mcs/gmcs/modifiers.cs

   1 //
   2 // modifiers.cs: Modifier handling.
   3 //
   4 using System;
   5 using System.Reflection;
   6
   7 namespace Mono.CSharp {
   8         public class Modifiers {
   9
  10                 //
  11                 // The ordering of the following 4 constants
  12                 // has been carefully done.
  13                 //
  14                 public const int PROTECTED = 0x0001;
  15                 public const int PUBLIC    = 0x0002;
  16                 public const int PRIVATE   = 0x0004;
  17                 public const int INTERNAL  = 0x0008;
  18                 public const int NEW       = 0x0010;
  19                 public const int ABSTRACT  = 0x0020;
  20                 public const int SEALED    = 0x0040;
  21                 public const int STATIC    = 0x0080;
  22                 public const int READONLY  = 0x0100;
  23                 public const int VIRTUAL   = 0x0200;
  24                 public const int OVERRIDE  = 0x0400;
  25                 public const int EXTERN    = 0x0800;
  26                 public const int VOLATILE  = 0x1000;
  27                 public const int UNSAFE    = 0x2000;
  28                 public const int TOP       = 0x2000;
  29
  30                 //
  31                 // We use this internally to flag that the method contains an iterator
  32                 //
  33                 public const int METHOD_YIELDS = 0x8000;
  34                 public const int METHOD_GENERIC = 0x10000;
  35
  36                 public const int Accessibility =
  37                         PUBLIC | PROTECTED | INTERNAL | PRIVATE;
  38                 public const int AllowedExplicitImplFlags =
  39                         UNSAFE | EXTERN;
  40
  41                 static public string Name (int i)
  42                 {
  43                         string s = "";
  44
  45                         switch (i) {
  46                         case Modifiers.NEW:
  47                                 s = "new"; break;
  48                         case Modifiers.PUBLIC:
  49                                 s = "public"; break;
  50                         case Modifiers.PROTECTED:
  51                                 s = "protected"; break;
  52                         case Modifiers.INTERNAL:
  53                                 s = "internal"; break;
  54                         case Modifiers.PRIVATE:
  55                                 s = "private"; break;
  56                         case Modifiers.ABSTRACT:
  57                                 s = "abstract"; break;
  58                         case Modifiers.SEALED:
  59                                 s = "sealed"; break;
  60                         case Modifiers.STATIC:
  61                                 s = "static"; break;
  62                         case Modifiers.READONLY:
  63                                 s = "readonly"; break;
  64                         case Modifiers.VIRTUAL:
  65                                 s = "virtual"; break;
  66                         case Modifiers.OVERRIDE:
  67                                 s = "override"; break;
  68                         case Modifiers.EXTERN:
  69                                 s = "extern"; break;
  70                         case Modifiers.VOLATILE:
  71                                 s = "volatile"; break;
  72                         case Modifiers.UNSAFE:
  73                                 s = "unsafe"; break;
  74                         }
  75
  76                         return s;
  77                 }
  78
  79                 public static TypeAttributes TypeAttr (int mod_flags, bool is_toplevel)
  80                 {
  81                         TypeAttributes t = 0;
  82
  83                         if (is_toplevel){
  84                                 if ((mod_flags & PUBLIC) != 0)
  85                                         t |= TypeAttributes.Public;
  86                                 if ((mod_flags & PRIVATE) != 0)
  87                                         t |= TypeAttributes.NotPublic;
  88                         } else {
  89                                 if ((mod_flags & PUBLIC) != 0)
  90                                         t |= TypeAttributes.NestedPublic;
  91                                 if ((mod_flags & PRIVATE) != 0)
  92                                         t |= TypeAttributes.NestedPrivate;
  93                                 if ((mod_flags & PROTECTED) != 0 && (mod_flags & INTERNAL) != 0)
  94                                         t |= TypeAttributes.NestedFamORAssem;
  95                                 if ((mod_flags & PROTECTED) != 0)
  96                                         t |= TypeAttributes.NestedFamily;
  97                                 if ((mod_flags & INTERNAL) != 0)
  98                                         t |= TypeAttributes.NestedAssembly;
  99                         }
 100
 101                         if ((mod_flags & SEALED) != 0)
 102                                 t |= TypeAttributes.Sealed;
 103                         if ((mod_flags & ABSTRACT) != 0)
 104                                 t |= TypeAttributes.Abstract;
 105
 106                         return t;
 107                 }
 108
 109                 public static TypeAttributes TypeAttr (int mod_flags, TypeContainer caller)
 110                 {
 111                         TypeAttributes t = TypeAttr (mod_flags, caller.IsTopLevel);
 112
 113                         // If we do not have static constructors, static methods
 114                         // can be invoked without initializing the type.
 115                         if (!caller.UserDefinedStaticConstructor &&
 116                             (caller.Kind != Kind.Interface))
 117                                 t |= TypeAttributes.BeforeFieldInit;
 118
 119                         return t;
 120                 }
 121
 122                 public static FieldAttributes FieldAttr (int mod_flags)
 123                 {
 124                         FieldAttributes fa = 0;
 125
 126                         if ((mod_flags & PUBLIC) != 0)
 127                                 fa |= FieldAttributes.Public;
 128                         if ((mod_flags & PRIVATE) != 0)
 129                                 fa |= FieldAttributes.Private;
 130                         if ((mod_flags & PROTECTED) != 0){
 131                                 if ((mod_flags & INTERNAL) != 0)
 132                                         fa |= FieldAttributes.FamORAssem;
 133                                 else
 134                                         fa |= FieldAttributes.Family;
 135                         } else {
 136                                 if ((mod_flags & INTERNAL) != 0)
 137                                         fa |= FieldAttributes.Assembly;
 138                         }
 139
 140                         if ((mod_flags & STATIC) != 0)
 141                                 fa |= FieldAttributes.Static;
 142                         if ((mod_flags & READONLY) != 0)
 143                                 fa |= FieldAttributes.InitOnly;
 144
 145                         return fa;
 146                 }
 147
 148                 public static MethodAttributes MethodAttr (int mod_flags)
 149                 {
 150                         MethodAttributes ma = MethodAttributes.HideBySig;
 151
 152                         if ((mod_flags & PUBLIC) != 0)
 153                                 ma |= MethodAttributes.Public;
 154                         if ((mod_flags & PRIVATE) != 0)
 155                                 ma |= MethodAttributes.Private;
 156                         if ((mod_flags & PROTECTED) != 0){
 157                                 if ((mod_flags & INTERNAL) != 0)
 158                                         ma |= MethodAttributes.FamORAssem;
 159                                 else
 160                                         ma |= MethodAttributes.Family;
 161                         } else {
 162                                 if ((mod_flags & INTERNAL) != 0)
 163                                         ma |= MethodAttributes.Assembly;
 164                         }
 165
 166                         if ((mod_flags & STATIC) != 0)
 167                                 ma |= MethodAttributes.Static;
 168                         if ((mod_flags & ABSTRACT) != 0){
 169                                 ma |= MethodAttributes.Abstract | MethodAttributes.Virtual;
 170                         }
 171                         if ((mod_flags & SEALED) != 0)
 172                                 ma |= MethodAttributes.Final;
 173
 174                         if ((mod_flags & VIRTUAL) != 0)
 175                                 ma |= MethodAttributes.Virtual;
 176
 177                         if ((mod_flags & OVERRIDE) != 0)
 178                                 ma |= MethodAttributes.Virtual;
 179                         else {
 180                                 if ((ma & MethodAttributes.Virtual) != 0)
 181                                         ma |= MethodAttributes.NewSlot;
 182                         }
 183
 184                         return ma;
 185                 }
 186
 187                 // <summary>
 188                 //   Checks the object @mod modifiers to be in @allowed.
 189                 //   Returns the new mask.  Side effect: reports any
 190                 //   incorrect attributes.
 191                 // </summary>
 192                 public static int Check (int allowed, int mod, int def_access, Location l)
 193                 {
 194                         int invalid_flags  = (~allowed) & mod;
 195                         int i;
 196
 197                         if (invalid_flags == 0){
 198                                 int a = mod;
 199
 200                                 if ((mod & Modifiers.UNSAFE) != 0){
 201                                         if (!RootContext.Unsafe){
 202                                                 Report.Error (227, l,
 203                                                               "Unsafe code requires the -unsafe command " +
 204                                                               "line option to be specified");
 205                                         }
 206                                 }
 207
 208                                 //
 209                                 // If no accessibility bits provided
 210                                 // then provide the defaults.
 211                                 //
 212                                 if ((mod & Accessibility) == 0){
 213                                         mod |= def_access;
 214                                         return mod;
 215                                 }
 216
 217                                 //
 218                                 // Make sure that no conflicting accessibility
 219                                 // bits have been set.  Protected+Internal is
 220                                 // allowed, that is why they are placed on bits
 221                                 // 1 and 4 (so the shift 3 basically merges them)
 222                                 //
 223                                 a &= 15;
 224                                 a |= (a >> 3);
 225                                 a = ((a & 2) >> 1) + (a & 5);
 226                                 a = ((a & 4) >> 2) + (a & 3);
 227                                 if (a > 1)
 228                                         Report.Error (107, l, "More than one protection modifier specified");
 229
 230                                 return mod;
 231                         }
 232
 233                         for (i = 1; i <= TOP; i <<= 1){
 234                                 if ((i & invalid_flags) == 0)
 235                                         continue;
 236
 237                                 Error_InvalidModifier (l, Name (i));
 238                         }
 239
 240                         return allowed & mod;
 241                 }
 242
 243                 public static void Error_InvalidModifier (Location l, string name)
 244                 {
 245                         Report.Error (106, l, "the modifier " + name + " is not valid for this item");
 246                 }
 247         }
 248 }