mcs/mcs/attribute.cs

   1 //
   2 // attribute.cs: Attribute Handler
   3 //
   4 // Author: Ravi Pratap (ravi@ximian.com)
   5 //         Marek Safar (marek.safar@seznam.cz)
   6 //
   7 // Licensed under the terms of the GNU GPL
   8 //
   9 // (C) 2001 Ximian, Inc (http://www.ximian.com)
  10 //
  11 //
  12
  13 using System;
  14 using System.Diagnostics;
  15 using System.Collections;
  16 using System.Collections.Specialized;
  17 using System.Reflection;
  18 using System.Reflection.Emit;
  19 using System.Runtime.InteropServices;
  20 using System.Runtime.CompilerServices;
  21 using System.Security;
  22 using System.Security.Permissions;
  23 using System.Text;
  24
  25 namespace Mono.CSharp {
  26
  27         /// <summary>
  28         ///   Base class for objects that can have Attributes applied to them.
  29         /// </summary>
  30         public abstract class Attributable {
  31                 /// <summary>
  32                 ///   Attributes for this type
  33                 /// </summary>
  34                 Attributes attributes;
  35
  36                 public Attributable (Attributes attrs)
  37                 {
  38                         attributes = attrs;
  39                 }
  40
  41                 public Attributes OptAttributes
  42                 {
  43                         get {
  44                                 return attributes;
  45                         }
  46                         set {
  47                                 attributes = value;
  48                         }
  49                 }
  50
  51                 /// <summary>
  52                 /// Use member-specific procedure to apply attribute @a in @cb to the entity being built in @builder
  53                 /// </summary>
  54                 public abstract void ApplyAttributeBuilder (Attribute a, CustomAttributeBuilder cb);
  55
  56                 /// <summary>
  57                 /// Returns one AttributeTarget for this element.
  58                 /// </summary>
  59                 public abstract AttributeTargets AttributeTargets { get; }
  60
  61                 public abstract bool IsClsCompliaceRequired (DeclSpace ds);
  62
  63                 /// <summary>
  64                 /// Gets list of valid attribute targets for explicit target declaration.
  65                 /// The first array item is default target. Don't break this rule.
  66                 /// </summary>
  67                 public abstract string[] ValidAttributeTargets { get; }
  68         };
  69
  70         public class Attribute {
  71                 public readonly string ExplicitTarget;
  72                 public AttributeTargets Target;
  73
  74                 public readonly string    Name;
  75                 public readonly Expression LeftExpr;
  76                 public readonly string Identifier;
  77
  78                 public readonly ArrayList Arguments;
  79
  80                 public readonly Location Location;
  81
  82                 public Type Type;
  83
  84                 bool resolve_error;
  85
  86                 static AttributeUsageAttribute DefaultUsageAttribute = new AttributeUsageAttribute (AttributeTargets.All);
  87
  88                 // non-null if named args present after Resolve () is called
  89                 PropertyInfo [] prop_info_arr;
  90                 FieldInfo [] field_info_arr;
  91                 object [] field_values_arr;
  92                 object [] prop_values_arr;
  93                 object [] pos_values;
  94
  95                 static PtrHashtable usage_attr_cache = new PtrHashtable ();
  96
  97                 public Attribute (string target, Expression left_expr, string identifier, ArrayList args, Location loc)
  98                 {
  99                         LeftExpr = left_expr;
 100                         Identifier = identifier;
 101                         Name = LeftExpr == null ? identifier : LeftExpr + "." + identifier;
 102                         Arguments = args;
 103                         Location = loc;
 104                         ExplicitTarget = target;
 105                 }
 106
 107                 void Error_InvalidNamedArgument (string name)
 108                 {
 109                         Report.Error (617, Location, "Invalid attribute argument: '{0}'.  Argument must be fields " +
 110                                       "fields which are not readonly, static or const;  or read-write instance properties.",
 111                                       name);
 112                 }
 113
 114                 void Error_InvalidNamedAgrumentType (string name)
 115                 {
 116                         Report.Error (655, Location, "'{0}' is not a valid named attribute argument because its type is not valid attribute type", name);
 117                 }
 118
 119                 static void Error_AttributeArgumentNotValid (string extra, Location loc)
 120                 {
 121                         Report.Error (182, loc,
 122                                       "An attribute argument must be a constant expression, typeof " +
 123                                       "expression or array creation expression" + extra);
 124                 }
 125
 126                 static void Error_AttributeArgumentNotValid (Location loc)
 127                 {
 128                         Error_AttributeArgumentNotValid ("", loc);
 129                 }
 130
 131
 132                 /// <summary>
 133                 /// This is rather hack. We report many emit attribute error with same error to be compatible with
 134                 /// csc. But because csc has to report them this way because error came from ilasm we needn't.
 135                 /// </summary>
 136                 public void Error_AttributeEmitError (string inner)
 137                 {
 138                         Report.Error (647, Location, "Error emitting '{0}' attribute because '{1}'", Name, inner);
 139                 }
 140
 141                 public void Error_InvalidSecurityParent ()
 142                 {
 143                         Error_AttributeEmitError ("it is attached to invalid parent");
 144                 }
 145
 146                 void Error_AttributeConstructorMismatch ()
 147                 {
 148                         Report.Error (-6, Location,
 149                                       "Could not find a constructor for this argument list.");
 150                 }
 151
 152
 153                 protected virtual FullNamedExpression ResolveAsTypeStep (Expression expr, EmitContext ec)
 154                 {
 155                         return expr.ResolveAsTypeStep (ec);
 156                 }
 157
 158                 void ResolvePossibleAttributeTypes (EmitContext ec, out Type t1, out Type t2)
 159                 {
 160                         t1 = null;
 161                         t2 = null;
 162
 163                         FullNamedExpression n1 = null;
 164                         FullNamedExpression n2 = null;
 165                         string IdentifierAttribute = Identifier + "Attribute";
 166                         if (LeftExpr == null) {
 167                                 n1 = ResolveAsTypeStep (new SimpleName (Identifier, Location), ec);
 168
 169                                 // FIXME: Shouldn't do this for quoted attributes: [@A]
 170                                 n2 = ResolveAsTypeStep (new SimpleName (IdentifierAttribute, Location), ec);
 171                         } else {
 172                                 FullNamedExpression l = ResolveAsTypeStep (LeftExpr, ec);
 173                                 if (l == null) {
 174                                         Report.Error (246, Location, "Couldn't find namespace or type '{0}'", LeftExpr);
 175                                         return;
 176                                 }
 177                                 n1 = new MemberAccess (l, Identifier, Location).ResolveNamespaceOrType (ec, true);
 178
 179                                 // FIXME: Shouldn't do this for quoted attributes: [X.@A]
 180                                 n2 = new MemberAccess (l, IdentifierAttribute, Location).ResolveNamespaceOrType (ec, true);
 181                         }
 182
 183                         TypeExpr te1 = n1 == null ? null : n1 as TypeExpr;
 184                         TypeExpr te2 = n2 == null ? null : n2 as TypeExpr;
 185
 186                         if (te1 != null)
 187                                 t1 = te1.ResolveType (ec);
 188                         if (te2 != null)
 189                                 t2 = te2.ResolveType (ec);
 190                 }
 191
 192                 /// <summary>
 193                 ///   Tries to resolve the type of the attribute. Flags an error if it can't, and complain is true.
 194                 /// </summary>
 195                 Type CheckAttributeType (EmitContext ec)
 196                 {
 197                         Type t1, t2;
 198
 199                         ResolvePossibleAttributeTypes (ec, out t1, out t2);
 200
 201                         String err0616 = null;
 202
 203                         if (t1 != null && ! t1.IsSubclassOf (TypeManager.attribute_type)) {
 204                                 t1 = null;
 205                                 err0616 = "'{0}' is not an attribute class";
 206                         }
 207                         if (t2 != null && ! t2.IsSubclassOf (TypeManager.attribute_type)) {
 208                                 t2 = null;
 209                                 err0616 = (err0616 != null)
 210                                         ? "Neither '{0}' nor '{0}Attribute' is an attribute class"
 211                                         : "'{0}Attribute': is not an attribute class";
 212                         }
 213
 214                         if (t1 != null && t2 != null) {
 215                                 Report.Error (1614, Location, "'{0}' is ambiguous; use either '@{0}' or '{0}Attribute'", Name);
 216                                 return null;
 217                         }
 218                         if (t1 != null)
 219                                 return t1;
 220                         if (t2 != null)
 221                                 return t2;
 222
 223                         if (err0616 != null) {
 224                                 Report.Error (616, Location, err0616, Name);
 225                                 return null;
 226                         }
 227
 228                         Report.Error (246, Location,
 229                                       "Could not find attribute '{0}' (are you missing a using directive or an assembly reference ?)",
 230                                       Name);
 231
 232                         resolve_error = true;
 233                         return null;
 234                 }
 235
 236                 public virtual Type ResolveType (EmitContext ec)
 237                 {
 238                         if (Type == null && !resolve_error)
 239                                 Type = CheckAttributeType (ec);
 240                         return Type;
 241                 }
 242
 243                 string GetFullMemberName (string member)
 244                 {
 245                         return Type.FullName + '.' + member;
 246                 }
 247
 248                 //
 249                 // Given an expression, if the expression is a valid attribute-argument-expression
 250                 // returns an object that can be used to encode it, or null on failure.
 251                 //
 252                 public static bool GetAttributeArgumentExpression (Expression e, Location loc, Type arg_type, out object result)
 253                 {
 254                         if (e is EnumConstant) {
 255                                 if (RootContext.StdLib)
 256                                         result = ((EnumConstant)e).GetValueAsEnumType ();
 257                                 else
 258                                         result = ((EnumConstant)e).GetValue ();
 259
 260                                 return true;
 261                         }
 262
 263                         Constant constant = e as Constant;
 264                         if (constant != null) {
 265                                 if (e.Type != arg_type) {
 266                                         constant = Const.ChangeType (loc, constant, arg_type);
 267                                         if (constant == null) {
 268                                                 result = null;
 269                                                 Error_AttributeArgumentNotValid (loc);
 270                                                 return false;
 271                                         }
 272                                 }
 273                                 result = constant.GetValue ();
 274                                 return true;
 275                         } else if (e is TypeOf) {
 276                                 result = ((TypeOf) e).TypeArg;
 277                                 return true;
 278                         } else if (e is ArrayCreation){
 279                                 result =  ((ArrayCreation) e).EncodeAsAttribute ();
 280                                 if (result != null)
 281                                         return true;
 282                         } else if (e is EmptyCast) {
 283                                 Expression child = ((EmptyCast)e).Child;
 284                                 return GetAttributeArgumentExpression (child, loc, child.Type, out result);
 285                         }
 286
 287                         result = null;
 288                         Error_AttributeArgumentNotValid (loc);
 289                         return false;
 290                 }
 291
 292                 bool IsValidArgumentType (Type t)
 293                 {
 294                         return TypeManager.IsPrimitiveType (t) ||
 295                                 (t.IsArray && TypeManager.IsPrimitiveType (t.GetElementType ())) ||
 296                                 TypeManager.IsEnumType (t) ||
 297                                 t == TypeManager.string_type ||
 298                                 t == TypeManager.object_type ||
 299                                 t == TypeManager.type_type;
 300                 }
 301
 302                 // Cache for parameter-less attributes
 303                 static PtrHashtable att_cache = new PtrHashtable ();
 304
 305                 public CustomAttributeBuilder Resolve (EmitContext ec)
 306                 {
 307                         if (resolve_error)
 308                                 return null;
 309
 310                         resolve_error = true;
 311
 312                         if (Type == null) {
 313                                 Type = CheckAttributeType (ec);
 314
 315                                 if (Type == null)
 316                                         return null;
 317                         }
 318
 319                         if (Type.IsAbstract) {
 320                                 Report.Error (653, Location, "Cannot apply attribute class '{0}' because it is abstract", Name);
 321                                 return null;
 322                         }
 323
 324                         if (Arguments == null) {
 325                                 object o = att_cache [Type];
 326                                 if (o != null) {
 327                                         resolve_error = false;
 328                                         return (CustomAttributeBuilder)o;
 329                                 }
 330                         }
 331
 332                         ConstructorInfo ctor = ResolveArguments (ec);
 333                         CustomAttributeBuilder cb;
 334
 335                         try {
 336                                 if (prop_info_arr != null || field_info_arr != null) {
 337                                         cb = new CustomAttributeBuilder (
 338                                                 ctor, pos_values,
 339                                                 prop_info_arr, prop_values_arr,
 340                                                 field_info_arr, field_values_arr);
 341                                 } else {
 342                                         cb = new CustomAttributeBuilder (
 343                                                 ctor, pos_values);
 344
 345                                         if (pos_values.Length == 0)
 346                                                 att_cache.Add (Type, cb);
 347                                 }
 348                         }
 349                         catch (Exception) {
 350                                 Error_AttributeArgumentNotValid (Location);
 351                                 return null;
 352                         }
 353
 354                         resolve_error = false;
 355                         return cb;
 356                 }
 357
 358                 protected virtual ConstructorInfo ResolveArguments (EmitContext ec)
 359                 {
 360                         // Now we extract the positional and named arguments
 361
 362                         ArrayList pos_args = null;
 363                         ArrayList named_args = null;
 364                         int pos_arg_count = 0;
 365                         int named_arg_count = 0;
 366
 367                         if (Arguments != null) {
 368                                 pos_args = (ArrayList) Arguments [0];
 369                                 if (pos_args != null)
 370                                         pos_arg_count = pos_args.Count;
 371                                 if (Arguments.Count > 1) {
 372                                         named_args = (ArrayList) Arguments [1];
 373                                         named_arg_count = named_args.Count;
 374                                 }
 375                         }
 376
 377                         pos_values = new object [pos_arg_count];
 378
 379                         //
 380                         // First process positional arguments
 381                         //
 382
 383                         int i;
 384                         for (i = 0; i < pos_arg_count; i++) {
 385                                 Argument a = (Argument) pos_args [i];
 386                                 Expression e;
 387
 388                                 if (!a.Resolve (ec, Location))
 389                                         return null;
 390
 391                                 e = a.Expr;
 392
 393                                 object val;
 394                                 if (!GetAttributeArgumentExpression (e, Location, a.Type, out val))
 395                                         return null;
 396
 397                                 pos_values [i] = val;
 398
 399                                 if (i == 0 && Type == TypeManager.attribute_usage_type && (int)val == 0) {
 400                                         Report.Error (591, Location, "Invalid value for argument to 'System.AttributeUsage' attribute");
 401                                         return null;
 402                                 }
 403                         }
 404
 405                         //
 406                         // Now process named arguments
 407                         //
 408
 409                         ArrayList field_infos = null;
 410                         ArrayList prop_infos  = null;
 411                         ArrayList field_values = null;
 412                         ArrayList prop_values = null;
 413                         Hashtable seen_names = null;
 414
 415                         if (named_arg_count > 0) {
 416                                 field_infos = new ArrayList ();
 417                                 prop_infos  = new ArrayList ();
 418                                 field_values = new ArrayList ();
 419                                 prop_values = new ArrayList ();
 420
 421                                 seen_names = new Hashtable();
 422                         }
 423
 424                         for (i = 0; i < named_arg_count; i++) {
 425                                 DictionaryEntry de = (DictionaryEntry) named_args [i];
 426                                 string member_name = (string) de.Key;
 427                                 Argument a  = (Argument) de.Value;
 428                                 Expression e;
 429
 430                                 if (seen_names.Contains(member_name)) {
 431                                         Report.Error(643, Location, "'" + member_name + "' duplicate named attribute argument");
 432                                         return null;
 433                                 }
 434                                 seen_names.Add(member_name, 1);
 435
 436                                 if (!a.Resolve (ec, Location))
 437                                         return null;
 438
 439                                 Expression member = Expression.MemberLookup (
 440                                         ec, Type, member_name,
 441                                         MemberTypes.Field | MemberTypes.Property,
 442                                         BindingFlags.Public | BindingFlags.Instance,
 443                                         Location);
 444
 445                                 if (member == null) {
 446                                         member = Expression.MemberLookup (ec, Type, member_name,
 447                                                 MemberTypes.Field | MemberTypes.Property, BindingFlags.NonPublic | BindingFlags.Instance,
 448                                                 Location);
 449
 450                                         if (member != null) {
 451                                                 Report.Error (122, Location, "'{0}' is inaccessible due to its protection level", GetFullMemberName (member_name));
 452                                                 return null;
 453                                         }
 454                                 }
 455
 456                                 if (member == null){
 457                                         Report.Error (117, Location, "Attribute `{0}' does not contain a definition for `{1}'",
 458                                                       Type, member_name);
 459                                         return null;
 460                                 }
 461
 462                                 if (!(member is PropertyExpr || member is FieldExpr)) {
 463                                         Error_InvalidNamedArgument (member_name);
 464                                         return null;
 465                                 }
 466
 467                                 e = a.Expr;
 468                                 if (member is PropertyExpr) {
 469                                         PropertyExpr pe = (PropertyExpr) member;
 470                                         PropertyInfo pi = pe.PropertyInfo;
 471
 472                                         if (!pi.CanWrite || !pi.CanRead) {
 473                                                 Report.SymbolRelatedToPreviousError (pi);
 474                                                 Error_InvalidNamedArgument (member_name);
 475                                                 return null;
 476                                         }
 477
 478                                         if (!IsValidArgumentType (pi.PropertyType)) {
 479                                                 Report.SymbolRelatedToPreviousError (pi);
 480                                                 Error_InvalidNamedAgrumentType (member_name);
 481                                                 return null;
 482                                         }
 483
 484                                         object value;
 485                                         if (!GetAttributeArgumentExpression (e, Location, pi.PropertyType, out value))
 486                                                 return null;
 487
 488                                         prop_values.Add (value);
 489                                         prop_infos.Add (pi);
 490
 491                                 } else if (member is FieldExpr) {
 492                                         FieldExpr fe = (FieldExpr) member;
 493                                         FieldInfo fi = fe.FieldInfo;
 494
 495                                         if (fi.IsInitOnly) {
 496                                                 Error_InvalidNamedArgument (member_name);
 497                                                 return null;
 498                                         }
 499
 500                                         if (!IsValidArgumentType (fi.FieldType)) {
 501                                                 Report.SymbolRelatedToPreviousError (fi);
 502                                                 Error_InvalidNamedAgrumentType (member_name);
 503                                                 return null;
 504                                         }
 505
 506                                         object value;
 507                                         if (!GetAttributeArgumentExpression (e, Location, fi.FieldType, out value))
 508                                                 return null;
 509
 510                                         field_values.Add (value);
 511                                         field_infos.Add (fi);
 512                                 }
 513                         }
 514
 515                         Expression mg = Expression.MemberLookup (
 516                                 ec, Type, ".ctor", MemberTypes.Constructor,
 517                                 BindingFlags.Public | BindingFlags.Instance | BindingFlags.DeclaredOnly,
 518                                 Location);
 519
 520                         if (mg == null) {
 521                                 Error_AttributeConstructorMismatch ();
 522                                 return null;
 523                         }
 524
 525                         MethodBase constructor = Invocation.OverloadResolve (
 526                                 ec, (MethodGroupExpr) mg, pos_args, false, Location);
 527
 528                         if (constructor == null) {
 529                                 return null;
 530                         }
 531
 532                         //
 533                         // Now we perform some checks on the positional args as they
 534                         // cannot be null for a constructor which expects a parameter
 535                         // of type object
 536                         //
 537
 538                         ParameterData pd = TypeManager.GetParameterData (constructor);
 539
 540                         int last_real_param = pd.Count;
 541                         if (pd.HasParams) {
 542                                 // When the params is not filled we need to put one
 543                                 if (last_real_param > pos_arg_count) {
 544                                         object [] new_pos_values = new object [pos_arg_count + 1];
 545                                         pos_values.CopyTo (new_pos_values, 0);
 546                                         new_pos_values [pos_arg_count] = new object [] {} ;
 547                                         pos_values = new_pos_values;
 548                                 }
 549                                 last_real_param--;
 550                         }
 551
 552                         for (int j = 0; j < pos_arg_count; ++j) {
 553                                 Argument a = (Argument) pos_args [j];
 554
 555                                 if (a.Expr is NullLiteral && pd.ParameterType (j) == TypeManager.object_type) {
 556                                         Error_AttributeArgumentNotValid (Location);
 557                                         return null;
 558                                 }
 559
 560                                 object value = pos_values [j];
 561                                 if (value != null && a.Type != value.GetType () && TypeManager.IsPrimitiveType (a.Type)) {
 562                                         bool fail;
 563                                         pos_values [j] = TypeManager.ChangeType (value, a.Type, out fail);
 564                                         if (fail) {
 565                                                 // TODO: Can failed ?
 566                                                 throw new NotImplementedException ();
 567                                         }
 568                                 }
 569
 570                                 if (j < last_real_param)
 571                                         continue;
 572
 573                                 if (j == last_real_param) {
 574                                         object [] array = new object [pos_arg_count - last_real_param];
 575                                         array [0] = pos_values [j];
 576                                         pos_values [j] = array;
 577                                         continue;
 578                                 }
 579
 580                                 object [] params_array = (object []) pos_values [last_real_param];
 581                                 params_array [j - last_real_param] = pos_values [j];
 582                         }
 583
 584                         // Adjust the size of the pos_values if it had params
 585                         if (last_real_param != pos_arg_count) {
 586                                 object [] new_pos_values = new object [last_real_param + 1];
 587                                 Array.Copy (pos_values, new_pos_values, last_real_param + 1);
 588                                 pos_values = new_pos_values;
 589                         }
 590
 591                         if (named_arg_count > 0) {
 592                                 prop_info_arr = new PropertyInfo [prop_infos.Count];
 593                                 field_info_arr = new FieldInfo [field_infos.Count];
 594                                 field_values_arr = new object [field_values.Count];
 595                                 prop_values_arr = new object [prop_values.Count];
 596
 597                                 field_infos.CopyTo  (field_info_arr, 0);
 598                                 field_values.CopyTo (field_values_arr, 0);
 599
 600                                 prop_values.CopyTo  (prop_values_arr, 0);
 601                                 prop_infos.CopyTo   (prop_info_arr, 0);
 602                         }
 603
 604                         return (ConstructorInfo) constructor;
 605                 }
 606
 607                 /// <summary>
 608                 ///   Get a string containing a list of valid targets for the attribute 'attr'
 609                 /// </summary>
 610                 public string GetValidTargets ()
 611                 {
 612                         StringBuilder sb = new StringBuilder ();
 613                         AttributeTargets targets = GetAttributeUsage (null).ValidOn;
 614
 615                         if ((targets & AttributeTargets.Assembly) != 0)
 616                                 sb.Append ("'assembly' ");
 617
 618                         if ((targets & AttributeTargets.Class) != 0)
 619                                 sb.Append ("'class' ");
 620
 621                         if ((targets & AttributeTargets.Constructor) != 0)
 622                                 sb.Append ("'constructor' ");
 623
 624                         if ((targets & AttributeTargets.Delegate) != 0)
 625                                 sb.Append ("'delegate' ");
 626
 627                         if ((targets & AttributeTargets.Enum) != 0)
 628                                 sb.Append ("'enum' ");
 629
 630                         if ((targets & AttributeTargets.Event) != 0)
 631                                 sb.Append ("'event' ");
 632
 633                         if ((targets & AttributeTargets.Field) != 0)
 634                                 sb.Append ("'field' ");
 635
 636                         if ((targets & AttributeTargets.Interface) != 0)
 637                                 sb.Append ("'interface' ");
 638
 639                         if ((targets & AttributeTargets.Method) != 0)
 640                                 sb.Append ("'method' ");
 641
 642                         if ((targets & AttributeTargets.Module) != 0)
 643                                 sb.Append ("'module' ");
 644
 645                         if ((targets & AttributeTargets.Parameter) != 0)
 646                                 sb.Append ("'parameter' ");
 647
 648                         if ((targets & AttributeTargets.Property) != 0)
 649                                 sb.Append ("'property' ");
 650
 651                         if ((targets & AttributeTargets.ReturnValue) != 0)
 652                                 sb.Append ("'return' ");
 653
 654                         if ((targets & AttributeTargets.Struct) != 0)
 655                                 sb.Append ("'struct' ");
 656
 657                         return sb.ToString ();
 658
 659                 }
 660
 661                 /// <summary>
 662                 /// Returns AttributeUsage attribute for this type
 663                 /// </summary>
 664                 AttributeUsageAttribute GetAttributeUsage (EmitContext ec)
 665                 {
 666                         AttributeUsageAttribute ua = usage_attr_cache [Type] as AttributeUsageAttribute;
 667                         if (ua != null)
 668                                 return ua;
 669
 670                         Class attr_class = TypeManager.LookupClass (Type);
 671
 672                         if (attr_class == null) {
 673                                 object[] usage_attr = Type.GetCustomAttributes (TypeManager.attribute_usage_type, true);
 674                                 ua = (AttributeUsageAttribute)usage_attr [0];
 675                                 usage_attr_cache.Add (Type, ua);
 676                                 return ua;
 677                         }
 678
 679                         Attribute a = attr_class.OptAttributes == null
 680                                 ? null
 681                                 : attr_class.OptAttributes.Search (TypeManager.attribute_usage_type, attr_class.EmitContext);
 682
 683                         ua = a == null
 684                                 ? DefaultUsageAttribute
 685                                 : a.GetAttributeUsageAttribute (attr_class.EmitContext);
 686
 687                         usage_attr_cache.Add (Type, ua);
 688                         return ua;
 689                 }
 690
 691                 AttributeUsageAttribute GetAttributeUsageAttribute (EmitContext ec)
 692                 {
 693                         if (pos_values == null)
 694                                 // TODO: It is not neccessary to call whole Resolve (ApplyAttribute does it now) we need only ctor args.
 695                                 // But because a lot of attribute class code must be rewritten will be better to wait...
 696                                 Resolve (ec);
 697
 698                         if (resolve_error)
 699                                 return DefaultUsageAttribute;
 700
 701                         AttributeUsageAttribute usage_attribute = new AttributeUsageAttribute ((AttributeTargets)pos_values [0]);
 702
 703                         object field = GetPropertyValue ("AllowMultiple");
 704                         if (field != null)
 705                                 usage_attribute.AllowMultiple = (bool)field;
 706
 707                         field = GetPropertyValue ("Inherited");
 708                         if (field != null)
 709                                 usage_attribute.Inherited = (bool)field;
 710
 711                         return usage_attribute;
 712                 }
 713
 714                 /// <summary>
 715                 /// Returns custom name of indexer
 716                 /// </summary>
 717                 public string GetIndexerAttributeValue (EmitContext ec)
 718                 {
 719                         if (pos_values == null)
 720                                 // TODO: It is not neccessary to call whole Resolve (ApplyAttribute does it now) we need only ctor args.
 721                                 // But because a lot of attribute class code must be rewritten will be better to wait...
 722                                 Resolve (ec);
 723
 724                         if (resolve_error)
 725                                 return null;
 726
 727                         return pos_values [0] as string;
 728                 }
 729
 730                 /// <summary>
 731                 /// Returns condition of ConditionalAttribute
 732                 /// </summary>
 733                 public string GetConditionalAttributeValue (EmitContext ec)
 734                 {
 735                         if (pos_values == null)
 736                                 // TODO: It is not neccessary to call whole Resolve (ApplyAttribute does it now) we need only ctor args.
 737                                 // But because a lot of attribute class code must be rewritten will be better to wait...
 738                                 Resolve (ec);
 739
 740                         if (resolve_error)
 741                                 return null;
 742
 743                         return (string)pos_values [0];
 744                 }
 745
 746                 /// <summary>
 747                 /// Creates the instance of ObsoleteAttribute from this attribute instance
 748                 /// </summary>
 749                 public ObsoleteAttribute GetObsoleteAttribute (EmitContext ec)
 750                 {
 751                         if (pos_values == null)
 752                                 // TODO: It is not neccessary to call whole Resolve (ApplyAttribute does it now) we need only ctor args.
 753                                 // But because a lot of attribute class code must be rewritten will be better to wait...
 754                                 Resolve (ec);
 755
 756                         if (resolve_error)
 757                                 return null;
 758
 759                         if (pos_values == null || pos_values.Length == 0)
 760                                 return new ObsoleteAttribute ();
 761
 762                         if (pos_values.Length == 1)
 763                                 return new ObsoleteAttribute ((string)pos_values [0]);
 764
 765                         return new ObsoleteAttribute ((string)pos_values [0], (bool)pos_values [1]);
 766                 }
 767
 768                 /// <summary>
 769                 /// Returns value of CLSCompliantAttribute contructor parameter but because the method can be called
 770                 /// before ApplyAttribute. We need to resolve the arguments.
 771                 /// This situation occurs when class deps is differs from Emit order.
 772                 /// </summary>
 773                 public bool GetClsCompliantAttributeValue (EmitContext ec)
 774                 {
 775                         if (pos_values == null)
 776                                 // TODO: It is not neccessary to call whole Resolve (ApplyAttribute does it now) we need only ctor args.
 777                                 // But because a lot of attribute class code must be rewritten will be better to wait...
 778                                 Resolve (ec);
 779
 780                         if (resolve_error)
 781                                 return false;
 782
 783                         return (bool)pos_values [0];
 784                 }
 785
 786                 /// <summary>
 787                 /// Tests permitted SecurityAction for assembly or other types
 788                 /// </summary>
 789                 public bool CheckSecurityActionValidity (bool for_assembly)
 790                 {
 791                         SecurityAction action  = GetSecurityActionValue ();
 792
 793                         if ((action == SecurityAction.RequestMinimum || action == SecurityAction.RequestOptional || action == SecurityAction.RequestRefuse) && for_assembly)
 794                                 return true;
 795
 796                         if (!for_assembly) {
 797                                 if (action < SecurityAction.Demand || action > SecurityAction.InheritanceDemand) {
 798                                         Error_AttributeEmitError ("SecurityAction is out of range");
 799                                         return false;
 800                                 }
 801
 802                                 if ((action != SecurityAction.RequestMinimum && action != SecurityAction.RequestOptional && action != SecurityAction.RequestRefuse) && !for_assembly)
 803                                         return true;
 804                         }
 805
 806                         Error_AttributeEmitError (String.Concat ("SecurityAction '", action, "' is not valid for this declaration"));
 807                         return false;
 808                 }
 809
 810                 System.Security.Permissions.SecurityAction GetSecurityActionValue ()
 811                 {
 812                         return (SecurityAction)pos_values [0];
 813                 }
 814
 815                 /// <summary>
 816                 /// Creates instance of SecurityAttribute class and add result of CreatePermission method to permission table.
 817                 /// </summary>
 818                 /// <returns></returns>
 819                 public void ExtractSecurityPermissionSet (ListDictionary permissions)
 820                 {
 821                         if (TypeManager.LookupDeclSpace (Type) != null && RootContext.StdLib) {
 822                                 Error_AttributeEmitError ("security custom attributes can not be referenced from defining assembly");
 823                                 return;
 824                         }
 825
 826                         SecurityAttribute sa;
 827                         // For all assemblies except corlib we can avoid all hacks
 828                         if (RootContext.StdLib) {
 829                                 sa = (SecurityAttribute) Activator.CreateInstance (Type, pos_values);
 830
 831                                 if (prop_info_arr != null) {
 832                                         for (int i = 0; i < prop_info_arr.Length; ++i) {
 833                                                 PropertyInfo pi = prop_info_arr [i];
 834                                                 pi.SetValue (sa, prop_values_arr [i], null);
 835                                         }
 836                                 }
 837                         } else {
 838                                 Type temp_type = Type.GetType (Type.FullName);
 839                                 // HACK: All mscorlib attributes have same ctor syntax
 840                                 sa = (SecurityAttribute) Activator.CreateInstance (temp_type, new object[] { GetSecurityActionValue () } );
 841
 842                                 // All types are from newly created corlib but for invocation with old we need to convert them
 843                                 if (prop_info_arr != null) {
 844                                         for (int i = 0; i < prop_info_arr.Length; ++i) {
 845                                                 PropertyInfo emited_pi = prop_info_arr [i];
 846                                                 PropertyInfo pi = temp_type.GetProperty (emited_pi.Name, emited_pi.PropertyType);
 847
 848                                                 object old_instance = pi.PropertyType.IsEnum ?
 849                                                         System.Enum.ToObject (pi.PropertyType, prop_values_arr [i]) :
 850                                                         prop_values_arr [i];
 851
 852                                                 pi.SetValue (sa, old_instance, null);
 853                                         }
 854                                 }
 855                         }
 856
 857                         IPermission perm;
 858                         perm = sa.CreatePermission ();
 859                         SecurityAction action = GetSecurityActionValue ();
 860
 861                         // IS is correct because for corlib we are using an instance from old corlib
 862                         if (!(perm is System.Security.CodeAccessPermission)) {
 863                                 switch (action) {
 864                                         case SecurityAction.Demand:
 865                                                 action = (SecurityAction)13;
 866                                                 break;
 867                                         case SecurityAction.LinkDemand:
 868                                                 action = (SecurityAction)14;
 869                                                 break;
 870                                         case SecurityAction.InheritanceDemand:
 871                                                 action = (SecurityAction)15;
 872                                                 break;
 873                                 }
 874                         }
 875
 876                         PermissionSet ps = (PermissionSet)permissions [action];
 877                         if (ps == null) {
 878                                 if (sa is PermissionSetAttribute)
 879                                         ps = new PermissionSet (sa.Unrestricted ? PermissionState.Unrestricted : PermissionState.None);
 880                                 else
 881                                         ps = new PermissionSet (PermissionState.None);
 882
 883                                 permissions.Add (action, ps);
 884                         } else if (!ps.IsUnrestricted () && (sa is PermissionSetAttribute) && sa.Unrestricted) {
 885                                 ps = ps.Union (new PermissionSet (PermissionState.Unrestricted));
 886                                 permissions [action] = ps;
 887                         }
 888                         ps.AddPermission (perm);
 889                 }
 890
 891                 object GetValue (object value)
 892                 {
 893                         if (value is EnumConstant)
 894                                 return ((EnumConstant) value).GetValue ();
 895                         else
 896                                 return value;
 897                 }
 898
 899                 object GetPropertyValue (string name)
 900                 {
 901                         if (prop_info_arr == null)
 902                                 return null;
 903
 904                         for (int i = 0; i < prop_info_arr.Length; ++i) {
 905                                 if (prop_info_arr [i].Name == name)
 906                                         return prop_values_arr [i];
 907                         }
 908
 909                         return null;
 910                 }
 911
 912                 object GetFieldValue (string name)
 913                 {
 914                         int i;
 915                         if (field_info_arr == null)
 916                                 return null;
 917                         i = 0;
 918                         foreach (FieldInfo fi in field_info_arr) {
 919                                 if (fi.Name == name)
 920                                         return GetValue (field_values_arr [i]);
 921                                 i++;
 922                         }
 923                         return null;
 924                 }
 925
 926                 public UnmanagedMarshal GetMarshal (Attributable attr)
 927                 {
 928                         UnmanagedType UnmanagedType = (UnmanagedType)System.Enum.Parse (typeof (UnmanagedType), pos_values [0].ToString ());
 929
 930                         object value = GetFieldValue ("SizeParamIndex");
 931                         if (value != null && UnmanagedType != UnmanagedType.LPArray) {
 932                                 Error_AttributeEmitError ("SizeParamIndex field is not valid for the specified unmanaged type");
 933                                 return null;
 934                         }
 935
 936                         object o = GetFieldValue ("ArraySubType");
 937                         UnmanagedType array_sub_type = o == null ? UnmanagedType.I4 : (UnmanagedType) o;
 938
 939                         switch (UnmanagedType) {
 940                         case UnmanagedType.CustomMarshaler: {
 941                                 MethodInfo define_custom = typeof (UnmanagedMarshal).GetMethod ("DefineCustom",
 942                                                                        BindingFlags.Static | BindingFlags.Public);
 943                                 if (define_custom == null) {
 944                                         Report.RuntimeMissingSupport (Location, "set marshal info");
 945                                         return null;
 946                                 }
 947
 948                                 object [] args = new object [4];
 949                                 args [0] = GetFieldValue ("MarshalTypeRef");
 950                                 args [1] = GetFieldValue ("MarshalCookie");
 951                                 args [2] = GetFieldValue ("MarshalType");
 952                                 args [3] = Guid.Empty;
 953                                 return (UnmanagedMarshal) define_custom.Invoke (null, args);
 954                         }
 955                         case UnmanagedType.LPArray: {
 956                                 object size_const = GetFieldValue ("SizeConst");
 957                                 object size_param_index = GetFieldValue ("SizeParamIndex");
 958
 959                                 if ((size_const != null) || (size_param_index != null)) {
 960                                         MethodInfo define_array = typeof (UnmanagedMarshal).GetMethod ("DefineLPArrayInternal", BindingFlags.Static | BindingFlags.Public | BindingFlags.NonPublic);
 961                                         if (define_array == null) {
 962                                                 Report.RuntimeMissingSupport (Location, "set marshal info");
 963                                                 return null;
 964                                         }
 965
 966                                         object [] args = new object [3];
 967                                         args [0] = array_sub_type;
 968                                         args [1] = size_const == null ? -1 : size_const;
 969                                         args [2] = size_param_index == null ? -1 : size_param_index;
 970                                         return (UnmanagedMarshal) define_array.Invoke (null, args);
 971                                 }
 972                                 else
 973                                         return UnmanagedMarshal.DefineLPArray (array_sub_type);
 974                         }
 975                         case UnmanagedType.SafeArray:
 976                                 return UnmanagedMarshal.DefineSafeArray (array_sub_type);
 977
 978                         case UnmanagedType.ByValArray:
 979                                 FieldMember fm = attr as FieldMember;
 980                                 if (fm == null) {
 981                                         Error_AttributeEmitError ("Specified unmanaged type is only valid on fields");
 982                                         return null;
 983                                 }
 984                                 return UnmanagedMarshal.DefineByValArray ((int) GetFieldValue ("SizeConst"));
 985
 986                         case UnmanagedType.ByValTStr:
 987                                 return UnmanagedMarshal.DefineByValTStr ((int) GetFieldValue ("SizeConst"));
 988
 989                         default:
 990                                 return UnmanagedMarshal.DefineUnmanagedMarshal (UnmanagedType);
 991                         }
 992                 }
 993
 994                 public CharSet GetCharSetValue ()
 995                 {
 996                         return (CharSet)System.Enum.Parse (typeof (CharSet), pos_values [0].ToString ());
 997                 }
 998
 999                 public MethodImplOptions GetMethodImplOptions ()
1000                 {
1001                         return (MethodImplOptions)System.Enum.Parse (typeof (MethodImplOptions), pos_values [0].ToString ());
1002                 }
1003
1004                 public LayoutKind GetLayoutKindValue ()
1005                 {
1006                         return (LayoutKind)System.Enum.Parse (typeof (LayoutKind), pos_values [0].ToString ());
1007                 }
1008
1009                 /// <summary>
1010                 /// Emit attribute for Attributable symbol
1011                 /// </summary>
1012                 public void Emit (EmitContext ec, Attributable ias, ListDictionary emitted_attr)
1013                 {
1014                         CustomAttributeBuilder cb = Resolve (ec);
1015                         if (cb == null)
1016                                 return;
1017
1018                         AttributeUsageAttribute usage_attr = GetAttributeUsage (ec);
1019                         if ((usage_attr.ValidOn & Target) == 0) {
1020                                 Report.Error (592, Location, "Attribute '{0}' is not valid on this declaration type. It is valid on {1} declarations only.", Name, GetValidTargets ());
1021                                 return;
1022                         }
1023
1024                         try {
1025                                 ias.ApplyAttributeBuilder (this, cb);
1026                         }
1027                         catch (Exception e) {
1028                                 Error_AttributeEmitError (e.Message);
1029                                 return;
1030                         }
1031
1032                         if (!usage_attr.AllowMultiple) {
1033                                 ArrayList emitted_targets = (ArrayList)emitted_attr [Type];
1034                                 if (emitted_targets == null) {
1035                                         emitted_targets = new ArrayList ();
1036                                         emitted_attr.Add (Type, emitted_targets);
1037                                 } else if (emitted_targets.Contains (Target)) {
1038                                         Report.Error (579, Location, "Duplicate '" + Name + "' attribute");
1039                                         return;
1040                                 }
1041                                 emitted_targets.Add (Target);
1042                         }
1043
1044                         if (!RootContext.VerifyClsCompliance)
1045                                 return;
1046
1047                         // Here we are testing attribute arguments for array usage (error 3016)
1048                         if (ias.IsClsCompliaceRequired (ec.DeclSpace)) {
1049                                 if (Arguments == null)
1050                                         return;
1051
1052                                 ArrayList pos_args = (ArrayList) Arguments [0];
1053                                 if (pos_args != null) {
1054                                         foreach (Argument arg in pos_args) {
1055                                                 // Type is undefined (was error 246)
1056                                                 if (arg.Type == null)
1057                                                         return;
1058
1059                                                 if (arg.Type.IsArray) {
1060                                                         Report.Error (3016, Location, "Arrays as attribute arguments are not CLS-compliant");
1061                                                         return;
1062                                                 }
1063                                         }
1064                                 }
1065
1066                                 if (Arguments.Count < 2)
1067                                         return;
1068
1069                                 ArrayList named_args = (ArrayList) Arguments [1];
1070                                 foreach (DictionaryEntry de in named_args) {
1071                                         Argument arg  = (Argument) de.Value;
1072
1073                                         // Type is undefined (was error 246)
1074                                         if (arg.Type == null)
1075                                                 return;
1076
1077                                         if (arg.Type.IsArray) {
1078                                                 Report.Error (3016, Location, "Arrays as attribute arguments are not CLS-compliant");
1079                                                 return;
1080                                         }
1081                                 }
1082                         }
1083                 }
1084
1085                 public MethodBuilder DefinePInvokeMethod (EmitContext ec, TypeBuilder builder, string name,
1086                                                           MethodAttributes flags, Type ret_type, Type [] param_types)
1087                 {
1088                         if (pos_values == null)
1089                                 // TODO: It is not neccessary to call whole Resolve (ApplyAttribute does it now) we need only ctor args.
1090                                 // But because a lot of attribute class code must be rewritten will be better to wait...
1091                                 Resolve (ec);
1092
1093                         if (resolve_error)
1094                                 return null;
1095
1096                         string dll_name = (string)pos_values [0];
1097
1098                         // Default settings
1099                         CallingConvention cc = CallingConvention.Winapi;
1100                         CharSet charset = CodeGen.Module.DefaultCharSet;
1101                         bool preserve_sig = true;
1102                         string entry_point = name;
1103                         bool best_fit_mapping = false;
1104                         bool throw_on_unmappable = false;
1105
1106                         bool best_fit_mapping_set = false;
1107                         bool throw_on_unmappable_set = false;
1108
1109                         MethodInfo set_best_fit = null;
1110                         MethodInfo set_throw_on = null;
1111
1112                         if (field_info_arr != null) {
1113                                 int char_set_extra = 0;
1114
1115                                 for (int i = 0; i < field_info_arr.Length; i++) {
1116                                         switch (field_info_arr [i].Name) {
1117                                                 case "BestFitMapping":
1118                                                         best_fit_mapping = (bool) field_values_arr [i];
1119                                                         best_fit_mapping_set = true;
1120                                                         break;
1121                                                 case "CallingConvention":
1122                                                         cc = (CallingConvention) field_values_arr [i];
1123                                                         break;
1124                                                 case "CharSet":
1125                                                         charset = (CharSet) field_values_arr [i];
1126                                                         break;
1127                                                 case "EntryPoint":
1128                                                         entry_point = (string) field_values_arr [i];
1129                                                         break;
1130                                                 case "ExactSpelling":
1131                                                         char_set_extra |= 0x01;
1132                                                         break;
1133                                                 case "PreserveSig":
1134                                                         preserve_sig = (bool) field_values_arr [i];
1135                                                         break;
1136                                                 case "SetLastError":
1137                                                         char_set_extra |= 0x40;
1138                                                         break;
1139                                                 case "ThrowOnUnmappableChar":
1140                                                         throw_on_unmappable = (bool) field_values_arr [i];
1141                                                         throw_on_unmappable_set = true;
1142                                                         break;
1143                                                 default:
1144                                                         throw new InternalErrorException (field_info_arr [i].ToString ());
1145                                         }
1146                                 }
1147                                 charset |= (CharSet)char_set_extra;
1148                         }
1149
1150                         if (throw_on_unmappable_set || best_fit_mapping_set) {
1151                                 set_best_fit = typeof (MethodBuilder).GetMethod ("set_BestFitMapping", BindingFlags.Instance | BindingFlags.Public | BindingFlags.NonPublic);
1152                                 set_throw_on = typeof (MethodBuilder).GetMethod ("set_ThrowOnUnmappableChar", BindingFlags.Instance | BindingFlags.Public | BindingFlags.NonPublic);
1153
1154                                 if ((set_best_fit == null) || (set_throw_on == null)) {
1155                                         Report.Error (-1, Location,
1156                                                                   "The ThrowOnUnmappableChar and BestFitMapping attributes can only be emitted when running on the mono runtime.");
1157                                         return null;
1158                                 }
1159                         }
1160
1161                         try {
1162                                 MethodBuilder mb = builder.DefinePInvokeMethod (
1163                                         name, dll_name, entry_point, flags | MethodAttributes.HideBySig | MethodAttributes.PinvokeImpl,
1164                                         CallingConventions.Standard, ret_type, param_types, cc, charset);
1165
1166                                 if (preserve_sig)
1167                                         mb.SetImplementationFlags (MethodImplAttributes.PreserveSig);
1168
1169                                 if (throw_on_unmappable_set)
1170                                         set_throw_on.Invoke (mb, 0, null, new object [] { throw_on_unmappable }, null);
1171                                 if (best_fit_mapping_set)
1172                                         set_best_fit.Invoke (mb, 0, null, new object [] { best_fit_mapping }, null);
1173
1174                                 return mb;
1175                         }
1176                         catch (ArgumentException e) {
1177                                 Error_AttributeEmitError (e.Message);
1178                                 return null;
1179                         }
1180                 }
1181
1182                 private Expression GetValue ()
1183                 {
1184                         if ((Arguments == null) || (Arguments.Count < 1))
1185                                 return null;
1186                         ArrayList al = (ArrayList) Arguments [0];
1187                         if ((al == null) || (al.Count < 1))
1188                                 return null;
1189                         Argument arg = (Argument) al [0];
1190                         if ((arg == null) || (arg.Expr == null))
1191                                 return null;
1192                         return arg.Expr;
1193                 }
1194
1195                 public string GetString ()
1196                 {
1197                         Expression e = GetValue ();
1198                         if (e is StringLiteral)
1199                                 return (e as StringLiteral).Value;
1200                         return null;
1201                 }
1202
1203                 public bool GetBoolean ()
1204                 {
1205                         Expression e = GetValue ();
1206                         if (e is BoolLiteral)
1207                                 return (e as BoolLiteral).Value;
1208                         return false;
1209                 }
1210         }
1211
1212
1213         /// <summary>
1214         /// For global attributes (assembly, module) we need special handling.
1215         /// Attributes can be located in the several files
1216         /// </summary>
1217         public class GlobalAttribute: Attribute
1218         {
1219                 public readonly NamespaceEntry ns;
1220
1221                 public GlobalAttribute (TypeContainer container, string target,
1222                                         Expression left_expr, string identifier, ArrayList args, Location loc):
1223                         base (target, left_expr, identifier, args, loc)
1224                 {
1225                         ns = container.NamespaceEntry;
1226                 }
1227
1228                 void Enter ()
1229                 {
1230                         // RootContext.Tree.Types has a single NamespaceEntry which gets overwritten
1231                         // each time a new file is parsed.  However, we need to use the NamespaceEntry
1232                         // in effect where the attribute was used.  Since code elsewhere cannot assume
1233                         // that the NamespaceEntry is right, just overwrite it.
1234                         //
1235                         // Precondition: RootContext.Tree.Types == null
1236
1237                         if (RootContext.Tree.Types.NamespaceEntry != null)
1238                                 throw new InternalErrorException (Location + " non-null NamespaceEntry");
1239
1240                         RootContext.Tree.Types.NamespaceEntry = ns;
1241                 }
1242
1243                 void Leave ()
1244                 {
1245                         RootContext.Tree.Types.NamespaceEntry = null;
1246                 }
1247
1248                 protected override FullNamedExpression ResolveAsTypeStep (Expression expr, EmitContext ec)
1249                 {
1250                         try {
1251                                 Enter ();
1252                                 return base.ResolveAsTypeStep (expr, ec);
1253                         }
1254                         finally {
1255                                 Leave ();
1256                         }
1257                 }
1258
1259                 protected override ConstructorInfo ResolveArguments (EmitContext ec)
1260                 {
1261                         try {
1262                                 Enter ();
1263                                 return base.ResolveArguments (ec);
1264                         }
1265                         finally {
1266                                 Leave ();
1267                         }
1268                 }
1269         }
1270
1271         public class Attributes {
1272                 public ArrayList Attrs;
1273
1274                 public Attributes (Attribute a)
1275                 {
1276                         Attrs = new ArrayList ();
1277                         Attrs.Add (a);
1278                 }
1279
1280                 public Attributes (ArrayList attrs)
1281                 {
1282                         Attrs = attrs;
1283                 }
1284
1285                 public void AddAttributes (ArrayList attrs)
1286                 {
1287                         Attrs.AddRange (attrs);
1288                 }
1289
1290                 /// <summary>
1291                 /// Checks whether attribute target is valid for the current element
1292                 /// </summary>
1293                 public bool CheckTargets (Attributable member)
1294                 {
1295                         string[] valid_targets = member.ValidAttributeTargets;
1296                         foreach (Attribute a in Attrs) {
1297                                 if (a.ExplicitTarget == null || a.ExplicitTarget == valid_targets [0]) {
1298                                         a.Target = member.AttributeTargets;
1299                                         continue;
1300                                 }
1301
1302                                 // TODO: we can skip the first item
1303                                 if (((IList) valid_targets).Contains (a.ExplicitTarget)) {
1304                                         switch (a.ExplicitTarget) {
1305                                                 case "return": a.Target = AttributeTargets.ReturnValue; continue;
1306                                                 case "param": a.Target = AttributeTargets.Parameter; continue;
1307                                                 case "field": a.Target = AttributeTargets.Field; continue;
1308                                                 case "method": a.Target = AttributeTargets.Method; continue;
1309                                                 case "property": a.Target = AttributeTargets.Property; continue;
1310                                         }
1311                                         throw new InternalErrorException ("Unknown explicit target: " + a.ExplicitTarget);
1312                                 }
1313
1314                                 StringBuilder sb = new StringBuilder ();
1315                                 foreach (string s in valid_targets) {
1316                                         sb.Append (s);
1317                                         sb.Append (", ");
1318                                 }
1319                                 sb.Remove (sb.Length - 2, 2);
1320                                 Report.Error (657, a.Location, "'{0}' is not a valid attribute location for this declaration. Valid attribute locations for this declaration are '{1}'", a.ExplicitTarget, sb.ToString ());
1321                                 return false;
1322                         }
1323                         return true;
1324                 }
1325
1326                 public Attribute Search (Type t, EmitContext ec)
1327                 {
1328                         foreach (Attribute a in Attrs) {
1329                                 if (a.ResolveType (ec) == t)
1330                                         return a;
1331                         }
1332                         return null;
1333                 }
1334
1335                 /// <summary>
1336                 /// Returns all attributes of type 't'. Use it when attribute is AllowMultiple = true
1337                 /// </summary>
1338                 public Attribute[] SearchMulti (Type t, EmitContext ec)
1339                 {
1340                         ArrayList ar = null;
1341
1342                         foreach (Attribute a in Attrs) {
1343                                 if (a.ResolveType (ec) == t) {
1344                                         if (ar == null)
1345                                                 ar = new ArrayList ();
1346                                         ar.Add (a);
1347                                 }
1348                         }
1349
1350                         return ar == null ? null : ar.ToArray (typeof (Attribute)) as Attribute[];
1351                 }
1352
1353                 public void Emit (EmitContext ec, Attributable ias)
1354                 {
1355                         CheckTargets (ias);
1356
1357                         ListDictionary ld = new ListDictionary ();
1358
1359                         foreach (Attribute a in Attrs)
1360                                 a.Emit (ec, ias, ld);
1361                 }
1362
1363                 public bool Contains (Type t, EmitContext ec)
1364                 {
1365                         return Search (t, ec) != null;
1366                 }
1367         }
1368
1369         /// <summary>
1370         /// Helper class for attribute verification routine.
1371         /// </summary>
1372         sealed class AttributeTester
1373         {
1374                 static PtrHashtable analyzed_types = new PtrHashtable ();
1375                 static PtrHashtable analyzed_types_obsolete = new PtrHashtable ();
1376                 static PtrHashtable analyzed_member_obsolete = new PtrHashtable ();
1377                 static PtrHashtable analyzed_method_excluded = new PtrHashtable ();
1378
1379 #if NET_2_0
1380                 static PtrHashtable fixed_buffer_cache = new PtrHashtable ();
1381 #endif
1382
1383                 static object TRUE = new object ();
1384                 static object FALSE = new object ();
1385
1386                 private AttributeTester ()
1387                 {
1388                 }
1389
1390                 /// <summary>
1391                 /// Returns true if parameters of two compared methods are CLS-Compliant.
1392                 /// It tests differing only in ref or out, or in array rank.
1393                 /// </summary>
1394                 public static bool AreOverloadedMethodParamsClsCompliant (Type[] types_a, Type[] types_b)
1395                 {
1396                         if (types_a == null || types_b == null)
1397                                 return true;
1398
1399                         if (types_a.Length != types_b.Length)
1400                                 return true;
1401
1402                         for (int i = 0; i < types_b.Length; ++i) {
1403                                 Type aType = types_a [i];
1404                                 Type bType = types_b [i];
1405
1406                                 if (aType.IsArray && bType.IsArray && aType.GetArrayRank () != bType.GetArrayRank () && aType.GetElementType () == bType.GetElementType ()) {
1407                                         return false;
1408                                 }
1409
1410                                 Type aBaseType = aType;
1411                                 bool is_either_ref_or_out = false;
1412
1413                                 if (aType.IsByRef || aType.IsPointer) {
1414                                         aBaseType = aType.GetElementType ();
1415                                         is_either_ref_or_out = true;
1416                                 }
1417
1418                                 Type bBaseType = bType;
1419                                 if (bType.IsByRef || bType.IsPointer)
1420                                 {
1421                                         bBaseType = bType.GetElementType ();
1422                                         is_either_ref_or_out = !is_either_ref_or_out;
1423                                 }
1424
1425                                 if (aBaseType != bBaseType)
1426                                         continue;
1427
1428                                 if (is_either_ref_or_out)
1429                                         return false;
1430                         }
1431                         return true;
1432                 }
1433
1434                 /// <summary>
1435                 /// Goes through all parameters and test if they are CLS-Compliant.
1436                 /// </summary>
1437                 public static bool AreParametersCompliant (Parameter[] fixedParameters, Location loc)
1438                 {
1439                         if (fixedParameters == null)
1440                                 return true;
1441
1442                         foreach (Parameter arg in fixedParameters) {
1443                                 if (!AttributeTester.IsClsCompliant (arg.ParameterType)) {
1444                                         Report.Error (3001, loc, "Argument type '{0}' is not CLS-compliant", arg.GetSignatureForError ());
1445                                         return false;
1446                                 }
1447                         }
1448                         return true;
1449                 }
1450
1451
1452                 /// <summary>
1453                 /// This method tests the CLS compliance of external types. It doesn't test type visibility.
1454                 /// </summary>
1455                 public static bool IsClsCompliant (Type type)
1456                 {
1457                         if (type == null)
1458                                 return true;
1459
1460                         object type_compliance = analyzed_types[type];
1461                         if (type_compliance != null)
1462                                 return type_compliance == TRUE;
1463
1464                         if (type.IsPointer) {
1465                                 analyzed_types.Add (type, null);
1466                                 return false;
1467                         }
1468
1469                         bool result;
1470                         if (type.IsArray || type.IsByRef)       {
1471                                 result = IsClsCompliant (TypeManager.GetElementType (type));
1472                         } else {
1473                                 result = AnalyzeTypeCompliance (type);
1474                         }
1475                         analyzed_types.Add (type, result ? TRUE : FALSE);
1476                         return result;
1477                 }
1478
1479                 /// <summary>
1480                 /// Returns IFixedBuffer implementation if field is fixed buffer else null.
1481                 /// </summary>
1482                 public static IFixedBuffer GetFixedBuffer (FieldInfo fi)
1483                 {
1484                         FieldBase fb = TypeManager.GetField (fi);
1485                         if (fb != null) {
1486                                 return fb as IFixedBuffer;
1487                         }
1488
1489 #if NET_2_0
1490                         object o = fixed_buffer_cache [fi];
1491                         if (o == null) {
1492                                 if (System.Attribute.GetCustomAttribute (fi, TypeManager.fixed_buffer_attr_type) == null) {
1493                                         fixed_buffer_cache.Add (fi, FALSE);
1494                                         return null;
1495                                 }
1496
1497                                 IFixedBuffer iff = new FixedFieldExternal (fi);
1498                                 fixed_buffer_cache.Add (fi, iff);
1499                                 return iff;
1500                         }
1501
1502                         if (o == FALSE)
1503                                 return null;
1504
1505                         return (IFixedBuffer)o;
1506 #else
1507                         return null;
1508 #endif
1509                 }
1510
1511                 public static void VerifyModulesClsCompliance ()
1512                 {
1513                         Module[] modules = TypeManager.Modules;
1514                         if (modules == null)
1515                                 return;
1516
1517                         // The first module is generated assembly
1518                         for (int i = 1; i < modules.Length; ++i) {
1519                                 Module module = modules [i];
1520                                 if (!IsClsCompliant (module)) {
1521                                         Report.Error (3013, "Added modules must be marked with the CLSCompliant attribute to match the assembly", module.Name);
1522                                         return;
1523                                 }
1524                         }
1525                 }
1526
1527                 /// <summary>
1528                 /// Tests container name for CLS-Compliant name (differing only in case)
1529                 /// </summary>
1530                 public static void VerifyTopLevelNameClsCompliance ()
1531                 {
1532                         Hashtable locase_table = new Hashtable ();
1533
1534                         // Convert imported type names to lower case and ignore not cls compliant
1535                         foreach (DictionaryEntry de in TypeManager.all_imported_types) {
1536                                 Type t = (Type)de.Value;
1537                                 if (!AttributeTester.IsClsCompliant (t))
1538                                         continue;
1539
1540                                 locase_table.Add (((string)de.Key).ToLower (System.Globalization.CultureInfo.InvariantCulture), t);
1541                         }
1542
1543                         foreach (DictionaryEntry de in RootContext.Tree.AllDecls) {
1544                                 if (!(de.Key is MemberName))
1545                                         throw new InternalErrorException ("");
1546                                 DeclSpace decl = (DeclSpace) de.Value;
1547                                 if (!decl.IsClsCompliaceRequired (decl))
1548                                         continue;
1549
1550                                 string lcase = decl.Name.ToLower (System.Globalization.CultureInfo.InvariantCulture);
1551                                 if (!locase_table.Contains (lcase)) {
1552                                         locase_table.Add (lcase, decl);
1553                                         continue;
1554                                 }
1555
1556                                 object conflict = locase_table [lcase];
1557                                 if (conflict is Type)
1558                                         Report.SymbolRelatedToPreviousError ((Type)conflict);
1559                                 else
1560                                         Report.SymbolRelatedToPreviousError ((MemberCore)conflict);
1561
1562                                 Report.Error (3005, decl.Location, "Identifier '{0}' differing only in case is not CLS-compliant", decl.GetSignatureForError ());
1563                         }
1564                 }
1565
1566                 static bool IsClsCompliant (ICustomAttributeProvider attribute_provider)
1567                 {
1568                         object[] CompliantAttribute = attribute_provider.GetCustomAttributes (TypeManager.cls_compliant_attribute_type, false);
1569                         if (CompliantAttribute.Length == 0)
1570                                 return false;
1571
1572                         return ((CLSCompliantAttribute)CompliantAttribute[0]).IsCompliant;
1573                 }
1574
1575                 static bool AnalyzeTypeCompliance (Type type)
1576                 {
1577                         DeclSpace ds = TypeManager.LookupDeclSpace (type);
1578                         if (ds != null) {
1579                                 return ds.IsClsCompliaceRequired (ds.Parent);
1580                         }
1581
1582                         object[] CompliantAttribute = type.GetCustomAttributes (TypeManager.cls_compliant_attribute_type, false);
1583                         if (CompliantAttribute.Length == 0)
1584                                 return IsClsCompliant (type.Assembly);
1585
1586                         return ((CLSCompliantAttribute)CompliantAttribute[0]).IsCompliant;
1587                 }
1588
1589                 /// <summary>
1590                 /// Returns instance of ObsoleteAttribute when type is obsolete
1591                 /// </summary>
1592                 public static ObsoleteAttribute GetObsoleteAttribute (Type type)
1593                 {
1594                         object type_obsolete = analyzed_types_obsolete [type];
1595                         if (type_obsolete == FALSE)
1596                                 return null;
1597
1598                         if (type_obsolete != null)
1599                                 return (ObsoleteAttribute)type_obsolete;
1600
1601                         ObsoleteAttribute result = null;
1602                         if (type.IsByRef || type.IsArray || type.IsPointer) {
1603                                 result = GetObsoleteAttribute (TypeManager.GetElementType (type));
1604                         } else {
1605                                 DeclSpace type_ds = TypeManager.LookupDeclSpace (type);
1606
1607                                 // Type is external, we can get attribute directly
1608                                 if (type_ds == null) {
1609                                         object[] attribute = type.GetCustomAttributes (TypeManager.obsolete_attribute_type, false);
1610                                         if (attribute.Length == 1)
1611                                                 result = (ObsoleteAttribute)attribute [0];
1612                                 } else {
1613                                         result = type_ds.GetObsoleteAttribute (type_ds);
1614                                 }
1615                         }
1616
1617                         analyzed_types_obsolete.Add (type, result == null ? FALSE : result);
1618                         return result;
1619                 }
1620
1621                 /// <summary>
1622                 /// Returns instance of ObsoleteAttribute when method is obsolete
1623                 /// </summary>
1624                 public static ObsoleteAttribute GetMethodObsoleteAttribute (MethodBase mb)
1625                 {
1626                         IMethodData mc = TypeManager.GetMethod (mb);
1627                         if (mc != null)
1628                                 return mc.GetObsoleteAttribute ();
1629
1630                         // compiler generated methods are not registered by AddMethod
1631                         if (mb.DeclaringType is TypeBuilder)
1632                                 return null;
1633
1634                         PropertyInfo pi = PropertyExpr.AccessorTable [mb] as PropertyInfo;
1635                         if (pi != null)
1636                                 return GetMemberObsoleteAttribute (pi);
1637
1638                         return GetMemberObsoleteAttribute (mb);
1639                 }
1640
1641                 /// <summary>
1642                 /// Returns instance of ObsoleteAttribute when member is obsolete
1643                 /// </summary>
1644                 public static ObsoleteAttribute GetMemberObsoleteAttribute (MemberInfo mi)
1645                 {
1646                         object type_obsolete = analyzed_member_obsolete [mi];
1647                         if (type_obsolete == FALSE)
1648                                 return null;
1649
1650                         if (type_obsolete != null)
1651                                 return (ObsoleteAttribute)type_obsolete;
1652
1653                         ObsoleteAttribute oa = System.Attribute.GetCustomAttribute (mi, TypeManager.obsolete_attribute_type, false) as ObsoleteAttribute;
1654                         analyzed_member_obsolete.Add (mi, oa == null ? FALSE : oa);
1655                         return oa;
1656                 }
1657
1658                 /// <summary>
1659                 /// Common method for Obsolete error/warning reporting.
1660                 /// </summary>
1661                 public static void Report_ObsoleteMessage (ObsoleteAttribute oa, string member, Location loc)
1662                 {
1663                         if (oa.IsError) {
1664                                 Report.Error (619, loc, "'{0}' is obsolete: '{1}'", member, oa.Message);
1665                                 return;
1666                         }
1667
1668                         if (oa.Message == null) {
1669                                 Report.Warning (612, loc, "'{0}' is obsolete", member);
1670                                 return;
1671                         }
1672                         if (RootContext.WarningLevel >= 2)
1673                                 Report.Warning (618, loc, "'{0}' is obsolete: '{1}'", member, oa.Message);
1674                 }
1675
1676                 public static bool IsConditionalMethodExcluded (MethodBase mb)
1677                 {
1678                         object excluded = analyzed_method_excluded [mb];
1679                         if (excluded != null)
1680                                 return excluded == TRUE ? true : false;
1681
1682                         ConditionalAttribute[] attrs = mb.GetCustomAttributes (TypeManager.conditional_attribute_type, true) as ConditionalAttribute[];
1683                         if (attrs.Length == 0) {
1684                                 analyzed_method_excluded.Add (mb, FALSE);
1685                                 return false;
1686                         }
1687
1688                         foreach (ConditionalAttribute a in attrs) {
1689                                 if (RootContext.AllDefines.Contains (a.ConditionString)) {
1690                                         analyzed_method_excluded.Add (mb, FALSE);
1691                                         return false;
1692                                 }
1693                         }
1694                         analyzed_method_excluded.Add (mb, TRUE);
1695                         return true;
1696                 }
1697
1698                 /// <summary>
1699                 /// Analyzes class whether it has attribute which has ConditionalAttribute
1700                 /// and its condition is not defined.
1701                 /// </summary>
1702                 public static bool IsAttributeExcluded (Type type)
1703                 {
1704                         if (!type.IsClass)
1705                                 return false;
1706
1707                         Class class_decl = TypeManager.LookupDeclSpace (type) as Class;
1708
1709                         // TODO: add caching
1710                         // TODO: merge all Type bases attribute caching to one cache to save memory
1711                         if (class_decl == null) {
1712                                 object[] attributes = type.GetCustomAttributes (TypeManager.conditional_attribute_type, false);
1713                                 foreach (ConditionalAttribute ca in attributes) {
1714                                         if (RootContext.AllDefines.Contains (ca.ConditionString))
1715                                                 return false;
1716                                 }
1717                                 return attributes.Length > 0;
1718                         }
1719
1720                         return class_decl.IsExcluded ();
1721                 }
1722         }
1723 }