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 //
   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
  17 namespace Mono.CSharp {
  18
  19         /// <summary>
  20         ///   Enumeration container
  21         /// </summary>
  22         public class Enum : DeclSpace {
  23
  24                 ArrayList ordered_enums;
  25                 public readonly string BaseType;
  26                 public Attributes  OptAttributes;
  27
  28                 public Type UnderlyingType;
  29
  30                 Hashtable member_to_location;
  31                 Hashtable member_to_attributes;
  32
  33                 //
  34                 // This is for members that have been defined
  35                 //
  36                 Hashtable member_to_value;
  37
  38                 ArrayList field_builders;
  39
  40                 public const int AllowedModifiers =
  41                         Modifiers.NEW |
  42                         Modifiers.PUBLIC |
  43                         Modifiers.PROTECTED |
  44                         Modifiers.INTERNAL |
  45                         Modifiers.PRIVATE;
  46
  47                 public Enum (TypeContainer parent, string type, int mod_flags, string name, Attributes attrs, Location l)
  48                         : base (parent, name, l)
  49                 {
  50                         this.BaseType = type;
  51                         ModFlags = Modifiers.Check (AllowedModifiers, mod_flags, Modifiers.PUBLIC, l);
  52                         OptAttributes = attrs;
  53
  54                         ordered_enums = new ArrayList ();
  55                         member_to_location = new Hashtable ();
  56                         member_to_value = new Hashtable ();
  57                         field_builders = new ArrayList ();
  58                 }
  59
  60                 /// <summary>
  61                 ///   Adds @name to the enumeration space, with @expr
  62                 ///   being its definition.
  63                 /// </summary>
  64                 public AdditionResult AddEnumMember (string name, Expression expr, Location loc,
  65                                                      Attributes opt_attrs)
  66                 {
  67                         if (defined_names.Contains (name))
  68                                 return AdditionResult.NameExists;
  69
  70                         DefineName (name, expr);
  71
  72                         ordered_enums.Add (name);
  73                         member_to_location.Add (name, loc);
  74
  75                         if (member_to_attributes == null)
  76                                 member_to_attributes = new Hashtable ();
  77
  78                         member_to_attributes.Add (name, opt_attrs);
  79
  80                         return AdditionResult.Success;
  81                 }
  82
  83                 //
  84                 // This is used by corlib compilation: we map from our
  85                 // type to a type that is consumable by the DefineField
  86                 //
  87                 Type MapToInternalType (Type t)
  88                 {
  89                         if (t == TypeManager.int32_type)
  90                                 return typeof (int);
  91                         if (t == TypeManager.int64_type)
  92                                 return typeof (long);
  93                         if (t == TypeManager.uint32_type)
  94                                 return typeof (uint);
  95                         if (t == TypeManager.uint64_type)
  96                                 return typeof (ulong);
  97                         if (t == TypeManager.float_type)
  98                                 return typeof (float);
  99                         if (t == TypeManager.double_type)
 100                                 return typeof (double);
 101                         if (t == TypeManager.byte_type)
 102                                 return typeof (byte);
 103                         if (t == TypeManager.sbyte_type)
 104                                 return typeof (sbyte);
 105                         if (t == TypeManager.char_type)
 106                                 return typeof (char);
 107                         if (t == TypeManager.short_type)
 108                                 return typeof (short);
 109                         if (t == TypeManager.ushort_type)
 110                                 return typeof (ushort);
 111
 112                         throw new Exception ();
 113                 }
 114
 115                 public override TypeBuilder DefineType ()
 116                 {
 117                         if (TypeBuilder != null)
 118                                 return TypeBuilder;
 119
 120                         TypeAttributes attr = TypeAttributes.Class | TypeAttributes.Sealed;
 121
 122                         UnderlyingType = TypeManager.LookupType (BaseType);
 123
 124                         if (UnderlyingType != TypeManager.int32_type &&
 125                             UnderlyingType != TypeManager.uint32_type &&
 126                             UnderlyingType != TypeManager.int64_type &&
 127                             UnderlyingType != TypeManager.uint64_type &&
 128                             UnderlyingType != TypeManager.short_type &&
 129                             UnderlyingType != TypeManager.ushort_type &&
 130                             UnderlyingType != TypeManager.byte_type  &&
 131                             UnderlyingType != TypeManager.sbyte_type) {
 132                                 Report.Error (1008, Location,
 133                                               "Type byte, sbyte, short, ushort, int, uint, " +
 134                                               "long, or ulong expected (got: " +
 135                                               TypeManager.CSharpName (UnderlyingType) + ")");
 136                                 return null;
 137                         }
 138
 139                         if (IsTopLevel) {
 140                                 ModuleBuilder builder = CodeGen.ModuleBuilder;
 141
 142                                 if ((ModFlags & Modifiers.PUBLIC) != 0)
 143                                         attr |= TypeAttributes.Public;
 144                                 else
 145                                         attr |= TypeAttributes.NotPublic;
 146
 147                                 TypeBuilder = builder.DefineType (Name, attr, TypeManager.enum_type);
 148                         } else {
 149                                 TypeBuilder builder = Parent.TypeBuilder;
 150
 151                                 if ((ModFlags & Modifiers.PUBLIC) != 0)
 152                                         attr |= TypeAttributes.NestedPublic;
 153                                 else
 154                                         attr |= TypeAttributes.NestedPrivate;
 155
 156
 157                                 TypeBuilder = builder.DefineNestedType (
 158                                         Basename, attr, TypeManager.enum_type);
 159                         }
 160
 161                         //
 162                         // Call MapToInternalType for corlib
 163                         //
 164                         TypeBuilder.DefineField ("value__", UnderlyingType,
 165                                                  FieldAttributes.Public | FieldAttributes.SpecialName
 166                                                  | FieldAttributes.RTSpecialName);
 167
 168                         TypeManager.AddEnumType (Name, TypeBuilder, this);
 169
 170                         return TypeBuilder;
 171                 }
 172
 173                 bool IsValidEnumConstant (Expression e)
 174                 {
 175                         if (!(e is Constant))
 176                                 return false;
 177
 178                         if (e is IntConstant || e is UIntConstant || e is LongConstant ||
 179                             e is ByteConstant || e is SByteConstant || e is ShortConstant ||
 180                             e is UShortConstant || e is ULongConstant || e is EnumConstant)
 181                                 return true;
 182                         else
 183                                 return false;
 184                 }
 185
 186                 object GetNextDefaultValue (object default_value)
 187                 {
 188                         if (UnderlyingType == TypeManager.int32_type) {
 189                                 int i = (int) default_value;
 190
 191                                 if (i < System.Int32.MaxValue)
 192                                         return ++i;
 193                                 else
 194                                         return null;
 195                         } else if (UnderlyingType == TypeManager.uint32_type) {
 196                                 uint i = (uint) default_value;
 197
 198                                 if (i < System.UInt32.MaxValue)
 199                                         return ++i;
 200                                 else
 201                                         return null;
 202                         } else if (UnderlyingType == TypeManager.int64_type) {
 203                                 long i = (long) default_value;
 204
 205                                 if (i < System.Int64.MaxValue)
 206                                         return ++i;
 207                                 else
 208                                         return null;
 209                         } else if (UnderlyingType == TypeManager.uint64_type) {
 210                                 ulong i = (ulong) default_value;
 211
 212                                 if (i < System.UInt64.MaxValue)
 213                                         return ++i;
 214                                 else
 215                                         return null;
 216                         } else if (UnderlyingType == TypeManager.short_type) {
 217                                 short i = (short) default_value;
 218
 219                                 if (i < System.Int16.MaxValue)
 220                                         return ++i;
 221                                 else
 222                                         return null;
 223                         } else if (UnderlyingType == TypeManager.ushort_type) {
 224                                 ushort i = (ushort) default_value;
 225
 226                                 if (i < System.UInt16.MaxValue)
 227                                         return ++i;
 228                                 else
 229                                         return null;
 230                         } else if (UnderlyingType == TypeManager.byte_type) {
 231                                 byte i = (byte) default_value;
 232
 233                                 if (i < System.Byte.MaxValue)
 234                                         return ++i;
 235                                 else
 236                                         return null;
 237                         } else if (UnderlyingType == TypeManager.sbyte_type) {
 238                                 sbyte i = (sbyte) default_value;
 239
 240                                 if (i < System.SByte.MaxValue)
 241                                         return ++i;
 242                                 else
 243                                         return null;
 244                         }
 245
 246                         return null;
 247                 }
 248
 249                 void Error_ConstantValueCannotBeConverted (object val, Location loc)
 250                 {
 251                         if (val is Constant)
 252                                 Report.Error (31, loc, "Constant value '" + ((Constant) val).AsString () +
 253                                               "' cannot be converted" +
 254                                               " to a " + TypeManager.CSharpName (UnderlyingType));
 255                         else
 256                                 Report.Error (31, loc, "Constant value '" + val +
 257                                               "' cannot be converted" +
 258                                               " to a " + TypeManager.CSharpName (UnderlyingType));
 259                         return;
 260                 }
 261
 262                 /// <summary>
 263                 ///  This is used to lookup the value of an enum member. If the member is undefined,
 264                 ///  it attempts to define it and return its value
 265                 /// </summary>
 266                 public object LookupEnumValue (EmitContext ec, string name, Location loc)
 267                 {
 268                         object default_value = null;
 269                         Constant c = null;
 270
 271                         default_value = member_to_value [name];
 272
 273                         if (default_value != null)
 274                                 return default_value;
 275
 276                         //
 277                         // This may happen if we're calling a method in System.Enum, for instance
 278                         // Enum.IsDefined().
 279                         //
 280                         if (!defined_names.Contains (name))
 281                                 return null;
 282
 283                         //
 284                         // So if the above doesn't happen, we have a member that is undefined
 285                         // We now proceed to define it
 286                         //
 287                         Expression val = this [name];
 288
 289                         if (val == null) {
 290
 291                                 int idx = ordered_enums.IndexOf (name);
 292
 293                                 if (idx == 0)
 294                                         default_value = 0;
 295                                 else {
 296                                         for (int i = 0; i < idx; ++i) {
 297                                                 string n = (string) ordered_enums [i];
 298                                                 Location m_loc = (Mono.CSharp.Location)
 299                                                         member_to_location [n];
 300                                                 default_value = LookupEnumValue (ec, n, m_loc);
 301                                         }
 302
 303                                         default_value = GetNextDefaultValue (default_value);
 304                                 }
 305
 306                         } else {
 307                                 bool old = ec.InEnumContext;
 308                                 ec.InEnumContext = true;
 309                                 val = val.Resolve (ec);
 310                                 ec.InEnumContext = old;
 311
 312                                 if (val == null) {
 313                                         Report.Error (-12, loc, "Definition is circular.");
 314                                         return null;
 315                                 }
 316
 317                                 if (IsValidEnumConstant (val)) {
 318                                         c = (Constant) val;
 319                                         default_value = c.GetValue ();
 320
 321                                         if (default_value == null) {
 322                                                 Error_ConstantValueCannotBeConverted (c, loc);
 323                                                 return null;
 324                                         }
 325
 326                                 } else {
 327                                         Report.Error (
 328                                                 1008, loc,
 329                                                 "Type byte, sbyte, short, ushort, int, uint, long, or " +
 330                                                 "ulong expected (have: " + val + ")");
 331                                         return null;
 332                                 }
 333                         }
 334
 335                         FieldAttributes attr = FieldAttributes.Public | FieldAttributes.Static
 336                                         | FieldAttributes.Literal;
 337
 338                         FieldBuilder fb = TypeBuilder.DefineField (name, UnderlyingType, attr);
 339
 340                         try {
 341                                 default_value = TypeManager.ChangeType (default_value, UnderlyingType);
 342                         } catch {
 343                                 Error_ConstantValueCannotBeConverted (c, loc);
 344                                 return null;
 345                         }
 346
 347                         fb.SetConstant (default_value);
 348                         field_builders.Add (fb);
 349                         member_to_value [name] = default_value;
 350
 351                         if (!TypeManager.RegisterFieldValue (fb, default_value))
 352                                 return null;
 353
 354                         //
 355                         // Now apply attributes
 356                         //
 357                         Attribute.ApplyAttributes (ec, fb, fb, (Attributes) member_to_attributes [name], loc);
 358
 359                         return default_value;
 360                 }
 361
 362                 public override bool Define (TypeContainer parent)
 363                 {
 364                         //
 365                         // If there was an error during DefineEnum, return
 366                         //
 367                         if (TypeBuilder == null)
 368                                 return false;
 369
 370                         EmitContext ec = new EmitContext (parent, this, Location, null,
 371                                                           UnderlyingType, ModFlags, false);
 372
 373                         object default_value = 0;
 374
 375                         FieldAttributes attr = FieldAttributes.Public | FieldAttributes.Static
 376                                              | FieldAttributes.Literal;
 377
 378
 379                         foreach (string name in ordered_enums) {
 380                                 //
 381                                 // Have we already been defined, thanks to some cross-referencing ?
 382                                 //
 383                                 if (member_to_value.Contains (name))
 384                                         continue;
 385
 386                                 Location loc = (Mono.CSharp.Location) member_to_location [name];
 387
 388                                 if (this [name] != null) {
 389                                         default_value = LookupEnumValue (ec, name, loc);
 390
 391                                         if (default_value == null)
 392                                                 return true;
 393
 394                                 } else {
 395                                         FieldBuilder fb = TypeBuilder.DefineField (
 396                                                 name, UnderlyingType, attr);
 397
 398                                         if (default_value == null) {
 399                                            Report.Error (543, loc, "Enumerator value for '" + name + "' is too large to " +
 400                                                               "fit in its type");
 401                                                 return false;
 402                                         }
 403
 404                                         try {
 405                                                 default_value = TypeManager.ChangeType (default_value, UnderlyingType);
 406                                         } catch {
 407                                                 Error_ConstantValueCannotBeConverted (default_value, loc);
 408                                                 return false;
 409                                         }
 410
 411                                         fb.SetConstant (default_value);
 412                                         field_builders.Add (fb);
 413                                         member_to_value [name] = default_value;
 414
 415                                         if (!TypeManager.RegisterFieldValue (fb, default_value))
 416                                                 return false;
 417
 418                                         //
 419                                         // Apply attributes on the enum member
 420                                         //
 421                                         Attribute.ApplyAttributes (ec, fb, fb, (Attributes) member_to_attributes [name], loc);
 422                                 }
 423
 424                                 default_value = GetNextDefaultValue (default_value);
 425                         }
 426
 427                         Attribute.ApplyAttributes (ec, TypeBuilder, this, OptAttributes, Location);
 428
 429                         return true;
 430                 }
 431
 432                 //
 433                 // Hack around System.Reflection as found everywhere else
 434                 //
 435                 public MemberInfo [] FindMembers (MemberTypes mt, BindingFlags bf,
 436                                                   MemberFilter filter, object criteria)
 437                 {
 438                         ArrayList members = new ArrayList ();
 439
 440                         if ((mt & MemberTypes.Field) != 0) {
 441                                 foreach (FieldBuilder fb in field_builders)
 442                                         if (filter (fb, criteria) == true)
 443                                                 members.Add (fb);
 444                         }
 445
 446                         int count = members.Count;
 447
 448                         if (count > 0) {
 449                                 MemberInfo [] mi = new MemberInfo [count];
 450                                 members.CopyTo (mi, 0);
 451                                 return mi;
 452                         }
 453
 454                         return null;
 455                 }
 456
 457                 public ArrayList ValueNames {
 458                         get {
 459                                 return ordered_enums;
 460                         }
 461                 }
 462
 463                 // indexer
 464                 public Expression this [string name] {
 465                         get {
 466                                 return (Expression) defined_names [name];
 467                         }
 468                 }
 469         }
 470 }