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