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                 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 = RootContext.LookupType (ec.TypeContainer, name, false, Location);\r
  73 \r
  74                         if (Type == null) {\r
  75                                 Report.Error (\r
  76                                         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                                 Argument a = (Argument) pos_args [i];\r
 104                                 Expression e;\r
 105 \r
 106                                 if (!a.Resolve (ec, Location))\r
 107                                         return null;\r
 108 \r
 109                                 e = a.Expr;\r
 110                                 if (e is Constant) {\r
 111                                         pos_values [i] = ((Constant) 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                                 DictionaryEntry de = (DictionaryEntry) named_args [i];\r
 132                                 string member_name = (string) de.Key;\r
 133                                 Argument a  = (Argument) de.Value;\r
 134                                 Expression e;\r
 135                                 \r
 136                                 if (!a.Resolve (ec, Location))\r
 137                                         return null;\r
 138 \r
 139                                 Expression member = Expression.MemberLookup (\r
 140                                         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                                 e = a.Expr;\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                                         if (e is Constant) {\r
 161                                                 object o = ((Constant) e).GetValue ();\r
 162                                                 prop_values.Add (o);\r
 163                                                 \r
 164                                                 if (UsageAttr) {\r
 165                                                         if (member_name == "AllowMultiple")\r
 166                                                                 this.AllowMultiple = (bool) o;\r
 167                                                         if (member_name == "Inherited")\r
 168                                                                 this.Inherited = (bool) o;\r
 169                                                 }\r
 170                                                 \r
 171                                         } else { \r
 172                                                 error182 ();\r
 173                                                 return null;\r
 174                                         }\r
 175                                         \r
 176                                         prop_infos.Add (pi);\r
 177                                         \r
 178                                 } else if (member is FieldExpr) {\r
 179                                         FieldExpr fe = (FieldExpr) member;\r
 180                                         FieldInfo fi = fe.FieldInfo;\r
 181 \r
 182                                         if (fi.IsInitOnly) {\r
 183                                                 error617 (member_name);\r
 184                                                 return null;\r
 185                                         }\r
 186 \r
 187                                         if (e is Constant)\r
 188                                                 field_values.Add (((Constant) e).GetValue ());\r
 189                                         else { \r
 190                                                 error182 ();\r
 191                                                 return null;\r
 192                                         }\r
 193                                         \r
 194                                         field_infos.Add (fi);\r
 195                                 }\r
 196                         }\r
 197                         \r
 198                         Expression mg = Expression.MemberLookup (\r
 199                                 ec, Type, ".ctor", false, MemberTypes.Constructor,\r
 200                                 BindingFlags.Public | BindingFlags.Instance, Location);\r
 201 \r
 202                         if (mg == null) {\r
 203                                 Report.Error (\r
 204                                         -6, Location,\r
 205                                         "Could not find a constructor for this argument list.");\r
 206                                 return null;\r
 207                         }\r
 208 \r
 209                         MethodBase constructor = Invocation.OverloadResolve (\r
 210                                 ec, (MethodGroupExpr) mg, pos_args, Location);\r
 211 \r
 212                         if (constructor == null) {\r
 213                                 Report.Error (\r
 214                                         -6, Location,\r
 215                                         "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 (\r
 231                                 (ConstructorInfo) constructor, pos_values,\r
 232                                 prop_info_arr, prop_values_arr,\r
 233                                 field_info_arr, field_values_arr); \r
 234                         \r
 235                         return cb;\r
 236                 }\r
 237 \r
 238                 static string GetValidPlaces (Attribute attr)\r
 239                 {\r
 240                         StringBuilder sb = new StringBuilder ();\r
 241                         AttributeTargets targets = 0;\r
 242                         \r
 243                         TypeContainer a = TypeManager.LookupAttr (attr.Type);\r
 244 \r
 245                         if (a == null) {\r
 246                                 System.Attribute [] attrs = System.Attribute.GetCustomAttributes (attr.Type);\r
 247                                 \r
 248                                 foreach (System.Attribute tmp in attrs)\r
 249                                         if (tmp is AttributeUsageAttribute) \r
 250                                                 targets = ((AttributeUsageAttribute) tmp).ValidOn;\r
 251                         } else\r
 252                                 targets = a.Targets;\r
 253 \r
 254                         \r
 255                         if ((targets & AttributeTargets.Assembly) != 0)\r
 256                                 sb.Append ("'assembly' ");\r
 257 \r
 258                         if ((targets & AttributeTargets.Class) != 0)\r
 259                                 sb.Append ("'class' ");\r
 260 \r
 261                         if ((targets & AttributeTargets.Constructor) != 0)\r
 262                                 sb.Append ("'constructor' ");\r
 263 \r
 264                         if ((targets & AttributeTargets.Delegate) != 0)\r
 265                                 sb.Append ("'delegate' ");\r
 266 \r
 267                         if ((targets & AttributeTargets.Enum) != 0)\r
 268                                 sb.Append ("'enum' ");\r
 269 \r
 270                         if ((targets & AttributeTargets.Event) != 0)\r
 271                                 sb.Append ("'event' ");\r
 272 \r
 273                         if ((targets & AttributeTargets.Field) != 0)\r
 274                                 sb.Append ("'field' ");\r
 275 \r
 276                         if ((targets & AttributeTargets.Interface) != 0)\r
 277                                 sb.Append ("'interface' ");\r
 278 \r
 279                         if ((targets & AttributeTargets.Method) != 0)\r
 280                                 sb.Append ("'method' ");\r
 281 \r
 282                         if ((targets & AttributeTargets.Module) != 0)\r
 283                                 sb.Append ("'module' ");\r
 284 \r
 285                         if ((targets & AttributeTargets.Parameter) != 0)\r
 286                                 sb.Append ("'parameter' ");\r
 287 \r
 288                         if ((targets & AttributeTargets.Property) != 0)\r
 289                                 sb.Append ("'property' ");\r
 290 \r
 291                         if ((targets & AttributeTargets.ReturnValue) != 0)\r
 292                                 sb.Append ("'return value' ");\r
 293 \r
 294                         if ((targets & AttributeTargets.Struct) != 0)\r
 295                                 sb.Append ("'struct' ");\r
 296 \r
 297                         return sb.ToString ();\r
 298 \r
 299                 }\r
 300 \r
 301                 public static void error592 (Attribute a, Location loc)\r
 302                 {\r
 303                         Report.Error (592, loc, "Attribute '" + a.Name + "' is not valid on this declaration type. " +\r
 304                                       "It is valid on " + GetValidPlaces (a) + "declarations only.");\r
 305                 }\r
 306 \r
 307                 public static bool CheckAttribute (Attribute a, object element)\r
 308                 {\r
 309                         TypeContainer attr = TypeManager.LookupAttr (a.Type);\r
 310                         AttributeTargets targets = 0;\r
 311                         \r
 312                         if (attr == null) {\r
 313                                 System.Attribute [] attrs = System.Attribute.GetCustomAttributes (a.Type);\r
 314 \r
 315                                 foreach (System.Attribute tmp in attrs)\r
 316                                         if (tmp is AttributeUsageAttribute) \r
 317                                                 targets = ((AttributeUsageAttribute) tmp).ValidOn;\r
 318                         } else\r
 319                                 targets = attr.Targets;\r
 320 \r
 321                         if (element is Class) {\r
 322                                 if ((targets & AttributeTargets.Class) != 0)\r
 323                                         return true;\r
 324                                 else\r
 325                                         return false;\r
 326                                 \r
 327                         } else if (element is Struct) {\r
 328                                 if ((targets & AttributeTargets.Struct) != 0)\r
 329                                         return true;\r
 330                                 else\r
 331                                         return false;\r
 332                         } else if (element is Constructor) {\r
 333                                 if ((targets & AttributeTargets.Constructor) != 0)\r
 334                                         return true;\r
 335                                 else\r
 336                                         return false;\r
 337                         } else if (element is Delegate) {\r
 338                                 if ((targets & AttributeTargets.Delegate) != 0)\r
 339                                         return true;\r
 340                                 else\r
 341                                         return false;\r
 342                         } else if (element is Enum) {\r
 343                                 if ((targets & AttributeTargets.Enum) != 0)\r
 344                                         return true;\r
 345                                 else\r
 346                                         return false;\r
 347                         } else if (element is Event) {\r
 348                                 if ((targets & AttributeTargets.Event) != 0)\r
 349                                         return true;\r
 350                                 else\r
 351                                         return false;\r
 352                         } else if (element is Field) {\r
 353                                 if ((targets & AttributeTargets.Field) != 0)\r
 354                                         return true;\r
 355                                 else\r
 356                                         return false;\r
 357                         } else if (element is Interface) {\r
 358                                 if ((targets & AttributeTargets.Interface) != 0)\r
 359                                         return true;\r
 360                                 else\r
 361                                         return false;\r
 362                         } else if (element is Method) {\r
 363                                 if ((targets & AttributeTargets.Method) != 0)\r
 364                                         return true;\r
 365                                 else\r
 366                                         return false;\r
 367                         } else if (element is Parameter) {\r
 368                                 if ((targets & AttributeTargets.Parameter) != 0)\r
 369                                         return true;\r
 370                                 else\r
 371                                         return false;\r
 372                         } else if (element is Property) {\r
 373                                 if ((targets & AttributeTargets.Property) != 0)\r
 374                                         return true;\r
 375                                 else\r
 376                                         return false;\r
 377                         }\r
 378 \r
 379                         return false;\r
 380                 }\r
 381 \r
 382                 public static void ApplyAttributes (EmitContext ec, object builder, object kind,\r
 383                                                     Attributes opt_attrs, Location loc)\r
 384                 {\r
 385                         if (opt_attrs == null)\r
 386                                 return;\r
 387 \r
 388                         if (opt_attrs.AttributeSections == null)\r
 389                                 return;\r
 390 \r
 391                         foreach (AttributeSection asec in opt_attrs.AttributeSections) {\r
 392 \r
 393                                 if (asec.Attributes == null)\r
 394                                         continue;\r
 395 \r
 396                                 foreach (Attribute a in asec.Attributes) {\r
 397                                         CustomAttributeBuilder cb = a.Resolve (ec);\r
 398                                         if (cb == null)\r
 399                                                 continue;\r
 400 \r
 401                                         if (!(kind is TypeContainer))\r
 402                                                 if (!CheckAttribute (a, kind)) {\r
 403                                                         error592 (a, loc);\r
 404                                                         return;\r
 405                                                 }\r
 406 \r
 407                                         \r
 408                                         if (kind is Method) {\r
 409                                                 if (a.Type != TypeManager.dllimport_type)\r
 410                                                         ((MethodBuilder) builder).SetCustomAttribute (cb);\r
 411 \r
 412                                         } else if (kind is Constructor) {\r
 413                                                 ((ConstructorBuilder) builder).SetCustomAttribute (cb);\r
 414 \r
 415                                         } else if (kind is Field) {\r
 416                                                 ((FieldBuilder) builder).SetCustomAttribute (cb);\r
 417 \r
 418                                         } else if (kind is Property || kind is Indexer) {\r
 419                                                 ((PropertyBuilder) builder).SetCustomAttribute (cb);\r
 420 \r
 421                                         } else if (kind is Event) {\r
 422                                                 ((EventBuilder) builder).SetCustomAttribute (cb);\r
 423 \r
 424                                         } else if (kind is Operator) {\r
 425                                                 ((MethodBuilder) builder).SetCustomAttribute (cb);\r
 426 \r
 427                                         } else if (kind is Enum) {\r
 428                                                 ((TypeBuilder) builder).SetCustomAttribute (cb); \r
 429 \r
 430                                         } else if (kind is TypeContainer) {\r
 431 \r
 432                                                 TypeContainer tc = (TypeContainer) kind;\r
 433                                                 \r
 434                                                 if (a.UsageAttr) {\r
 435                                                         tc.Targets = a.Targets;\r
 436                                                         tc.AllowMultiple = a.AllowMultiple;\r
 437                                                         tc.Inherited = a.Inherited;\r
 438                                                         \r
 439                                                         RootContext.TypeManager.RegisterAttrType (\r
 440                                                                                  (TypeBuilder) builder, tc);\r
 441 \r
 442                                                 } else {\r
 443                                                         if (!CheckAttribute (a, kind)) {\r
 444                                                                 error592 (a, loc);\r
 445                                                                 return;\r
 446                                                         }\r
 447                                                 }\r
 448                                                 \r
 449                                                 ((TypeBuilder) builder).SetCustomAttribute (cb);\r
 450                                                 \r
 451                                         }\r
 452                                 }\r
 453                         }\r
 454                 }\r
 455 \r
 456                 public MethodBuilder DefinePInvokeMethod (EmitContext ec, TypeBuilder builder, string name,\r
 457                                                           MethodAttributes flags, Type ret_type, Type [] param_types)\r
 458                 {\r
 459                         //\r
 460                         // We extract from the attribute the information we need \r
 461                         //\r
 462 \r
 463                         if (Arguments == null) {\r
 464                                 Console.WriteLine ("Internal error : this is not supposed to happen !");\r
 465                                 return null;\r
 466                         }\r
 467 \r
 468                         string attr_name = Name;\r
 469 \r
 470                         if (Name.IndexOf ("Attribute") == -1)\r
 471                                 attr_name = Name + "Attribute";\r
 472                         else if (Name.LastIndexOf ("Attribute") == 0)\r
 473                                 attr_name = Name + "Attribute";\r
 474                         \r
 475                         Type = RootContext.LookupType (ec.TypeContainer, attr_name, false, Location);\r
 476 \r
 477                         if (Type == null) {\r
 478                                 Report.Error (246, Location, "Could not find attribute '" + Name + "' (are you" +\r
 479                                               " missing a using directive or an assembly reference ?)");\r
 480                                 return null;\r
 481                         }\r
 482                         \r
 483                         ArrayList named_args = new ArrayList ();\r
 484                         \r
 485                         ArrayList pos_args = (ArrayList) Arguments [0];\r
 486                         if (Arguments.Count > 1)\r
 487                                 named_args = (ArrayList) Arguments [1];\r
 488                         \r
 489 \r
 490                         string dll_name = null;\r
 491                         \r
 492                         Argument tmp = (Argument) pos_args [0];\r
 493 \r
 494                         if (!tmp.Resolve (ec, Location))\r
 495                                 return null;\r
 496                         \r
 497                         if (tmp.Expr is Constant)\r
 498                                 dll_name = (string) ((Constant) tmp.Expr).GetValue ();\r
 499                         else { \r
 500                                 error182 ();\r
 501                                 return null;\r
 502                         }\r
 503 \r
 504                         // Now we process the named arguments\r
 505                         CallingConvention cc = 0;\r
 506                         CharSet charset = 0;\r
 507                         bool preserve_sig = false;\r
 508                         bool exact_spelling = false;\r
 509                         bool set_last_err = false;\r
 510                         string entry_point = null;\r
 511                         \r
 512                         for (int i = 0; i < named_args.Count; i++) {\r
 513 \r
 514                                 DictionaryEntry de = (DictionaryEntry) named_args [i];\r
 515 \r
 516                                 string member_name = (string) de.Key;\r
 517                                 Argument a  = (Argument) de.Value;\r
 518 \r
 519                                 if (!a.Resolve (ec, Location))\r
 520                                         return null;\r
 521 \r
 522                                 Expression member = Expression.MemberLookup (ec, Type, member_name, false,\r
 523                                                                              MemberTypes.Field | MemberTypes.Property,\r
 524                                                                              BindingFlags.Public | BindingFlags.Instance,\r
 525                                                                              Location);\r
 526 \r
 527                                 if (member == null || !(member is FieldExpr)) {\r
 528                                         error617 (member_name);\r
 529                                         return null;\r
 530                                 }\r
 531 \r
 532                                 if (member is FieldExpr) {\r
 533                                         FieldExpr fe = (FieldExpr) member;\r
 534                                         FieldInfo fi = fe.FieldInfo;\r
 535 \r
 536                                         if (fi.IsInitOnly) {\r
 537                                                 error617 (member_name);\r
 538                                                 return null;\r
 539                                         }\r
 540 \r
 541                                         if (a.Expr is Constant) {\r
 542                                                 Constant c = (Constant) a.Expr;\r
 543                                                 \r
 544                                                 if (member_name == "CallingConvention")\r
 545                                                         cc = (CallingConvention) c.GetValue ();\r
 546                                                 else if (member_name == "CharSet")\r
 547                                                         charset = (CharSet) c.GetValue ();\r
 548                                                 else if (member_name == "EntryPoint")\r
 549                                                         entry_point = (string) c.GetValue ();\r
 550                                                 else if (member_name == "SetLastError")\r
 551                                                         set_last_err = (bool) c.GetValue ();\r
 552                                                 else if (member_name == "ExactSpelling")\r
 553                                                         exact_spelling = (bool) c.GetValue ();\r
 554                                                 else if (member_name == "PreserveSig")\r
 555                                                         preserve_sig = (bool) c.GetValue ();\r
 556                                         } else { \r
 557                                                 error182 ();\r
 558                                                 return null;\r
 559                                         }\r
 560                                         \r
 561                                 }\r
 562                         }\r
 563 \r
 564                         MethodBuilder mb = builder.DefinePInvokeMethod (\r
 565                                 name, dll_name, flags,\r
 566                                 CallingConventions.Standard,\r
 567                                 ret_type,\r
 568                                 param_types,\r
 569                                 cc,\r
 570                                 charset); \r
 571                         \r
 572                         return mb;\r
 573                 }\r
 574                 \r
 575         }\r
 576         \r
 577         public class AttributeSection {\r
 578                 \r
 579                 public readonly string    Target;\r
 580                 public readonly ArrayList Attributes;\r
 581                 \r
 582                 public AttributeSection (string target, ArrayList attrs)\r
 583                 {\r
 584                         Target = target;\r
 585                         Attributes = attrs;\r
 586                 }\r
 587                 \r
 588         }\r
 589 \r
 590         public class Attributes {\r
 591 \r
 592                 public ArrayList AttributeSections;\r
 593 \r
 594                 public Attributes (AttributeSection a)\r
 595                 {\r
 596                         AttributeSections = new ArrayList ();\r
 597                         AttributeSections.Add (a);\r
 598 \r
 599                 }\r
 600 \r
 601                 public void AddAttribute (AttributeSection a)\r
 602                 {\r
 603                         if (a != null)\r
 604                                 AttributeSections.Add (a);\r
 605                 }\r
 606         }\r
 607 }\r