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 : TypeDefinition
 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 (TypeContainer parent, TypeExpression type, Modifiers mod_flags, MemberName name, Attributes attrs)
 168                         : base (parent, name, attrs, MemberKind.Enum)
 169                 {
 170                         underlying_type_expr = type;
 171                         var accmods = IsTopLevel ? Modifiers.INTERNAL : Modifiers.PRIVATE;
 172                         ModFlags = ModifiersExtensions.Check (AllowedModifiers, mod_flags, accmods, Location, Report);
 173                         spec = new EnumSpec (null, this, null, null, ModFlags);
 174                 }
 175
 176                 #region Properties
 177
 178                 public override AttributeTargets AttributeTargets {
 179                         get {
 180                                 return AttributeTargets.Enum;
 181                         }
 182                 }
 183
 184                 public TypeExpr BaseTypeExpression {
 185                         get {
 186                                 return underlying_type_expr;
 187                         }
 188                 }
 189
 190                 protected override TypeAttributes TypeAttr {
 191                         get {
 192                                 return ModifiersExtensions.TypeAttr (ModFlags, IsTopLevel) |
 193                                         TypeAttributes.Class | TypeAttributes.Sealed | base.TypeAttr;
 194                         }
 195                 }
 196
 197                 public TypeSpec UnderlyingType {
 198                         get {
 199                                 return ((EnumSpec) spec).UnderlyingType;
 200                         }
 201                 }
 202
 203                 #endregion
 204
 205                 public override void Accept (StructuralVisitor visitor)
 206                 {
 207                         visitor.Visit (this);
 208                 }
 209
 210                 public void AddEnumMember (EnumMember em)
 211                 {
 212                         if (em.Name == UnderlyingValueField) {
 213                                 Report.Error (76, em.Location, "An item in an enumeration cannot have an identifier `{0}'",
 214                                         UnderlyingValueField);
 215                                 return;
 216                         }
 217
 218                         AddConstant (em);
 219                 }
 220
 221                 public static void Error_1008 (Location loc, Report Report)
 222                 {
 223                         Report.Error (1008, loc,
 224                                 "Type byte, sbyte, short, ushort, int, uint, long or ulong expected");
 225                 }
 226
 227                 protected override void DoDefineContainer ()
 228                 {
 229                         ((EnumSpec) spec).UnderlyingType = underlying_type_expr == null ? Compiler.BuiltinTypes.Int : underlying_type_expr.Type;
 230
 231                         TypeBuilder.DefineField (UnderlyingValueField, UnderlyingType.GetMetaInfo (),
 232                                 FieldAttributes.Public | FieldAttributes.SpecialName | FieldAttributes.RTSpecialName);
 233
 234                         DefineBaseTypes ();
 235                 }
 236
 237                 protected override bool DoDefineMembers ()
 238                 {
 239                         if (constants != null) {
 240                                 for (int i = 0; i < constants.Count; ++i) {
 241                                         EnumMember em = (EnumMember) constants [i];
 242                                         if (em.Initializer == null) {
 243                                                 em.Initializer = new ImplicitInitializer (em, i == 0 ? null : (EnumMember) constants[i - 1]);
 244                                         }
 245
 246                                         em.Define ();
 247                                 }
 248                         }
 249
 250                         return true;
 251                 }
 252
 253                 public override bool IsUnmanagedType ()
 254                 {
 255                         return true;
 256                 }
 257
 258                 protected override TypeSpec[] ResolveBaseTypes (out FullNamedExpression base_class)
 259                 {
 260                         base_type = Compiler.BuiltinTypes.Enum;
 261                         base_class = null;
 262                         return null;
 263                 }
 264
 265                 protected override bool VerifyClsCompliance ()
 266                 {
 267                         if (!base.VerifyClsCompliance ())
 268                                 return false;
 269
 270                         switch (UnderlyingType.BuiltinType) {
 271                         case BuiltinTypeSpec.Type.UInt:
 272                         case BuiltinTypeSpec.Type.ULong:
 273                         case BuiltinTypeSpec.Type.UShort:
 274                                 Report.Warning (3009, 1, Location, "`{0}': base type `{1}' is not CLS-compliant",
 275                                         GetSignatureForError (), TypeManager.CSharpName (UnderlyingType));
 276                                 break;
 277                         }
 278
 279                         return true;
 280                 }
 281         }
 282
 283         class EnumSpec : TypeSpec
 284         {
 285                 TypeSpec underlying;
 286
 287                 public EnumSpec (TypeSpec declaringType, ITypeDefinition definition, TypeSpec underlyingType, MetaType info, Modifiers modifiers)
 288                         : base (MemberKind.Enum, declaringType, definition, info, modifiers | Modifiers.SEALED)
 289                 {
 290                         this.underlying = underlyingType;
 291                 }
 292
 293                 public TypeSpec UnderlyingType {
 294                         get {
 295                                 return underlying;
 296                         }
 297                         set {
 298                                 if (underlying != null)
 299                                         throw new InternalErrorException ("UnderlyingType reset");
 300
 301                                 underlying = value;
 302                         }
 303                 }
 304
 305                 public static TypeSpec GetUnderlyingType (TypeSpec t)
 306                 {
 307                         return ((EnumSpec) t.GetDefinition ()).UnderlyingType;
 308                 }
 309
 310                 public static bool IsValidUnderlyingType (TypeSpec type)
 311                 {
 312                         switch (type.BuiltinType) {
 313                         case BuiltinTypeSpec.Type.Int:
 314                         case BuiltinTypeSpec.Type.UInt:
 315                         case BuiltinTypeSpec.Type.Long:
 316                         case BuiltinTypeSpec.Type.Byte:
 317                         case BuiltinTypeSpec.Type.SByte:
 318                         case BuiltinTypeSpec.Type.Short:
 319                         case BuiltinTypeSpec.Type.UShort:
 320                         case BuiltinTypeSpec.Type.ULong:
 321                                 return true;
 322                         }
 323
 324                         return false;
 325                 }
 326         }
 327 }