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         // Maybe can be usefull to derive from MemberCore
  21         class EnumMember: Attributable {
  22                 string name;
  23                 Enum parent;
  24                 Location loc;
  25
  26                 static string[] attribute_targets = new string [] { "field" };
  27
  28                 public FieldBuilder builder;
  29
  30                 public EnumMember (string name, Enum parent, Location loc, Attributes attrs):
  31                         base (attrs)
  32                 {
  33                         this.name = name;
  34                         this.parent = parent;
  35                         this.loc = loc;
  36                 }
  37
  38                 public override void ApplyAttributeBuilder(Attribute a, CustomAttributeBuilder cb)
  39                 {
  40                         if (a.Type == TypeManager.marshal_as_attr_type) {
  41                                 UnmanagedMarshal marshal = a.GetMarshal ();
  42                                 if (marshal != null) {
  43                                         builder.SetMarshal (marshal);
  44                                         return;
  45                                 }
  46                                 Report.Warning_T (-24, a.Location);
  47                                 return;
  48                         }
  49
  50                         builder.SetCustomAttribute (cb);
  51                 }
  52
  53                 public override AttributeTargets AttributeTargets {
  54                         get {
  55                                 return AttributeTargets.Field;
  56                         }
  57                 }
  58
  59                 public override bool IsClsCompliaceRequired(DeclSpace ds)
  60                 {
  61                         return parent.IsClsCompliaceRequired (ds);
  62                 }
  63
  64                 public void DefineMember (TypeBuilder tb)
  65                 {
  66                         FieldAttributes attr = FieldAttributes.Public | FieldAttributes.Static
  67                                 | FieldAttributes.Literal;
  68
  69                         builder = tb.DefineField (name, tb, attr);
  70                 }
  71
  72                 public void Emit (EmitContext ec)
  73                 {
  74                         if (OptAttributes != null)
  75                                 OptAttributes.Emit (ec, this);
  76                 }
  77
  78                 // TODO: caching would be usefull
  79                 public ObsoleteAttribute GetObsoleteAttribute (EmitContext ec)
  80                 {
  81                         if (OptAttributes == null)
  82                                 return null;
  83
  84                         Attribute obsolete_attr = OptAttributes.Search (TypeManager.obsolete_attribute_type, ec);
  85                         if (obsolete_attr == null)
  86                                 return null;
  87
  88                         ObsoleteAttribute obsolete = obsolete_attr.GetObsoleteAttribute (ec.DeclSpace);
  89                         if (obsolete == null)
  90                                 return null;
  91
  92                         return obsolete;
  93                 }
  94
  95                 protected override string[] ValidAttributeTargets {
  96                         get {
  97                                 return attribute_targets;
  98                         }
  99                 }
 100         }
 101
 102         /// <summary>
 103         ///   Enumeration container
 104         /// </summary>
 105         public class Enum : DeclSpace {
 106                 ArrayList ordered_enums;
 107
 108                 public Expression BaseType;
 109
 110                 public Type UnderlyingType;
 111
 112                 Hashtable member_to_location;
 113                 Hashtable member_to_attributes;
 114
 115                 //
 116                 // This is for members that have been defined
 117                 //
 118                 Hashtable member_to_value;
 119
 120                 //
 121                 // This is used to mark members we're currently defining
 122                 //
 123                 Hashtable in_transit;
 124
 125                 ArrayList field_builders;
 126
 127
 128                 Hashtable name_to_member;
 129
 130                 public const int AllowedModifiers =
 131                         Modifiers.NEW |
 132                         Modifiers.PUBLIC |
 133                         Modifiers.PROTECTED |
 134                         Modifiers.INTERNAL |
 135                         Modifiers.PRIVATE;
 136
 137                 public Enum (NamespaceEntry ns, TypeContainer parent, Expression type,
 138                              int mod_flags, MemberName name, Attributes attrs, Location l)
 139                         : base (ns, parent, name, attrs, l)
 140                 {
 141                         this.BaseType = type;
 142                         ModFlags = Modifiers.Check (AllowedModifiers, mod_flags,
 143                                                     IsTopLevel ? Modifiers.INTERNAL : Modifiers.PRIVATE, l);
 144
 145                         ordered_enums = new ArrayList ();
 146                         member_to_location = new Hashtable ();
 147                         member_to_value = new Hashtable ();
 148                         in_transit = new Hashtable ();
 149                         field_builders = new ArrayList ();
 150
 151                         name_to_member = new Hashtable ();
 152                 }
 153
 154                 /// <summary>
 155                 ///   Adds @name to the enumeration space, with @expr
 156                 ///   being its definition.
 157                 /// </summary>
 158                 public AdditionResult AddEnumMember (string name, Expression expr, Location loc,
 159                                                      Attributes opt_attrs)
 160                 {
 161                         if (defined_names.Contains (name))
 162                                 return AdditionResult.NameExists;
 163
 164                         if (name == "value__") {
 165                                 Report.Error (76, loc, "An item in an enumeration can't have an identifier `value__'");
 166                                 return AdditionResult.Error;
 167                         }
 168
 169                         DefineName (name, expr);
 170
 171                         ordered_enums.Add (name);
 172                         member_to_location.Add (name, loc);
 173
 174                         if (member_to_attributes == null)
 175                                 member_to_attributes = new Hashtable ();
 176
 177                         member_to_attributes.Add (name, opt_attrs);
 178
 179                         name_to_member.Add (name, new EnumMember (name, this, loc, opt_attrs));
 180
 181                         return AdditionResult.Success;
 182                 }
 183
 184                 //
 185                 // This is used by corlib compilation: we map from our
 186                 // type to a type that is consumable by the DefineField
 187                 //
 188                 Type MapToInternalType (Type t)
 189                 {
 190                         if (t == TypeManager.int32_type)
 191                                 return typeof (int);
 192                         if (t == TypeManager.int64_type)
 193                                 return typeof (long);
 194                         if (t == TypeManager.uint32_type)
 195                                 return typeof (uint);
 196                         if (t == TypeManager.uint64_type)
 197                                 return typeof (ulong);
 198                         if (t == TypeManager.float_type)
 199                                 return typeof (float);
 200                         if (t == TypeManager.double_type)
 201                                 return typeof (double);
 202                         if (t == TypeManager.byte_type)
 203                                 return typeof (byte);
 204                         if (t == TypeManager.sbyte_type)
 205                                 return typeof (sbyte);
 206                         if (t == TypeManager.char_type)
 207                                 return typeof (char);
 208                         if (t == TypeManager.short_type)
 209                                 return typeof (short);
 210                         if (t == TypeManager.ushort_type)
 211                                 return typeof (ushort);
 212
 213                         throw new Exception ();
 214                 }
 215
 216                 public override TypeBuilder DefineType ()
 217                 {
 218                         if (TypeBuilder != null)
 219                                 return TypeBuilder;
 220
 221                         TypeAttributes attr = Modifiers.TypeAttr (ModFlags, IsTopLevel);
 222
 223                         attr |= TypeAttributes.Class | TypeAttributes.Sealed;
 224
 225                         if (!(BaseType is TypeLookupExpression)) {
 226                                 Report.Error (1008, Location,
 227                                               "Type byte, sbyte, short, ushort, int, uint, " +
 228                                               "long, or ulong expected (got: `{0}')", BaseType);
 229                                 return null;
 230                         }
 231
 232                         UnderlyingType = ResolveType (BaseType, false, Location);
 233
 234                         if (UnderlyingType != TypeManager.int32_type &&
 235                             UnderlyingType != TypeManager.uint32_type &&
 236                             UnderlyingType != TypeManager.int64_type &&
 237                             UnderlyingType != TypeManager.uint64_type &&
 238                             UnderlyingType != TypeManager.short_type &&
 239                             UnderlyingType != TypeManager.ushort_type &&
 240                             UnderlyingType != TypeManager.byte_type  &&
 241                             UnderlyingType != TypeManager.sbyte_type) {
 242                                 Report.Error (1008, Location,
 243                                               "Type byte, sbyte, short, ushort, int, uint, " +
 244                                               "long, or ulong expected (got: " +
 245                                               TypeManager.CSharpName (UnderlyingType) + ")");
 246                                 return null;
 247                         }
 248
 249                         if (IsTopLevel) {
 250                                 if (TypeManager.NamespaceClash (Name, Location))
 251                                         return null;
 252
 253                                 ModuleBuilder builder = CodeGen.Module.Builder;
 254
 255                                 TypeBuilder = builder.DefineType (Name, attr, TypeManager.enum_type);
 256                         } else {
 257                                 TypeBuilder builder = Parent.TypeBuilder;
 258
 259                                 TypeBuilder = builder.DefineNestedType (
 260                                         Basename, attr, TypeManager.enum_type);
 261                         }
 262
 263                         //
 264                         // Call MapToInternalType for corlib
 265                         //
 266                         TypeBuilder.DefineField ("value__", UnderlyingType,
 267                                                  FieldAttributes.Public | FieldAttributes.SpecialName
 268                                                  | FieldAttributes.RTSpecialName);
 269
 270                         TypeManager.AddEnumType (Name, TypeBuilder, this);
 271
 272                         return TypeBuilder;
 273                 }
 274
 275                 bool IsValidEnumConstant (Expression e)
 276                 {
 277                         if (!(e is Constant))
 278                                 return false;
 279
 280                         if (e is IntConstant || e is UIntConstant || e is LongConstant ||
 281                             e is ByteConstant || e is SByteConstant || e is ShortConstant ||
 282                             e is UShortConstant || e is ULongConstant || e is EnumConstant ||
 283                             e is CharConstant)
 284                                 return true;
 285                         else
 286                                 return false;
 287                 }
 288
 289                 object GetNextDefaultValue (object default_value)
 290                 {
 291                         if (UnderlyingType == TypeManager.int32_type) {
 292                                 int i = (int) default_value;
 293
 294                                 if (i < System.Int32.MaxValue)
 295                                         return ++i;
 296                                 else
 297                                         return null;
 298                         } else if (UnderlyingType == TypeManager.uint32_type) {
 299                                 uint i = (uint) default_value;
 300
 301                                 if (i < System.UInt32.MaxValue)
 302                                         return ++i;
 303                                 else
 304                                         return null;
 305                         } else if (UnderlyingType == TypeManager.int64_type) {
 306                                 long i = (long) default_value;
 307
 308                                 if (i < System.Int64.MaxValue)
 309                                         return ++i;
 310                                 else
 311                                         return null;
 312                         } else if (UnderlyingType == TypeManager.uint64_type) {
 313                                 ulong i = (ulong) default_value;
 314
 315                                 if (i < System.UInt64.MaxValue)
 316                                         return ++i;
 317                                 else
 318                                         return null;
 319                         } else if (UnderlyingType == TypeManager.short_type) {
 320                                 short i = (short) default_value;
 321
 322                                 if (i < System.Int16.MaxValue)
 323                                         return ++i;
 324                                 else
 325                                         return null;
 326                         } else if (UnderlyingType == TypeManager.ushort_type) {
 327                                 ushort i = (ushort) default_value;
 328
 329                                 if (i < System.UInt16.MaxValue)
 330                                         return ++i;
 331                                 else
 332                                         return null;
 333                         } else if (UnderlyingType == TypeManager.byte_type) {
 334                                 byte i = (byte) default_value;
 335
 336                                 if (i < System.Byte.MaxValue)
 337                                         return ++i;
 338                                 else
 339                                         return null;
 340                         } else if (UnderlyingType == TypeManager.sbyte_type) {
 341                                 sbyte i = (sbyte) default_value;
 342
 343                                 if (i < System.SByte.MaxValue)
 344                                         return ++i;
 345                                 else
 346                                         return null;
 347                         }
 348
 349                         return null;
 350                 }
 351
 352                 void Error_ConstantValueCannotBeConverted (object val, Location loc)
 353                 {
 354                         if (val is Constant)
 355                                 Report.Error (31, loc, "Constant value '" + ((Constant) val).AsString () +
 356                                               "' cannot be converted" +
 357                                               " to a " + TypeManager.CSharpName (UnderlyingType));
 358                         else
 359                                 Report.Error (31, loc, "Constant value '" + val +
 360                                               "' cannot be converted" +
 361                                               " to a " + TypeManager.CSharpName (UnderlyingType));
 362                         return;
 363                 }
 364
 365                 /// <summary>
 366                 ///  Determines if a standard implicit conversion exists from
 367                 ///  expr_type to target_type
 368                 /// </summary>
 369                 public static bool ImplicitConversionExists (Type expr_type, Type target_type)
 370                 {
 371                         expr_type = TypeManager.TypeToCoreType (expr_type);
 372
 373                         if (expr_type == TypeManager.void_type)
 374                                 return false;
 375
 376                         if (expr_type == target_type)
 377                                 return true;
 378
 379                         // First numeric conversions
 380
 381                         if (expr_type == TypeManager.sbyte_type){
 382                                 //
 383                                 // From sbyte to short, int, long, float, double.
 384                                 //
 385                                 if ((target_type == TypeManager.int32_type) ||
 386                                     (target_type == TypeManager.int64_type) ||
 387                                     (target_type == TypeManager.double_type) ||
 388                                     (target_type == TypeManager.float_type)  ||
 389                                     (target_type == TypeManager.short_type) ||
 390                                     (target_type == TypeManager.decimal_type))
 391                                         return true;
 392
 393                         } else if (expr_type == TypeManager.byte_type){
 394                                 //
 395                                 // From byte to short, ushort, int, uint, long, ulong, float, double
 396                                 //
 397                                 if ((target_type == TypeManager.short_type) ||
 398                                     (target_type == TypeManager.ushort_type) ||
 399                                     (target_type == TypeManager.int32_type) ||
 400                                     (target_type == TypeManager.uint32_type) ||
 401                                     (target_type == TypeManager.uint64_type) ||
 402                                     (target_type == TypeManager.int64_type) ||
 403                                     (target_type == TypeManager.float_type) ||
 404                                     (target_type == TypeManager.double_type) ||
 405                                     (target_type == TypeManager.decimal_type))
 406                                         return true;
 407
 408                         } else if (expr_type == TypeManager.short_type){
 409                                 //
 410                                 // From short to int, long, float, double
 411                                 //
 412                                 if ((target_type == TypeManager.int32_type) ||
 413                                     (target_type == TypeManager.int64_type) ||
 414                                     (target_type == TypeManager.double_type) ||
 415                                     (target_type == TypeManager.float_type) ||
 416                                     (target_type == TypeManager.decimal_type))
 417                                         return true;
 418
 419                         } else if (expr_type == TypeManager.ushort_type){
 420                                 //
 421                                 // From ushort to int, uint, long, ulong, float, double
 422                                 //
 423                                 if ((target_type == TypeManager.uint32_type) ||
 424                                     (target_type == TypeManager.uint64_type) ||
 425                                     (target_type == TypeManager.int32_type) ||
 426                                     (target_type == TypeManager.int64_type) ||
 427                                     (target_type == TypeManager.double_type) ||
 428                                     (target_type == TypeManager.float_type) ||
 429                                     (target_type == TypeManager.decimal_type))
 430                                         return true;
 431
 432                         } else if (expr_type == TypeManager.int32_type){
 433                                 //
 434                                 // From int to long, float, double
 435                                 //
 436                                 if ((target_type == TypeManager.int64_type) ||
 437                                     (target_type == TypeManager.double_type) ||
 438                                     (target_type == TypeManager.float_type) ||
 439                                     (target_type == TypeManager.decimal_type))
 440                                         return true;
 441
 442                         } else if (expr_type == TypeManager.uint32_type){
 443                                 //
 444                                 // From uint to long, ulong, float, double
 445                                 //
 446                                 if ((target_type == TypeManager.int64_type) ||
 447                                     (target_type == TypeManager.uint64_type) ||
 448                                     (target_type == TypeManager.double_type) ||
 449                                     (target_type == TypeManager.float_type) ||
 450                                     (target_type == TypeManager.decimal_type))
 451                                         return true;
 452
 453                         } else if ((expr_type == TypeManager.uint64_type) ||
 454                                    (expr_type == TypeManager.int64_type)) {
 455                                 //
 456                                 // From long/ulong to float, double
 457                                 //
 458                                 if ((target_type == TypeManager.double_type) ||
 459                                     (target_type == TypeManager.float_type) ||
 460                                     (target_type == TypeManager.decimal_type))
 461                                         return true;
 462
 463                         } else if (expr_type == TypeManager.char_type){
 464                                 //
 465                                 // From char to ushort, int, uint, long, ulong, float, double
 466                                 //
 467                                 if ((target_type == TypeManager.ushort_type) ||
 468                                     (target_type == TypeManager.int32_type) ||
 469                                     (target_type == TypeManager.uint32_type) ||
 470                                     (target_type == TypeManager.uint64_type) ||
 471                                     (target_type == TypeManager.int64_type) ||
 472                                     (target_type == TypeManager.float_type) ||
 473                                     (target_type == TypeManager.double_type) ||
 474                                     (target_type == TypeManager.decimal_type))
 475                                         return true;
 476
 477                         } else if (expr_type == TypeManager.float_type){
 478                                 //
 479                                 // float to double
 480                                 //
 481                                 if (target_type == TypeManager.double_type)
 482                                         return true;
 483                         }
 484
 485                         return false;
 486                 }
 487
 488                 //
 489                 // Horrible, horrible.  But there is no other way we can pass the EmitContext
 490                 // to the recursive definition triggered by the evaluation of a forward
 491                 // expression
 492                 //
 493                 static EmitContext current_ec = null;
 494
 495                 /// <summary>
 496                 ///  This is used to lookup the value of an enum member. If the member is undefined,
 497                 ///  it attempts to define it and return its value
 498                 /// </summary>
 499                 public object LookupEnumValue (EmitContext ec, string name, Location loc)
 500                 {
 501
 502                         object default_value = null;
 503                         Constant c = null;
 504
 505                         default_value = member_to_value [name];
 506
 507                         if (default_value != null)
 508                                 return default_value;
 509
 510                         //
 511                         // This may happen if we're calling a method in System.Enum, for instance
 512                         // Enum.IsDefined().
 513                         //
 514                         if (!defined_names.Contains (name))
 515                                 return null;
 516
 517                         if (in_transit.Contains (name)) {
 518                                 Report.Error (110, loc, "The evaluation of the constant value for `" +
 519                                               Name + "." + name + "' involves a circular definition.");
 520                                 return null;
 521                         }
 522
 523                         //
 524                         // So if the above doesn't happen, we have a member that is undefined
 525                         // We now proceed to define it
 526                         //
 527                         Expression val = this [name];
 528
 529                         if (val == null) {
 530
 531                                 int idx = ordered_enums.IndexOf (name);
 532
 533                                 if (idx == 0)
 534                                         default_value = 0;
 535                                 else {
 536                                         for (int i = 0; i < idx; ++i) {
 537                                                 string n = (string) ordered_enums [i];
 538                                                 Location m_loc = (Mono.CSharp.Location)
 539                                                         member_to_location [n];
 540                                                 in_transit.Add (name, true);
 541
 542                                                 EmitContext old_ec = current_ec;
 543                                                 current_ec = ec;
 544
 545                                                 default_value = LookupEnumValue (ec, n, m_loc);
 546
 547                                                 current_ec = old_ec;
 548
 549                                                 in_transit.Remove (name);
 550                                                 if (default_value == null)
 551                                                         return null;
 552                                         }
 553
 554                                         default_value = GetNextDefaultValue (default_value);
 555                                 }
 556
 557                         } else {
 558                                 bool old = ec.InEnumContext;
 559                                 ec.InEnumContext = true;
 560                                 in_transit.Add (name, true);
 561
 562                                 EmitContext old_ec = current_ec;
 563                                 current_ec = ec;
 564                                 val = val.Resolve (ec);
 565                                 current_ec = old_ec;
 566
 567                                 in_transit.Remove (name);
 568                                 ec.InEnumContext = old;
 569
 570                                 if (val == null)
 571                                         return null;
 572
 573                                 if (!IsValidEnumConstant (val)) {
 574                                         Report.Error (
 575                                                 1008, loc,
 576                                                 "Type byte, sbyte, short, ushort, int, uint, long, or " +
 577                                                 "ulong expected (have: " + val + ")");
 578                                         return null;
 579                                 }
 580
 581                                 c = (Constant) val;
 582                                 default_value = c.GetValue ();
 583
 584                                 if (default_value == null) {
 585                                         Error_ConstantValueCannotBeConverted (c, loc);
 586                                         return null;
 587                                 }
 588
 589                                 if (val is EnumConstant){
 590                                         Type etype = TypeManager.EnumToUnderlying (c.Type);
 591
 592                                         if (!ImplicitConversionExists (etype, UnderlyingType)){
 593                                                 Convert.Error_CannotImplicitConversion (
 594                                                         loc, c.Type, UnderlyingType);
 595                                                 return null;
 596                                         }
 597                                 }
 598                         }
 599
 600                         EnumMember em = name_to_member [name] as EnumMember;
 601                         em.DefineMember (TypeBuilder);
 602
 603                         bool fail;
 604                         default_value = TypeManager.ChangeType (default_value, UnderlyingType, out fail);
 605                         if (fail){
 606                                 Error_ConstantValueCannotBeConverted (c, loc);
 607                                 return null;
 608                         }
 609
 610                         em.builder.SetConstant (default_value);
 611                         field_builders.Add (em.builder);
 612                         member_to_value [name] = default_value;
 613
 614                         if (!TypeManager.RegisterFieldValue (em.builder, default_value))
 615                                 return null;
 616
 617                         return default_value;
 618                 }
 619
 620                 public override bool DefineMembers (TypeContainer parent)
 621                 {
 622                         return true;
 623                 }
 624
 625                 public override bool Define (TypeContainer parent)
 626                 {
 627                         //
 628                         // If there was an error during DefineEnum, return
 629                         //
 630                         if (TypeBuilder == null)
 631                                 return false;
 632
 633                         EmitContext ec = new EmitContext (this, this, Location, null,
 634                                                           UnderlyingType, ModFlags, false);
 635
 636
 637                         object default_value = 0;
 638
 639
 640                         foreach (string name in ordered_enums) {
 641                                 //
 642                                 // Have we already been defined, thanks to some cross-referencing ?
 643                                 //
 644                                 if (member_to_value.Contains (name))
 645                                         continue;
 646
 647                                 Location loc = (Mono.CSharp.Location) member_to_location [name];
 648
 649                                 if (this [name] != null) {
 650                                         default_value = LookupEnumValue (ec, name, loc);
 651
 652                                         if (default_value == null)
 653                                                 return true;
 654                                 } else {
 655                                         if (name == "value__"){
 656                                                 Report.Error (76, loc, "The name `value__' is reserved for enumerations");
 657                                                 return false;
 658                                         }
 659
 660                                         EnumMember em = name_to_member [name] as EnumMember;
 661
 662                                         em.DefineMember (TypeBuilder);
 663                                         FieldBuilder fb = em.builder;
 664
 665                                         if (default_value == null) {
 666                                            Report.Error (543, loc, "Enumerator value for '" + name + "' is too large to " +
 667                                                               "fit in its type");
 668                                                 return false;
 669                                         }
 670
 671                                         bool fail;
 672                                         default_value = TypeManager.ChangeType (default_value, UnderlyingType, out fail);
 673                                         if (fail){
 674                                                 Error_ConstantValueCannotBeConverted (default_value, loc);
 675                                                 return false;
 676                                         }
 677
 678                                         fb.SetConstant (default_value);
 679                                         field_builders.Add (fb);
 680                                         member_to_value [name] = default_value;
 681
 682                                         if (!TypeManager.RegisterFieldValue (fb, default_value))
 683                                                 return false;
 684                                 }
 685
 686                                 default_value = GetNextDefaultValue (default_value);
 687                         }
 688                         return true;
 689                 }
 690
 691                 public override void Emit (TypeContainer tc)
 692                 {
 693                                 EmitContext ec = new EmitContext (tc, this, Location, null, null, ModFlags, false);
 694
 695                         if (OptAttributes != null) {
 696                                 OptAttributes.Emit (ec, this);
 697                         }
 698
 699                         foreach (EnumMember em in name_to_member.Values) {
 700                                 em.Emit (ec);
 701                         }
 702
 703                         base.Emit (tc);
 704                 }
 705
 706                 protected override bool IsIdentifierClsCompliant (DeclSpace ds)
 707                 {
 708                         if (!base.IsIdentifierClsCompliant (ds))
 709                                 return false;
 710
 711                         for (int i = 1; i < ordered_enums.Count; ++i) {
 712                                 string checked_name = ordered_enums [i] as string;
 713                                 for (int ii = 0; ii < ordered_enums.Count; ++ii) {
 714                                         if (ii == i)
 715                                                 continue;
 716
 717                                         string enumerator_name = ordered_enums [ii] as string;
 718                                         if (String.Compare (checked_name, enumerator_name, true, CultureInfo.InvariantCulture) == 0) {
 719                                                 Report.SymbolRelatedToPreviousError ((Location)member_to_location [enumerator_name], enumerator_name);
 720                                                 Report.Error_T (3005, (Location)member_to_location [checked_name], GetEnumeratorName (checked_name));
 721                                                 break;
 722                                         }
 723                                 }
 724                         }
 725                         return true;
 726                 }
 727
 728                 protected override bool VerifyClsCompliance (DeclSpace ds)
 729                 {
 730                         if (!base.VerifyClsCompliance (ds))
 731                                 return false;
 732
 733                         if (!AttributeTester.IsClsCompliant (UnderlyingType)) {
 734                                 Report.Error_T (3009, Location, GetSignatureForError (), TypeManager.CSharpName (UnderlyingType));
 735                         }
 736
 737                         return true;
 738                 }
 739
 740                 /// <summary>
 741                 /// Returns full enum name.
 742                 /// </summary>
 743                 string GetEnumeratorName (string valueName)
 744                 {
 745                         return String.Concat (Name, ".", valueName);
 746                 }
 747
 748                 //
 749                 // IMemberFinder
 750                 //
 751                 public override MemberList FindMembers (MemberTypes mt, BindingFlags bf,
 752                                                         MemberFilter filter, object criteria)
 753                 {
 754                         ArrayList members = new ArrayList ();
 755
 756                         if ((mt & MemberTypes.Field) != 0) {
 757                                 if (criteria is string){
 758                                         if (member_to_value [criteria] == null && current_ec != null){
 759                                                 LookupEnumValue (current_ec, (string) criteria, Location.Null);
 760                                         }
 761                                 }
 762
 763                                 foreach (FieldBuilder fb in field_builders)
 764                                         if (filter (fb, criteria) == true)
 765                                                 members.Add (fb);
 766                         }
 767
 768                         return new MemberList (members);
 769                 }
 770
 771                 public override MemberCache MemberCache {
 772                         get {
 773                                 return null;
 774                         }
 775                 }
 776
 777                 public ArrayList ValueNames {
 778                         get {
 779                                 return ordered_enums;
 780                         }
 781                 }
 782
 783                 // indexer
 784                 public Expression this [string name] {
 785                         get {
 786                                 return (Expression) defined_names [name];
 787                         }
 788                 }
 789
 790                 public override AttributeTargets AttributeTargets {
 791                         get {
 792                                 return AttributeTargets.Enum;
 793                         }
 794                 }
 795
 796                 protected override void VerifyObsoleteAttribute()
 797                 {
 798                         // UnderlyingType is never obsolete
 799                 }
 800
 801                 /// <summary>
 802                 /// Returns ObsoleteAttribute for both enum type and enum member
 803                 /// </summary>
 804                 public ObsoleteAttribute GetObsoleteAttribute (EmitContext ec, string identifier)
 805                 {
 806                         if ((caching_flags & Flags.Obsolete_Undetected) == 0 && (caching_flags & Flags.Obsolete) == 0) {
 807                                 return null;
 808                         }
 809
 810                         ObsoleteAttribute oa = GetObsoleteAttribute (ec.DeclSpace);
 811                         if (oa != null)
 812                                 return oa;
 813
 814                         EnumMember em = (EnumMember)name_to_member [identifier];
 815                         oa = em.GetObsoleteAttribute (ec);
 816
 817                         if (oa == null)
 818                                 return null;
 819
 820                         caching_flags |= Flags.Obsolete;
 821                         return oa;
 822                 }
 823         }
 824 }