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 // Licensed under the terms of the GNU GPL
   9 //
  10 // (C) 2001 Ximian, Inc (http://www.ximian.com)
  11 //
  12
  13 using System;
  14 using System.Collections;
  15 using System.Collections.Specialized;
  16 using System.Reflection;
  17 using System.Reflection.Emit;
  18 using System.Globalization;
  19
  20 namespace Mono.CSharp {
  21
  22         public class EnumMember : Const {
  23                 protected readonly Enum ParentEnum;
  24                 protected readonly Expression ValueExpr;
  25                 readonly EnumMember prev_member;
  26
  27                 public EnumMember (Enum parent, EnumMember prev_member, string name, Expression expr,
  28                                    Attributes attrs, Location loc)
  29                         : base (parent, new EnumTypeExpr (parent), name, expr, Modifiers.PUBLIC,
  30                                 attrs, loc)
  31                 {
  32                         this.ParentEnum = parent;
  33                         this.ValueExpr = expr;
  34                         this.prev_member = prev_member;
  35                 }
  36
  37                 protected class EnumTypeExpr : TypeExpr
  38                 {
  39                         public readonly Enum Enum;
  40
  41                         public EnumTypeExpr (Enum e)
  42                         {
  43                                 this.Enum = e;
  44                         }
  45
  46                         protected override TypeExpr DoResolveAsTypeStep (IResolveContext ec)
  47                         {
  48                                 type = Enum.CurrentType != null ? Enum.CurrentType : Enum.TypeBuilder;
  49                                 return this;
  50                         }
  51
  52                         public override TypeExpr ResolveAsTypeTerminal (IResolveContext ec, bool silent)
  53                         {
  54                                 return DoResolveAsTypeStep (ec);
  55                         }
  56
  57                         public override string Name {
  58                                 get { return Enum.Name; }
  59                         }
  60
  61                         public override string FullName {
  62                                 get { return Enum.Name; }
  63                         }
  64                 }
  65
  66                 static bool IsValidEnumType (Type t)
  67                 {
  68                         return (t == TypeManager.int32_type || t == TypeManager.uint32_type || t == TypeManager.int64_type ||
  69                                 t == TypeManager.byte_type || t == TypeManager.sbyte_type || t == TypeManager.short_type ||
  70                                 t == TypeManager.ushort_type || t == TypeManager.uint64_type || t == TypeManager.char_type ||
  71                                 t.IsEnum);
  72                 }
  73
  74                 public object Value {
  75                         get { return value.GetValue (); }
  76                 }
  77
  78                 public override bool Define ()
  79                 {
  80                         const FieldAttributes attr = FieldAttributes.Public | FieldAttributes.Static | FieldAttributes.Literal;
  81                         FieldBuilder = Parent.TypeBuilder.DefineField (Name, MemberType, attr);
  82                         TypeManager.RegisterConstant (FieldBuilder, this);
  83                         return true;
  84                 }
  85
  86                 protected override Constant DoResolveValue (EmitContext ec)
  87                 {
  88                         if (ValueExpr != null) {
  89                                 Constant c = ValueExpr.ResolveAsConstant (ec, this);
  90                                 if (c == null)
  91                                         return null;
  92
  93                                 if (c is EnumConstant)
  94                                         c = ((EnumConstant)c).Child;
  95
  96                                 c = c.ImplicitConversionRequired (ParentEnum.UnderlyingType, Location);
  97                                 if (c == null)
  98                                         return null;
  99
 100                                 if (!IsValidEnumType (c.Type)) {
 101                                         Enum.Error_1008 (Location);
 102                                         return null;
 103                                 }
 104
 105                                 return new EnumConstant (c, MemberType);
 106                         }
 107
 108                         if (prev_member == null) {
 109                                 return new EnumConstant (
 110                                         New.Constantify (ParentEnum.UnderlyingType), MemberType);
 111                         }
 112
 113                         if (!prev_member.ResolveValue ()) {
 114                                 prev_member.value = new EnumConstant (
 115                                         New.Constantify (ParentEnum.UnderlyingType), MemberType);
 116                                 return null;
 117                         }
 118
 119                         try {
 120                                 return (EnumConstant) prev_member.value.Increment ();
 121                         } catch (OverflowException) {
 122                                 Report.Error (543, Location, "The enumerator value `{0}' is too " +
 123                                               "large to fit in its type `{1}'", GetSignatureForError (),
 124                                               TypeManager.CSharpName (ParentEnum.UnderlyingType));
 125                                 return null;
 126                         }
 127                 }
 128         }
 129
 130         /// <summary>
 131         ///   Enumeration container
 132         /// </summary>
 133         public class Enum : TypeContainer
 134         {
 135                 Expression base_type;
 136
 137                 public Type UnderlyingType;
 138
 139                 public const int AllowedModifiers =
 140                         Modifiers.NEW |
 141                         Modifiers.PUBLIC |
 142                         Modifiers.PROTECTED |
 143                         Modifiers.INTERNAL |
 144                         Modifiers.PRIVATE;
 145
 146                 public Enum (NamespaceEntry ns, DeclSpace parent, Expression type,
 147                              int mod_flags, MemberName name, Attributes attrs)
 148                         : base (ns, parent, name, attrs, Kind.Enum)
 149                 {
 150                         this.base_type = type;
 151                         int accmods = IsTopLevel ? Modifiers.INTERNAL : Modifiers.PRIVATE;
 152                         ModFlags = Modifiers.Check (AllowedModifiers, mod_flags, accmods, Location);
 153                 }
 154
 155                 public void AddEnumMember (EnumMember em)
 156                 {
 157                         if (em.Name == "value__") {
 158                                 Report.Error (76, em.Location, "An item in an enumeration cannot " +
 159                                               "have an identifier `value__'");
 160                                 return;
 161                         }
 162
 163                         AddConstant (em);
 164                 }
 165
 166                 public static void Error_1008 (Location loc)
 167                 {
 168                         Report.Error (1008, loc, "Type byte, sbyte, short, ushort, " +
 169                                       "int, uint, long or ulong expected");
 170                 }
 171
 172                 protected override bool DefineNestedTypes ()
 173                 {
 174                         if (!base.DefineNestedTypes ())
 175                                 return false;
 176
 177                         if (!(base_type is TypeLookupExpression)) {
 178                                 Error_1008 (Location);
 179                                 return false;
 180                         }
 181
 182                         TypeExpr ute = base_type.ResolveAsTypeTerminal (this, false);
 183                         UnderlyingType = ute.Type;
 184
 185                         if (UnderlyingType != TypeManager.int32_type &&
 186                             UnderlyingType != TypeManager.uint32_type &&
 187                             UnderlyingType != TypeManager.int64_type &&
 188                             UnderlyingType != TypeManager.uint64_type &&
 189                             UnderlyingType != TypeManager.short_type &&
 190                             UnderlyingType != TypeManager.ushort_type &&
 191                             UnderlyingType != TypeManager.byte_type  &&
 192                             UnderlyingType != TypeManager.sbyte_type) {
 193                                 Error_1008 (Location);
 194                                 return false;
 195                         }
 196
 197                         //
 198                         // Call MapToInternalType for corlib
 199                         //
 200                         TypeBuilder.DefineField ("value__", UnderlyingType,
 201                                                  FieldAttributes.Public | FieldAttributes.SpecialName
 202                                                  | FieldAttributes.RTSpecialName);
 203
 204                         return true;
 205                 }
 206
 207                 //
 208                 // Used for error reporting only
 209                 //
 210                 public EnumMember GetDefinition (object value)
 211                 {
 212                         foreach (EnumMember e in defined_names.Values) {
 213                                 if (e.Value.Equals (value))
 214                                         return e;
 215                         }
 216
 217                         throw new ArgumentOutOfRangeException (value.ToString ());
 218                 }
 219
 220                 protected override bool VerifyClsCompliance ()
 221                 {
 222                         if (!base.VerifyClsCompliance ())
 223                                 return false;
 224
 225                         if (UnderlyingType == TypeManager.uint32_type ||
 226                                 UnderlyingType == TypeManager.uint64_type ||
 227                                 UnderlyingType == TypeManager.ushort_type) {
 228                                 Report.Error (3009, Location, "`{0}': base type `{1}' is not CLS-compliant", GetSignatureForError (), TypeManager.CSharpName (UnderlyingType));
 229                         }
 230
 231                         return true;
 232                 }
 233
 234                 public override AttributeTargets AttributeTargets {
 235                         get {
 236                                 return AttributeTargets.Enum;
 237                         }
 238                 }
 239
 240                 protected override TypeAttributes TypeAttr {
 241                         get {
 242                                 return Modifiers.TypeAttr (ModFlags, IsTopLevel) |
 243                                         TypeAttributes.Class | TypeAttributes.Sealed | base.TypeAttr;
 244                         }
 245                 }
 246         }
 247 }