mcs/mbas/enum.cs

   1 //
   2 // enum.cs: Enum handling.
   3 //
   4 // Author: Miguel de Icaza (miguel@gnu.org)
   5 //         Ravi Pratap     (ravi@ximian.com)
   6 //         Anirban Bhattacharjee (banirban@novell.com)
   7 //
   8 // Licensed under the terms of the GNU GPL
   9 //
  10 // (C) 2001 Ximian, Inc (http://www.ximian.com)
  11 //
  12
  13 using System;
  14 using System.Collections;
  15 using System.Reflection;
  16 using System.Reflection.Emit;
  17
  18 namespace Mono.MonoBASIC {
  19
  20         /// <summary>
  21         ///   Enumeration container
  22         /// </summary>
  23         public class Enum : DeclSpace {
  24                 ArrayList ordered_enums;
  25
  26                 public Expression BaseType;
  27                 public Attributes  OptAttributes;
  28
  29                 public Type UnderlyingType;
  30
  31                 Hashtable member_to_location;
  32                 Hashtable member_to_attributes;
  33
  34                 //
  35                 // This is for members that have been defined
  36                 //
  37                 Hashtable member_to_value;
  38
  39                 //
  40                 // This is used to mark members we're currently defining
  41                 //
  42                 Hashtable in_transit;
  43
  44                 ArrayList field_builders;
  45
  46                 public const int AllowedModifiers =
  47                         Modifiers.NEW |
  48                         Modifiers.PUBLIC |
  49                         Modifiers.PROTECTED |
  50                         Modifiers.INTERNAL |
  51                         Modifiers.PRIVATE;
  52
  53                 public Enum (TypeContainer parent, Expression type, int mod_flags, string name, Attributes attrs, Location l)
  54                         : base (parent, name, l)
  55                 {
  56                         this.BaseType = type;
  57                         ModFlags = Modifiers.Check (AllowedModifiers, mod_flags,
  58                                                     IsTopLevel ? Modifiers.INTERNAL : Modifiers.PUBLIC, l);
  59                         OptAttributes = attrs;
  60
  61                         ordered_enums = new ArrayList ();
  62                         member_to_location = new Hashtable ();
  63                         member_to_value = new Hashtable ();
  64                         in_transit = new Hashtable ();
  65                         field_builders = new ArrayList ();
  66                 }
  67
  68                 /// <summary>
  69                 ///   Adds @name to the enumeration space, with @expr
  70                 ///   being its definition.
  71                 /// </summary>
  72                 public AdditionResult AddEnumMember (string name, Expression expr, Location loc,
  73                                                      Attributes opt_attrs)
  74                 {
  75                         if (defined_names.Contains (name))
  76                                 return AdditionResult.NameExists;
  77
  78                         DefineName (name, expr);
  79
  80                         ordered_enums.Add (name);
  81                         member_to_location.Add (name, loc);
  82
  83                         if (member_to_attributes == null)
  84                                 member_to_attributes = new Hashtable ();
  85
  86                         member_to_attributes.Add (name, opt_attrs);
  87
  88                         return AdditionResult.Success;
  89                 }
  90
  91                 //
  92                 // This is used by corlib compilation: we map from our
  93                 // type to a type that is consumable by the DefineField
  94                 //
  95                 Type MapToInternalType (Type t)
  96                 {
  97                         if (t == TypeManager.int32_type)
  98                                 return typeof (int);
  99                         if (t == TypeManager.int64_type)
 100                                 return typeof (long);
 101                         if (t == TypeManager.uint32_type)
 102                                 return typeof (uint);
 103                         if (t == TypeManager.uint64_type)
 104                                 return typeof (ulong);
 105                         if (t == TypeManager.float_type)
 106                                 return typeof (float);
 107                         if (t == TypeManager.double_type)
 108                                 return typeof (double);
 109                         if (t == TypeManager.byte_type)
 110                                 return typeof (byte);
 111                         if (t == TypeManager.sbyte_type)
 112                                 return typeof (sbyte);
 113                         if (t == TypeManager.char_type)
 114                                 return typeof (char);
 115                         if (t == TypeManager.short_type)
 116                                 return typeof (short);
 117                         if (t == TypeManager.ushort_type)
 118                                 return typeof (ushort);
 119
 120                         throw new Exception ();
 121                 }
 122
 123                 public override TypeBuilder DefineType ()
 124                 {
 125                         if (TypeBuilder != null)
 126                                 return TypeBuilder;
 127
 128                         TypeAttributes attr = Modifiers.TypeAttr (ModFlags, IsTopLevel);
 129
 130                         attr |= TypeAttributes.Class | TypeAttributes.Sealed;
 131
 132                         UnderlyingType = ResolveType (BaseType, false, Location);
 133
 134                         if (UnderlyingType != TypeManager.int32_type &&
 135                             UnderlyingType != TypeManager.uint32_type &&
 136                             UnderlyingType != TypeManager.int64_type &&
 137                             UnderlyingType != TypeManager.uint64_type &&
 138                             UnderlyingType != TypeManager.short_type &&
 139                             UnderlyingType != TypeManager.ushort_type &&
 140                             UnderlyingType != TypeManager.byte_type  &&
 141                             UnderlyingType != TypeManager.sbyte_type) {
 142                                 Report.Error (30650, Location,
 143                                               "Type byte, sbyte, short, ushort, int, uint, " +
 144                                               "long, or ulong expected (got: " +
 145                                               TypeManager.MonoBASIC_Name (UnderlyingType) + ")");
 146                                 return null;
 147                         }
 148
 149                         if (IsTopLevel) {
 150                                 ModuleBuilder builder = CodeGen.ModuleBuilder;
 151
 152                                 TypeBuilder = builder.DefineType (Name, attr, TypeManager.enum_type);
 153                         } else {
 154                                 TypeBuilder builder = Parent.TypeBuilder;
 155
 156                                 TypeBuilder = builder.DefineNestedType (
 157                                         Basename, attr, TypeManager.enum_type);
 158                         }
 159
 160                         //
 161                         // Call MapToInternalType for corlib
 162                         //
 163                         TypeBuilder.DefineField ("value__", UnderlyingType,
 164                                                  FieldAttributes.Public | FieldAttributes.SpecialName
 165                                                  | FieldAttributes.RTSpecialName);
 166
 167                         TypeManager.AddEnumType (Name, TypeBuilder, this);
 168
 169                         return TypeBuilder;
 170                 }
 171
 172             bool IsValidEnumConstant (Expression e)
 173                 {
 174                         if (!(e is Constant))
 175                                 return false;
 176
 177                         if (e is IntConstant || e is UIntConstant || e is LongConstant ||
 178                             e is ByteConstant || e is SByteConstant || e is ShortConstant ||
 179                             e is UShortConstant || e is ULongConstant || e is EnumConstant)
 180                                 return true;
 181                         else
 182                                 return false;
 183                 }
 184
 185                 object GetNextDefaultValue (object default_value)
 186                 {
 187                         if (UnderlyingType == TypeManager.int32_type) {
 188                                 int i = (int) default_value;
 189
 190                                 if (i < System.Int32.MaxValue)
 191                                         return ++i;
 192                                 else
 193                                         return null;
 194                         } else if (UnderlyingType == TypeManager.uint32_type) {
 195                                 uint i = (uint) default_value;
 196
 197                                 if (i < System.UInt32.MaxValue)
 198                                         return ++i;
 199                                 else
 200                                         return null;
 201                         } else if (UnderlyingType == TypeManager.int64_type) {
 202                                 long i = (long) default_value;
 203
 204                                 if (i < System.Int64.MaxValue)
 205                                         return ++i;
 206                                 else
 207                                         return null;
 208                         } else if (UnderlyingType == TypeManager.uint64_type) {
 209                                 ulong i = (ulong) default_value;
 210
 211                                 if (i < System.UInt64.MaxValue)
 212                                         return ++i;
 213                                 else
 214                                         return null;
 215                         } else if (UnderlyingType == TypeManager.short_type) {
 216                                 short i = (short) default_value;
 217
 218                                 if (i < System.Int16.MaxValue)
 219                                         return ++i;
 220                                 else
 221                                         return null;
 222                         } else if (UnderlyingType == TypeManager.ushort_type) {
 223                                 ushort i = (ushort) default_value;
 224
 225                                 if (i < System.UInt16.MaxValue)
 226                                         return ++i;
 227                                 else
 228                                         return null;
 229                         } else if (UnderlyingType == TypeManager.byte_type) {
 230                                 byte i = (byte) default_value;
 231
 232                                 if (i < System.Byte.MaxValue)
 233                                         return ++i;
 234                                 else
 235                                         return null;
 236                         } else if (UnderlyingType == TypeManager.sbyte_type) {
 237                                 sbyte i = (sbyte) default_value;
 238
 239                                 if (i < System.SByte.MaxValue)
 240                                         return ++i;
 241                                 else
 242                                         return null;
 243                         }
 244
 245                         return null;
 246                 }
 247
 248                 void Error_ConstantValueCannotBeConverted (object val, Location loc)
 249                 {
 250                         if (val is Constant)
 251                                 Report.Error (30439, loc, "Constant value '" + ((Constant) val).AsString () +
 252                                               "' cannot be converted" +
 253                                               " to a " + TypeManager.MonoBASIC_Name (UnderlyingType));
 254                         else
 255                                 Report.Error (30439, loc, "Constant value '" + val +
 256                                               "' cannot be converted" +
 257                                               " to a " + TypeManager.MonoBASIC_Name (UnderlyingType));
 258                         return;
 259                 }
 260
 261                 /// <summary>
 262                 ///  Determines if a standard implicit conversion exists from
 263                 ///  expr_type to target_type
 264                 /// </summary>
 265                 public static bool ImplicitConversionExists (Type expr_type, Type target_type)
 266                 {
 267                         expr_type = TypeManager.TypeToCoreType (expr_type);
 268
 269                         if (expr_type == TypeManager.void_type)
 270                                 return false;
 271
 272                         if (expr_type == target_type)
 273                                 return true;
 274
 275                         // First numeric conversions
 276
 277                         if (expr_type == TypeManager.sbyte_type){
 278                                 //
 279                                 // From sbyte to short, int, long, float, double.
 280                                 //
 281                                 if ((target_type == TypeManager.int32_type) ||
 282                                     (target_type == TypeManager.int64_type) ||
 283                                     (target_type == TypeManager.double_type) ||
 284                                     (target_type == TypeManager.float_type)  ||
 285                                     (target_type == TypeManager.short_type) ||
 286                                     (target_type == TypeManager.decimal_type))
 287                                         return true;
 288
 289                         } else if (expr_type == TypeManager.byte_type){
 290                                 //
 291                                 // From byte to short, ushort, int, uint, long, ulong, float, double
 292                                 //
 293                                 if ((target_type == TypeManager.short_type) ||
 294                                     (target_type == TypeManager.ushort_type) ||
 295                                     (target_type == TypeManager.int32_type) ||
 296                                     (target_type == TypeManager.uint32_type) ||
 297                                     (target_type == TypeManager.uint64_type) ||
 298                                     (target_type == TypeManager.int64_type) ||
 299                                     (target_type == TypeManager.float_type) ||
 300                                     (target_type == TypeManager.double_type) ||
 301                                     (target_type == TypeManager.decimal_type))
 302                                         return true;
 303
 304                         } else if (expr_type == TypeManager.short_type){
 305                                 //
 306                                 // From short to int, long, float, double
 307                                 //
 308                                 if ((target_type == TypeManager.int32_type) ||
 309                                     (target_type == TypeManager.int64_type) ||
 310                                     (target_type == TypeManager.double_type) ||
 311                                     (target_type == TypeManager.float_type) ||
 312                                     (target_type == TypeManager.decimal_type))
 313                                         return true;
 314
 315                         } else if (expr_type == TypeManager.ushort_type){
 316                                 //
 317                                 // From ushort to int, uint, long, ulong, float, double
 318                                 //
 319                                 if ((target_type == TypeManager.uint32_type) ||
 320                                     (target_type == TypeManager.uint64_type) ||
 321                                     (target_type == TypeManager.int32_type) ||
 322                                     (target_type == TypeManager.int64_type) ||
 323                                     (target_type == TypeManager.double_type) ||
 324                                     (target_type == TypeManager.float_type) ||
 325                                     (target_type == TypeManager.decimal_type))
 326                                         return true;
 327
 328                         } else if (expr_type == TypeManager.int32_type){
 329                                 //
 330                                 // From int to long, float, double
 331                                 //
 332                                 if ((target_type == TypeManager.int64_type) ||
 333                                     (target_type == TypeManager.double_type) ||
 334                                     (target_type == TypeManager.float_type) ||
 335                                     (target_type == TypeManager.decimal_type))
 336                                         return true;
 337
 338                         } else if (expr_type == TypeManager.uint32_type){
 339                                 //
 340                                 // From uint to long, ulong, float, double
 341                                 //
 342                                 if ((target_type == TypeManager.int64_type) ||
 343                                     (target_type == TypeManager.uint64_type) ||
 344                                     (target_type == TypeManager.double_type) ||
 345                                     (target_type == TypeManager.float_type) ||
 346                                     (target_type == TypeManager.decimal_type))
 347                                         return true;
 348
 349                         } else if ((expr_type == TypeManager.uint64_type) ||
 350                                    (expr_type == TypeManager.int64_type)) {
 351                                 //
 352                                 // From long/ulong to float, double
 353                                 //
 354                                 if ((target_type == TypeManager.double_type) ||
 355                                     (target_type == TypeManager.float_type) ||
 356                                     (target_type == TypeManager.decimal_type))
 357                                         return true;
 358
 359                         } else if (expr_type == TypeManager.char_type){
 360                                 //
 361                                 // From char to ushort, int, uint, long, ulong, float, double
 362                                 //
 363                                 if ((target_type == TypeManager.ushort_type) ||
 364                                     (target_type == TypeManager.int32_type) ||
 365                                     (target_type == TypeManager.uint32_type) ||
 366                                     (target_type == TypeManager.uint64_type) ||
 367                                     (target_type == TypeManager.int64_type) ||
 368                                     (target_type == TypeManager.float_type) ||
 369                                     (target_type == TypeManager.double_type) ||
 370                                     (target_type == TypeManager.decimal_type))
 371                                         return true;
 372
 373                         } else if (expr_type == TypeManager.float_type){
 374                                 //
 375                                 // float to double
 376                                 //
 377                                 if (target_type == TypeManager.double_type)
 378                                         return true;
 379                         }
 380
 381                         return false;
 382                 }
 383
 384                 /// <summary>
 385                 ///  This is used to lookup the value of an enum member. If the member is undefined,
 386                 ///  it attempts to define it and return its value
 387                 /// </summary>
 388                 public object LookupEnumValue (EmitContext ec, string name, Location loc)
 389                 {
 390                         object default_value = null;
 391                         Constant c = null;
 392                         TypeContainer parent = ec.TypeContainer;
 393
 394                         // first check whether the requested name is there
 395                         // in the member list of enum
 396                         if (!(ordered_enums.Contains(name)))
 397                                 Report.Error (30456, loc,
 398                                         name + " is not found in member list of enum " + this.Name);
 399
 400                         default_value = member_to_value [name];
 401
 402                         if (default_value != null)
 403                                 return default_value;
 404
 405                         //
 406                         // This may happen if we're calling a method in System.Enum, for instance
 407                         // Enum.IsDefined().
 408                         //
 409                         if (!defined_names.Contains (name))
 410                                 return null;
 411
 412                         if (in_transit.Contains (name)) {
 413                                 Report.Error (110, loc, "The evaluation of the constant value for `" +
 414                                               Name + "." + name + "' involves a circular definition.");
 415                                 return null;
 416                         }
 417
 418                         //
 419                         // So if the above doesn't happen, we have a member that is undefined
 420                         // We now proceed to define it
 421                         //
 422                         Expression val = this [name];
 423                         int idx = ordered_enums.IndexOf (name);
 424
 425                         if (val == null) {
 426
 427                                 //int idx = ordered_enums.IndexOf (name);
 428
 429                                 if (idx == 0)
 430                                         default_value = 0;
 431                                 else {
 432                                         for (int i = 0; i < idx; ++i) {
 433                                                 string n = (string) ordered_enums [i];
 434                                                 Location m_loc = (Mono.MonoBASIC.Location)
 435                                                         member_to_location [n];
 436                                                 in_transit.Add (name, true);
 437                                                 default_value = LookupEnumValue (ec, n, m_loc);
 438                                                 in_transit.Remove (name);
 439                                                 if (default_value == null)
 440                                                         return null;
 441                                         }
 442
 443                                         default_value = GetNextDefaultValue (default_value);
 444                                 }
 445
 446                         } else {
 447                                 // check for any cyclic dependency
 448                                 if (val is Mono.MonoBASIC.SimpleName) {
 449                                         int var_idx = ordered_enums.IndexOf (val.ToString());
 450
 451                                         if (idx <= var_idx)
 452                                                 Report.Error(30500, loc,
 453                                                         "The evaluation of the constant value for `" +
 454                                                         Name + "." + name + "' involves a circular definition");
 455                                         else
 456                                                 default_value = member_to_value [val.ToString()];
 457                                 }
 458                                 else {
 459                                         bool old = ec.InEnumContext;
 460                                         ec.InEnumContext = true;
 461                                         in_transit.Add (name, true);
 462                                         val = val.Resolve (ec);
 463                                         in_transit.Remove (name);
 464                                         ec.InEnumContext = old;
 465
 466                                         if (val == null)
 467                                                 return null;
 468
 469                                         if (!IsValidEnumConstant (val)) {
 470                                                 Report.Error (
 471                                                         30650, loc,
 472                                                         "Type byte, sbyte, short, ushort, int, uint, long, or " +
 473                                                         "ulong expected (have: " + val + ")");
 474                                                 return null;
 475                                         }
 476
 477                                         c = (Constant) val;
 478
 479                                         default_value = c.GetValue ();
 480                                 }
 481
 482                                 if (default_value == null) {
 483                                         Error_ConstantValueCannotBeConverted (c, loc);
 484                                         return null;
 485                                 }
 486
 487                                 if (val is EnumConstant) {
 488                                         Type etype = TypeManager.EnumToUnderlying (c.Type);
 489
 490                                         if ( (!ImplicitConversionExists (etype, UnderlyingType)) &&
 491                                                 (!Expression.RuntimeConversionExists (ec, val, UnderlyingType)) ){
 492                                                 Expression.Error_CannotConvertImplicit (
 493                                                         loc, c.Type, UnderlyingType);
 494                                                 return null;
 495                                         }
 496                                 }
 497                         }
 498
 499                         FieldAttributes attr = FieldAttributes.Public | FieldAttributes.Static
 500                                         | FieldAttributes.Literal;
 501
 502                         FieldBuilder fb = TypeBuilder.DefineField (name, TypeBuilder, attr);
 503
 504                         try {
 505                                 default_value = TypeManager.ChangeType (default_value, UnderlyingType);
 506                         } catch {
 507                                 Error_ConstantValueCannotBeConverted (c, loc);
 508                                 return null;
 509                         }
 510
 511                         fb.SetConstant (default_value);
 512                         field_builders.Add (fb);
 513                         member_to_value [name] = default_value;
 514
 515                         if (!TypeManager.RegisterFieldValue (fb, default_value))
 516                                 return null;
 517
 518                         //
 519                         // Now apply attributes
 520                         //
 521                         Attribute.ApplyAttributes (ec, fb, fb, (Attributes) member_to_attributes [name], loc);
 522
 523                         return default_value;
 524                 }
 525
 526                 public override bool DefineMembers (TypeContainer parent)
 527                 {
 528                         return true;
 529                 }
 530
 531                 public override bool Define (TypeContainer parent)
 532                 {
 533                         //
 534                         // If there was an error during DefineEnum, return
 535                         //
 536                         if (TypeBuilder == null)
 537                                 return false;
 538
 539                         EmitContext ec = new EmitContext (parent, this, Location, null,
 540                                                           UnderlyingType, ModFlags, false);
 541
 542                         object default_value = 0;
 543
 544                         foreach (string name in ordered_enums) {
 545                                 if (member_to_value.Contains (name))
 546                                         continue;
 547
 548                                 Location loc = (Mono.MonoBASIC.Location) member_to_location [name];
 549
 550                                 if (this [name] != null) {
 551                                         default_value = LookupEnumValue (ec, name, loc);
 552
 553                                         if (default_value == null)
 554                                                 return true;
 555                                 } else {
 556                                         FieldAttributes attr = FieldAttributes.Public | FieldAttributes.Static
 557                                                 | FieldAttributes.Literal;
 558
 559                                         FieldBuilder fb = TypeBuilder.DefineField (name, TypeBuilder, attr);
 560
 561                                         if (default_value == null) {
 562                                                 Report.Error (30439, loc, "Enumerator value for '" + name + "' is too large to " +
 563                                                         "fit in its type");
 564                                                 return false;
 565                                         }
 566
 567                                         try     {
 568                                                 default_value = TypeManager.ChangeType (default_value, UnderlyingType);
 569                                         } catch {
 570                                                 Error_ConstantValueCannotBeConverted (default_value, loc);
 571                                                 return false;
 572                                         }
 573
 574                                         fb.SetConstant (default_value);
 575                                         field_builders.Add (fb);
 576                                         member_to_value [name] = default_value;
 577
 578                                         if (!TypeManager.RegisterFieldValue (fb, default_value))
 579                                                 return false;
 580
 581                                         //
 582                                         // Now apply attributes
 583                                         //
 584                                         Attribute.ApplyAttributes (ec, fb, fb, (Attributes) member_to_attributes [name], loc);
 585                                 }
 586
 587                                 default_value = GetNextDefaultValue (default_value);
 588                         }
 589
 590                         Attribute.ApplyAttributes (ec, TypeBuilder, this, OptAttributes, Location);
 591                         return true;
 592                 }
 593
 594                 //
 595                 // IMemberFinder
 596                 //
 597                 public override MemberList FindMembers (MemberTypes mt, BindingFlags bf,
 598                                                         MemberFilter filter, object criteria)
 599                 {
 600                         ArrayList members = new ArrayList ();
 601
 602                         if ((mt & MemberTypes.Field) != 0) {
 603                                 foreach (FieldBuilder fb in field_builders)
 604                                         if (filter (fb, criteria) == true)
 605                                                 members.Add (fb);
 606                         }
 607
 608                         return new MemberList (members);
 609                 }
 610
 611                 public override MemberCache MemberCache {
 612                         get {
 613                                 return null;
 614                         }
 615                 }
 616
 617                 public ArrayList ValueNames {
 618                         get {
 619                                 return ordered_enums;
 620                         }
 621                 }
 622
 623                 // indexer
 624                 public Expression this [string name] {
 625                         get {
 626                                 return (Expression) defined_names [name];
 627                         }
 628                 }
 629         }
 630 }