mcs/bmcs/enum.cs

   1 //
   2 // enum.cs: Enum handling.
   3 //
   4 // Author: Miguel de Icaza (miguel@gnu.org)
   5 //         Ravi Pratap     (ravi@ximian.com)
   6 //
   7 // Licensed under the terms of the GNU GPL
   8 //
   9 // (C) 2001 Ximian, Inc (http://www.ximian.com)
  10 //
  11
  12 using System;
  13 using System.Collections;
  14 using System.Reflection;
  15 using System.Reflection.Emit;
  16 using System.Globalization;
  17 using System.Xml;
  18
  19 namespace Mono.CSharp {
  20
  21         class EnumMember: MemberCore {
  22                 static string[] attribute_targets = new string [] { "field" };
  23
  24                 Enum parent_enum;
  25                 public FieldBuilder builder;
  26                 internal readonly Expression Type;
  27
  28                 public EnumMember (Enum parent_enum, Expression expr, string name,
  29                                    Location loc, Attributes attrs):
  30                         base (null, new MemberName (name), attrs, loc)
  31                 {
  32                         this.parent_enum = parent_enum;
  33                         this.ModFlags = parent_enum.ModFlags;
  34                         this.Type = expr;
  35                 }
  36
  37                 public override void ApplyAttributeBuilder(Attribute a, CustomAttributeBuilder cb)
  38                 {
  39                         if (a.Type == TypeManager.marshal_as_attr_type) {
  40                                 UnmanagedMarshal marshal = a.GetMarshal (this);
  41                                 if (marshal != null) {
  42                                         builder.SetMarshal (marshal);
  43                                 }
  44                                         return;
  45                                 }
  46
  47                         if (a.Type.IsSubclassOf (TypeManager.security_attr_type)) {
  48                                 a.Error_InvalidSecurityParent ();
  49                                 return;
  50                         }
  51
  52                         builder.SetCustomAttribute (cb);
  53                 }
  54
  55                 public override AttributeTargets AttributeTargets {
  56                         get {
  57                                 return AttributeTargets.Field;
  58                         }
  59                 }
  60
  61                 public void DefineMember (TypeBuilder tb)
  62                 {
  63                         FieldAttributes attr = FieldAttributes.Public | FieldAttributes.Static
  64                                 | FieldAttributes.Literal;
  65
  66                         builder = tb.DefineField (Name, tb, attr);
  67                 }
  68
  69                 public override bool Define ()
  70                 {
  71                         throw new NotImplementedException ();
  72                 }
  73
  74                 public void Emit (EmitContext ec)
  75                 {
  76                         if (OptAttributes != null)
  77                                 OptAttributes.Emit (ec, this);
  78
  79                         Emit ();
  80                 }
  81
  82                 public override string GetSignatureForError()
  83                 {
  84                         return String.Concat (parent_enum.GetSignatureForError (), '.', base.GetSignatureForError ());
  85                 }
  86
  87                 public override string[] ValidAttributeTargets {
  88                         get {
  89                                 return attribute_targets;
  90                         }
  91                 }
  92
  93                 protected override bool VerifyClsCompliance(DeclSpace ds)
  94                 {
  95                         // Because parent is TypeContainer and we have only DeclSpace parent.
  96                         // Parameter replacing is required
  97                         return base.VerifyClsCompliance (parent_enum);
  98                 }
  99
 100                 // There is no base type
 101                 protected override void VerifyObsoleteAttribute()
 102                 {
 103                 }
 104
 105                 public override string DocCommentHeader {
 106                         get { return "F:"; }
 107                 }
 108         }
 109
 110         /// <summary>
 111         ///   Enumeration container
 112         /// </summary>
 113         public class Enum : DeclSpace {
 114                 public ArrayList ordered_enums;
 115
 116                 public Expression BaseType;
 117
 118                 public Type UnderlyingType;
 119
 120                 Hashtable member_to_location;
 121
 122                 //
 123                 // This is for members that have been defined
 124                 //
 125                 Hashtable member_to_value;
 126
 127                 //
 128                 // This is used to mark members we're currently defining
 129                 //
 130                 Hashtable in_transit;
 131
 132                 ArrayList field_builders;
 133
 134                 public const int AllowedModifiers =
 135                         Modifiers.NEW |
 136                         Modifiers.PUBLIC |
 137                         Modifiers.PROTECTED |
 138                         Modifiers.INTERNAL |
 139                         Modifiers.PRIVATE;
 140
 141                 public Enum (NamespaceEntry ns, TypeContainer parent, Expression type,
 142                              int mod_flags, MemberName name, Attributes attrs, Location l)
 143                         : base (ns, parent, name, attrs, l)
 144                 {
 145                         this.BaseType = type;
 146                         ModFlags = Modifiers.Check (AllowedModifiers, mod_flags,
 147                                                     IsTopLevel ? Modifiers.INTERNAL : Modifiers.PRIVATE, l);
 148
 149                         ordered_enums = new ArrayList ();
 150                         member_to_location = new Hashtable ();
 151                         member_to_value = new Hashtable ();
 152                         in_transit = new Hashtable ();
 153                         field_builders = new ArrayList ();
 154                 }
 155
 156                 /// <summary>
 157                 ///   Adds @name to the enumeration space, with @expr
 158                 ///   being its definition.
 159                 /// </summary>
 160                 public void AddEnumMember (string name, Expression expr, Location loc, Attributes opt_attrs, string documentation)
 161                 {
 162                         if (name == "value__") {
 163                                 Report.Error (76, loc, "An item in an enumeration can't have an identifier `value__'");
 164                                 return;
 165                         }
 166
 167                         EnumMember em = new EnumMember (this, expr, name, loc, opt_attrs);
 168                         em.DocComment = documentation;
 169                         if (!AddToContainer (em, name, ""))
 170                                 return;
 171
 172
 173                         // TODO: can be almost deleted
 174                         ordered_enums.Add (name);
 175                         member_to_location.Add (name, loc);
 176                 }
 177
 178                 //
 179                 // This is used by corlib compilation: we map from our
 180                 // type to a type that is consumable by the DefineField
 181                 //
 182                 Type MapToInternalType (Type t)
 183                 {
 184                         if (t == TypeManager.int32_type)
 185                                 return typeof (int);
 186                         if (t == TypeManager.int64_type)
 187                                 return typeof (long);
 188                         if (t == TypeManager.uint32_type)
 189                                 return typeof (uint);
 190                         if (t == TypeManager.uint64_type)
 191                                 return typeof (ulong);
 192                         if (t == TypeManager.float_type)
 193                                 return typeof (float);
 194                         if (t == TypeManager.double_type)
 195                                 return typeof (double);
 196                         if (t == TypeManager.byte_type)
 197                                 return typeof (byte);
 198                         if (t == TypeManager.sbyte_type)
 199                                 return typeof (sbyte);
 200                         if (t == TypeManager.char_type)
 201                                 return typeof (char);
 202                         if (t == TypeManager.short_type)
 203                                 return typeof (short);
 204                         if (t == TypeManager.ushort_type)
 205                                 return typeof (ushort);
 206
 207                         throw new Exception ();
 208                 }
 209
 210                 public override TypeBuilder DefineType ()
 211                 {
 212                         if (TypeBuilder != null)
 213                                 return TypeBuilder;
 214
 215                         TypeAttributes attr = Modifiers.TypeAttr (ModFlags, IsTopLevel);
 216
 217                         ec = new EmitContext (this, this, Location, null, null, ModFlags, false);
 218
 219                         attr |= TypeAttributes.Class | TypeAttributes.Sealed;
 220
 221                         if (!(BaseType is TypeLookupExpression)) {
 222                                 Report.Error (1008, Location,
 223                                               "Type byte, sbyte, short, ushort, int, uint, " +
 224                                               "long, or ulong expected (got: `{0}')", BaseType);
 225                                 return null;
 226                         }
 227
 228                         TypeExpr ute = ResolveBaseTypeExpr (BaseType, false, Location);
 229                         if (ute == null)
 230                                 return null;
 231
 232                         UnderlyingType = ute.Type;
 233
 234                         if (UnderlyingType != TypeManager.int32_type &&
 235                             UnderlyingType != TypeManager.uint32_type &&
 236                             UnderlyingType != TypeManager.int64_type &&
 237                             UnderlyingType != TypeManager.uint64_type &&
 238                             UnderlyingType != TypeManager.short_type &&
 239                             UnderlyingType != TypeManager.ushort_type &&
 240                             UnderlyingType != TypeManager.byte_type  &&
 241                             UnderlyingType != TypeManager.sbyte_type) {
 242                                 Report.Error (1008, Location,
 243                                               "Type byte, sbyte, short, ushort, int, uint, " +
 244                                               "long, or ulong expected (got: " +
 245                                               TypeManager.CSharpName (UnderlyingType) + ")");
 246                                 return null;
 247                         }
 248
 249                         if (IsTopLevel) {
 250                                 if (TypeManager.NamespaceClash (Name, Location))
 251                                         return null;
 252
 253                                 ModuleBuilder builder = CodeGen.Module.Builder;
 254
 255                                 TypeBuilder = builder.DefineType (Name, attr, TypeManager.enum_type);
 256                         } else {
 257                                 TypeBuilder builder = Parent.TypeBuilder;
 258
 259                                 TypeBuilder = builder.DefineNestedType (
 260                                         Basename, attr, TypeManager.enum_type);
 261                         }
 262
 263                         //
 264                         // Call MapToInternalType for corlib
 265                         //
 266                         TypeBuilder.DefineField ("value__", UnderlyingType,
 267                                                  FieldAttributes.Public | FieldAttributes.SpecialName
 268                                                  | FieldAttributes.RTSpecialName);
 269
 270                         TypeManager.AddEnumType (Name, TypeBuilder, this);
 271
 272                         return TypeBuilder;
 273                 }
 274
 275                 bool IsValidEnumConstant (Expression e)
 276                 {
 277                         if (!(e is Constant))
 278                                 return false;
 279
 280                         if (e is IntConstant || e is UIntConstant || e is LongConstant ||
 281                             e is ByteConstant || e is SByteConstant || e is ShortConstant ||
 282                             e is UShortConstant || e is ULongConstant || e is EnumConstant ||
 283                             e is CharConstant)
 284                                 return true;
 285                         else
 286                                 return false;
 287                 }
 288
 289                 object GetNextDefaultValue (object default_value)
 290                 {
 291                         if (UnderlyingType == TypeManager.int32_type) {
 292                                 int i = (int) default_value;
 293
 294                                 if (i < System.Int32.MaxValue)
 295                                         return ++i;
 296                                 else
 297                                         return null;
 298                         } else if (UnderlyingType == TypeManager.uint32_type) {
 299                                 uint i = (uint) default_value;
 300
 301                                 if (i < System.UInt32.MaxValue)
 302                                         return ++i;
 303                                 else
 304                                         return null;
 305                         } else if (UnderlyingType == TypeManager.int64_type) {
 306                                 long i = (long) default_value;
 307
 308                                 if (i < System.Int64.MaxValue)
 309                                         return ++i;
 310                                 else
 311                                         return null;
 312                         } else if (UnderlyingType == TypeManager.uint64_type) {
 313                                 ulong i = (ulong) default_value;
 314
 315                                 if (i < System.UInt64.MaxValue)
 316                                         return ++i;
 317                                 else
 318                                         return null;
 319                         } else if (UnderlyingType == TypeManager.short_type) {
 320                                 short i = (short) default_value;
 321
 322                                 if (i < System.Int16.MaxValue)
 323                                         return ++i;
 324                                 else
 325                                         return null;
 326                         } else if (UnderlyingType == TypeManager.ushort_type) {
 327                                 ushort i = (ushort) default_value;
 328
 329                                 if (i < System.UInt16.MaxValue)
 330                                         return ++i;
 331                                 else
 332                                         return null;
 333                         } else if (UnderlyingType == TypeManager.byte_type) {
 334                                 byte i = (byte) default_value;
 335
 336                                 if (i < System.Byte.MaxValue)
 337                                         return ++i;
 338                                 else
 339                                         return null;
 340                         } else if (UnderlyingType == TypeManager.sbyte_type) {
 341                                 sbyte i = (sbyte) default_value;
 342
 343                                 if (i < System.SByte.MaxValue)
 344                                         return ++i;
 345                                 else
 346                                         return null;
 347                         }
 348
 349                         return null;
 350                 }
 351
 352                 void Error_ConstantValueCannotBeConverted (object val, Location loc)
 353                 {
 354                         if (val is Constant)
 355                                 Report.Error (31, loc, "Constant value '" + ((Constant) val).AsString () +
 356                                               "' cannot be converted" +
 357                                               " to a " + TypeManager.CSharpName (UnderlyingType));
 358                         else
 359                                 Report.Error (31, loc, "Constant value '" + val +
 360                                               "' cannot be converted" +
 361                                               " to a " + TypeManager.CSharpName (UnderlyingType));
 362                         return;
 363                 }
 364
 365                 /// <summary>
 366                 ///  Determines if a standard implicit conversion exists from
 367                 ///  expr_type to target_type
 368                 /// </summary>
 369                 public static bool WideningConversionExists (Type expr_type, Type target_type)
 370                 {
 371                         expr_type = TypeManager.TypeToCoreType (expr_type);
 372
 373                         if (expr_type == TypeManager.void_type)
 374                                 return false;
 375
 376                         if (expr_type == target_type)
 377                                 return true;
 378
 379                         // First numeric conversions
 380
 381                         if (expr_type == TypeManager.sbyte_type){
 382                                 //
 383                                 // From sbyte to short, int, long, float, double.
 384                                 //
 385                                 if ((target_type == TypeManager.int32_type) ||
 386                                     (target_type == TypeManager.int64_type) ||
 387                                     (target_type == TypeManager.double_type) ||
 388                                     (target_type == TypeManager.float_type)  ||
 389                                     (target_type == TypeManager.short_type) ||
 390                                     (target_type == TypeManager.decimal_type))
 391                                         return true;
 392
 393                         } else if (expr_type == TypeManager.byte_type){
 394                                 //
 395                                 // From byte to short, ushort, int, uint, long, ulong, float, double
 396                                 //
 397                                 if ((target_type == TypeManager.short_type) ||
 398                                     (target_type == TypeManager.ushort_type) ||
 399                                     (target_type == TypeManager.int32_type) ||
 400                                     (target_type == TypeManager.uint32_type) ||
 401                                     (target_type == TypeManager.uint64_type) ||
 402                                     (target_type == TypeManager.int64_type) ||
 403                                     (target_type == TypeManager.float_type) ||
 404                                     (target_type == TypeManager.double_type) ||
 405                                     (target_type == TypeManager.decimal_type))
 406                                         return true;
 407
 408                         } else if (expr_type == TypeManager.short_type){
 409                                 //
 410                                 // From short to int, long, float, double
 411                                 //
 412                                 if ((target_type == TypeManager.int32_type) ||
 413                                     (target_type == TypeManager.int64_type) ||
 414                                     (target_type == TypeManager.double_type) ||
 415                                     (target_type == TypeManager.float_type) ||
 416                                     (target_type == TypeManager.decimal_type))
 417                                         return true;
 418
 419                         } else if (expr_type == TypeManager.ushort_type){
 420                                 //
 421                                 // From ushort to int, uint, long, ulong, float, double
 422                                 //
 423                                 if ((target_type == TypeManager.uint32_type) ||
 424                                     (target_type == TypeManager.uint64_type) ||
 425                                     (target_type == TypeManager.int32_type) ||
 426                                     (target_type == TypeManager.int64_type) ||
 427                                     (target_type == TypeManager.double_type) ||
 428                                     (target_type == TypeManager.float_type) ||
 429                                     (target_type == TypeManager.decimal_type))
 430                                         return true;
 431
 432                         } else if (expr_type == TypeManager.int32_type){
 433                                 //
 434                                 // From int to long, float, double
 435                                 //
 436                                 if ((target_type == TypeManager.int64_type) ||
 437                                     (target_type == TypeManager.double_type) ||
 438                                     (target_type == TypeManager.float_type) ||
 439                                     (target_type == TypeManager.decimal_type))
 440                                         return true;
 441
 442                         } else if (expr_type == TypeManager.uint32_type){
 443                                 //
 444                                 // From uint to long, ulong, float, double
 445                                 //
 446                                 if ((target_type == TypeManager.int64_type) ||
 447                                     (target_type == TypeManager.uint64_type) ||
 448                                     (target_type == TypeManager.double_type) ||
 449                                     (target_type == TypeManager.float_type) ||
 450                                     (target_type == TypeManager.decimal_type))
 451                                         return true;
 452
 453                         } else if ((expr_type == TypeManager.uint64_type) ||
 454                                    (expr_type == TypeManager.int64_type)) {
 455                                 //
 456                                 // From long/ulong to float, double
 457                                 //
 458                                 if ((target_type == TypeManager.double_type) ||
 459                                     (target_type == TypeManager.float_type) ||
 460                                     (target_type == TypeManager.decimal_type))
 461                                         return true;
 462
 463                         } else if (expr_type == TypeManager.char_type){
 464                                 //
 465                                 // From char to ushort, int, uint, long, ulong, float, double
 466                                 //
 467                                 if ((target_type == TypeManager.ushort_type) ||
 468                                     (target_type == TypeManager.int32_type) ||
 469                                     (target_type == TypeManager.uint32_type) ||
 470                                     (target_type == TypeManager.uint64_type) ||
 471                                     (target_type == TypeManager.int64_type) ||
 472                                     (target_type == TypeManager.float_type) ||
 473                                     (target_type == TypeManager.double_type) ||
 474                                     (target_type == TypeManager.decimal_type))
 475                                         return true;
 476
 477                         } else if (expr_type == TypeManager.float_type){
 478                                 //
 479                                 // float to double
 480                                 //
 481                                 if (target_type == TypeManager.double_type)
 482                                         return true;
 483                         }
 484
 485                         return false;
 486                 }
 487
 488                 //
 489                 // Horrible, horrible.  But there is no other way we can pass the EmitContext
 490                 // to the recursive definition triggered by the evaluation of a forward
 491                 // expression
 492                 //
 493                 static EmitContext current_ec = null;
 494
 495                 /// <summary>
 496                 ///  This is used to lookup the value of an enum member. If the member is undefined,
 497                 ///  it attempts to define it and return its value
 498                 /// </summary>
 499                 public object LookupEnumValue (EmitContext ec, string name, Location loc)
 500                 {
 501
 502                         object default_value = null;
 503                         Constant c = null;
 504
 505                         default_value = member_to_value [name];
 506
 507                         if (default_value != null)
 508                                 return default_value;
 509
 510                         //
 511                         // This may happen if we're calling a method in System.Enum, for instance
 512                         // Enum.IsDefined().
 513                         //
 514                         if (!defined_names.Contains (name))
 515                                 return null;
 516
 517                         if (in_transit.Contains (name)) {
 518                                 Report.Error (110, loc, "The evaluation of the constant value for `" +
 519                                               Name + "." + name + "' involves a circular definition.");
 520                                 return null;
 521                         }
 522
 523                         //
 524                         // So if the above doesn't happen, we have a member that is undefined
 525                         // We now proceed to define it
 526                         //
 527                         Expression val = this [name];
 528
 529                         if (val == null) {
 530
 531                                 int idx = ordered_enums.IndexOf (name);
 532
 533                                 if (idx == 0)
 534                                         default_value = 0;
 535                                 else {
 536                                         for (int i = 0; i < idx; ++i) {
 537                                                 string n = (string) ordered_enums [i];
 538                                                 Location m_loc = (Mono.CSharp.Location)
 539                                                         member_to_location [n];
 540                                                 in_transit.Add (name, true);
 541
 542                                                 EmitContext old_ec = current_ec;
 543                                                 current_ec = ec;
 544
 545                                                 default_value = LookupEnumValue (ec, n, m_loc);
 546
 547                                                 current_ec = old_ec;
 548
 549                                                 in_transit.Remove (name);
 550                                                 if (default_value == null)
 551                                                         return null;
 552                                         }
 553
 554                                         default_value = GetNextDefaultValue (default_value);
 555                                 }
 556
 557                         } else {
 558                                 bool old = ec.InEnumContext;
 559                                 ec.InEnumContext = true;
 560                                 in_transit.Add (name, true);
 561
 562                                 EmitContext old_ec = current_ec;
 563                                 current_ec = ec;
 564                                 val = val.Resolve (ec);
 565                                 current_ec = old_ec;
 566
 567                                 in_transit.Remove (name);
 568                                 ec.InEnumContext = old;
 569
 570                                 if (val == null)
 571                                         return null;
 572
 573                                 if (!IsValidEnumConstant (val)) {
 574                                         Report.Error (
 575                                                 1008, loc,
 576                                                 "Type byte, sbyte, short, ushort, int, uint, long, or " +
 577                                                 "ulong expected (have: " + val + ")");
 578                                         return null;
 579                                 }
 580
 581                                 c = (Constant) val;
 582                                 default_value = c.GetValue ();
 583
 584                                 if (default_value == null) {
 585                                         Error_ConstantValueCannotBeConverted (c, loc);
 586                                         return null;
 587                                 }
 588
 589                                 if (val is EnumConstant){
 590                                         Type etype = TypeManager.EnumToUnderlying (c.Type);
 591
 592                                         if (!WideningConversionExists (etype, UnderlyingType)){
 593                                                 Convert.Error_CannotWideningConversion (
 594                                                         loc, c.Type, UnderlyingType);
 595                                                 return null;
 596                                         }
 597                                 }
 598                         }
 599
 600                         EnumMember em = (EnumMember) defined_names [name];
 601                         em.DefineMember (TypeBuilder);
 602
 603                         bool fail;
 604                         default_value = TypeManager.ChangeType (default_value, UnderlyingType, out fail);
 605                         if (fail){
 606                                 Error_ConstantValueCannotBeConverted (c, loc);
 607                                 return null;
 608                         }
 609
 610                         em.builder.SetConstant (default_value);
 611                         field_builders.Add (em.builder);
 612                         member_to_value [name] = default_value;
 613
 614                         if (!TypeManager.RegisterFieldValue (em.builder, default_value))
 615                                 return null;
 616
 617                         return default_value;
 618                 }
 619
 620                 public override bool DefineMembers (TypeContainer parent)
 621                 {
 622                         return true;
 623                 }
 624
 625                 public override bool Define ()
 626                 {
 627                         //
 628                         // If there was an error during DefineEnum, return
 629                         //
 630                         if (TypeBuilder == null)
 631                                 return false;
 632
 633                         ec = new EmitContext (this, this, Location, null, UnderlyingType, ModFlags, false);
 634
 635                         object default_value = 0;
 636
 637
 638                         foreach (string name in ordered_enums) {
 639                                 //
 640                                 // Have we already been defined, thanks to some cross-referencing ?
 641                                 //
 642                                 if (member_to_value.Contains (name))
 643                                         continue;
 644
 645                                 Location loc = (Mono.CSharp.Location) member_to_location [name];
 646
 647                                 if (this [name] != null) {
 648                                         default_value = LookupEnumValue (ec, name, loc);
 649
 650                                         if (default_value == null)
 651                                                 return true;
 652                                 } else {
 653                                         if (name == "value__"){
 654                                                 Report.Error (76, loc, "The name `value__' is reserved for enumerations");
 655                                                 return false;
 656                                         }
 657
 658                                         EnumMember em = (EnumMember) defined_names [name];
 659
 660                                         em.DefineMember (TypeBuilder);
 661                                         FieldBuilder fb = em.builder;
 662
 663                                         if (default_value == null) {
 664                                            Report.Error (543, loc, "Enumerator value for '" + name + "' is too large to " +
 665                                                               "fit in its type");
 666                                                 return false;
 667                                         }
 668
 669                                         bool fail;
 670                                         default_value = TypeManager.ChangeType (default_value, UnderlyingType, out fail);
 671                                         if (fail){
 672                                                 Error_ConstantValueCannotBeConverted (default_value, loc);
 673                                                 return false;
 674                                         }
 675
 676                                         fb.SetConstant (default_value);
 677                                         field_builders.Add (fb);
 678                                         member_to_value [name] = default_value;
 679
 680                                         if (!TypeManager.RegisterFieldValue (fb, default_value))
 681                                                 return false;
 682                                 }
 683
 684                                 default_value = GetNextDefaultValue (default_value);
 685                         }
 686
 687                         return true;
 688                 }
 689
 690                 public override void Emit ()
 691                 {
 692                         if (OptAttributes != null) {
 693                                 OptAttributes.Emit (ec, this);
 694                         }
 695
 696                         foreach (EnumMember em in defined_names.Values) {
 697                                 em.Emit (ec);
 698                         }
 699
 700                         base.Emit ();
 701                 }
 702
 703                 void VerifyClsName ()
 704                 {
 705                         Hashtable ht = new Hashtable ();
 706                         foreach (string name in ordered_enums) {
 707                                 string locase = name.ToLower (System.Globalization.CultureInfo.InvariantCulture);
 708                                 if (!ht.Contains (locase)) {
 709                                         ht.Add (locase, defined_names [name]);
 710                                         continue;
 711                                 }
 712
 713                                 MemberCore conflict = (MemberCore)ht [locase];
 714                                 Report.SymbolRelatedToPreviousError (conflict);
 715                                 conflict = GetDefinition (name);
 716                                 Report.Error (3005, conflict.Location, "Identifier '{0}' differing only in case is not CLS-compliant", conflict.GetSignatureForError ());
 717                         }
 718                 }
 719
 720                 protected override bool VerifyClsCompliance (DeclSpace ds)
 721                 {
 722                         if (!base.VerifyClsCompliance (ds))
 723                                 return false;
 724
 725                         VerifyClsName ();
 726
 727                         if (!AttributeTester.IsClsCompliant (UnderlyingType)) {
 728                                 Report.Error (3009, Location, "'{0}': base type '{1}' is not CLS-compliant", GetSignatureForError (), TypeManager.CSharpName (UnderlyingType));
 729                         }
 730
 731                         return true;
 732                 }
 733
 734                 /// <summary>
 735                 /// Returns full enum name.
 736                 /// </summary>
 737                 string GetEnumeratorName (string valueName)
 738                 {
 739                         return String.Concat (Name, ".", valueName);
 740                 }
 741
 742                 //
 743                 // IMemberFinder
 744                 //
 745                 public override MemberList FindMembers (MemberTypes mt, BindingFlags bf,
 746                                                         MemberFilter filter, object criteria)
 747                 {
 748                         ArrayList members = new ArrayList ();
 749
 750                         if ((mt & MemberTypes.Field) != 0) {
 751                                 if (criteria is string){
 752                                         if (member_to_value [criteria] == null && current_ec != null){
 753                                                 LookupEnumValue (current_ec, (string) criteria, Location.Null);
 754                                         }
 755                                 }
 756
 757                                 foreach (FieldBuilder fb in field_builders)
 758                                         if (filter (fb, criteria) == true)
 759                                                 members.Add (fb);
 760                         }
 761
 762                         return new MemberList (members);
 763                 }
 764
 765                 public override MemberCache MemberCache {
 766                         get {
 767                                 return null;
 768                         }
 769                 }
 770
 771                 public ArrayList ValueNames {
 772                         get {
 773                                 return ordered_enums;
 774                         }
 775                 }
 776
 777                 // indexer
 778                 public Expression this [string name] {
 779                         get {
 780                                 return ((EnumMember) defined_names [name]).Type;
 781                         }
 782                 }
 783
 784                 public override AttributeTargets AttributeTargets {
 785                         get {
 786                                 return AttributeTargets.Enum;
 787                         }
 788                 }
 789
 790                 protected override void VerifyObsoleteAttribute()
 791                 {
 792                         // UnderlyingType is never obsolete
 793                 }
 794
 795                 //
 796                 // Generates xml doc comments (if any), and if required,
 797                 // handle warning report.
 798                 //
 799                 internal override void GenerateDocComment (DeclSpace ds)
 800                 {
 801                         DocUtil.GenerateEnumDocComment (this, ds);
 802                 }
 803
 804                 //
 805                 //   Represents header string for documentation comment.
 806                 //
 807                 public override string DocCommentHeader {
 808                         get { return "T:"; }
 809                 }
 810         }
 811 }