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.Runtime.CompilerServices;\r
  18 using System.Text;\r
  19 \r
  20 namespace Mono.CSharp {\r
  21 \r
  22         public class Attribute {\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 MethodImplOptions ImplOptions;\r
  41                 \r
  42                 public Attribute (string name, ArrayList args, Location loc)\r
  43                 {\r
  44                         Name = name;\r
  45                         Arguments = args;\r
  46                         Location = loc;\r
  47                 }\r
  48 \r
  49                 void error617 (string name)\r
  50                 {\r
  51                         Report.Error (617, Location, "'" + name + "' is not a valid named attribute " +\r
  52                                       "argument. Named attribute arguments must be fields which are not " +\r
  53                                       "readonly, static or const, or properties with a set accessor which "+\r
  54                                       "are not static.");\r
  55                 }\r
  56 \r
  57                 void error182 ()\r
  58                 {\r
  59                         Report.Error (182, Location,\r
  60                                       "An attribute argument must be a constant expression, typeof " +\r
  61                                       "expression or array creation expression");\r
  62                 }\r
  63 \r
  64                 public CustomAttributeBuilder Resolve (EmitContext ec)\r
  65                 {\r
  66                         string name = Name;\r
  67                         bool MethodImplAttr = false;\r
  68 \r
  69                         UsageAttr = false;\r
  70 \r
  71                         if (Name.IndexOf ("Attribute") == -1)\r
  72                                 name = Name + "Attribute";\r
  73                         else if (Name.LastIndexOf ("Attribute") == 0)\r
  74                                 name = Name + "Attribute";\r
  75 \r
  76                         Type = RootContext.LookupType (ec.TypeContainer, name, false, Location);\r
  77 \r
  78                         if (Type == null) {\r
  79                                 Report.Error (\r
  80                                         246, Location, "Could not find attribute '" + Name + "' (are you" +\r
  81                                         " missing a using directive or an assembly reference ?)");\r
  82                                 return null;\r
  83                         }\r
  84 \r
  85                         if (Type == TypeManager.attribute_usage_type)\r
  86                                 UsageAttr = true;\r
  87                         if (Type == TypeManager.methodimpl_attr_type)\r
  88                                 MethodImplAttr = true;\r
  89 \r
  90                         // Now we extract the positional and named arguments\r
  91                         \r
  92                         ArrayList pos_args = new ArrayList ();\r
  93                         ArrayList named_args = new ArrayList ();\r
  94                         \r
  95                         if (Arguments != null) {\r
  96                                 pos_args = (ArrayList) Arguments [0];\r
  97                                 if (Arguments.Count > 1)\r
  98                                         named_args = (ArrayList) Arguments [1];\r
  99                         }\r
 100                                 \r
 101                         object [] pos_values = new object [pos_args.Count];\r
 102 \r
 103                         //\r
 104                         // First process positional arguments \r
 105                         //\r
 106                         \r
 107                         int i;\r
 108                         for (i = 0; i < pos_args.Count; i++) {\r
 109                                 Argument a = (Argument) pos_args [i];\r
 110                                 Expression e;\r
 111 \r
 112                                 if (!a.Resolve (ec, Location))\r
 113                                         return null;\r
 114 \r
 115                                 e = a.Expr;\r
 116                                 if (e is Constant) {\r
 117                                         pos_values [i] = ((Constant) e).GetValue ();\r
 118 \r
 119                                         if (UsageAttr)\r
 120                                                 this.Targets = (AttributeTargets) pos_values [0];\r
 121 \r
 122                                         if (MethodImplAttr)\r
 123                                                 this.ImplOptions = (MethodImplOptions) pos_values [0];\r
 124                                         \r
 125                                 } else { \r
 126                                         error182 ();\r
 127                                         return null;\r
 128                                 }\r
 129                         }\r
 130 \r
 131                         //\r
 132                         // Now process named arguments\r
 133                         //\r
 134 \r
 135                         ArrayList field_infos = new ArrayList ();\r
 136                         ArrayList prop_infos  = new ArrayList ();\r
 137                         ArrayList field_values = new ArrayList ();\r
 138                         ArrayList prop_values = new ArrayList ();\r
 139                         \r
 140                         for (i = 0; i < named_args.Count; i++) {\r
 141                                 DictionaryEntry de = (DictionaryEntry) named_args [i];\r
 142                                 string member_name = (string) de.Key;\r
 143                                 Argument a  = (Argument) de.Value;\r
 144                                 Expression e;\r
 145                                 \r
 146                                 if (!a.Resolve (ec, Location))\r
 147                                         return null;\r
 148 \r
 149                                 Expression member = Expression.MemberLookup (\r
 150                                         ec, Type, member_name,\r
 151                                         MemberTypes.Field | MemberTypes.Property,\r
 152                                         BindingFlags.Public | BindingFlags.Instance,\r
 153                                         Location);\r
 154 \r
 155                                 if (member == null || !(member is PropertyExpr || member is FieldExpr)) {\r
 156                                         error617 (member_name);\r
 157                                         return null;\r
 158                                 }\r
 159 \r
 160                                 e = a.Expr;\r
 161                                 if (member is PropertyExpr) {\r
 162                                         PropertyExpr pe = (PropertyExpr) member;\r
 163                                         PropertyInfo pi = pe.PropertyInfo;\r
 164 \r
 165                                         if (!pi.CanWrite) {\r
 166                                                 error617 (member_name);\r
 167                                                 return null;\r
 168                                         }\r
 169 \r
 170                                         if (e is Constant) {\r
 171                                                 object o = ((Constant) e).GetValue ();\r
 172                                                 prop_values.Add (o);\r
 173                                                 \r
 174                                                 if (UsageAttr) {\r
 175                                                         if (member_name == "AllowMultiple")\r
 176                                                                 this.AllowMultiple = (bool) o;\r
 177                                                         if (member_name == "Inherited")\r
 178                                                                 this.Inherited = (bool) o;\r
 179                                                 }\r
 180                                                 \r
 181                                         } else { \r
 182                                                 error182 ();\r
 183                                                 return null;\r
 184                                         }\r
 185                                         \r
 186                                         prop_infos.Add (pi);\r
 187                                         \r
 188                                 } else if (member is FieldExpr) {\r
 189                                         FieldExpr fe = (FieldExpr) member;\r
 190                                         FieldInfo fi = fe.FieldInfo;\r
 191 \r
 192                                         if (fi.IsInitOnly) {\r
 193                                                 error617 (member_name);\r
 194                                                 return null;\r
 195                                         }\r
 196 \r
 197                                         if (e is Constant)\r
 198                                                 field_values.Add (((Constant) e).GetValue ());\r
 199                                         else { \r
 200                                                 error182 ();\r
 201                                                 return null;\r
 202                                         }\r
 203                                         \r
 204                                         field_infos.Add (fi);\r
 205                                 }\r
 206                         }\r
 207                         \r
 208                         Expression mg = Expression.MemberLookup (\r
 209                                 ec, Type, ".ctor", MemberTypes.Constructor,\r
 210                                 BindingFlags.Public | BindingFlags.Instance, Location);\r
 211 \r
 212                         if (mg == 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                         MethodBase constructor = Invocation.OverloadResolve (\r
 220                                 ec, (MethodGroupExpr) mg, pos_args, Location);\r
 221 \r
 222                         if (constructor == null) {\r
 223                                 Report.Error (\r
 224                                         -6, Location,\r
 225                                         "Could not find a constructor for this argument list.");\r
 226                                 return null;\r
 227                         }\r
 228                         \r
 229                         PropertyInfo [] prop_info_arr = new PropertyInfo [prop_infos.Count];\r
 230                         FieldInfo [] field_info_arr = new FieldInfo [field_infos.Count];\r
 231                         object [] field_values_arr = new object [field_values.Count];\r
 232                         object [] prop_values_arr = new object [prop_values.Count];\r
 233 \r
 234                         field_infos.CopyTo  (field_info_arr, 0);\r
 235                         field_values.CopyTo (field_values_arr, 0);\r
 236 \r
 237                         prop_values.CopyTo  (prop_values_arr, 0);\r
 238                         prop_infos.CopyTo   (prop_info_arr, 0);\r
 239                         \r
 240                         CustomAttributeBuilder cb = new CustomAttributeBuilder (\r
 241                                 (ConstructorInfo) constructor, pos_values,\r
 242                                 prop_info_arr, prop_values_arr,\r
 243                                 field_info_arr, field_values_arr); \r
 244                         \r
 245                         return cb;\r
 246                 }\r
 247 \r
 248                 static string GetValidPlaces (Attribute attr)\r
 249                 {\r
 250                         StringBuilder sb = new StringBuilder ();\r
 251                         AttributeTargets targets = 0;\r
 252                         \r
 253                         TypeContainer a = TypeManager.LookupAttr (attr.Type);\r
 254 \r
 255                         if (a == null) {\r
 256                                 System.Attribute [] attrs = System.Attribute.GetCustomAttributes (attr.Type);\r
 257                                 \r
 258                                 foreach (System.Attribute tmp in attrs)\r
 259                                         if (tmp is AttributeUsageAttribute) \r
 260                                                 targets = ((AttributeUsageAttribute) tmp).ValidOn;\r
 261                         } else\r
 262                                 targets = a.Targets;\r
 263 \r
 264                         \r
 265                         if ((targets & AttributeTargets.Assembly) != 0)\r
 266                                 sb.Append ("'assembly' ");\r
 267 \r
 268                         if ((targets & AttributeTargets.Class) != 0)\r
 269                                 sb.Append ("'class' ");\r
 270 \r
 271                         if ((targets & AttributeTargets.Constructor) != 0)\r
 272                                 sb.Append ("'constructor' ");\r
 273 \r
 274                         if ((targets & AttributeTargets.Delegate) != 0)\r
 275                                 sb.Append ("'delegate' ");\r
 276 \r
 277                         if ((targets & AttributeTargets.Enum) != 0)\r
 278                                 sb.Append ("'enum' ");\r
 279 \r
 280                         if ((targets & AttributeTargets.Event) != 0)\r
 281                                 sb.Append ("'event' ");\r
 282 \r
 283                         if ((targets & AttributeTargets.Field) != 0)\r
 284                                 sb.Append ("'field' ");\r
 285 \r
 286                         if ((targets & AttributeTargets.Interface) != 0)\r
 287                                 sb.Append ("'interface' ");\r
 288 \r
 289                         if ((targets & AttributeTargets.Method) != 0)\r
 290                                 sb.Append ("'method' ");\r
 291 \r
 292                         if ((targets & AttributeTargets.Module) != 0)\r
 293                                 sb.Append ("'module' ");\r
 294 \r
 295                         if ((targets & AttributeTargets.Parameter) != 0)\r
 296                                 sb.Append ("'parameter' ");\r
 297 \r
 298                         if ((targets & AttributeTargets.Property) != 0)\r
 299                                 sb.Append ("'property' ");\r
 300 \r
 301                         if ((targets & AttributeTargets.ReturnValue) != 0)\r
 302                                 sb.Append ("'return value' ");\r
 303 \r
 304                         if ((targets & AttributeTargets.Struct) != 0)\r
 305                                 sb.Append ("'struct' ");\r
 306 \r
 307                         return sb.ToString ();\r
 308 \r
 309                 }\r
 310 \r
 311                 public static void error592 (Attribute a, Location loc)\r
 312                 {\r
 313                         Report.Error (\r
 314                                 592, loc, "Attribute '" + a.Name +\r
 315                                 "' is not valid on this declaration type. " +\r
 316                                 "It is valid on " + GetValidPlaces (a) + "declarations only.");\r
 317                 }\r
 318 \r
 319                 public static bool CheckAttribute (Attribute a, object element)\r
 320                 {\r
 321                         TypeContainer attr = TypeManager.LookupAttr (a.Type);\r
 322                         AttributeTargets targets = 0;\r
 323                         \r
 324                         if (attr == null) {\r
 325                                 System.Attribute [] attrs = System.Attribute.GetCustomAttributes (a.Type);\r
 326 \r
 327                                 foreach (System.Attribute tmp in attrs)\r
 328                                         if (tmp is AttributeUsageAttribute) \r
 329                                                 targets = ((AttributeUsageAttribute) tmp).ValidOn;\r
 330                         } else\r
 331                                 targets = attr.Targets;\r
 332 \r
 333                         if (element is Class) {\r
 334                                 if ((targets & AttributeTargets.Class) != 0)\r
 335                                         return true;\r
 336                                 else\r
 337                                         return false;\r
 338                                 \r
 339                         } else if (element is Struct) {\r
 340                                 if ((targets & AttributeTargets.Struct) != 0)\r
 341                                         return true;\r
 342                                 else\r
 343                                         return false;\r
 344                         } else if (element is Constructor) {\r
 345                                 if ((targets & AttributeTargets.Constructor) != 0)\r
 346                                         return true;\r
 347                                 else\r
 348                                         return false;\r
 349                         } else if (element is Delegate) {\r
 350                                 if ((targets & AttributeTargets.Delegate) != 0)\r
 351                                         return true;\r
 352                                 else\r
 353                                         return false;\r
 354                         } else if (element is Enum) {\r
 355                                 if ((targets & AttributeTargets.Enum) != 0)\r
 356                                         return true;\r
 357                                 else\r
 358                                         return false;\r
 359                         } else if (element is Event) {\r
 360                                 if ((targets & AttributeTargets.Event) != 0)\r
 361                                         return true;\r
 362                                 else\r
 363                                         return false;\r
 364                         } else if (element is Field) {\r
 365                                 if ((targets & AttributeTargets.Field) != 0)\r
 366                                         return true;\r
 367                                 else\r
 368                                         return false;\r
 369                         } else if (element is Interface) {\r
 370                                 if ((targets & AttributeTargets.Interface) != 0)\r
 371                                         return true;\r
 372                                 else\r
 373                                         return false;\r
 374                         } else if (element is Method || element is Operator) {\r
 375                                 if ((targets & AttributeTargets.Method) != 0)\r
 376                                         return true;\r
 377                                 else\r
 378                                         return false;\r
 379                         } else if (element is ParameterBuilder) {\r
 380                                 if ((targets & AttributeTargets.Parameter) != 0)\r
 381                                         return true;\r
 382                                 else\r
 383                                         return false;\r
 384                         } else if (element is Property) {\r
 385                                 if ((targets & AttributeTargets.Property) != 0)\r
 386                                         return true;\r
 387                                 else\r
 388                                         return false;\r
 389                         } else if (element is AssemblyBuilder){\r
 390                                 if ((targets & AttributeTargets.Assembly) != 0)\r
 391                                         return true;\r
 392                                 else\r
 393                                         return false;\r
 394                         }\r
 395 \r
 396                         return false;\r
 397                 }\r
 398 \r
 399                 public static void ApplyAttributes (EmitContext ec, object builder, object kind,\r
 400                                                     Attributes opt_attrs, Location loc)\r
 401                 {\r
 402                         if (opt_attrs == null)\r
 403                                 return;\r
 404 \r
 405                         if (opt_attrs.AttributeSections == null)\r
 406                                 return;\r
 407 \r
 408                         foreach (AttributeSection asec in opt_attrs.AttributeSections) {\r
 409 \r
 410                                 if (asec.Attributes == null)\r
 411                                         continue;\r
 412 \r
 413                                 foreach (Attribute a in asec.Attributes) {\r
 414                                         CustomAttributeBuilder cb = a.Resolve (ec);\r
 415                                         if (cb == null)\r
 416                                                 continue;\r
 417 \r
 418                                         if (!(kind is TypeContainer))\r
 419                                                 if (!CheckAttribute (a, kind)) {\r
 420                                                         error592 (a, loc);\r
 421                                                         return;\r
 422                                                 }\r
 423 \r
 424                                         \r
 425                                         if (kind is Method || kind is Operator) {\r
 426                                                 if (a.Type == TypeManager.methodimpl_attr_type) {\r
 427                                                         if (a.ImplOptions == MethodImplOptions.InternalCall)\r
 428                                                                 ((MethodBuilder) builder).SetImplementationFlags (\r
 429                                                                            MethodImplAttributes.InternalCall |\r
 430                                                                            MethodImplAttributes.Runtime);\r
 431                                                 } else if (a.Type != TypeManager.dllimport_type)\r
 432                                                         ((MethodBuilder) builder).SetCustomAttribute (cb);\r
 433                                         } else if (kind is Constructor) {\r
 434                                                 ((ConstructorBuilder) builder).SetCustomAttribute (cb);\r
 435                                         } else if (kind is Field) {\r
 436                                                 ((FieldBuilder) builder).SetCustomAttribute (cb);\r
 437                                         } else if (kind is Property || kind is Indexer) {\r
 438                                                 ((PropertyBuilder) builder).SetCustomAttribute (cb);\r
 439                                         } else if (kind is Event) {\r
 440                                                 ((EventBuilder) builder).SetCustomAttribute (cb);\r
 441                                         } else if (kind is ParameterBuilder){\r
 442                                                 ((ParameterBuilder) builder).SetCustomAttribute (cb);\r
 443                                         } else if (kind is Enum) {\r
 444                                                 ((TypeBuilder) builder).SetCustomAttribute (cb); \r
 445 \r
 446                                         } else if (kind is TypeContainer) {\r
 447 \r
 448                                                 TypeContainer tc = (TypeContainer) kind;\r
 449                                                 \r
 450                                                 if (a.UsageAttr) {\r
 451                                                         tc.Targets = a.Targets;\r
 452                                                         tc.AllowMultiple = a.AllowMultiple;\r
 453                                                         tc.Inherited = a.Inherited;\r
 454                                                         \r
 455                                                         RootContext.TypeManager.RegisterAttrType (\r
 456                                                                                  (TypeBuilder) builder, tc);\r
 457 \r
 458                                                 } else if (a.Type == TypeManager.default_member_type) {\r
 459                                                         if (tc.Indexers != null) {\r
 460                                                                 Report.Error (646, loc,\r
 461                                                                       "Cannot specify the DefaultMember attribute on " +\r
 462                                                                       " a type containing an indexer");\r
 463                                                                 return;\r
 464                                                         }\r
 465 \r
 466                                                 } else {\r
 467                                                         if (!CheckAttribute (a, kind)) {\r
 468                                                                 error592 (a, loc);\r
 469                                                                 return;\r
 470                                                         }\r
 471                                                 }\r
 472                                                 \r
 473                                                 ((TypeBuilder) builder).SetCustomAttribute (cb);\r
 474                                                 \r
 475                                         } else if (kind is AssemblyBuilder){\r
 476                                                 ((AssemblyBuilder) builder).SetCustomAttribute (cb);\r
 477                                         } else if (kind is ModuleBuilder) {\r
 478                                                 ((ModuleBuilder) builder).SetCustomAttribute (cb);\r
 479                                         } else\r
 480                                                 throw new Exception ("Unknown kind: " + kind);\r
 481                                 }\r
 482                         }\r
 483                 }\r
 484 \r
 485                 public MethodBuilder DefinePInvokeMethod (EmitContext ec, TypeBuilder builder, string name,\r
 486                                                           MethodAttributes flags, Type ret_type, Type [] param_types)\r
 487                 {\r
 488                         //\r
 489                         // We extract from the attribute the information we need \r
 490                         //\r
 491 \r
 492                         if (Arguments == null) {\r
 493                                 Console.WriteLine ("Internal error : this is not supposed to happen !");\r
 494                                 return null;\r
 495                         }\r
 496 \r
 497                         string attr_name = Name;\r
 498 \r
 499                         if (Name.IndexOf ("Attribute") == -1)\r
 500                                 attr_name = Name + "Attribute";\r
 501                         else if (Name.LastIndexOf ("Attribute") == 0)\r
 502                                 attr_name = Name + "Attribute";\r
 503                         \r
 504                         Type = RootContext.LookupType (ec.TypeContainer, attr_name, false, Location);\r
 505 \r
 506                         if (Type == null) {\r
 507                                 Report.Error (246, Location, "Could not find attribute '" + Name + "' (are you" +\r
 508                                               " missing a using directive or an assembly reference ?)");\r
 509                                 return null;\r
 510                         }\r
 511                         \r
 512                         ArrayList named_args = new ArrayList ();\r
 513                         \r
 514                         ArrayList pos_args = (ArrayList) Arguments [0];\r
 515                         if (Arguments.Count > 1)\r
 516                                 named_args = (ArrayList) Arguments [1];\r
 517                         \r
 518 \r
 519                         string dll_name = null;\r
 520                         \r
 521                         Argument tmp = (Argument) pos_args [0];\r
 522 \r
 523                         if (!tmp.Resolve (ec, Location))\r
 524                                 return null;\r
 525                         \r
 526                         if (tmp.Expr is Constant)\r
 527                                 dll_name = (string) ((Constant) tmp.Expr).GetValue ();\r
 528                         else { \r
 529                                 error182 ();\r
 530                                 return null;\r
 531                         }\r
 532 \r
 533                         // Now we process the named arguments\r
 534                         CallingConvention cc = CallingConvention.Winapi;\r
 535                         CharSet charset = CharSet.Ansi;\r
 536                         bool preserve_sig = true;\r
 537                         bool exact_spelling = false;\r
 538                         bool set_last_err = false;\r
 539                         string entry_point = null;\r
 540 \r
 541                         for (int i = 0; i < named_args.Count; i++) {\r
 542 \r
 543                                 DictionaryEntry de = (DictionaryEntry) named_args [i];\r
 544 \r
 545                                 string member_name = (string) de.Key;\r
 546                                 Argument a  = (Argument) de.Value;\r
 547 \r
 548                                 if (!a.Resolve (ec, Location))\r
 549                                         return null;\r
 550 \r
 551                                 Expression member = Expression.MemberLookup (\r
 552                                         ec, Type, member_name, \r
 553                                         MemberTypes.Field | MemberTypes.Property,\r
 554                                         BindingFlags.Public | BindingFlags.Instance,\r
 555                                         Location);\r
 556 \r
 557                                 if (member == null || !(member is FieldExpr)) {\r
 558                                         error617 (member_name);\r
 559                                         return null;\r
 560                                 }\r
 561 \r
 562                                 if (member is FieldExpr) {\r
 563                                         FieldExpr fe = (FieldExpr) member;\r
 564                                         FieldInfo fi = fe.FieldInfo;\r
 565 \r
 566                                         if (fi.IsInitOnly) {\r
 567                                                 error617 (member_name);\r
 568                                                 return null;\r
 569                                         }\r
 570 \r
 571                                         if (a.Expr is Constant) {\r
 572                                                 Constant c = (Constant) a.Expr;\r
 573                                                 \r
 574                                                 if (member_name == "CallingConvention")\r
 575                                                         cc = (CallingConvention) c.GetValue ();\r
 576                                                 else if (member_name == "CharSet")\r
 577                                                         charset = (CharSet) c.GetValue ();\r
 578                                                 else if (member_name == "EntryPoint")\r
 579                                                         entry_point = (string) c.GetValue ();\r
 580                                                 else if (member_name == "SetLastError")\r
 581                                                         set_last_err = (bool) c.GetValue ();\r
 582                                                 else if (member_name == "ExactSpelling")\r
 583                                                         exact_spelling = (bool) c.GetValue ();\r
 584                                                 else if (member_name == "PreserveSig")\r
 585                                                         preserve_sig = (bool) c.GetValue ();\r
 586                                         } else { \r
 587                                                 error182 ();\r
 588                                                 return null;\r
 589                                         }\r
 590                                         \r
 591                                 }\r
 592                         }\r
 593 \r
 594                         MethodBuilder mb = builder.DefinePInvokeMethod (\r
 595                                 name, dll_name, flags | MethodAttributes.HideBySig,\r
 596                                 CallingConventions.Standard,\r
 597                                 ret_type,\r
 598                                 param_types,\r
 599                                 cc,\r
 600                                 charset);\r
 601 \r
 602                         if (preserve_sig)\r
 603                                 mb.SetImplementationFlags (MethodImplAttributes.PreserveSig);\r
 604                         \r
 605                         return mb;\r
 606                 }\r
 607                 \r
 608         }\r
 609         \r
 610         public class AttributeSection {\r
 611                 \r
 612                 public readonly string    Target;\r
 613                 public readonly ArrayList Attributes;\r
 614                 \r
 615                 public AttributeSection (string target, ArrayList attrs)\r
 616                 {\r
 617                         Target = target;\r
 618                         Attributes = attrs;\r
 619                 }\r
 620                 \r
 621         }\r
 622 \r
 623         public class Attributes {\r
 624                 public ArrayList AttributeSections;\r
 625                 public Location Location;\r
 626 \r
 627                 public Attributes (AttributeSection a, Location loc)\r
 628                 {\r
 629                         AttributeSections = new ArrayList ();\r
 630                         AttributeSections.Add (a);\r
 631 \r
 632                 }\r
 633 \r
 634                 public void AddAttribute (AttributeSection a)\r
 635                 {\r
 636                         if (a != null)\r
 637                                 AttributeSections.Add (a);\r
 638                 }\r
 639         }\r
 640 }\r