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