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 using System.Collections;
  16 using System.Collections.Specialized;
  17 using System.Reflection;
  18 using System.Reflection.Emit;
  19 using System.Globalization;
  20
  21 namespace Mono.CSharp {
  22
  23         public class EnumMember : Const {
  24                 protected readonly Enum ParentEnum;
  25                 protected readonly Expression ValueExpr;
  26                 readonly EnumMember prev_member;
  27
  28                 public EnumMember (Enum parent, EnumMember prev_member, string name, Expression expr,
  29                                    Attributes attrs, Location loc)
  30                         : base (parent, new EnumTypeExpr (parent), name, expr, Modifiers.PUBLIC,
  31                                 attrs, loc)
  32                 {
  33                         this.ParentEnum = parent;
  34                         this.ValueExpr = expr;
  35                         this.prev_member = prev_member;
  36                 }
  37
  38                 protected class EnumTypeExpr : TypeExpr
  39                 {
  40                         public readonly Enum Enum;
  41
  42                         public EnumTypeExpr (Enum e)
  43                         {
  44                                 this.Enum = e;
  45                         }
  46
  47                         protected override TypeExpr DoResolveAsTypeStep (IMemberContext ec)
  48                         {
  49                                 type = Enum.CurrentType != null ? Enum.CurrentType : Enum.TypeBuilder;
  50                                 return this;
  51                         }
  52
  53                         public override TypeExpr ResolveAsTypeTerminal (IMemberContext ec, bool silent)
  54                         {
  55                                 return DoResolveAsTypeStep (ec);
  56                         }
  57                 }
  58
  59                 static bool IsValidEnumType (Type t)
  60                 {
  61                         return (t == TypeManager.int32_type || t == TypeManager.uint32_type || t == TypeManager.int64_type ||
  62                                 t == TypeManager.byte_type || t == TypeManager.sbyte_type || t == TypeManager.short_type ||
  63                                 t == TypeManager.ushort_type || t == TypeManager.uint64_type || t == TypeManager.char_type ||
  64                                 TypeManager.IsEnumType (t));
  65                 }
  66
  67                 public object Value {
  68                         get { return ResolveValue () ? value.GetValue () : null; }
  69                 }
  70
  71                 public override bool Define ()
  72                 {
  73                         if (!ResolveMemberType ())
  74                                 return false;
  75
  76                         const FieldAttributes attr = FieldAttributes.Public | FieldAttributes.Static | FieldAttributes.Literal;
  77                         FieldBuilder = Parent.TypeBuilder.DefineField (Name, MemberType, attr);
  78                         Parent.MemberCache.AddMember (FieldBuilder, this);
  79                         TypeManager.RegisterConstant (FieldBuilder, this);
  80                         return true;
  81                 }
  82
  83                 protected override Constant DoResolveValue (ResolveContext ec)
  84                 {
  85                         if (ValueExpr != null) {
  86                                 Constant c = ValueExpr.ResolveAsConstant (ec, this);
  87                                 if (c == null)
  88                                         return null;
  89
  90                                 if (c is EnumConstant)
  91                                         c = ((EnumConstant)c).Child;
  92
  93                                 c = c.ImplicitConversionRequired (ec, ParentEnum.UnderlyingType, Location);
  94                                 if (c == null)
  95                                         return null;
  96
  97                                 if (!IsValidEnumType (c.Type)) {
  98                                         Enum.Error_1008 (Location, ec.Report);
  99                                         return null;
 100                                 }
 101
 102                                 return new EnumConstant (c, MemberType).Resolve (ec);
 103                         }
 104
 105                         if (prev_member == null)
 106                                 return new EnumConstant (New.Constantify (ParentEnum.UnderlyingType), MemberType).Resolve (ec);
 107
 108                         if (!prev_member.ResolveValue ())
 109                                 return null;
 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                 public static readonly string UnderlyingValueField = "value__";
 128
 129                 TypeExpr base_type;
 130
 131                 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, TypeExpr 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, Report);
 145                 }
 146
 147                 public void AddEnumMember (EnumMember em)
 148                 {
 149                         if (em.Name == UnderlyingValueField) {
 150                                 Report.Error (76, em.Location, "An item in an enumeration cannot have an identifier `{0}'",
 151                                         UnderlyingValueField);
 152                                 return;
 153                         }
 154
 155                         AddConstant (em);
 156                 }
 157
 158                 public static void Error_1008 (Location loc, Report Report)
 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                         //
 170                         // Call MapToInternalType for corlib
 171                         //
 172                         TypeBuilder.DefineField (UnderlyingValueField, UnderlyingType,
 173                                                  FieldAttributes.Public | FieldAttributes.SpecialName
 174                                                  | FieldAttributes.RTSpecialName);
 175
 176                         return true;
 177                 }
 178
 179                 protected override bool DoDefineMembers ()
 180                 {
 181                         member_cache = new MemberCache (TypeManager.enum_type, this);
 182                         DefineContainerMembers (constants);
 183                         return true;
 184                 }
 185
 186                 public override bool IsUnmanagedType ()
 187                 {
 188                         return true;
 189                 }
 190
 191                 public Type UnderlyingType {
 192                         get {
 193                                 return base_type.Type;
 194                         }
 195                 }
 196
 197                 protected override bool VerifyClsCompliance ()
 198                 {
 199                         if (!base.VerifyClsCompliance ())
 200                                 return false;
 201
 202                         if (UnderlyingType == TypeManager.uint32_type ||
 203                                 UnderlyingType == TypeManager.uint64_type ||
 204                                 UnderlyingType == TypeManager.ushort_type) {
 205                                 Report.Warning (3009, 1, Location, "`{0}': base type `{1}' is not CLS-compliant", GetSignatureForError (), TypeManager.CSharpName (UnderlyingType));
 206                         }
 207
 208                         return true;
 209                 }
 210
 211                 public override AttributeTargets AttributeTargets {
 212                         get {
 213                                 return AttributeTargets.Enum;
 214                         }
 215                 }
 216
 217                 protected override TypeAttributes TypeAttr {
 218                         get {
 219                                 return Modifiers.TypeAttr (ModFlags, IsTopLevel) |
 220                                         TypeAttributes.Class | TypeAttributes.Sealed | base.TypeAttr;
 221                         }
 222                 }
 223         }
 224 }