributes.Public |
  32                         MethodAttributes.Abstract |
  33                         MethodAttributes.HideBySig |
  34                         MethodAttributes.NewSlot |
  35                         MethodAttributes.SpecialName |
  36                         MethodAttributes.Virtual;
  37
  38                 ArrayList bases;
  39
  40                 ArrayList defined_method;
  41                 ArrayList defined_indexer;
  42                 ArrayList defined_events;
  43                 ArrayList defined_properties;
  44
  45                 ArrayList method_builders;
  46                 ArrayList property_builders;
  47                 ArrayList event_builders;
  48
  49                 Attributes OptAttributes;
  50
  51                 public string IndexerName;
  52
  53                 IMemberContainer parent_container;
  54                 MemberCache member_cache;
  55
  56                 bool members_defined;
  57
  58                 // These will happen after the semantic analysis
  59
  60                 // Hashtable defined_indexers;
  61                 // Hashtable defined_methods;
  62
  63                 /// <summary>
  64                 ///   Modifiers allowed in a class declaration
  65                 /// </summary>
  66                 public const int AllowedModifiers =
  67                         Modifiers.NEW       |
  68                         Modifiers.PUBLIC    |
  69                         Modifiers.PROTECTED |
  70                         Modifiers.INTERNAL  |
  71                         Modifiers.UNSAFE    |
  72                         Modifiers.PRIVATE;
  73
  74                 public Interface (TypeContainer parent, string name, int mod, Attributes attrs, Location l)
  75                         : base (parent, name, l)
  76                 {
  77                         ModFlags = Modifiers.Check (AllowedModifiers, mod, Modifiers.PRIVATE, l);
  78                         OptAttributes = attrs;
  79
  80                         method_builders = new ArrayList ();
  81                         property_builders = new ArrayList ();
  82                         event_builders = new ArrayList ();
  83                 }
  84
  85                 public AdditionResult AddMethod (InterfaceMethod imethod)
  86                 {
  87                         string name = imethod.Name;
  88                         Object value = defined_names [name];
  89
  90                         if (value != null){
  91                                 if (!(value is InterfaceMethod))
  92                                         return AdditionResult.NameExists;
  93                         }
  94
  95                         if (defined_method == null)
  96                                 defined_method = new ArrayList ();
  97
  98                         defined_method.Add (imethod);
  99                         if (value == null)
 100                                 DefineName (name, imethod);
 101
 102                         return AdditionResult.Success;
 103                 }
 104
 105                 public AdditionResult AddProperty (InterfaceProperty iprop)
 106                 {
 107                         AdditionResult res;
 108                         string name = iprop.Name;
 109
 110                         if ((res = IsValid (name)) != AdditionResult.Success)
 111                                 return res;
 112
 113                         DefineName (name, iprop);
 114
 115                         if (defined_properties == null)
 116                                 defined_properties = new ArrayList ();
 117
 118                         defined_properties.Add (iprop);
 119                         return AdditionResult.Success;
 120                 }
 121
 122                 public AdditionResult AddEvent (InterfaceEvent ievent)
 123                 {
 124                         string name = ievent.Name;
 125                         AdditionResult res;
 126
 127                         if ((res = IsValid (name)) != AdditionResult.Success)
 128                                 return res;
 129
 130                         DefineName (name, ievent);
 131
 132                         if (defined_events == null)
 133                                 defined_events = new ArrayList ();
 134
 135                         defined_events.Add (ievent);
 136                         return AdditionResult.Success;
 137                 }
 138
 139                 public bool AddIndexer (InterfaceIndexer iindexer)
 140                 {
 141                         if (defined_indexer == null)
 142                                 defined_indexer = new ArrayList ();
 143
 144                         defined_indexer.Add (iindexer);
 145                         return true;
 146                 }
 147
 148                 public ArrayList InterfaceMethods {
 149                         get {
 150                                 return defined_method;
 151                         }
 152                 }
 153
 154                 public ArrayList InterfaceProperties {
 155                         get {
 156                                 return defined_properties;
 157                         }
 158                 }
 159
 160                 public ArrayList InterfaceEvents {
 161                         get {
 162                                 return defined_events;
 163                         }
 164                 }
 165
 166                 public ArrayList InterfaceIndexers {
 167                         get {
 168                                 return defined_indexer;
 169                         }
 170                 }
 171
 172                 public ArrayList Bases {
 173                         get {
 174                                 return bases;
 175                         }
 176
 177                         set {
 178                                 bases = value;
 179                         }
 180                 }
 181
 182                 public virtual TypeAttributes InterfaceAttr {
 183                         get {
 184                                 TypeAttributes x = TypeAttributes.Interface | TypeAttributes.Abstract;
 185
 186                                 if (IsTopLevel == false) {
 187
 188                                         if ((ModFlags & Modifiers.PROTECTED) != 0
 189                                             && (ModFlags & Modifiers.INTERNAL) != 0)
 190                                                 x |= TypeAttributes.NestedFamORAssem;
 191                                         else if ((ModFlags & Modifiers.PROTECTED) != 0)
 192                                                 x |= TypeAttributes.NestedFamily;
 193                                         else if ((ModFlags & Modifiers.INTERNAL) != 0)
 194                                                 x |= TypeAttributes.NestedAssembly;
 195                                         else if ((ModFlags & Modifiers.PUBLIC) != 0)
 196                                                 x |= TypeAttributes.NestedPublic;
 197                                         else
 198                                                 x |= TypeAttributes.NestedPrivate;
 199                                 } else {
 200                                         if ((ModFlags & Modifiers.PUBLIC) != 0)
 201                                                 x |= TypeAttributes.Public;
 202                                         else if ((ModFlags & Modifiers.PRIVATE) != 0)
 203                                                 x |= TypeAttributes.NotPublic;
 204                                 }
 205
 206                                 if ((ModFlags & Modifiers.ABSTRACT) != 0)
 207                                         x |= TypeAttributes.Abstract;
 208
 209                                 if ((ModFlags & Modifiers.SEALED) != 0)
 210                                         x |= TypeAttributes.Sealed;
 211
 212                                 return x;
 213                         }
 214                 }
 215
 216                 void Error111 (InterfaceMemberBase ib)
 217                 {
 218                         Report.Error (
 219                                 111,
 220                                 "Interface `" + Name + "' already contains a definition with the " +
 221                                 "same return value and parameter types for member `" + ib.Name + "'");
 222                 }
 223
 224                 bool RegisterMethod (MethodBase mb, InternalParameters ip, Type [] types)
 225                 {
 226                         if (!TypeManager.RegisterMethod (mb, ip, types))
 227                                 return false;
 228
 229                         method_builders.Add (mb);
 230                         return true;
 231                 }
 232
 233                 //
 234                 // This might trigger a definition of the methods.  This happens only
 235                 // with Attributes, as Attribute classes are processed before interfaces.
 236                 // Ideally, we should make everything just define recursively in terms
 237                 // of its dependencies.
 238                 //
 239                 public MethodInfo [] GetMethods (TypeContainer container)
 240                 {
 241                         int n = 0;
 242
 243                         if (!members_defined){
 244                                 if (DefineMembers (container))
 245                                         n = method_builders.Count;
 246                         } else
 247                                 n = method_builders.Count;
 248
 249                         MethodInfo [] mi = new MethodInfo [n];
 250
 251                         method_builders.CopyTo (mi, 0);
 252
 253                         return mi;
 254                 }
 255
 256                 // Hack around System.Reflection as found everywhere else
 257                 public override MemberList FindMembers (MemberTypes mt, BindingFlags bf,
 258                                                         MemberFilter filter, object criteria)
 259                 {
 260                         ArrayList members = new ArrayList ();
 261
 262                         if ((mt & MemberTypes.Method) != 0) {
 263                                 foreach (MethodBuilder mb in method_builders)
 264                                         if (filter (mb, criteria))
 265                                                 members.Add (mb);
 266                         }
 267
 268                         if ((mt & MemberTypes.Property) != 0) {
 269                                 foreach (PropertyBuilder pb in property_builders)
 270                                         if (filter (pb, criteria))
 271                                                 members.Add (pb);
 272                         }
 273
 274                         if ((mt & MemberTypes.Event) != 0) {
 275                                 foreach (MyEventBuilder eb in event_builders)
 276                                         if (filter (eb, criteria))
 277                                                 members.Add (eb);
 278                         }
 279
 280                         if (((bf & BindingFlags.DeclaredOnly) == 0) && (TypeBuilder.BaseType != null)) {
 281                                 MemberList parent_mi;
 282
 283                                 parent_mi = TypeContainer.FindMembers (
 284                                         TypeBuilder.BaseType, mt, bf, filter, criteria);
 285
 286                                 members.AddRange (parent_mi);
 287                         }
 288
 289                         return new MemberList (members);
 290                 }
 291
 292                 public override MemberCache MemberCache {
 293                         get {
 294                                 return member_cache;
 295                         }
 296                 }
 297
 298                 //
 299                 // Populates the methods in the interface
 300                 //
 301                 void PopulateMethod (TypeContainer parent, DeclSpace decl_space, InterfaceMethod im)
 302                 {
 303                         Type return_type = im.ReturnType.Type;
 304                         if (return_type == null)
 305                                 return_type = this.ResolveType (im.ReturnType, false, im.Location);
 306
 307                         Type [] arg_types = im.ParameterTypes (this);
 308                         MethodBuilder mb;
 309                         Parameter [] p;
 310                         int i;
 311
 312                         if (return_type == null)
 313                                 return;
 314
 315                         if (return_type.IsPointer && !UnsafeOK (this))
 316                                 return;
 317
 318                         if (arg_types == null)
 319                                 return;
 320
 321                         foreach (Type t in arg_types){
 322
 323                                 if (t == null)
 324                                         return;
 325
 326                                 if (t.IsPointer && !UnsafeOK (this))
 327                                         return;
 328                         }
 329
 330                         //
 331                         // Create the method
 332                         //
 333                         mb = TypeBuilder.DefineMethod (
 334                                 im.Name, interface_method_attributes,
 335                                 return_type, arg_types);
 336
 337                         InternalParameters ip = new InternalParameters (arg_types, im.Parameters);
 338
 339                         if (!RegisterMethod (mb, ip, arg_types)) {
 340                                 Error111 (im);
 341                                 return;
 342                         }
 343
 344                         //
 345                         // Define each type attribute (in/out/ref) and
 346                         // the argument names.
 347                         //
 348                         p = im.Parameters.FixedParameters;
 349                         if (p != null){
 350                                 for (i = 0; i < p.Length; i++)
 351                                         mb.DefineParameter (i + 1, p [i].Attributes, p [i].Name);
 352
 353                                 if (i != arg_types.Length)
 354                                         Console.WriteLine ("Implement the type definition for params");
 355                         }
 356
 357                         EmitContext ec = new EmitContext (parent, decl_space, Location, null,
 358                                                           return_type, ModFlags, false);
 359
 360                         if (im.OptAttributes != null)
 361                                 Attribute.ApplyAttributes (ec, mb, im, im.OptAttributes);
 362                 }
 363
 364                 //
 365                 // Populates the properties in the interface
 366                 //
 367                 void PopulateProperty (TypeContainer parent, DeclSpace decl_space, InterfaceProperty ip)
 368                 {
 369                         PropertyBuilder pb;
 370                         MethodBuilder get = null, set = null;
 371                         ip.Type = this.ResolveTypeExpr (ip.Type, false, ip.Location);
 372                         if (ip.Type == null)
 373                                 return;
 374
 375                         Type prop_type = ip.Type.Type;
 376                         Type [] setter_args = new Type [1];
 377
 378                         if (prop_type == null)
 379                                 return;
 380
 381                         if (prop_type.IsPointer && !UnsafeOK (this))
 382                                 return;
 383
 384                         setter_args [0] = prop_type;
 385
 386                         //
 387                         // FIXME: properties are missing the following
 388                         // flags: hidebysig newslot specialname
 389                         //
 390                         pb = TypeBuilder.DefineProperty (
 391                                 ip.Name, PropertyAttributes.None,
 392                                 prop_type, null);
 393
 394                         if (ip.HasGet){
 395                                 get = TypeBuilder.DefineMethod (
 396                                         "get_" + ip.Name, property_attributes ,
 397                                         prop_type, null);
 398
 399                                 //
 400                                 // HACK because System.Reflection.Emit is lame
 401                                 //
 402                                 Type [] null_types = null;
 403                                 InternalParameters inp = new InternalParameters
 404                                         (null_types, Parameters.EmptyReadOnlyParameters);
 405
 406                                 if (!RegisterMethod (get, inp, null)) {
 407                                         Error111 (ip);
 408                                         return;
 409                                 }
 410
 411                                 pb.SetGetMethod (get);
 412                         }
 413
 414                         if (ip.HasSet){
 415                                 setter_args [0] = prop_type;
 416
 417                                 set = TypeBuilder.DefineMethod (
 418                                         "set_" + ip.Name, property_attributes,
 419                                         TypeManager.void_type, setter_args);
 420
 421                                 set.DefineParameter (1, ParameterAttributes.None, "value");
 422                                 pb.SetSetMethod (set);
 423
 424                                 //
 425                                 // HACK because System.Reflection.Emit is lame
 426                                 //
 427                                 Parameter [] parms = new Parameter [1];
 428                                 parms [0] = new Parameter (ip.Type, "value", Parameter.Modifier.NONE, null);
 429                                 InternalParameters ipp = new InternalParameters (
 430                                         this, new Parameters (parms, null, Location.Null));
 431
 432                                 if (!RegisterMethod (set, ipp, setter_args)) {
 433                                         Error111 (ip);
 434                                         return;
 435                                 }
 436                         }
 437
 438                         EmitContext ec = new EmitContext (parent, decl_space, Location, null,
 439                                                           null, ModFlags, false);
 440
 441                         if (ip.OptAttributes != null)
 442                                 Attribute.ApplyAttributes (ec, pb, ip, ip.OptAttributes);
 443
 444                         TypeManager.RegisterProperty (pb, get, set);
 445                         property_builders.Add (pb);
 446                 }
 447
 448                 //
 449                 // Populates the events in the interface
 450                 //
 451                 void PopulateEvent (TypeContainer parent, DeclSpace decl_space, InterfaceEvent ie)
 452                 {
 453                         //
 454                         // FIXME: We need to do this after delegates have been
 455                         // declared or we declare them recursively.
 456                         //
 457                         MyEventBuilder eb;
 458                         MethodBuilder add = null, remove = null;
 459                         ie.Type = this.ResolveTypeExpr (ie.Type, false, ie.Location);
 460                         if (ie.Type == null)
 461                                 return;
 462
 463                         Type event_type = ie.Type.Type;
 464
 465                         if (event_type == null)
 466                                 return;
 467
 468                         if (event_type.IsPointer && !UnsafeOK (this))
 469                                 return;
 470
 471                         Type [] parameters = new Type [1];
 472                         parameters [0] = event_type;
 473
 474                         eb = new MyEventBuilder (null, TypeBuilder, ie.Name,
 475                                                  EventAttributes.None, event_type);
 476
 477                         //
 478                         // Now define the accessors
 479                         //
 480                         string add_name = "add_" + ie.Name;
 481
 482                         add = TypeBuilder.DefineMethod (
 483                                 add_name, property_attributes, null, parameters);
 484                         add.DefineParameter (1, ParameterAttributes.None, "value");
 485                         eb.SetAddOnMethod (add);
 486
 487                         string remove_name = "remove_" + ie.Name;
 488                         remove = TypeBuilder.DefineMethod (
 489                                 remove_name, property_attributes, null, parameters);
 490                         remove.DefineParameter (1, ParameterAttributes.None, "value");
 491                         eb.SetRemoveOnMethod (remove);
 492
 493                         Parameter [] parms = new Parameter [1];
 494                         parms [0] = new Parameter (ie.Type, "value", Parameter.Modifier.NONE, null);
 495                         InternalParameters ip = new InternalParameters (
 496                                 this, new Parameters (parms, null, Location.Null));
 497
 498                         if (!RegisterMethod (add, ip, parameters)) {
 499                                 Error111 (ie);
 500                                 return;
 501                         }
 502
 503                         if (!RegisterMethod (remove, ip, parameters)) {
 504                                 Error111 (ie);
 505                                 return;
 506                         }
 507
 508                         EmitContext ec = new EmitContext (parent, decl_space, Location, null,
 509                                                           null, ModFlags, false);
 510
 511
 512                         if (ie.OptAttributes != null)
 513                                 Attribute.ApplyAttributes (ec, eb, ie, ie.OptAttributes);
 514
 515                         TypeManager.RegisterEvent (eb, add, remove);
 516                         event_builders.Add (eb);
 517                 }
 518
 519                 //
 520                 // Populates the indexers in the interface
 521                 //
 522                 void PopulateIndexer (TypeContainer parent, DeclSpace decl_space, InterfaceIndexer ii)
 523                 {
 524                         PropertyBuilder pb;
 525                         ii.Type = this.ResolveTypeExpr (ii.Type, false, ii.Location);
 526                         if (ii.Type == null)
 527                                 return;
 528
 529                         Type prop_type = ii.Type.Type;
 530                         Type [] arg_types = ii.ParameterTypes (this);
 531                         Type [] value_arg_types;
 532
 533                         if (prop_type == null)
 534                                 return;
 535
 536                         if (prop_type.IsPointer && !UnsafeOK (this))
 537                                 return;
 538
 539                         //
 540                         // Sets up the extra invisible `value' argument for setters.
 541                         //
 542                         if (arg_types != null){
 543                                 int count = arg_types.Length;
 544                                 value_arg_types = new Type [count + 1];
 545
 546                                 arg_types.CopyTo (value_arg_types, 0);
 547                                 value_arg_types [count] = prop_type;
 548
 549                                 foreach (Type t in arg_types){
 550                                         if (t.IsPointer && !UnsafeOK (this))
 551                                                 return;
 552                                 }
 553                         } else {
 554                                 value_arg_types = new Type [1];
 555
 556                                 value_arg_types [1] = prop_type;
 557                         }
 558
 559                         EmitContext ec = new EmitContext (parent, decl_space, Location, null,
 560                                                           null, ModFlags, false);
 561
 562                         IndexerName = Attribute.ScanForIndexerName (ec, ii.OptAttributes);
 563                         if (IndexerName == null)
 564                                 IndexerName = "Item";
 565
 566                         pb = TypeBuilder.DefineProperty (
 567                                 IndexerName, PropertyAttributes.None,
 568                                 prop_type, arg_types);
 569
 570                         MethodBuilder set_item = null, get_item = null;
 571                         if (ii.HasGet){
 572                                 Parameter [] p = ii.Parameters.FixedParameters;
 573
 574                                 get_item = TypeBuilder.DefineMethod (
 575                                         "get_" + IndexerName, property_attributes,
 576                                         prop_type, arg_types);
 577                                 pb.SetGetMethod (get_item);
 578                                 //
 579                                 // HACK because System.Reflection.Emit is lame
 580                                 //
 581                                 InternalParameters ip = new InternalParameters (
 582                                         arg_types, ii.Parameters);
 583
 584                                 if (!RegisterMethod (get_item, ip, arg_types)) {
 585                                         Error111 (ii);
 586                                         return;
 587                                 }
 588
 589                                 if (p != null){
 590                                         for (int i = 0; i < p.Length; i++)
 591                                                 get_item.DefineParameter (
 592                                                         i + 1,
 593                                                         p [i].Attributes, p [i].Name);
 594                                 }
 595                         }
 596
 597                         if (ii.HasSet){
 598                                 Parameter [] p = ii.Parameters.FixedParameters;
 599                                 Parameter [] pv;
 600                                 int i = 0;
 601
 602                                 pv = new Parameter [p.Length + 1];
 603                                 p.CopyTo (pv, 0);
 604                                 pv [p.Length] = new Parameter (ii.Type, "value", Parameter.Modifier.NONE, null);
 605                                 Parameters value_params = new Parameters (pv, null, Location.Null);
 606                                 value_params.GetParameterInfo (decl_space);
 607
 608                                 set_item = TypeBuilder.DefineMethod (
 609                                         "set_" + IndexerName, property_attributes,
 610                                         TypeManager.void_type, value_arg_types);
 611                                 pb.SetSetMethod (set_item);
 612                                 //
 613                                 // HACK because System.Reflection.Emit is lame
 614                                 //
 615                                 InternalParameters ip = new InternalParameters (
 616                                         value_arg_types, value_params);
 617                                 if (!RegisterMethod (set_item, ip, value_arg_types)) {
 618                                         Error111 (ii);
 619                                         return;
 620                                 }
 621
 622                                 if (p != null){
 623                                         for (; i < p.Length; i++)
 624                                                 set_item.DefineParameter (
 625                                                         i + 1,
 626                                                         p [i].Attributes, p [i].Name);
 627                                 }
 628
 629                                 set_item.DefineParameter (i + 1, ParameterAttributes.None, "value");
 630                         }
 631
 632                         if (ii.OptAttributes != null)
 633                                 Attribute.ApplyAttributes (ec, pb, ii, ii.OptAttributes);
 634
 635                         property_builders.Add (pb);
 636                 }
 637
 638                 /// <summary>
 639                 ///   Performs the semantic analysis for all the interface members
 640                 ///   that were declared
 641                 /// </summary>
 642                 bool SemanticAnalysis ()
 643                 {
 644                         Hashtable methods = new Hashtable ();
 645
 646
 647                         if (defined_method != null){
 648                                 foreach (InterfaceMethod im in defined_method){
 649                                         string sig = im.GetSignature (this);
 650
 651                                         //
 652                                         // If there was an undefined Type on the signatures
 653                                         //
 654                                         if (sig == null)
 655                                                 continue;
 656
 657                                         if (methods [sig] != null){
 658                                                 Error111 (im);
 659                                                 return false;
 660                                         }
 661                                 }
 662                         }
 663
 664                         //
 665                         // FIXME: Here I should check i
 666                         //
 667                         return true;
 668                 }
 669
 670                 Type GetInterfaceTypeByName (string name)
 671                 {
 672                         Type t = FindType (Location, name);
 673
 674                         if (t == null) {
 675                                 Report.Error (246, Location, "The type or namespace `" + name +
 676                                               "' could not be found");
 677                                 return null;
 678                         }
 679
 680                         if (t.IsInterface)
 681                                 return t;
 682
 683                         string cause;
 684
 685                         if (t.IsValueType)
 686                                 cause = "is a struct";
 687                         else if (t.IsClass)
 688                                 cause = "is a class";
 689                         else
 690                                 cause = "Should not happen.";
 691
 692                         Report.Error (527, Location, "`"+name+"' " + cause +
 693                                       ", need an interface instead");
 694
 695                         return null;
 696                 }
 697
 698                 //
 699                 // Returns the list of interfaces that this interface implements
 700                 // Or null if it does not implement any interface.
 701                 //
 702                 // Sets the error boolean accoringly.
 703                 //
 704                 Type [] GetInterfaceBases (out bool error)
 705                 {
 706                         Type [] tbases;
 707                         int i;
 708
 709                         error = false;
 710                         if (Bases == null)
 711                                 return null;
 712
 713                         tbases = new Type [Bases.Count];
 714                         i = 0;
 715
 716                         foreach (string name in Bases){
 717                                 Type t;
 718
 719                                 t = GetInterfaceTypeByName (name);
 720                                 if (t == null){
 721                                         error = true;
 722                                         return null;
 723                                 }
 724
 725                                 if (!Parent.AsAccessible (t, ModFlags))
 726                                         Report.Error (61, Location,
 727                                                       "Inconsistent accessibility: base interface `" +
 728                                                       TypeManager.CSharpName (t) + "' is less " +
 729                                                       "accessible than interface `" +
 730                                                       Name + "'");
 731
 732                                 tbases [i++] = t;
 733                         }
 734
 735                         return TypeManager.ExpandInterfaces (tbases);
 736                 }
 737
 738                 //
 739                 // <summary>
 740                 //  Defines the Interface in the appropriate ModuleBuilder or TypeBuilder
 741                 // </summary>
 742                 //
 743                 // TODO:
 744                 //   Rework the way we recurse, because for recursive
 745                 //   definitions of interfaces (A:B and B:A) we report the
 746                 //   error twice, rather than once.
 747
 748                 public override TypeBuilder DefineType ()
 749                 {
 750                         Type [] ifaces;
 751                         bool error;
 752
 753                         if (TypeBuilder != null)
 754                                 return TypeBuilder;
 755
 756                         if (InTransit)
 757                                 return null;
 758
 759                         InTransit = true;
 760
 761                         ifaces = GetInterfaceBases (out error);
 762
 763                         if (error)
 764                                 return null;
 765
 766                         if (IsTopLevel) {
 767                                 ModuleBuilder builder = CodeGen.ModuleBuilder;
 768
 769                                 TypeBuilder = builder.DefineType (
 770                                         Name,
 771                                         InterfaceAttr,
 772                                         (Type)null,   // Parent Type
 773                                         ifaces);
 774                                 RootContext.RegisterOrder (this);
 775                         } else {
 776                                 TypeBuilder builder = Parent.TypeBuilder;
 777
 778                                 TypeBuilder = builder.DefineNestedType (
 779                                         Basename,
 780                                         InterfaceAttr,
 781                                         (Type) null, //parent type
 782                                         ifaces);
 783
 784                                 TypeContainer tc = TypeManager.LookupTypeContainer (builder);
 785                                 tc.RegisterOrder (this);
 786                         }
 787
 788                         TypeManager.AddUserInterface (Name, TypeBuilder, this, ifaces);
 789                         InTransit = false;
 790
 791                         return TypeBuilder;
 792                 }
 793
 794                 //
 795                 // Defines the indexers, and also verifies that the IndexerNameAttribute in the
 796                 // interface is consistent.  Either it is `Item' or it is the name defined by all the
 797                 // indexers with the `IndexerName' attribute.
 798                 //
 799                 // Turns out that the IndexerNameAttribute is applied to each indexer,
 800                 // but it is never emitted, instead a DefaultName attribute is attached
 801                 // to the interface
 802                 //
 803                 void DefineIndexers (TypeContainer parent)
 804                 {
 805                         string interface_indexer_name = null;
 806
 807                         foreach (InterfaceIndexer ii in defined_indexer){
 808
 809                                 PopulateIndexer (parent, this, ii);
 810
 811                                 if (interface_indexer_name == null){
 812                                         interface_indexer_name = IndexerName;
 813                                         continue;
 814                                 }
 815
 816                                 if (IndexerName == interface_indexer_name)
 817                                         continue;
 818
 819                                 Report.Error (
 820                                         668, "Two indexers have different names, " +
 821                                         " you should use the same name for all your indexers");
 822                         }
 823                         if (interface_indexer_name == null)
 824                                 interface_indexer_name = "Item";
 825                         IndexerName = interface_indexer_name;
 826                 }
 827
 828                 /// <summary>
 829                 ///   Performs semantic analysis, and then generates the IL interfaces
 830                 /// </summary>
 831                 public override bool DefineMembers (TypeContainer parent)
 832                 {
 833                         if (members_defined)
 834                                 return true;
 835
 836                         if (!SemanticAnalysis ())
 837                                 return false;
 838
 839
 840                         if (defined_method != null){
 841                                 foreach (InterfaceMethod im in defined_method)
 842                                         PopulateMethod (parent, this, im);
 843                         }
 844
 845                         if (defined_properties != null){
 846                                 foreach (InterfaceProperty ip in defined_properties)
 847                                         PopulateProperty (parent, this, ip);
 848                         }
 849
 850                         if (defined_events != null)
 851                                 foreach (InterfaceEvent ie in defined_events)
 852                                         PopulateEvent (parent, this, ie);
 853
 854                         if (defined_indexer != null) {
 855                                 DefineIndexers (parent);
 856
 857                                 CustomAttributeBuilder cb = EmitDefaultMemberAttr (
 858                                         parent, IndexerName, ModFlags, Location);
 859                                 if (cb != null)
 860                                         TypeBuilder.SetCustomAttribute (cb);
 861                         }
 862
 863 #if CACHE
 864                         if (TypeBuilder.BaseType != null)
 865                                 parent_container = TypeManager.LookupMemberContainer (TypeBuilder.BaseType);
 866
 867                         member_cache = new MemberCache (this);
 868 #endif
 869                         members_defined = true;
 870                         return true;
 871                 }
 872
 873                 /// <summary>
 874                 ///   Applies all the attributes.
 875                 /// </summary>
 876                 public override bool Define (TypeContainer parent)
 877                 {
 878                         if (OptAttributes != null) {
 879                                 EmitContext ec = new EmitContext (parent, this, Location, null, null,
 880                                                                   ModFlags, false);
 881                                 Attribute.ApplyAttributes (ec, TypeBuilder, this, OptAttributes);
 882                         }
 883
 884                         return true;
 885                 }
 886
 887                 public static CustomAttributeBuilder EmitDefaultMemberAttr (TypeContainer parent,
 888                                                                             string name,
 889                                                                             int flags,
 890                                                                             Location loc)
 891                 {
 892                         EmitContext ec = new EmitContext (parent, loc, null, null, flags);
 893
 894                         Expression ml = Expression.MemberLookup (ec, TypeManager.default_member_type,
 895                                                                  ".ctor", MemberTypes.Constructor,
 896                                                                  BindingFlags.Public | BindingFlags.Instance,
 897                                                                  Location.Null);
 898
 899                         if (!(ml is MethodGroupExpr)) {
 900                                 Console.WriteLine ("Internal error !!!!");
 901                                 return null;
 902                         }
 903
 904                         MethodGroupExpr mg = (MethodGroupExpr) ml;
 905
 906                         MethodBase constructor = mg.Methods [0];
 907
 908                         string [] vals = { name };
 909
 910                         CustomAttributeBuilder cb = null;
 911                         try {
 912                                 cb = new CustomAttributeBuilder ((ConstructorInfo) constructor, vals);
 913                         } catch {
 914                                 Report.Warning (-100, "Can not set the indexer default member attribute");
 915                         }
 916
 917                         return cb;
 918                 }
 919
 920                 //
 921                 // IMemberContainer
 922                 //
 923
 924                 string IMemberContainer.Name {
 925                         get {
 926                                 return Name;
 927                         }
 928                 }
 929
 930                 Type IMemberContainer.Type {
 931                         get {
 932                                 return TypeBuilder;
 933                         }
 934                 }
 935
 936                 IMemberContainer IMemberContainer.Parent {
 937                         get {
 938                                 return parent_container;
 939                         }
 940                 }
 941
 942                 MemberCache IMemberContainer.MemberCache {
 943                         get {
 944                                 return member_cache;
 945                         }
 946                 }
 947
 948                 bool IMemberContainer.IsInterface {
 949                         get {
 950                                 return true;
 951                         }
 952                 }
 953
 954                 MemberList IMemberContainer.GetMembers (MemberTypes mt, BindingFlags bf)
 955                 {
 956                         // Interfaces only contain instance members.
 957                         if ((bf & BindingFlags.Instance) == 0)
 958                                 return MemberList.Empty;
 959                         if ((bf & BindingFlags.Public) == 0)
 960                                 return MemberList.Empty;
 961
 962                         ArrayList members = new ArrayList ();
 963
 964                         if ((mt & MemberTypes.Method) != 0)
 965                                 members.AddRange (method_builders);
 966
 967                         if ((mt & MemberTypes.Property) != 0)
 968                                 members.AddRange (property_builders);
 969
 970                         if ((mt & MemberTypes.Event) != 0)
 971                                 members.AddRange (event_builders);
 972
 973                         return new MemberList (members);
 974                 }
 975         }
 976
 977         public class InterfaceMemberBase {
 978                 public readonly string Name;
 979                 public readonly bool IsNew;
 980                 public Attributes OptAttributes;
 981
 982                 public InterfaceMemberBase (string name, bool is_new, Attributes attrs)
 983                 {
 984                         Name = name;
 985                         IsNew = is_new;
 986                         OptAttributes = attrs;
 987                 }
 988         }
 989
 990         public class InterfaceProperty : InterfaceMemberBase {
 991                 public readonly bool HasSet;
 992                 public readonly bool HasGet;
 993                 public readonly Location Location;
 994                 public Expression Type;
 995
 996                 public InterfaceProperty (Expression type, string name,
 997                                           bool is_new, bool has_get, bool has_set,
 998                                           Attributes attrs, Location loc)
 999                         : base (name, is_new, attrs)
1000                 {
1001                         Type = type;
1002                         HasGet = has_get;
1003                         HasSet = has_set;
1004                         Location = loc;
1005                 }
1006         }
1007
1008         public class InterfaceEvent : InterfaceMemberBase {
1009                 public readonly Location Location;
1010                 public Expression Type;
1011
1012                 public InterfaceEvent (Expression type, string name, bool is_new, Attributes attrs,
1013                                        Location loc)
1014                         : base (name, is_new, attrs)
1015                 {
1016                         Type = type;
1017                         Location = loc;
1018                 }
1019         }
1020
1021         public class InterfaceMethod : InterfaceMemberBase {
1022                 public Expression ReturnType;
1023                 public readonly Parameters Parameters;
1024                 public readonly Location Location;
1025
1026                 public InterfaceMethod (Expression return_type, string name, bool is_new, Parameters args,
1027                                         Attributes attrs, Location l)
1028                         : base (name, is_new, attrs)
1029                 {
1030                         this.ReturnType = return_type;
1031                         this.Parameters = args;
1032                         Location = l;
1033                 }
1034
1035                 /// <summary>
1036                 ///   Returns the signature for this interface method
1037                 /// </summary>
1038                 public string GetSignature (DeclSpace ds)
1039                 {
1040                         ReturnType = ds.ResolveTypeExpr (ReturnType, false, Location);
1041                         if (ReturnType == null)
1042                                 return null;
1043
1044                         Type ret = ReturnType.Type;
1045                         string args = Parameters.GetSignature (ds);
1046
1047                         if ((ret == null) || (args == null))
1048                                 return null;
1049
1050                         return (IsNew ? "new-" : "") + ret.FullName + "(" + args + ")";
1051                 }
1052
1053                 public Type [] ParameterTypes (DeclSpace ds)
1054                 {
1055                         return Parameters.GetParameterInfo (ds);
1056                 }
1057         }
1058
1059         public class InterfaceIndexer : InterfaceMemberBase {
1060                 public readonly bool HasGet, HasSet;
1061                 public readonly Parameters Parameters;
1062                 public readonly Location Location;
1063                 public Expression Type;
1064
1065                 public InterfaceIndexer (Expression type, Parameters args, bool do_get, bool do_set,
1066                                          bool is_new, Attributes attrs, Location loc)
1067                         : base ("", is_new, attrs)
1068                 {
1069                         Type = type;
1070                         Parameters = args;
1071                         HasGet = do_get;
1072                         HasSet = do_set;
1073                         Location = loc;
1074                 }
1075
1076                 public Type [] ParameterTypes (DeclSpace ds)
1077                 {
1078                         return Parameters.GetParameterInfo (ds);
1079                 }
1080         }
1081 }