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