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