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