mcs/mbas/modifiers.cs

   1 //
   2 // modifiers.cs: Modifier handling.
   3 //
   4 using System;
   5 using System.Reflection;
   6
   7 namespace Mono.MonoBASIC {
   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 = 0x00001;
  15                 public const int PUBLIC    = 0x00002;
  16                 public const int PRIVATE   = 0x00004;
  17                 public const int INTERNAL  = 0x00008;
  18                 public const int NEW       = 0x00010;
  19                 public const int ABSTRACT  = 0x00020;
  20                 public const int SEALED    = 0x00040;
  21                 public const int STATIC    = 0x00080;
  22                 public const int READONLY  = 0x00100;
  23                 public const int VIRTUAL   = 0x00200;
  24                 public const int OVERRIDE  = 0x00400;
  25                 public const int EXTERN    = 0x00800;
  26                 public const int VOLATILE  = 0x01000;
  27                 public const int UNSAFE    = 0x02000;
  28                 public const int WRITEONLY = 0x04000;
  29                 public const int OVERLOADS = 0x08000;
  30                 public const int DEFAULT   = 0x10000;
  31                 public const int NONVIRTUAL= 0x20000;
  32                 private const int TOP      = 0x20000;
  33
  34                 public const int Accessibility =
  35                         PUBLIC | PROTECTED | INTERNAL | PRIVATE;
  36
  37                 static public string Name (int i)
  38                 {
  39                         string s = "";
  40
  41                         switch (i) {
  42                         case Modifiers.NEW:
  43                                 s = "new"; break;
  44                         case Modifiers.PUBLIC:
  45                                 s = "public"; break;
  46                         case Modifiers.PROTECTED:
  47                                 s = "protected"; break;
  48                         case Modifiers.INTERNAL:
  49                                 s = "internal"; break;
  50                         case Modifiers.PRIVATE:
  51                                 s = "private"; break;
  52                         case Modifiers.ABSTRACT:
  53                                 s = "abstract"; break;
  54                         case Modifiers.SEALED:
  55                                 s = "sealed"; break;
  56                         case Modifiers.STATIC:
  57                                 s = "static"; break;
  58                         case Modifiers.READONLY:
  59                                 s = "readonly"; break;
  60                         case Modifiers.VIRTUAL:
  61                                 s = "virtual"; break;
  62                         case Modifiers.OVERRIDE:
  63                                 s = "override"; break;
  64                         case Modifiers.EXTERN:
  65                                 s = "extern"; break;
  66                         case Modifiers.VOLATILE:
  67                                 s = "volatile"; break;
  68                         }
  69
  70                         return s;
  71                 }
  72
  73                 public static TypeAttributes TypeAttr (int mod_flags, bool is_toplevel)
  74                 {
  75                         TypeAttributes t = 0;
  76
  77                         if (is_toplevel){
  78                                 if ((mod_flags & PUBLIC) != 0)
  79                                         t |= TypeAttributes.Public;
  80                                 if ((mod_flags & PRIVATE) != 0)
  81                                         t |= TypeAttributes.NotPublic;
  82                         } else {
  83                                 if ((mod_flags & PUBLIC) != 0)
  84                                         t |= TypeAttributes.NestedPublic;
  85                                 if ((mod_flags & PRIVATE) != 0)
  86                                         t |= TypeAttributes.NestedPrivate;
  87                                 if ((mod_flags & PROTECTED) != 0 && (mod_flags & INTERNAL) != 0)
  88                                         t |= TypeAttributes.NestedFamORAssem;
  89                                 if ((mod_flags & PROTECTED) != 0)
  90                                         t |= TypeAttributes.NestedFamily;
  91                                 if ((mod_flags & INTERNAL) != 0)
  92                                         t |= TypeAttributes.NestedAssembly;
  93                         }
  94
  95                         if ((mod_flags & SEALED) != 0)
  96                                 t |= TypeAttributes.Sealed;
  97                         if ((mod_flags & ABSTRACT) != 0)
  98                                 t |= TypeAttributes.Abstract;
  99
 100                         return t;
 101                 }
 102
 103                 public static TypeAttributes TypeAttr (int mod_flags, TypeContainer caller)
 104                 {
 105                         TypeAttributes t = TypeAttr (mod_flags, caller.IsTopLevel);
 106
 107                         // If we do not have static constructors, static methods
 108                         // can be invoked without initializing the type.
 109                         if (!caller.HaveStaticConstructor)
 110                                 t |= TypeAttributes.BeforeFieldInit;
 111
 112                         return t;
 113                 }
 114
 115                 public static FieldAttributes FieldAttr (int mod_flags)
 116                 {
 117                         FieldAttributes fa = 0;
 118
 119                         if ((mod_flags & PUBLIC) != 0)
 120                                 fa |= FieldAttributes.Public;
 121                         if ((mod_flags & PRIVATE) != 0)
 122                                 fa |= FieldAttributes.Private;
 123                         if ((mod_flags & PROTECTED) != 0){
 124                                 if ((mod_flags & INTERNAL) != 0)
 125                                         fa |= FieldAttributes.FamORAssem;
 126                                 else
 127                                         fa |= FieldAttributes.Family;
 128                         } else {
 129                                 if ((mod_flags & INTERNAL) != 0)
 130                                         fa |= FieldAttributes.Assembly;
 131                         }
 132
 133                         if ((mod_flags & STATIC) != 0)
 134                                 fa |= FieldAttributes.Static;
 135                         if ((mod_flags & READONLY) != 0)
 136                                 fa |= FieldAttributes.InitOnly;
 137
 138                         return fa;
 139                 }
 140
 141                 public static MethodAttributes MethodAttr (int mod_flags)
 142                 {
 143                         MethodAttributes ma = 0;
 144
 145                         if ((mod_flags & PUBLIC) != 0)
 146                                 ma |= MethodAttributes.Public;
 147                         if ((mod_flags & PRIVATE) != 0)
 148                                 ma |= MethodAttributes.Private;
 149                         if ((mod_flags & PROTECTED) != 0){
 150                                 if ((mod_flags & INTERNAL) != 0)
 151                                         ma |= MethodAttributes.FamORAssem;
 152                                 else
 153                                         ma |= MethodAttributes.Family;
 154                         } else {
 155                                 if ((mod_flags & INTERNAL) != 0)
 156                                         ma |= MethodAttributes.Assembly;
 157                         }
 158
 159                         if ((mod_flags & STATIC) != 0)
 160                                 ma |= MethodAttributes.Static;
 161                         if ((mod_flags & ABSTRACT) != 0){
 162                                 ma |= MethodAttributes.Abstract | MethodAttributes.Virtual |
 163                                         MethodAttributes.HideBySig;
 164                         }
 165                         if ((mod_flags & SEALED) != 0)
 166                                 ma |= MethodAttributes.Final;
 167
 168                         if ((mod_flags & VIRTUAL) != 0)
 169                                 ma |= MethodAttributes.Virtual;
 170
 171                         if ((mod_flags & OVERRIDE) != 0)
 172                                 ma |= MethodAttributes.Virtual | MethodAttributes.HideBySig;
 173                         else {
 174                                 if ((ma & MethodAttributes.Virtual) != 0)
 175                                         ma |= MethodAttributes.NewSlot;
 176                         }
 177
 178                         if ((mod_flags & NEW) != 0)
 179                                 ma |= MethodAttributes.HideBySig;
 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 }