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
  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 {
  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
  48                 Attributes OptAttributes;
  49
  50                 // These will happen after the semantic analysis
  51
  52                 // Hashtable defined_indexers;
  53                 // Hashtable defined_methods;
  54
  55                 /// <summary>
  56                 ///   Modifiers allowed in a class declaration
  57                 /// </summary>
  58                 public const int AllowedModifiers =
  59                         Modifiers.NEW       |
  60                         Modifiers.PUBLIC    |
  61                         Modifiers.PROTECTED |
  62                         Modifiers.INTERNAL  |
  63                         Modifiers.UNSAFE    |
  64                         Modifiers.PRIVATE;
  65
  66                 public Interface (TypeContainer parent, string name, int mod, Attributes attrs, Location l)
  67                         : base (parent, name, l)
  68                 {
  69                         ModFlags = Modifiers.Check (AllowedModifiers, mod, Modifiers.PRIVATE, l);
  70                         OptAttributes = attrs;
  71
  72                         method_builders = new ArrayList ();
  73                         property_builders = new ArrayList ();
  74                 }
  75
  76                 public AdditionResult AddMethod (InterfaceMethod imethod)
  77                 {
  78                         string name = imethod.Name;
  79                         Object value = defined_names [name];
  80
  81                         if (value != null){
  82                                 if (!(value is InterfaceMethod))
  83                                         return AdditionResult.NameExists;
  84                         }
  85
  86                         if (defined_method == null)
  87                                 defined_method = new ArrayList ();
  88
  89                         defined_method.Add (imethod);
  90                         if (value == null)
  91                                 DefineName (name, imethod);
  92
  93                         return AdditionResult.Success;
  94                 }
  95
  96                 public AdditionResult AddProperty (InterfaceProperty iprop)
  97                 {
  98                         AdditionResult res;
  99                         string name = iprop.Name;
 100
 101                         if ((res = IsValid (name)) != AdditionResult.Success)
 102                                 return res;
 103
 104                         DefineName (name, iprop);
 105
 106                         if (defined_properties == null)
 107                                 defined_properties = new ArrayList ();
 108
 109                         defined_properties.Add (iprop);
 110                         return AdditionResult.Success;
 111                 }
 112
 113                 public AdditionResult AddEvent (InterfaceEvent ievent)
 114                 {
 115                         string name = ievent.Name;
 116                         AdditionResult res;
 117
 118                         if ((res = IsValid (name)) != AdditionResult.Success)
 119                                 return res;
 120
 121                         DefineName (name, ievent);
 122
 123                         if (defined_events == null)
 124                                 defined_events = new ArrayList ();
 125
 126                         defined_events.Add (ievent);
 127                         return AdditionResult.Success;
 128                 }
 129
 130                 public bool AddIndexer (InterfaceIndexer iindexer)
 131                 {
 132                         if (defined_indexer == null)
 133                                 defined_indexer = new ArrayList ();
 134
 135                         defined_indexer.Add (iindexer);
 136                         return true;
 137                 }
 138
 139                 public ArrayList InterfaceMethods {
 140                         get {
 141                                 return defined_method;
 142                         }
 143                 }
 144
 145                 public ArrayList InterfaceProperties {
 146                         get {
 147                                 return defined_properties;
 148                         }
 149                 }
 150
 151                 public ArrayList InterfaceEvents {
 152                         get {
 153                                 return defined_events;
 154                         }
 155                 }
 156
 157                 public ArrayList InterfaceIndexers {
 158                         get {
 159                                 return defined_indexer;
 160                         }
 161                 }
 162
 163                 public ArrayList Bases {
 164                         get {
 165                                 return bases;
 166                         }
 167
 168                         set {
 169                                 bases = value;
 170                         }
 171                 }
 172
 173                 public virtual TypeAttributes InterfaceAttr {
 174                         get {
 175                                 TypeAttributes x = TypeAttributes.Interface | TypeAttributes.Abstract;
 176
 177                                 if (IsTopLevel == false) {
 178
 179                                         if ((ModFlags & Modifiers.PROTECTED) != 0
 180                                             && (ModFlags & Modifiers.INTERNAL) != 0)
 181                                                 x |= TypeAttributes.NestedFamORAssem;
 182                                         else if ((ModFlags & Modifiers.PROTECTED) != 0)
 183                                                 x |= TypeAttributes.NestedFamily;
 184                                         else if ((ModFlags & Modifiers.INTERNAL) != 0)
 185                                                 x |= TypeAttributes.NestedAssembly;
 186                                         else if ((ModFlags & Modifiers.PUBLIC) != 0)
 187                                                 x |= TypeAttributes.NestedPublic;
 188                                         else
 189                                                 x |= TypeAttributes.NestedPrivate;
 190                                 } else {
 191                                         if ((ModFlags & Modifiers.PUBLIC) != 0)
 192                                                 x |= TypeAttributes.Public;
 193                                         else if ((ModFlags & Modifiers.PRIVATE) != 0)
 194                                                 x |= TypeAttributes.NotPublic;
 195                                 }
 196
 197                                 if ((ModFlags & Modifiers.ABSTRACT) != 0)
 198                                         x |= TypeAttributes.Abstract;
 199
 200                                 if ((ModFlags & Modifiers.SEALED) != 0)
 201                                         x |= TypeAttributes.Sealed;
 202
 203                                 return x;
 204                         }
 205                 }
 206
 207                 void Error111 (InterfaceMemberBase ib)
 208                 {
 209                         Report.Error (
 210                                 111,
 211                                 "Interface `" + Name + "' already contains a definition with the " +
 212                                 "same return value and parameter types for member `" + ib.Name + "'");
 213                 }
 214
 215                 bool RegisterMethod (MethodBase mb, InternalParameters ip, Type [] types)
 216                 {
 217                         if (!TypeManager.RegisterMethod (mb, ip, types))
 218                                 return false;
 219
 220                         method_builders.Add (mb);
 221                         return true;
 222                 }
 223
 224                 public MethodInfo [] GetMethods ()
 225                 {
 226                         int n = method_builders.Count;
 227                         MethodInfo [] mi = new MethodInfo [n];
 228
 229                         method_builders.CopyTo (mi, 0);
 230
 231                         return mi;
 232                 }
 233
 234                 // Hack around System.Reflection as found everywhere else
 235                 public MemberInfo [] FindMembers (MemberTypes mt, BindingFlags bf, MemberFilter filter, object criteria)
 236                 {
 237                         ArrayList members = new ArrayList ();
 238
 239                         if ((mt & MemberTypes.Method) != 0) {
 240                                 foreach (MethodBuilder mb in method_builders)
 241                                         if (filter (mb, criteria))
 242                                                 members.Add (mb);
 243                         }
 244
 245                         if ((mt & MemberTypes.Property) != 0) {
 246                                 foreach (PropertyBuilder pb in property_builders)
 247                                         if (filter (pb, criteria))
 248                                                 members.Add (pb);
 249                         }
 250
 251                         if ((bf & BindingFlags.DeclaredOnly) == 0){
 252                                 MemberInfo [] parent_mi;
 253
 254                                 parent_mi = TypeContainer.FindMembers (
 255                                         TypeBuilder.BaseType, mt, bf, filter, criteria);
 256
 257                                 if (parent_mi != null)
 258                                         members.AddRange (parent_mi);
 259                         }
 260
 261                         // The rest of the cases, if any, are unhandled at present.
 262
 263                         int count = members.Count;
 264
 265                         if (count > 0) {
 266                                 MemberInfo [] mi = new MemberInfo [count];
 267                                 members.CopyTo (mi, 0);
 268                                 return mi;
 269                         }
 270
 271                         return null;
 272                 }
 273
 274                 //
 275                 // Populates the methods in the interface
 276                 //
 277                 void PopulateMethod (InterfaceMethod im)
 278                 {
 279                         Type return_type = RootContext.LookupType (this, im.ReturnType, false, im.Location);
 280                         Type [] arg_types = im.ParameterTypes (this);
 281                         MethodBuilder mb;
 282                         Parameter [] p;
 283                         int i;
 284
 285                         if (return_type == null)
 286                                 return;
 287
 288                         if (return_type.IsPointer && !UnsafeOK (this))
 289                                 return;
 290
 291                         foreach (Type t in arg_types){
 292
 293                                 if (t == null)
 294                                         return;
 295
 296                                 if (t.IsPointer && !UnsafeOK (this))
 297                                         return;
 298                         }
 299
 300                         //
 301                         // Create the method
 302                         //
 303                         mb = TypeBuilder.DefineMethod (
 304                                 im.Name, interface_method_attributes,
 305                                 return_type, arg_types);
 306
 307                         InternalParameters ip = new InternalParameters (arg_types, im.Parameters);
 308
 309                         if (!RegisterMethod (mb, ip, arg_types)) {
 310                                 Error111 (im);
 311                                 return;
 312                         }
 313
 314                         //
 315                         // Define each type attribute (in/out/ref) and
 316                         // the argument names.
 317                         //
 318                         p = im.Parameters.FixedParameters;
 319                         if (p != null){
 320                                 for (i = 0; i < p.Length; i++)
 321                                         mb.DefineParameter (i + 1, p [i].Attributes, p [i].Name);
 322
 323                                 if (i != arg_types.Length)
 324                                         Console.WriteLine ("Implement the type definition for params");
 325                         }
 326                 }
 327
 328                 //
 329                 // Populates the properties in the interface
 330                 //
 331                 void PopulateProperty (InterfaceProperty ip)
 332                 {
 333                         PropertyBuilder pb;
 334                         MethodBuilder get = null, set = null;
 335                         Type prop_type = RootContext.LookupType (this, ip.Type, false, ip.Location);
 336                         Type [] setter_args = new Type [1];
 337
 338                         if (prop_type == null)
 339                                 return;
 340
 341                         if (prop_type.IsPointer && !UnsafeOK (this))
 342                                 return;
 343
 344                         setter_args [0] = prop_type;
 345
 346                         //
 347                         // FIXME: properties are missing the following
 348                         // flags: hidebysig newslot specialname
 349                         //
 350                         pb = TypeBuilder.DefineProperty (
 351                                 ip.Name, PropertyAttributes.None,
 352                                 prop_type, null);
 353
 354                         if (ip.HasGet){
 355                                 get = TypeBuilder.DefineMethod (
 356                                         "get_" + ip.Name, property_attributes ,
 357                                         prop_type, null);
 358
 359                                 //
 360                                 // HACK because System.Reflection.Emit is lame
 361                                 //
 362                                 Type [] null_types = null;
 363                                 InternalParameters inp = new InternalParameters
 364                                         (null_types, Parameters.GetEmptyReadOnlyParameters ());
 365
 366                                 if (!RegisterMethod (get, inp, null)) {
 367                                         Error111 (ip);
 368                                         return;
 369                                 }
 370
 371                                 pb.SetGetMethod (get);
 372                         }
 373
 374                         if (ip.HasSet){
 375                                 setter_args [0] = prop_type;
 376
 377                                 set = TypeBuilder.DefineMethod (
 378                                         "set_" + ip.Name, property_attributes,
 379                                         TypeManager.void_type, setter_args);
 380
 381                                 set.DefineParameter (1, ParameterAttributes.None, "value");
 382                                 pb.SetSetMethod (set);
 383
 384                                 //
 385                                 // HACK because System.Reflection.Emit is lame
 386                                 //
 387                                 Parameter [] parms = new Parameter [1];
 388                                 parms [0] = new Parameter (ip.Type, "value", Parameter.Modifier.NONE, null);
 389                                 InternalParameters ipp = new InternalParameters (
 390                                         this, new Parameters (parms, null, Location.Null));
 391
 392                                 if (!RegisterMethod (set, ipp, setter_args)) {
 393                                         Error111 (ip);
 394                                         return;
 395                                 }
 396                         }
 397
 398                         TypeManager.RegisterProperty (pb, get, set);
 399                         property_builders.Add (pb);
 400                 }
 401
 402                 //
 403                 // Populates the events in the interface
 404                 //
 405                 void PopulateEvent (InterfaceEvent ie)
 406                 {
 407                         //
 408                         // FIXME: We need to do this after delegates have been
 409                         // declared or we declare them recursively.
 410                         //
 411                 }
 412
 413                 //
 414                 // Populates the indexers in the interface
 415                 //
 416                 void PopulateIndexer (InterfaceIndexer ii)
 417                 {
 418                         PropertyBuilder pb;
 419                         Type prop_type = RootContext.LookupType (this, ii.Type, false, ii.Location);
 420                         Type [] arg_types = ii.ParameterTypes (this);
 421                         Type [] value_arg_types;
 422
 423                         if (prop_type == null)
 424                                 return;
 425
 426                         if (prop_type.IsPointer && !UnsafeOK (this))
 427                                 return;
 428
 429                         //
 430                         // Sets up the extra invisible `value' argument for setters.
 431                         //
 432                         if (arg_types != null){
 433                                 int count = arg_types.Length;
 434                                 value_arg_types = new Type [count + 1];
 435
 436                                 arg_types.CopyTo (value_arg_types, 0);
 437                                 value_arg_types [count] = prop_type;
 438
 439                                 foreach (Type t in arg_types){
 440                                         if (t.IsPointer && !UnsafeOK (this))
 441                                                 return;
 442                                 }
 443                         } else {
 444                                 value_arg_types = new Type [1];
 445
 446                                 value_arg_types [1] = prop_type;
 447                         }
 448
 449                         pb = TypeBuilder.DefineProperty (
 450                                 "Item", PropertyAttributes.None,
 451                                 prop_type, arg_types);
 452
 453                         if (ii.HasGet){
 454                                 MethodBuilder get_item;
 455                                 Parameter [] p = ii.Parameters.FixedParameters;
 456
 457                                 get_item = TypeBuilder.DefineMethod (
 458                                         "get_Item", property_attributes, prop_type, arg_types);
 459                                 pb.SetGetMethod (get_item);
 460                                 //
 461                                 // HACK because System.Reflection.Emit is lame
 462                                 //
 463                                 InternalParameters ip = new InternalParameters (
 464                                         arg_types, ii.Parameters);
 465
 466                                 if (!RegisterMethod (get_item, ip, arg_types)) {
 467                                         Error111 (ii);
 468                                         return;
 469                                 }
 470
 471                                 if (p != null){
 472                                         for (int i = 0; i < p.Length; i++)
 473                                                 get_item.DefineParameter (
 474                                                         i + 1,
 475                                                         p [i].Attributes, p [i].Name);
 476                                 }
 477                         }
 478
 479                         if (ii.HasSet){
 480                                 Parameter [] p = ii.Parameters.FixedParameters;
 481                                 MethodBuilder set_item;
 482                                 int i = 0;
 483
 484                                 set_item = TypeBuilder.DefineMethod (
 485                                         "set_Item", property_attributes,
 486                                         TypeManager.void_type, value_arg_types);
 487                                 pb.SetSetMethod (set_item);
 488                                 //
 489                                 // HACK because System.Reflection.Emit is lame
 490                                 //
 491                                 InternalParameters ip = new InternalParameters (
 492                                         value_arg_types, ii.Parameters);
 493                                 if (!RegisterMethod (set_item, ip, value_arg_types)) {
 494                                         Error111 (ii);
 495                                         return;
 496                                 }
 497
 498                                 if (p != null){
 499                                         for (; i < p.Length; i++)
 500                                                 set_item.DefineParameter (
 501                                                         i + 1,
 502                                                         p [i].Attributes, p [i].Name);
 503                                 }
 504
 505                                 set_item.DefineParameter (i + 1, ParameterAttributes.None, "value");
 506                         }
 507                 }
 508
 509                 /// <summary>
 510                 ///   Performs the semantic analysis for all the interface members
 511                 ///   that were declared
 512                 /// </summary>
 513                 bool SemanticAnalysis ()
 514                 {
 515                         Hashtable methods = new Hashtable ();
 516
 517
 518                         if (defined_method != null){
 519                                 foreach (InterfaceMethod im in defined_method){
 520                                         string sig = im.GetSignature (this);
 521
 522                                         //
 523                                         // If there was an undefined Type on the signatures
 524                                         //
 525                                         if (sig == null)
 526                                                 continue;
 527
 528                                         if (methods [sig] != null){
 529                                                 Error111 (im);
 530                                                 return false;
 531                                         }
 532                                 }
 533                         }
 534
 535                         //
 536                         // FIXME: Here I should check i
 537                         //
 538                         return true;
 539                 }
 540
 541                 Type GetInterfaceTypeByName (string name)
 542                 {
 543                         Type t = FindType (name);
 544
 545                         if (t == null)
 546                                 return null;
 547
 548                         if (t.IsInterface)
 549                                 return t;
 550
 551                         string cause;
 552
 553                         if (t.IsValueType)
 554                                 cause = "is a struct";
 555                         else if (t.IsClass)
 556                                 cause = "is a class";
 557                         else
 558                                 cause = "Should not happen.";
 559
 560                         Report.Error (527, Location, "`"+name+"' " + cause +
 561                                       ", need an interface instead");
 562
 563                         return null;
 564                 }
 565
 566                 //
 567                 // Returns the list of interfaces that this interface implements
 568                 // Or null if it does not implement any interface.
 569                 //
 570                 // Sets the error boolean accoringly.
 571                 //
 572                 Type [] GetInterfaceBases (out bool error)
 573                 {
 574                         Type [] tbases;
 575                         int i;
 576
 577                         error = false;
 578                         if (Bases == null)
 579                                 return null;
 580
 581                         tbases = new Type [Bases.Count];
 582                         i = 0;
 583
 584                         foreach (string name in Bases){
 585                                 Type t;
 586
 587                                 t = GetInterfaceTypeByName (name);
 588                                 if (t == null){
 589                                         error = true;
 590                                         return null;
 591                                 }
 592
 593                                 tbases [i++] = t;
 594                         }
 595
 596                         return tbases;
 597                 }
 598
 599                 //
 600                 // <summary>
 601                 //  Defines the Interface in the appropriate ModuleBuilder or TypeBuilder
 602                 // </summary>
 603                 //
 604                 // TODO:
 605                 //   Rework the way we recurse, because for recursive
 606                 //   definitions of interfaces (A:B and B:A) we report the
 607                 //   error twice, rather than once.
 608
 609                 public override TypeBuilder DefineType ()
 610                 {
 611                         Type [] ifaces;
 612                         bool error;
 613
 614                         if (TypeBuilder != null)
 615                                 return TypeBuilder;
 616
 617                         if (InTransit)
 618                                 return null;
 619
 620                         InTransit = true;
 621
 622                         ifaces = GetInterfaceBases (out error);
 623
 624                         if (error)
 625                                 return null;
 626
 627                         if (IsTopLevel) {
 628                                 ModuleBuilder builder = CodeGen.ModuleBuilder;
 629
 630                                 TypeBuilder = builder.DefineType (
 631                                         Name,
 632                                         InterfaceAttr,
 633                                         (Type)null,   // Parent Type
 634                                         ifaces);
 635                                 RootContext.RegisterOrder (this);
 636                         } else {
 637                                 TypeBuilder builder = Parent.TypeBuilder;
 638
 639                                 TypeBuilder = builder.DefineNestedType (
 640                                         Basename,
 641                                         InterfaceAttr,
 642                                         (Type) null, //parent type
 643                                         ifaces);
 644
 645                                 TypeContainer tc = TypeManager.LookupTypeContainer (builder);
 646                                 tc.RegisterOrder (this);
 647                         }
 648
 649                         TypeManager.AddUserInterface (Name, TypeBuilder, this);
 650                         InTransit = false;
 651
 652                         return TypeBuilder;
 653                 }
 654
 655                 /// <summary>
 656                 ///   Performs semantic analysis, and then generates the IL interfaces
 657                 /// </summary>
 658                 public override bool Define (TypeContainer parent)
 659                 {
 660                         if (!SemanticAnalysis ())
 661                                 return false;
 662
 663                         if (defined_method != null){
 664                                 foreach (InterfaceMethod im in defined_method)
 665                                         PopulateMethod (im);
 666                         }
 667
 668                         if (defined_properties != null){
 669                                 foreach (InterfaceProperty ip in defined_properties)
 670                                         PopulateProperty (ip);
 671                         }
 672
 673                         if (defined_events != null)
 674                                 foreach (InterfaceEvent ie in defined_events)
 675                                         PopulateEvent (ie);
 676
 677                         if (defined_indexer != null) {
 678                                 foreach (InterfaceIndexer ii in defined_indexer)
 679                                         PopulateIndexer (ii);
 680
 681                                 CustomAttributeBuilder cb = EmitDefaultMemberAttr (parent, ModFlags, Location);
 682                                 if (cb != null)
 683                                         TypeBuilder.SetCustomAttribute (cb);
 684                         }
 685
 686                         return true;
 687                 }
 688
 689                 public static CustomAttributeBuilder EmitDefaultMemberAttr (TypeContainer parent, int flags,
 690                                                                             Location loc)
 691                 {
 692                         EmitContext ec = new EmitContext (parent, loc, null, null, flags);
 693
 694                         Expression ml = Expression.MemberLookup (ec, TypeManager.default_member_type,
 695                                                                  ".ctor", MemberTypes.Constructor,
 696                                                                  BindingFlags.Public | BindingFlags.Instance,
 697                                                                  Location.Null);
 698
 699                         if (!(ml is MethodGroupExpr)) {
 700                                 Console.WriteLine ("Internal error !!!!");
 701                                 return null;
 702                         }
 703
 704                         MethodGroupExpr mg = (MethodGroupExpr) ml;
 705
 706                         MethodBase constructor = mg.Methods [0];
 707
 708                         string [] vals = { "Item" };
 709
 710                         CustomAttributeBuilder cb = null;
 711                         try {
 712                                 cb = new CustomAttributeBuilder ((ConstructorInfo) constructor, vals);
 713                         } catch {
 714                                 Report.Warning (-100, "Can not set the indexer default member attribute");
 715                         }
 716
 717                         return cb;
 718                 }
 719
 720         }
 721
 722         public class InterfaceMemberBase {
 723                 public readonly string Name;
 724                 public readonly bool IsNew;
 725                 public Attributes OptAttributes;
 726
 727                 public InterfaceMemberBase (string name, bool is_new, Attributes attrs)
 728                 {
 729                         Name = name;
 730                         IsNew = is_new;
 731                         OptAttributes = attrs;
 732                 }
 733         }
 734
 735         public class InterfaceProperty : InterfaceMemberBase {
 736                 public readonly bool HasSet;
 737                 public readonly bool HasGet;
 738                 public readonly string Type;
 739                 public readonly string type;
 740                 public readonly Location Location;
 741
 742                 public InterfaceProperty (string type, string name,
 743                                           bool is_new, bool has_get, bool has_set,
 744                                           Attributes attrs, Location loc)
 745                         : base (name, is_new, attrs)
 746                 {
 747                         Type = type;
 748                         HasGet = has_get;
 749                         HasSet = has_set;
 750                         Location = loc;
 751                 }
 752         }
 753
 754         public class InterfaceEvent : InterfaceMemberBase {
 755                 public readonly string Type;
 756
 757                 public InterfaceEvent (string type, string name, bool is_new, Attributes attrs)
 758                         : base (name, is_new, attrs)
 759                 {
 760                         Type = type;
 761                 }
 762         }
 763
 764         public class InterfaceMethod : InterfaceMemberBase {
 765                 public readonly string     ReturnType;
 766                 public readonly Parameters Parameters;
 767                 public readonly Location Location;
 768
 769                 public InterfaceMethod (string return_type, string name, bool is_new, Parameters args,
 770                                         Attributes attrs, Location l)
 771                         : base (name, is_new, attrs)
 772                 {
 773                         this.ReturnType = return_type;
 774                         this.Parameters = args;
 775                         Location = l;
 776                 }
 777
 778                 /// <summary>
 779                 ///   Returns the signature for this interface method
 780                 /// </summary>
 781                 public string GetSignature (DeclSpace ds)
 782                 {
 783                         Type ret = RootContext.LookupType (ds, ReturnType, false, Location);
 784                         string args = Parameters.GetSignature (ds);
 785
 786                         if ((ret == null) || (args == null))
 787                                 return null;
 788
 789                         return (IsNew ? "new-" : "") + ret.FullName + "(" + args + ")";
 790                 }
 791
 792                 public Type [] ParameterTypes (DeclSpace ds)
 793                 {
 794                         return Parameters.GetParameterInfo (ds);
 795                 }
 796         }
 797
 798         public class InterfaceIndexer : InterfaceMemberBase {
 799                 public readonly bool HasGet, HasSet;
 800                 public readonly Parameters Parameters;
 801                 public readonly string Type;
 802                 public readonly Location Location;
 803
 804                 public InterfaceIndexer (string type, Parameters args, bool do_get, bool do_set,
 805                                          bool is_new, Attributes attrs, Location loc)
 806                         : base ("", is_new, attrs)
 807                 {
 808                         Type = type;
 809                         Parameters = args;
 810                         HasGet = do_get;
 811                         HasSet = do_set;
 812                         Location = loc;
 813                 }
 814
 815                 public Type [] ParameterTypes (DeclSpace ds)
 816                 {
 817                         return Parameters.GetParameterInfo (ds);
 818                 }
 819         }
 820 }