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