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