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