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