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                 // Todo : Shadows needs implementation
  30                 public const int SHADOWS   = 0x08000;
  31                 public const int DEFAULT   = 0x10000;
  32                 public const int NONVIRTUAL= 0x20000;
  33                 private const int TOP      = 0x20000;
  34
  35
  36                 public const int Accessibility =
  37                         PUBLIC | PROTECTED | INTERNAL | PRIVATE;
  38
  39                 static public string Name (int i)
  40                 {
  41                         string s = "";
  42
  43                         switch (i) {
  44                         case Modifiers.NEW:
  45                                 s = "overloads"; break;
  46                         case Modifiers.PUBLIC:
  47                                 s = "public"; break;
  48                         case Modifiers.PROTECTED:
  49                                 s = "protected"; break;
  50                         case Modifiers.INTERNAL:
  51                                 s = "friend"; break;
  52                         case Modifiers.PRIVATE:
  53                                 s = "private"; break;
  54                         case Modifiers.ABSTRACT:
  55                                 s = "mustinherit"; break;
  56                         case Modifiers.SEALED:
  57                                 s = "notinheritable"; break;
  58                         case Modifiers.STATIC:
  59                                 s = "shared"; break;
  60                         case Modifiers.READONLY:
  61                                 s = "readonly"; break;
  62                         case Modifiers.VIRTUAL:
  63                                 s = "overridable"; break;
  64                         case Modifiers.OVERRIDE:
  65                                 s = "overrides"; break;
  66                         case Modifiers.EXTERN:
  67                                 s = "extern"; break;
  68                         case Modifiers.VOLATILE:
  69                                 s = "volatile"; break;
  70                         case Modifiers.SHADOWS:
  71                                 s = "shadows"; break;
  72                         case Modifiers.NONVIRTUAL:
  73                                 s = "notoveridable"; 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.HaveStaticConstructor)
 116                                 t |= TypeAttributes.BeforeFieldInit;
 117
 118                         return t;
 119                 }
 120
 121                 public static FieldAttributes FieldAttr (int mod_flags)
 122                 {
 123                         FieldAttributes fa = 0;
 124
 125                         if ((mod_flags & PUBLIC) != 0)
 126                                 fa |= FieldAttributes.Public;
 127                         if ((mod_flags & PRIVATE) != 0)
 128                                 fa |= FieldAttributes.Private;
 129                         if ((mod_flags & PROTECTED) != 0){
 130                                 if ((mod_flags & INTERNAL) != 0)
 131                                         fa |= FieldAttributes.FamORAssem;
 132                                 else
 133                                         fa |= FieldAttributes.Family;
 134                         } else {
 135                                 if ((mod_flags & INTERNAL) != 0)
 136                                         fa |= FieldAttributes.Assembly;
 137                         }
 138
 139                         if ((mod_flags & STATIC) != 0)
 140                                 fa |= FieldAttributes.Static;
 141                         if ((mod_flags & READONLY) != 0)
 142                                 fa |= FieldAttributes.InitOnly;
 143                         return fa;
 144                 }
 145
 146                 public static MethodAttributes MethodAttr (int mod_flags)
 147                 {
 148                         MethodAttributes ma = 0;
 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                                         MethodAttributes.HideBySig;
 168                         }
 169                         if ((mod_flags & NONVIRTUAL) != 0)
 170                                 ma |= MethodAttributes.Final;
 171
 172                         if ((mod_flags & VIRTUAL) != 0)
 173                                 ma |= MethodAttributes.Virtual;
 174
 175                         if ((mod_flags & OVERRIDE) != 0)
 176                                 ma |= MethodAttributes.Virtual | MethodAttributes.HideBySig;
 177                         else {
 178                                 if ((ma & MethodAttributes.Virtual) != 0)
 179                                         ma |= MethodAttributes.NewSlot;
 180                         }
 181
 182                         if ((mod_flags & NEW) != 0)
 183                                 ma |= MethodAttributes.HideBySig;
 184
 185                         //if ((mod_flags & SHADOWS) != 0)
 186                                 // needs to be fixed
 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 (30176, 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 (30233, l, "the modifier " + name + " is not valid for this item");
 250                 }
 251         }
 252 }