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