mcs/mcs/attribute.cs

   1 //\r
   2 // attribute.cs: Attribute Handler\r
   3 //\r
   4 // Author: Ravi Pratap (ravi@ximian.com)\r
   5 //\r
   6 // Licensed under the terms of the GNU GPL\r
   7 //\r
   8 // (C) 2001 Ximian, Inc (http://www.ximian.com)\r
   9 //\r
  10 //\r
  11 \r
  12 using System;\r
  13 using System.Collections;\r
  14 using System.Reflection;\r
  15 using System.Reflection.Emit;\r
  16 using System.Text;\r
  17 \r
  18 namespace Mono.CSharp {\r
  19 \r
  20         public class Attribute {\r
  21                 \r
  22                 public readonly string    Name;\r
  23                 public readonly ArrayList Arguments;\r
  24 \r
  25                 Location Location;\r
  26 \r
  27                 public Type Type;\r
  28                 \r
  29                 //\r
  30                 // The following are only meaningful when the attribute\r
  31                 // being emitted is one of the builtin ones\r
  32                 //\r
  33                 public AttributeTargets Targets;\r
  34                 public bool AllowMultiple;\r
  35                 public bool Inherited;\r
  36 \r
  37                 public bool UsageAttr = false;\r
  38                 \r
  39                 public Attribute (string name, ArrayList args, Location loc)\r
  40                 {\r
  41                         Name = name;\r
  42                         Arguments = args;\r
  43                         Location = loc;\r
  44                 }\r
  45 \r
  46                 void error617 (string name)\r
  47                 {\r
  48                         Report.Error (617, Location, "'" + name + "' is not a valid named attribute " +\r
  49                                       "argument. Named attribute arguments must be fields which are not " +\r
  50                                       "readonly, static or const, or properties with a set accessor which "+\r
  51                                       "are not static.");\r
  52                 }\r
  53 \r
  54                 void error182 ()\r
  55                 {\r
  56                         Report.Error (182, Location,\r
  57                                       "An attribute argument must be a constant expression, typeof " +\r
  58                                       "expression or array creation expression");\r
  59                 }\r
  60 \r
  61                 public CustomAttributeBuilder Resolve (EmitContext ec)\r
  62                 {\r
  63                         string name = Name;\r
  64 \r
  65                         UsageAttr = false;\r
  66 \r
  67                         if (Name.IndexOf ("Attribute") == -1)\r
  68                                 name = Name + "Attribute";\r
  69                         else if (Name.LastIndexOf ("Attribute") == 0)\r
  70                                 name = Name + "Attribute";\r
  71                         \r
  72                         Type = ec.TypeContainer.LookupType (name, false);\r
  73 \r
  74                         if (Type == null) {\r
  75                                 Report.Error (246, Location, "Could not find attribute '" + Name + "' (are you" +\r
  76                                               " missing a using directive or an assembly reference ?)");\r
  77                                 return null;\r
  78                         }\r
  79 \r
  80                         if (Type == TypeManager.attribute_usage_type)\r
  81                                 UsageAttr = true;\r
  82                         \r
  83                         // Now we extract the positional and named arguments\r
  84                         \r
  85                         ArrayList pos_args = new ArrayList ();\r
  86                         ArrayList named_args = new ArrayList ();\r
  87                         \r
  88                         if (Arguments != null) {\r
  89                                 pos_args = (ArrayList) Arguments [0];\r
  90                                 if (Arguments.Count > 1)\r
  91                                         named_args = (ArrayList) Arguments [1];\r
  92                         }\r
  93                                 \r
  94                         object [] pos_values = new object [pos_args.Count];\r
  95 \r
  96                         //\r
  97                         // First process positional arguments \r
  98                         //\r
  99                         \r
 100                         int i;\r
 101                         for (i = 0; i < pos_args.Count; i++) {\r
 102 \r
 103                                 Argument a = (Argument) pos_args [i];\r
 104 \r
 105                                 if (!a.Resolve (ec, Location))\r
 106                                         return null;\r
 107 \r
 108                                 Expression e = Expression.Reduce (ec, a.Expr);\r
 109 \r
 110                                 if (e is Literal) {\r
 111                                         pos_values [i] = ((Literal) e).GetValue ();\r
 112 \r
 113                                         if (UsageAttr)\r
 114                                                 this.Targets = (AttributeTargets) pos_values [0];\r
 115                                 } else { \r
 116                                         error182 ();\r
 117                                         return null;\r
 118                                 }\r
 119                         }\r
 120 \r
 121                         //\r
 122                         // Now process named arguments\r
 123                         //\r
 124 \r
 125                         ArrayList field_infos = new ArrayList ();\r
 126                         ArrayList prop_infos  = new ArrayList ();\r
 127                         ArrayList field_values = new ArrayList ();\r
 128                         ArrayList prop_values = new ArrayList ();\r
 129 \r
 130                         for (i = 0; i < named_args.Count; i++) {\r
 131 \r
 132                                 DictionaryEntry de = (DictionaryEntry) named_args [i];\r
 133 \r
 134                                 string member_name = (string) de.Key;\r
 135                                 Argument a  = (Argument) de.Value;\r
 136 \r
 137                                 if (!a.Resolve (ec, Location))\r
 138                                         return null;\r
 139 \r
 140                                 Expression member = Expression.MemberLookup (ec, Type, member_name, false,\r
 141                                                                              MemberTypes.Field | MemberTypes.Property,\r
 142                                                                              BindingFlags.Public | BindingFlags.Instance,\r
 143                                                                              Location);\r
 144 \r
 145                                 if (member == null || !(member is PropertyExpr || member is FieldExpr)) {\r
 146                                         error617 (member_name);\r
 147                                         return null;\r
 148                                 }\r
 149 \r
 150                                 if (member is PropertyExpr) {\r
 151                                         PropertyExpr pe = (PropertyExpr) member;\r
 152                                         PropertyInfo pi = pe.PropertyInfo;\r
 153 \r
 154                                         if (!pi.CanWrite) {\r
 155                                                 error617 (member_name);\r
 156                                                 return null;\r
 157                                         }\r
 158 \r
 159                                         Expression e = Expression.Reduce (ec, a.Expr);\r
 160                                         \r
 161                                         if (e is Literal) {\r
 162                                                 object o = ((Literal) e).GetValue ();\r
 163                                                 prop_values.Add (o);\r
 164                                                 \r
 165                                                 if (UsageAttr) {\r
 166                                                         if (member_name == "AllowMultiple")\r
 167                                                                 this.AllowMultiple = (bool) o;\r
 168                                                         if (member_name == "Inherited")\r
 169                                                                 this.Inherited = (bool) o;\r
 170                                                 }\r
 171                                                 \r
 172                                         } else { \r
 173                                                 error182 ();\r
 174                                                 return null;\r
 175                                         }\r
 176                                         \r
 177                                         prop_infos.Add (pi);\r
 178                                         \r
 179                                 } else if (member is FieldExpr) {\r
 180                                         FieldExpr fe = (FieldExpr) member;\r
 181                                         FieldInfo fi = fe.FieldInfo;\r
 182 \r
 183                                         if (fi.IsInitOnly) {\r
 184                                                 error617 (member_name);\r
 185                                                 return null;\r
 186                                         }\r
 187 \r
 188                                         Expression e = Expression.Reduce (ec, a.Expr);\r
 189                                         \r
 190                                         if (e is Literal)\r
 191                                                 field_values.Add (((Literal) e).GetValue ());\r
 192                                         else { \r
 193                                                 error182 ();\r
 194                                                 return null;\r
 195                                         }\r
 196                                         \r
 197                                         field_infos.Add (fi);\r
 198                                 }\r
 199                         }\r
 200                         \r
 201                         Expression mg = Expression.MemberLookup (ec, Type, ".ctor", false,\r
 202                                                                  MemberTypes.Constructor,\r
 203                                                                  BindingFlags.Public | BindingFlags.Instance,\r
 204                                                                  Location);\r
 205 \r
 206                         if (mg == null) {\r
 207                                 Report.Error (-6, Location, "Could not find a constructor for this argument list.");\r
 208                                 return null;\r
 209                         }\r
 210 \r
 211                         MethodBase constructor = Invocation.OverloadResolve (ec, (MethodGroupExpr) mg, pos_args, Location);\r
 212 \r
 213                         if (constructor == null) {\r
 214                                 Report.Error (-6, Location, "Could not find a constructor for this argument list.");\r
 215                                 return null;\r
 216                         }\r
 217                         \r
 218                         PropertyInfo [] prop_info_arr = new PropertyInfo [prop_infos.Count];\r
 219                         FieldInfo [] field_info_arr = new FieldInfo [field_infos.Count];\r
 220                         object [] field_values_arr = new object [field_values.Count];\r
 221                         object [] prop_values_arr = new object [prop_values.Count];\r
 222 \r
 223                         field_infos.CopyTo  (field_info_arr, 0);\r
 224                         field_values.CopyTo (field_values_arr, 0);\r
 225 \r
 226                         prop_values.CopyTo  (prop_values_arr, 0);\r
 227                         prop_infos.CopyTo   (prop_info_arr, 0);\r
 228                         \r
 229                         CustomAttributeBuilder cb = new CustomAttributeBuilder ((ConstructorInfo) constructor, pos_values,\r
 230                                                                                 prop_info_arr, prop_values_arr,\r
 231                                                                                 field_info_arr, field_values_arr); \r
 232                         \r
 233                         return cb;\r
 234                 }\r
 235 \r
 236                 static string GetValidPlaces (Attribute attr)\r
 237                 {\r
 238                         StringBuilder sb = new StringBuilder ();\r
 239 \r
 240                         TypeContainer a = TypeManager.LookupAttr (attr.Type);\r
 241 \r
 242                         if (a == null)\r
 243                                 return "(none) ";\r
 244 \r
 245                         if ((a.Targets & AttributeTargets.Assembly) != 0)\r
 246                                 sb.Append ("'assembly' ");\r
 247 \r
 248                         if ((a.Targets & AttributeTargets.Class) != 0)\r
 249                                 sb.Append ("'class' ");\r
 250 \r
 251                         if ((a.Targets & AttributeTargets.Constructor) != 0)\r
 252                                 sb.Append ("'constructor' ");\r
 253 \r
 254                         if ((a.Targets & AttributeTargets.Delegate) != 0)\r
 255                                 sb.Append ("'delegate' ");\r
 256 \r
 257                         if ((a.Targets & AttributeTargets.Enum) != 0)\r
 258                                 sb.Append ("'enum' ");\r
 259 \r
 260                         if ((a.Targets & AttributeTargets.Event) != 0)\r
 261                                 sb.Append ("'event' ");\r
 262 \r
 263                         if ((a.Targets & AttributeTargets.Field) != 0)\r
 264                                 sb.Append ("'field' ");\r
 265 \r
 266                         if ((a.Targets & AttributeTargets.Interface) != 0)\r
 267                                 sb.Append ("'interface' ");\r
 268 \r
 269                         if ((a.Targets & AttributeTargets.Method) != 0)\r
 270                                 sb.Append ("'method' ");\r
 271 \r
 272                         if ((a.Targets & AttributeTargets.Module) != 0)\r
 273                                 sb.Append ("'module' ");\r
 274 \r
 275                         if ((a.Targets & AttributeTargets.Parameter) != 0)\r
 276                                 sb.Append ("'parameter' ");\r
 277 \r
 278                         if ((a.Targets & AttributeTargets.Property) != 0)\r
 279                                 sb.Append ("'property' ");\r
 280 \r
 281                         if ((a.Targets & AttributeTargets.ReturnValue) != 0)\r
 282                                 sb.Append ("'return value' ");\r
 283 \r
 284                         if ((a.Targets & AttributeTargets.Struct) != 0)\r
 285                                 sb.Append ("'struct' ");\r
 286 \r
 287                         return sb.ToString ();\r
 288 \r
 289                 }\r
 290 \r
 291                 public static void Error592 (Attribute a, Location loc)\r
 292                 {\r
 293                         Report.Error (592, loc, "Attribute '" + a.Name + "' is not valid on this declaration type. " +\r
 294                                       "It is valid on " + GetValidPlaces (a) + "declarations only.");\r
 295                 }\r
 296 \r
 297                 public static bool CheckAttribute (Attribute a, object element)\r
 298                 {\r
 299                         TypeContainer attr = TypeManager.LookupAttr (a.Type);\r
 300 \r
 301                         if (attr == null)\r
 302                                 return false;\r
 303 \r
 304                         if (element is Class) {\r
 305                                 if ((attr.Targets & AttributeTargets.Class) != 0)\r
 306                                         return true;\r
 307                                 else\r
 308                                         return false;\r
 309                                 \r
 310                         } else if (element is Struct) {\r
 311                                 if ((attr.Targets & AttributeTargets.Struct) != 0)\r
 312                                         return true;\r
 313                                 else\r
 314                                         return false;\r
 315                         } else if (element is Constructor) {\r
 316                                 if ((attr.Targets & AttributeTargets.Constructor) != 0)\r
 317                                         return true;\r
 318                                 else\r
 319                                         return false;\r
 320                         } else if (element is Delegate) {\r
 321                                 if ((attr.Targets & AttributeTargets.Delegate) != 0)\r
 322                                         return true;\r
 323                                 else\r
 324                                         return false;\r
 325                         } else if (element is Enum) {\r
 326                                 if ((attr.Targets & AttributeTargets.Enum) != 0)\r
 327                                         return true;\r
 328                                 else\r
 329                                         return false;\r
 330                         } else if (element is Event) {\r
 331                                 if ((attr.Targets & AttributeTargets.Event) != 0)\r
 332                                         return true;\r
 333                                 else\r
 334                                         return false;\r
 335                         } else if (element is Field) {\r
 336                                 if ((attr.Targets & AttributeTargets.Field) != 0)\r
 337                                         return true;\r
 338                                 else\r
 339                                         return false;\r
 340                         } else if (element is Interface) {\r
 341                                 if ((attr.Targets & AttributeTargets.Interface) != 0)\r
 342                                         return true;\r
 343                                 else\r
 344                                         return false;\r
 345                         } else if (element is Method) {\r
 346                                 if ((attr.Targets & AttributeTargets.Method) != 0)\r
 347                                         return true;\r
 348                                 else\r
 349                                         return false;\r
 350                         } else if (element is Parameter) {\r
 351                                 if ((attr.Targets & AttributeTargets.Parameter) != 0)\r
 352                                         return true;\r
 353                                 else\r
 354                                         return false;\r
 355                         } else if (element is Property) {\r
 356                                 if ((attr.Targets & AttributeTargets.Property) != 0)\r
 357                                         return true;\r
 358                                 else\r
 359                                         return false;\r
 360                         }\r
 361                         \r
 362                         return false;\r
 363                 }\r
 364         }\r
 365         \r
 366         public class AttributeSection {\r
 367                 \r
 368                 public readonly string    Target;\r
 369                 public readonly ArrayList Attributes;\r
 370                 \r
 371                 public AttributeSection (string target, ArrayList attrs)\r
 372                 {\r
 373                         Target = target;\r
 374                         Attributes = attrs;\r
 375                 }\r
 376                 \r
 377         }\r
 378 \r
 379         public class Attributes {\r
 380 \r
 381                 public ArrayList AttributeSections;\r
 382 \r
 383                 public Attributes (AttributeSection a)\r
 384                 {\r
 385                         AttributeSections = new ArrayList ();\r
 386                         AttributeSections.Add (a);\r
 387 \r
 388                 }\r
 389 \r
 390                 public void AddAttribute (AttributeSection a)\r
 391                 {\r
 392                         if (a != null)\r
 393                                 AttributeSections.Add (a);\r
 394                 }\r
 395         }\r
 396 }\r