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 // 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                 protected override Constant DoResolveValue (EmitContext ec)
  79                 {
  80                         if (ValueExpr != null) {
  81                                 Constant c = ValueExpr.ResolveAsConstant (ec, this);
  82                                 if (c == null)
  83                                         return null;
  84
  85                                 if (c is EnumConstant)
  86                                         c = ((EnumConstant)c).Child;
  87
  88                                 c = c.ImplicitConversionRequired (ParentEnum.UnderlyingType, Location);
  89                                 if (c == null)
  90                                         return null;
  91
  92                                 if (!IsValidEnumType (c.Type)) {
  93                                         Enum.Error_1008 (Location);
  94                                         return null;
  95                                 }
  96
  97                                 return new EnumConstant (c, MemberType);
  98                         }
  99
 100                         if (prev_member == null) {
 101                                 return new EnumConstant (
 102                                         New.Constantify (ParentEnum.UnderlyingType), MemberType);
 103                         }
 104
 105                         if (!prev_member.ResolveValue ()) {
 106                                 prev_member.value = new EnumConstant (
 107                                         New.Constantify (ParentEnum.UnderlyingType), MemberType);
 108                                 return null;
 109                         }
 110
 111                         try {
 112                                 return (EnumConstant) prev_member.value.Increment ();
 113                         } catch (OverflowException) {
 114                                 Report.Error (543, Location, "The enumerator value `{0}' is too " +
 115                                               "large to fit in its type `{1}'", GetSignatureForError (),
 116                                               TypeManager.CSharpName (ParentEnum.UnderlyingType));
 117                                 return null;
 118                         }
 119                 }
 120         }
 121
 122         /// <summary>
 123         ///   Enumeration container
 124         /// </summary>
 125         public class Enum : TypeContainer
 126         {
 127                 Expression base_type;
 128
 129                 public Type UnderlyingType;
 130
 131                 public const int AllowedModifiers =
 132                         Modifiers.NEW |
 133                         Modifiers.PUBLIC |
 134                         Modifiers.PROTECTED |
 135                         Modifiers.INTERNAL |
 136                         Modifiers.PRIVATE;
 137
 138                 public Enum (NamespaceEntry ns, DeclSpace parent, Expression type,
 139                              int mod_flags, MemberName name, Attributes attrs)
 140                         : base (ns, parent, name, attrs, Kind.Enum)
 141                 {
 142                         this.base_type = type;
 143                         int accmods = IsTopLevel ? Modifiers.INTERNAL : Modifiers.PRIVATE;
 144                         ModFlags = Modifiers.Check (AllowedModifiers, mod_flags, accmods, Location);
 145                 }
 146
 147                 public void AddEnumMember (EnumMember em)
 148                 {
 149                         if (em.Name == "value__") {
 150                                 Report.Error (76, em.Location, "An item in an enumeration cannot " +
 151                                               "have an identifier `value__'");
 152                                 return;
 153                         }
 154
 155                         AddConstant (em);
 156                 }
 157
 158                 public static void Error_1008 (Location loc)
 159                 {
 160                         Report.Error (1008, loc, "Type byte, sbyte, short, ushort, " +
 161                                       "int, uint, long or ulong expected");
 162                 }
 163
 164                 protected override bool DefineNestedTypes ()
 165                 {
 166                         if (!base.DefineNestedTypes ())
 167                                 return false;
 168
 169                         if (!(base_type is TypeLookupExpression)) {
 170                                 Error_1008 (Location);
 171                                 return false;
 172                         }
 173
 174                         TypeExpr ute = base_type.ResolveAsTypeTerminal (this, false);
 175                         UnderlyingType = ute.Type;
 176
 177                         if (UnderlyingType != TypeManager.int32_type &&
 178                             UnderlyingType != TypeManager.uint32_type &&
 179                             UnderlyingType != TypeManager.int64_type &&
 180                             UnderlyingType != TypeManager.uint64_type &&
 181                             UnderlyingType != TypeManager.short_type &&
 182                             UnderlyingType != TypeManager.ushort_type &&
 183                             UnderlyingType != TypeManager.byte_type  &&
 184                             UnderlyingType != TypeManager.sbyte_type) {
 185                                 Error_1008 (Location);
 186                                 return false;
 187                         }
 188
 189                         //
 190                         // Call MapToInternalType for corlib
 191                         //
 192                         TypeBuilder.DefineField ("value__", UnderlyingType,
 193                                                  FieldAttributes.Public | FieldAttributes.SpecialName
 194                                                  | FieldAttributes.RTSpecialName);
 195
 196                         return true;
 197                 }
 198
 199                 //
 200                 // Used for error reporting only
 201                 //
 202                 public EnumMember GetDefinition (object value)
 203                 {
 204                         foreach (EnumMember e in defined_names.Values) {
 205                                 if (e.Value.Equals (value))
 206                                         return e;
 207                         }
 208
 209                         throw new ArgumentOutOfRangeException (value.ToString ());
 210                 }
 211
 212                 protected override bool VerifyClsCompliance ()
 213                 {
 214                         if (!base.VerifyClsCompliance ())
 215                                 return false;
 216
 217                         if (UnderlyingType == TypeManager.uint32_type ||
 218                                 UnderlyingType == TypeManager.uint64_type ||
 219                                 UnderlyingType == TypeManager.ushort_type) {
 220                                 Report.Error (3009, Location, "`{0}': base type `{1}' is not CLS-compliant", GetSignatureForError (), TypeManager.CSharpName (UnderlyingType));
 221                         }
 222
 223                         return true;
 224                 }
 225
 226                 public override AttributeTargets AttributeTargets {
 227                         get {
 228                                 return AttributeTargets.Enum;
 229                         }
 230                 }
 231
 232                 protected override TypeAttributes TypeAttr {
 233                         get {
 234                                 return Modifiers.TypeAttr (ModFlags, IsTopLevel) |
 235                                         TypeAttributes.Class | TypeAttributes.Sealed | base.TypeAttr;
 236                         }
 237                 }
 238         }
 239 }