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 //         Marek Safar     (marek.safar@seznam.cz)
   7 //
   8 // Dual licensed under the terms of the MIT X11 or GNU GPL
   9 //
  10 // Copyright 2001 Ximian, Inc (http://www.ximian.com)
  11 // Copyright 2003-2003 Novell, Inc (http://www.novell.com)
  12 // Copyright 2011 Xamarin Inc
  13 //
  14
  15 using System;
  16
  17 #if STATIC
  18 using MetaType = IKVM.Reflection.Type;
  19 using IKVM.Reflection;
  20 #else
  21 using MetaType = System.Type;
  22 using System.Reflection;
  23 #endif
  24
  25 namespace Mono.CSharp {
  26
  27         public class EnumMember : Const
  28         {
  29                 class EnumTypeExpr : TypeExpr
  30                 {
  31                         public override TypeSpec ResolveAsType (IMemberContext ec)
  32                         {
  33                                 type = ec.CurrentType;
  34                                 eclass = ExprClass.Type;
  35                                 return type;
  36                         }
  37                 }
  38
  39                 public EnumMember (Enum parent, MemberName name, Attributes attrs)
  40                         : base (parent, new EnumTypeExpr (), Modifiers.PUBLIC, name, attrs)
  41                 {
  42                 }
  43
  44                 static bool IsValidEnumType (TypeSpec t)
  45                 {
  46                         switch (t.BuiltinType) {
  47                         case BuiltinTypeSpec.Type.Int:
  48                         case BuiltinTypeSpec.Type.UInt:
  49                         case BuiltinTypeSpec.Type.Long:
  50                         case BuiltinTypeSpec.Type.Byte:
  51                         case BuiltinTypeSpec.Type.SByte:
  52                         case BuiltinTypeSpec.Type.Short:
  53                         case BuiltinTypeSpec.Type.UShort:
  54                         case BuiltinTypeSpec.Type.ULong:
  55                         case BuiltinTypeSpec.Type.Char:
  56                                 return true;
  57                         default:
  58                                 return t.IsEnum;
  59                         }
  60                 }
  61
  62                 public override Constant ConvertInitializer (ResolveContext rc, Constant expr)
  63                 {
  64                         if (expr is EnumConstant)
  65                                 expr = ((EnumConstant) expr).Child;
  66
  67                         var underlying = ((Enum) Parent).UnderlyingType;
  68                         if (expr != null) {
  69                                 expr = expr.ImplicitConversionRequired (rc, underlying, Location);
  70                                 if (expr != null && !IsValidEnumType (expr.Type)) {
  71                                         Enum.Error_1008 (Location, Report);
  72                                         expr = null;
  73                                 }
  74                         }
  75
  76                         if (expr == null)
  77                                 expr = New.Constantify (underlying, Location);
  78
  79                         return new EnumConstant (expr, MemberType);
  80                 }
  81
  82                 public override bool Define ()
  83                 {
  84                         if (!ResolveMemberType ())
  85                                 return false;
  86
  87                         const FieldAttributes attr = FieldAttributes.Public | FieldAttributes.Static | FieldAttributes.Literal;
  88                         FieldBuilder = Parent.TypeBuilder.DefineField (Name, MemberType.GetMetaInfo (), attr);
  89                         spec = new ConstSpec (Parent.Definition, this, MemberType, FieldBuilder, ModFlags, initializer);
  90
  91                         Parent.MemberCache.AddMember (spec);
  92                         return true;
  93                 }
  94
  95                 public override void Accept (StructuralVisitor visitor)
  96                 {
  97                         visitor.Visit (this);
  98                 }
  99
 100         }
 101
 102         /// <summary>
 103         ///   Enumeration container
 104         /// </summary>
 105         public class Enum : TypeContainer
 106         {
 107                 //
 108                 // Implicit enum member initializer, used when no constant value is provided
 109                 //
 110                 sealed class ImplicitInitializer : Expression
 111                 {
 112                         readonly EnumMember prev;
 113                         readonly EnumMember current;
 114
 115                         public ImplicitInitializer (EnumMember current, EnumMember prev)
 116                         {
 117                                 this.current = current;
 118                                 this.prev = prev;
 119                         }
 120
 121                         public override bool ContainsEmitWithAwait ()
 122                         {
 123                                 return false;
 124                         }
 125
 126                         public override Expression CreateExpressionTree (ResolveContext ec)
 127                         {
 128                                 throw new NotSupportedException ("Missing Resolve call");
 129                         }
 130
 131                         protected override Expression DoResolve (ResolveContext rc)
 132                         {
 133                                 // We are the first member
 134                                 if (prev == null) {
 135                                         return New.Constantify (current.Parent.Definition, Location);
 136                                 }
 137
 138                                 var c = ((ConstSpec) prev.Spec).GetConstant (rc) as EnumConstant;
 139                                 try {
 140                                         return c.Increment ();
 141                                 } catch (OverflowException) {
 142                                         rc.Report.Error (543, current.Location,
 143                                                 "The enumerator value `{0}' is outside the range of enumerator underlying type `{1}'",
 144                                                 current.GetSignatureForError (), ((Enum) current.Parent).UnderlyingType.GetSignatureForError ());
 145
 146                                         return New.Constantify (current.Parent.Definition, current.Location);
 147                                 }
 148                         }
 149
 150                         public override void Emit (EmitContext ec)
 151                         {
 152                                 throw new NotSupportedException ("Missing Resolve call");
 153                         }
 154                 }
 155
 156                 public static readonly string UnderlyingValueField = "value__";
 157
 158                 const Modifiers AllowedModifiers =
 159                         Modifiers.NEW |
 160                         Modifiers.PUBLIC |
 161                         Modifiers.PROTECTED |
 162                         Modifiers.INTERNAL |
 163                         Modifiers.PRIVATE;
 164
 165                 readonly TypeExpr underlying_type_expr;
 166
 167                 public Enum (NamespaceContainer ns, DeclSpace parent, TypeExpression type,
 168                              Modifiers mod_flags, MemberName name, Attributes attrs)
 169                         : base (ns, parent, name, attrs, MemberKind.Enum)
 170                 {
 171                         underlying_type_expr = type;
 172                         var accmods = IsTopLevel ? Modifiers.INTERNAL : Modifiers.PRIVATE;
 173                         ModFlags = ModifiersExtensions.Check (AllowedModifiers, mod_flags, accmods, Location, Report);
 174                         spec = new EnumSpec (null, this, null, null, ModFlags);
 175                 }
 176
 177                 #region Properties
 178
 179                 public override AttributeTargets AttributeTargets {
 180                         get {
 181                                 return AttributeTargets.Enum;
 182                         }
 183                 }
 184
 185                 public TypeExpr BaseTypeExpression {
 186                         get {
 187                                 return underlying_type_expr;
 188                         }
 189                 }
 190
 191                 protected override TypeAttributes TypeAttr {
 192                         get {
 193                                 return ModifiersExtensions.TypeAttr (ModFlags, IsTopLevel) |
 194                                         TypeAttributes.Class | TypeAttributes.Sealed | base.TypeAttr;
 195                         }
 196                 }
 197
 198                 public TypeSpec UnderlyingType {
 199                         get {
 200                                 return ((EnumSpec) spec).UnderlyingType;
 201                         }
 202                 }
 203
 204                 #endregion
 205
 206                 public override void Accept (StructuralVisitor visitor)
 207                 {
 208                         visitor.Visit (this);
 209                 }
 210
 211                 public void AddEnumMember (EnumMember em)
 212                 {
 213                         if (em.Name == UnderlyingValueField) {
 214                                 Report.Error (76, em.Location, "An item in an enumeration cannot have an identifier `{0}'",
 215                                         UnderlyingValueField);
 216                                 return;
 217                         }
 218
 219                         AddConstant (em);
 220                 }
 221
 222                 public static void Error_1008 (Location loc, Report Report)
 223                 {
 224                         Report.Error (1008, loc,
 225                                 "Type byte, sbyte, short, ushort, int, uint, long or ulong expected");
 226                 }
 227
 228                 protected override bool DefineNestedTypes ()
 229                 {
 230                         ((EnumSpec) spec).UnderlyingType = underlying_type_expr == null ? Compiler.BuiltinTypes.Int : underlying_type_expr.Type;
 231
 232                         TypeBuilder.DefineField (UnderlyingValueField, UnderlyingType.GetMetaInfo (),
 233                                 FieldAttributes.Public | FieldAttributes.SpecialName | FieldAttributes.RTSpecialName);
 234
 235                         return true;
 236                 }
 237
 238                 protected override bool DoDefineMembers ()
 239                 {
 240                         if (constants != null) {
 241                                 for (int i = 0; i < constants.Count; ++i) {
 242                                         EnumMember em = (EnumMember) constants [i];
 243                                         if (em.Initializer == null) {
 244                                                 em.Initializer = new ImplicitInitializer (em, i == 0 ? null : (EnumMember) constants[i - 1]);
 245                                         }
 246
 247                                         em.Define ();
 248                                 }
 249                         }
 250
 251                         return true;
 252                 }
 253
 254                 public override bool IsUnmanagedType ()
 255                 {
 256                         return true;
 257                 }
 258
 259                 protected override TypeSpec[] ResolveBaseTypes (out FullNamedExpression base_class)
 260                 {
 261                         base_type = Compiler.BuiltinTypes.Enum;
 262                         base_class = null;
 263                         return null;
 264                 }
 265
 266                 protected override bool VerifyClsCompliance ()
 267                 {
 268                         if (!base.VerifyClsCompliance ())
 269                                 return false;
 270
 271                         switch (UnderlyingType.BuiltinType) {
 272                         case BuiltinTypeSpec.Type.UInt:
 273                         case BuiltinTypeSpec.Type.ULong:
 274                         case BuiltinTypeSpec.Type.UShort:
 275                                 Report.Warning (3009, 1, Location, "`{0}': base type `{1}' is not CLS-compliant",
 276                                         GetSignatureForError (), TypeManager.CSharpName (UnderlyingType));
 277                                 break;
 278                         }
 279
 280                         return true;
 281                 }
 282         }
 283
 284         class EnumSpec : TypeSpec
 285         {
 286                 TypeSpec underlying;
 287
 288                 public EnumSpec (TypeSpec declaringType, ITypeDefinition definition, TypeSpec underlyingType, MetaType info, Modifiers modifiers)
 289                         : base (MemberKind.Enum, declaringType, definition, info, modifiers | Modifiers.SEALED)
 290                 {
 291                         this.underlying = underlyingType;
 292                 }
 293
 294                 public TypeSpec UnderlyingType {
 295                         get {
 296                                 return underlying;
 297                         }
 298                         set {
 299                                 if (underlying != null)
 300                                         throw new InternalErrorException ("UnderlyingType reset");
 301
 302                                 underlying = value;
 303                         }
 304                 }
 305
 306                 public static TypeSpec GetUnderlyingType (TypeSpec t)
 307                 {
 308                         return ((EnumSpec) t.GetDefinition ()).UnderlyingType;
 309                 }
 310
 311                 public static bool IsValidUnderlyingType (TypeSpec type)
 312                 {
 313                         switch (type.BuiltinType) {
 314                         case BuiltinTypeSpec.Type.Int:
 315                         case BuiltinTypeSpec.Type.UInt:
 316                         case BuiltinTypeSpec.Type.Long:
 317                         case BuiltinTypeSpec.Type.Byte:
 318                         case BuiltinTypeSpec.Type.SByte:
 319                         case BuiltinTypeSpec.Type.Short:
 320                         case BuiltinTypeSpec.Type.UShort:
 321                         case BuiltinTypeSpec.Type.ULong:
 322                                 return true;
 323                         }
 324
 325                         return false;
 326                 }
 327         }
 328 }