bmcs/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 WRITEONLY = 0x04000;
  29                 public const int SHADOWS   = 0x08000;
  30                 public const int DEFAULT   = 0x10000;
  31                 public const int NONVIRTUAL= 0x20000;
  32                 private const int TOP      = 0x20000;
  33
  34                 //
  35                 // We use this internally to flag that the method contains an iterator
  36                 //
  37                 public const int METHOD_YIELDS = 0x8000;
  38                 public const int METHOD_GENERIC = 0x10000;
  39
  40                 public const int Accessibility =
  41                         PUBLIC | PROTECTED | INTERNAL | PRIVATE;
  42                 public const int AllowedExplicitImplFlags =
  43                         UNSAFE | EXTERN;
  44
  45                 static public string Name (int i)
  46                 {
  47                         string s = "";
  48
  49                         switch (i) {
  50                         case Modifiers.NEW:
  51                                 s = "new"; break;
  52                         case Modifiers.PUBLIC:
  53                                 s = "public"; break;
  54                         case Modifiers.PROTECTED:
  55                                 s = "protected"; break;
  56                         case Modifiers.INTERNAL:
  57                                 s = "internal"; break;
  58                         case Modifiers.PRIVATE:
  59                                 s = "private"; break;
  60                         case Modifiers.ABSTRACT:
  61                                 s = "abstract"; break;
  62                         case Modifiers.SEALED:
  63                                 s = "sealed"; break;
  64                         case Modifiers.STATIC:
  65                                 s = "static"; break;
  66                         case Modifiers.READONLY:
  67                                 s = "readonly"; break;
  68                         case Modifiers.VIRTUAL:
  69                                 s = "virtual"; break;
  70                         case Modifiers.OVERRIDE:
  71                                 s = "override"; break;
  72                         case Modifiers.EXTERN:
  73                                 s = "extern"; break;
  74                         case Modifiers.VOLATILE:
  75                                 s = "volatile"; break;
  76                         case Modifiers.UNSAFE:
  77                                 s = "unsafe"; break;
  78                         }
  79
  80                         return s;
  81                 }
  82
  83                 public static TypeAttributes TypeAttr (int mod_flags, bool is_toplevel)
  84                 {
  85                         TypeAttributes t = 0;
  86
  87                         if (is_toplevel){
  88                                 if ((mod_flags & PUBLIC) != 0)
  89                                         t |= TypeAttributes.Public;
  90                                 if ((mod_flags & PRIVATE) != 0)
  91                                         t |= TypeAttributes.NotPublic;
  92                         } else {
  93                                 if ((mod_flags & PUBLIC) != 0)
  94                                         t |= TypeAttributes.NestedPublic;
  95                                 if ((mod_flags & PRIVATE) != 0)
  96                                         t |= TypeAttributes.NestedPrivate;
  97                                 if ((mod_flags & PROTECTED) != 0 && (mod_flags & INTERNAL) != 0)
  98                                         t |= TypeAttributes.NestedFamORAssem;
  99                                 if ((mod_flags & PROTECTED) != 0)
 100                                         t |= TypeAttributes.NestedFamily;
 101                                 if ((mod_flags & INTERNAL) != 0)
 102                                         t |= TypeAttributes.NestedAssembly;
 103                         }
 104
 105                         if ((mod_flags & SEALED) != 0)
 106                                 t |= TypeAttributes.Sealed;
 107                         if ((mod_flags & ABSTRACT) != 0)
 108                                 t |= TypeAttributes.Abstract;
 109
 110                         return t;
 111                 }
 112
 113                 public static TypeAttributes TypeAttr (int mod_flags, TypeContainer caller)
 114                 {
 115                         TypeAttributes t = TypeAttr (mod_flags, caller.IsTopLevel);
 116
 117                         // If we do not have static constructors, static methods
 118                         // can be invoked without initializing the type.
 119                         if (!caller.UserDefinedStaticConstructor &&
 120                             (caller.Kind != Kind.Interface))
 121                                 t |= TypeAttributes.BeforeFieldInit;
 122
 123                         return t;
 124                 }
 125
 126                 public static FieldAttributes FieldAttr (int mod_flags)
 127                 {
 128                         FieldAttributes fa = 0;
 129
 130                         if ((mod_flags & PUBLIC) != 0)
 131                                 fa |= FieldAttributes.Public;
 132                         if ((mod_flags & PRIVATE) != 0)
 133                                 fa |= FieldAttributes.Private;
 134                         if ((mod_flags & PROTECTED) != 0){
 135                                 if ((mod_flags & INTERNAL) != 0)
 136                                         fa |= FieldAttributes.FamORAssem;
 137                                 else
 138                                         fa |= FieldAttributes.Family;
 139                         } else {
 140                                 if ((mod_flags & INTERNAL) != 0)
 141                                         fa |= FieldAttributes.Assembly;
 142                         }
 143
 144                         if ((mod_flags & STATIC) != 0)
 145                                 fa |= FieldAttributes.Static;
 146                         if ((mod_flags & READONLY) != 0)
 147                                 fa |= FieldAttributes.InitOnly;
 148
 149                         return fa;
 150                 }
 151
 152                 public static MethodAttributes MethodAttr (int mod_flags)
 153                 {
 154                         MethodAttributes ma = MethodAttributes.HideBySig;
 155
 156                         if ((mod_flags & PUBLIC) != 0)
 157                                 ma |= MethodAttributes.Public;
 158                         if ((mod_flags & PRIVATE) != 0)
 159                                 ma |= MethodAttributes.Private;
 160                         if ((mod_flags & PROTECTED) != 0){
 161                                 if ((mod_flags & INTERNAL) != 0)
 162                                         ma |= MethodAttributes.FamORAssem;
 163                                 else
 164                                         ma |= MethodAttributes.Family;
 165                         } else {
 166                                 if ((mod_flags & INTERNAL) != 0)
 167                                         ma |= MethodAttributes.Assembly;
 168                         }
 169
 170                         if ((mod_flags & STATIC) != 0)
 171                                 ma |= MethodAttributes.Static;
 172                         if ((mod_flags & ABSTRACT) != 0){
 173                                 ma |= MethodAttributes.Abstract | MethodAttributes.Virtual;
 174                         }
 175                         if ((mod_flags & SEALED) != 0)
 176                                 ma |= MethodAttributes.Final;
 177
 178                         if ((mod_flags & VIRTUAL) != 0)
 179                                 ma |= MethodAttributes.Virtual;
 180
 181                         if ((mod_flags & OVERRIDE) != 0)
 182                                 ma |= MethodAttributes.Virtual;
 183                         else {
 184                                 if ((ma & MethodAttributes.Virtual) != 0)
 185                                         ma |= MethodAttributes.NewSlot;
 186                         }
 187
 188                         return ma;
 189                 }
 190
 191                 // <summary>
 192                 //   Checks the object @mod modifiers to be in @allowed.
 193                 //   Returns the new mask.  Side effect: reports any
 194                 //   incorrect attributes.
 195                 // </summary>
 196                 public static int Check (int allowed, int mod, int def_access, Location l)
 197                 {
 198                         int invalid_flags  = (~allowed) & mod;
 199                         int i;
 200
 201                         if (invalid_flags == 0){
 202                                 int a = mod;
 203
 204                                 if ((mod & Modifiers.UNSAFE) != 0){
 205                                         if (!RootContext.Unsafe){
 206                                                 Report.Error (227, l,
 207                                                               "Unsafe code requires the -unsafe command " +
 208                                                               "line option to be specified");
 209                                         }
 210                                 }
 211
 212                                 //
 213                                 // If no accessibility bits provided
 214                                 // then provide the defaults.
 215                                 //
 216                                 if ((mod & Accessibility) == 0){
 217                                         mod |= def_access;
 218                                         return mod;
 219                                 }
 220
 221                                 //
 222                                 // Make sure that no conflicting accessibility
 223                                 // bits have been set.  Protected+Internal is
 224                                 // allowed, that is why they are placed on bits
 225                                 // 1 and 4 (so the shift 3 basically merges them)
 226                                 //
 227                                 a &= 15;
 228                                 a |= (a >> 3);
 229                                 a = ((a & 2) >> 1) + (a & 5);
 230                                 a = ((a & 4) >> 2) + (a & 3);
 231                                 if (a > 1)
 232                                         Report.Error (107, l, "More than one protection modifier specified");
 233
 234                                 return mod;
 235                         }
 236
 237                         for (i = 1; i <= TOP; i <<= 1){
 238                                 if ((i & invalid_flags) == 0)
 239                                         continue;
 240
 241                                 Error_InvalidModifier (l, Name (i));
 242                         }
 243
 244                         return allowed & mod;
 245                 }
 246
 247                 public static void Error_InvalidModifier (Location l, string name)
 248                 {
 249                         Report.Error (106, l, "the modifier " + name + " is not valid for this item");
 250                 }
 251         }
 252 }