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 using System.IO;
  25
  26 namespace Mono.CSharp {
  27
  28         /// <summary>
  29         ///   Base class for objects that can have Attributes applied to them.
  30         /// </summary>
  31         public abstract class Attributable {
  32                 /// <summary>
  33                 ///   Attributes for this type
  34                 /// </summary>
  35                 protected Attributes attributes;
  36
  37                 public Attributable (Attributes attrs)
  38                 {
  39                         if (attrs != null)
  40                                 OptAttributes = attrs;
  41                 }
  42
  43                 public Attributes OptAttributes
  44                 {
  45                         get {
  46                                 return attributes;
  47                         }
  48                         set {
  49                                 attributes = value;
  50
  51                                 if (attributes != null) {
  52                                         attributes.AttachTo (this);
  53                                 }
  54                         }
  55                 }
  56
  57                 /// <summary>
  58                 /// Use member-specific procedure to apply attribute @a in @cb to the entity being built in @builder
  59                 /// </summary>
  60                 public abstract void ApplyAttributeBuilder (Attribute a, CustomAttributeBuilder cb);
  61
  62                 /// <summary>
  63                 /// Returns one AttributeTarget for this element.
  64                 /// </summary>
  65                 public abstract AttributeTargets AttributeTargets { get; }
  66
  67                 public abstract IResolveContext ResolveContext { get; }
  68
  69                 public abstract bool IsClsComplianceRequired ();
  70
  71                 /// <summary>
  72                 /// Gets list of valid attribute targets for explicit target declaration.
  73                 /// The first array item is default target. Don't break this rule.
  74                 /// </summary>
  75                 public abstract string[] ValidAttributeTargets { get; }
  76         };
  77
  78         public class Attribute {
  79                 public readonly string ExplicitTarget;
  80                 public AttributeTargets Target;
  81
  82                 // TODO: remove this member
  83                 public readonly string    Name;
  84                 public readonly Expression LeftExpr;
  85                 public readonly string Identifier;
  86
  87                 readonly ArrayList PosArguments;
  88                 ArrayList NamedArguments;
  89
  90                 public readonly Location Location;
  91
  92                 public Type Type;
  93
  94                 bool resolve_error;
  95                 readonly bool nameEscaped;
  96
  97                 // It can contain more onwers when the attribute is applied to multiple fiels.
  98                 Attributable[] owners;
  99
 100                 static readonly AttributeUsageAttribute DefaultUsageAttribute = new AttributeUsageAttribute (AttributeTargets.All);
 101                 static Assembly orig_sec_assembly;
 102                 public static readonly object[] EmptyObject = new object [0];
 103
 104                 // non-null if named args present after Resolve () is called
 105                 PropertyInfo [] prop_info_arr;
 106                 FieldInfo [] field_info_arr;
 107                 object [] field_values_arr;
 108                 object [] prop_values_arr;
 109                 object [] pos_values;
 110
 111                 static PtrHashtable usage_attr_cache;
 112                 // Cache for parameter-less attributes
 113                 static PtrHashtable att_cache;
 114
 115                 public Attribute (string target, Expression left_expr, string identifier, object[] args, Location loc, bool nameEscaped)
 116                 {
 117                         LeftExpr = left_expr;
 118                         Identifier = identifier;
 119                         Name = LeftExpr == null ? identifier : LeftExpr + "." + identifier;
 120                         if (args != null) {
 121                                 PosArguments = (ArrayList)args [0];
 122                                 NamedArguments = (ArrayList)args [1];
 123                         }
 124                         Location = loc;
 125                         ExplicitTarget = target;
 126                         this.nameEscaped = nameEscaped;
 127                 }
 128
 129                 static Attribute ()
 130                 {
 131                         Reset ();
 132                 }
 133
 134                 public static void Reset ()
 135                 {
 136                         usage_attr_cache = new PtrHashtable ();
 137                         att_cache = new PtrHashtable ();
 138                 }
 139
 140                 public void AttachTo (Attributable owner)
 141                 {
 142                         if (this.owners == null) {
 143                                 this.owners = new Attributable[1] { owner };
 144                                 return;
 145                         }
 146
 147                         // When the same attribute is attached to multiple fiels
 148                         // we use this extra_owners as a list of owners. The attribute
 149                         // then can be removed because will be emitted when first owner
 150                         // is served
 151                         Attributable[] new_array = new Attributable [this.owners.Length + 1];
 152                         owners.CopyTo (new_array, 0);
 153                         new_array [owners.Length] = owner;
 154                         this.owners = new_array;
 155                         owner.OptAttributes = null;
 156                 }
 157
 158                 void Error_InvalidNamedArgument (string name)
 159                 {
 160                         Report.Error (617, Location, "`{0}' is not a valid named attribute argument. Named attribute arguments " +
 161                                       "must be fields which are not readonly, static, const or read-write properties which are " +
 162                                       "public and not static",
 163                               name);
 164                 }
 165
 166                 void Error_InvalidNamedAgrumentType (string name)
 167                 {
 168                         Report.Error (655, Location, "`{0}' is not a valid named attribute argument because it is not a valid " +
 169                                       "attribute parameter type", name);
 170                 }
 171
 172                 public static void Error_AttributeArgumentNotValid (Location loc)
 173                 {
 174                         Report.Error (182, loc,
 175                                       "An attribute argument must be a constant expression, typeof " +
 176                                       "expression or array creation expression");
 177                 }
 178
 179                 static void Error_TypeParameterInAttribute (Location loc)
 180                 {
 181                         Report.Error (
 182                                 -202, loc, "Can not use a type parameter in an attribute");
 183                 }
 184
 185                 public void Error_MissingGuidAttribute ()
 186                 {
 187                         Report.Error (596, Location, "The Guid attribute must be specified with the ComImport attribute");
 188                 }
 189
 190                 public void Error_MisusedExtensionAttribute ()
 191                 {
 192                         Report.Error (1112, Location, "Do not use `{0}' directly. Use parameter modifier `this' instead", GetSignatureForError ());
 193                 }
 194
 195                 /// <summary>
 196                 /// This is rather hack. We report many emit attribute error with same error to be compatible with
 197                 /// csc. But because csc has to report them this way because error came from ilasm we needn't.
 198                 /// </summary>
 199                 public void Error_AttributeEmitError (string inner)
 200                 {
 201                         Report.Error (647, Location, "Error during emitting `{0}' attribute. The reason is `{1}'",
 202                                       TypeManager.CSharpName (Type), inner);
 203                 }
 204
 205                 public void Error_InvalidSecurityParent ()
 206                 {
 207                         Error_AttributeEmitError ("it is attached to invalid parent");
 208                 }
 209
 210                 Attributable Owner {
 211                         get {
 212                                 return owners [0];
 213                         }
 214                 }
 215
 216                 protected virtual TypeExpr ResolveAsTypeTerminal (Expression expr, IResolveContext ec, bool silent)
 217                 {
 218                         return expr.ResolveAsTypeTerminal (ec, silent);
 219                 }
 220
 221                 Type ResolvePossibleAttributeType (string name, bool silent, ref bool is_attr)
 222                 {
 223                         IResolveContext rc = Owner.ResolveContext;
 224
 225                         TypeExpr te;
 226                         if (LeftExpr == null) {
 227                                 te = ResolveAsTypeTerminal (new SimpleName (name, Location), rc, silent);
 228                         } else {
 229                                 te = ResolveAsTypeTerminal (new MemberAccess (LeftExpr, name), rc, silent);
 230                         }
 231
 232                         if (te == null)
 233                                 return null;
 234
 235                         Type t = te.Type;
 236                         if (TypeManager.IsSubclassOf (t, TypeManager.attribute_type)) {
 237                                 is_attr = true;
 238                         } else if (!silent) {
 239                                 Report.SymbolRelatedToPreviousError (t);
 240                                 Report.Error (616, Location, "`{0}': is not an attribute class", TypeManager.CSharpName (t));
 241                         }
 242                         return t;
 243                 }
 244
 245                 /// <summary>
 246                 ///   Tries to resolve the type of the attribute. Flags an error if it can't, and complain is true.
 247                 /// </summary>
 248                 void ResolveAttributeType ()
 249                 {
 250                         bool t1_is_attr = false;
 251                         Type t1 = ResolvePossibleAttributeType (Identifier, true, ref t1_is_attr);
 252
 253                         bool t2_is_attr = false;
 254                         Type t2 = nameEscaped ? null :
 255                                 ResolvePossibleAttributeType (Identifier + "Attribute", true, ref t2_is_attr);
 256
 257                         if (t1_is_attr && t2_is_attr) {
 258                                 Report.Error (1614, Location, "`{0}' is ambiguous between `{0}' and `{0}Attribute'. " +
 259                                               "Use either `@{0}' or `{0}Attribute'", GetSignatureForError ());
 260                                 resolve_error = true;
 261                                 return;
 262                         }
 263
 264                         if (t1_is_attr) {
 265                                 Type = t1;
 266                                 return;
 267                         }
 268
 269                         if (t2_is_attr) {
 270                                 Type = t2;
 271                                 return;
 272                         }
 273
 274                         if (t1 == null && t2 == null)
 275                                 ResolvePossibleAttributeType (Identifier, false, ref t1_is_attr);
 276                         if (t1 != null)
 277                                 ResolvePossibleAttributeType (Identifier, false, ref t1_is_attr);
 278                         if (t2 != null)
 279                                 ResolvePossibleAttributeType (Identifier + "Attribute", false, ref t2_is_attr);
 280
 281                         resolve_error = true;
 282                 }
 283
 284                 public virtual Type ResolveType ()
 285                 {
 286                         if (Type == null && !resolve_error)
 287                                 ResolveAttributeType ();
 288                         return Type;
 289                 }
 290
 291                 public string GetSignatureForError ()
 292                 {
 293                         if (Type != null)
 294                                 return TypeManager.CSharpName (Type);
 295
 296                         return LeftExpr == null ? Identifier : LeftExpr.GetSignatureForError () + "." + Identifier;
 297                 }
 298
 299                 bool IsValidArgumentType (Type t)
 300                 {
 301                         if (t.IsArray)
 302                                 t = t.GetElementType ();
 303
 304                         return TypeManager.IsPrimitiveType (t) ||
 305                                 TypeManager.IsEnumType (t) ||
 306                                 t == TypeManager.string_type ||
 307                                 t == TypeManager.object_type ||
 308                                 t == TypeManager.type_type;
 309                 }
 310
 311                 [Conditional ("GMCS_SOURCE")]
 312                 void ApplyModuleCharSet ()
 313                 {
 314                         if (Type != TypeManager.dllimport_type)
 315                                 return;
 316
 317                         if (!CodeGen.Module.HasDefaultCharSet)
 318                                 return;
 319
 320                         const string CharSetEnumMember = "CharSet";
 321                         if (NamedArguments == null) {
 322                                 NamedArguments = new ArrayList (1);
 323                         } else {
 324                                 foreach (DictionaryEntry de in NamedArguments) {
 325                                         if ((string)de.Key == CharSetEnumMember)
 326                                                 return;
 327                                 }
 328                         }
 329
 330                         NamedArguments.Add (new DictionaryEntry (CharSetEnumMember,
 331                                 new Argument (Constant.CreateConstant (typeof (CharSet), CodeGen.Module.DefaultCharSet, Location))));
 332                 }
 333
 334                 public CustomAttributeBuilder Resolve ()
 335                 {
 336                         if (resolve_error)
 337                                 return null;
 338
 339                         resolve_error = true;
 340
 341                         if (Type == null) {
 342                                 ResolveAttributeType ();
 343                                 if (Type == null)
 344                                         return null;
 345                         }
 346
 347                         if (Type.IsAbstract) {
 348                                 Report.Error (653, Location, "Cannot apply attribute class `{0}' because it is abstract", GetSignatureForError ());
 349                                 return null;
 350                         }
 351
 352                         ObsoleteAttribute obsolete_attr = AttributeTester.GetObsoleteAttribute (Type);
 353                         if (obsolete_attr != null) {
 354                                 AttributeTester.Report_ObsoleteMessage (obsolete_attr, TypeManager.CSharpName (Type), Location);
 355                         }
 356
 357                         if (PosArguments == null && NamedArguments == null) {
 358                                 object o = att_cache [Type];
 359                                 if (o != null) {
 360                                         resolve_error = false;
 361                                         return (CustomAttributeBuilder)o;
 362                                 }
 363                         }
 364
 365                         Attributable owner = Owner;
 366                         EmitContext ec = new EmitContext (owner.ResolveContext, owner.ResolveContext.DeclContainer, owner.ResolveContext.DeclContainer,
 367                                 Location, null, null, owner.ResolveContext.DeclContainer.ModFlags, false);
 368                         ec.IsAnonymousMethodAllowed = false;
 369
 370                         ConstructorInfo ctor = ResolveConstructor (ec);
 371                         if (ctor == null) {
 372                                 if (Type is TypeBuilder &&
 373                                     TypeManager.LookupDeclSpace (Type).MemberCache == null)
 374                                         // The attribute type has been DefineType'd, but not Defined.  Let's not treat it as an error.
 375                                         // It'll be resolved again when the attached-to entity is emitted.
 376                                         resolve_error = false;
 377                                 return null;
 378                         }
 379
 380                         ApplyModuleCharSet ();
 381
 382                         CustomAttributeBuilder cb;
 383                         try {
 384                                 if (NamedArguments == null) {
 385                                         cb = new CustomAttributeBuilder (ctor, pos_values);
 386
 387                                         if (pos_values.Length == 0)
 388                                                 att_cache.Add (Type, cb);
 389
 390                                         resolve_error = false;
 391                                         return cb;
 392                                 }
 393
 394                                 if (!ResolveNamedArguments (ec)) {
 395                                         return null;
 396                                 }
 397
 398                                 cb = new CustomAttributeBuilder (ctor, pos_values,
 399                                                 prop_info_arr, prop_values_arr,
 400                                                 field_info_arr, field_values_arr);
 401
 402                                 resolve_error = false;
 403                                 return cb;
 404                         }
 405                         catch (Exception) {
 406                                 Error_AttributeArgumentNotValid (Location);
 407                                 return null;
 408                         }
 409                 }
 410
 411                 protected virtual ConstructorInfo ResolveConstructor (EmitContext ec)
 412                 {
 413                         if (PosArguments != null) {
 414                                 for (int i = 0; i < PosArguments.Count; i++) {
 415                                         Argument a = (Argument) PosArguments [i];
 416
 417                                         if (!a.Resolve (ec, Location))
 418                                                 return null;
 419                                 }
 420                         }
 421
 422                         Expression mg = Expression.MemberLookup (ec.ContainerType,
 423                                 Type, ".ctor", MemberTypes.Constructor,
 424                                 BindingFlags.Public | BindingFlags.Instance | BindingFlags.DeclaredOnly,
 425                                 Location);
 426
 427                         if (mg == null)
 428                                 return null;
 429
 430                         MethodBase constructor = ((MethodGroupExpr)mg).OverloadResolve (
 431                                 ec, PosArguments, false, Location);
 432
 433                         if (constructor == null)
 434                                 return null;
 435
 436                         ObsoleteAttribute oa = AttributeTester.GetMethodObsoleteAttribute (constructor);
 437                         if (oa != null && !Owner.ResolveContext.IsInObsoleteScope) {
 438                                 AttributeTester.Report_ObsoleteMessage (oa, mg.GetSignatureForError (), mg.Location);
 439                         }
 440
 441                         if (PosArguments == null) {
 442                                 pos_values = EmptyObject;
 443                                 return (ConstructorInfo)constructor;
 444                         }
 445
 446                         ParameterData pd = TypeManager.GetParameterData (constructor);
 447
 448                         int pos_arg_count = PosArguments.Count;
 449                         int last_real_param = pd.Count;
 450
 451                         pos_values = new object [pos_arg_count];
 452
 453                         if (pd.HasParams) {
 454                                 // When the params is not filled we need to put one
 455                                 if (last_real_param > pos_arg_count) {
 456                                         object [] new_pos_values = new object [pos_arg_count + 1];
 457                                         pos_values.CopyTo (new_pos_values, 0);
 458                                         new_pos_values [pos_arg_count] = new object [] {} ;
 459                                         pos_values = new_pos_values;
 460                                 }
 461                                 last_real_param--;
 462                         }
 463
 464                         for (int j = 0; j < pos_arg_count; ++j) {
 465                                 Argument a = (Argument) PosArguments [j];
 466
 467                                 if (!a.Expr.GetAttributableValue (a.Type, out pos_values [j]))
 468                                         return null;
 469
 470                                 if (j < last_real_param)
 471                                         continue;
 472
 473                                 if (j == last_real_param) {
 474                                         object [] array = new object [pos_arg_count - last_real_param];
 475                                         array [0] = pos_values [j];
 476                                         pos_values [j] = array;
 477                                         continue;
 478                                 }
 479
 480                                 object [] params_array = (object []) pos_values [last_real_param];
 481                                 params_array [j - last_real_param] = pos_values [j];
 482                         }
 483
 484                         // Adjust the size of the pos_values if it had params
 485                         if (last_real_param != pos_arg_count) {
 486                                 object [] new_pos_values = new object [last_real_param + 1];
 487                                 Array.Copy (pos_values, new_pos_values, last_real_param + 1);
 488                                 pos_values = new_pos_values;
 489                         }
 490
 491                         // Here we do the checks which should be done by corlib or by runtime.
 492                         // However Zoltan doesn't like it and every Mono compiler has to do it again.
 493
 494                         if (Type == TypeManager.guid_attr_type) {
 495                                 try {
 496                                         new Guid ((string)pos_values [0]);
 497                                 }
 498                                 catch (Exception e) {
 499                                         Error_AttributeEmitError (e.Message);
 500                                         return null;
 501                                 }
 502                         }
 503
 504                         if (Type == TypeManager.attribute_usage_type && (int)pos_values [0] == 0) {
 505                                 Report.Error (591, Location, "Invalid value for argument to `System.AttributeUsage' attribute");
 506                                 return null;
 507                         }
 508
 509                         if (Type == TypeManager.indexer_name_type || Type == TypeManager.conditional_attribute_type) {
 510                                 if (!Tokenizer.IsValidIdentifier ((string)pos_values [0])) {
 511                                         Report.Error (633, ((Argument)PosArguments[0]).Expr.Location,
 512                                                 "The argument to the `{0}' attribute must be a valid identifier", GetSignatureForError ());
 513                                         return null;
 514                                 }
 515                         }
 516
 517                         if (Type == TypeManager.methodimpl_attr_type && pos_values.Length == 1 &&
 518                                 pd.ParameterType (0) == TypeManager.short_type &&
 519                                 !System.Enum.IsDefined (typeof (MethodImplOptions), pos_values [0].ToString ())) {
 520                                 Error_AttributeEmitError ("Incorrect argument value.");
 521                                 return null;
 522                         }
 523
 524                         return (ConstructorInfo)constructor;
 525                 }
 526
 527                 protected virtual bool ResolveNamedArguments (EmitContext ec)
 528                 {
 529                         int named_arg_count = NamedArguments.Count;
 530
 531                         ArrayList field_infos = new ArrayList (named_arg_count);
 532                         ArrayList prop_infos  = new ArrayList (named_arg_count);
 533                         ArrayList field_values = new ArrayList (named_arg_count);
 534                         ArrayList prop_values = new ArrayList (named_arg_count);
 535
 536                         ArrayList seen_names = new ArrayList(named_arg_count);
 537
 538                         foreach (DictionaryEntry de in NamedArguments) {
 539                                 string member_name = (string) de.Key;
 540
 541                                 if (seen_names.Contains(member_name)) {
 542                                         Report.Error(643, Location, "'" + member_name + "' duplicate named attribute argument");
 543                                         return false;
 544                                 }
 545                                 seen_names.Add(member_name);
 546
 547                                 Argument a = (Argument) de.Value;
 548                                 if (!a.Resolve (ec, Location))
 549                                         return false;
 550
 551                                 Expression member = Expression.MemberLookup (
 552                                         ec.ContainerType, Type, member_name,
 553                                         MemberTypes.Field | MemberTypes.Property,
 554                                         BindingFlags.Public | BindingFlags.Instance,
 555                                         Location);
 556
 557                                 if (member == null) {
 558                                         member = Expression.MemberLookup (ec.ContainerType, Type, member_name,
 559                                                 MemberTypes.Field | MemberTypes.Property, BindingFlags.NonPublic | BindingFlags.Instance,
 560                                                 Location);
 561
 562                                         if (member != null) {
 563                                                 Report.SymbolRelatedToPreviousError (member.Type);
 564                                                 Expression.ErrorIsInaccesible (Location, member.GetSignatureForError ());
 565                                                 return false;
 566                                         }
 567                                 }
 568
 569                                 if (member == null){
 570                                         Expression.Error_TypeDoesNotContainDefinition (Location, Type, member_name);
 571                                         return false;
 572                                 }
 573
 574                                 if (!(member is PropertyExpr || member is FieldExpr)) {
 575                                         Error_InvalidNamedArgument (member_name);
 576                                         return false;
 577                                 }
 578
 579                                 if (a.Expr is TypeParameterExpr){
 580                                         Error_TypeParameterInAttribute (Location);
 581                                         return false;
 582                                 }
 583
 584                                 ObsoleteAttribute obsolete_attr;
 585
 586                                 if (member is PropertyExpr) {
 587                                         PropertyInfo pi = ((PropertyExpr) member).PropertyInfo;
 588
 589                                         if (!pi.CanWrite || !pi.CanRead) {
 590                                                 Report.SymbolRelatedToPreviousError (pi);
 591                                                 Error_InvalidNamedArgument (member_name);
 592                                                 return false;
 593                                         }
 594
 595                                         if (!IsValidArgumentType (pi.PropertyType)) {
 596                                                 Report.SymbolRelatedToPreviousError (pi);
 597                                                 Error_InvalidNamedAgrumentType (member_name);
 598                                                 return false;
 599                                         }
 600
 601                                         object value;
 602                                         if (!a.Expr.GetAttributableValue (pi.PropertyType, out value))
 603                                                 return false;
 604
 605                                         PropertyBase pb = TypeManager.GetProperty (pi);
 606                                         if (pb != null)
 607                                                 obsolete_attr = pb.GetObsoleteAttribute ();
 608                                         else
 609                                                 obsolete_attr = AttributeTester.GetMemberObsoleteAttribute (pi);
 610
 611                                         prop_values.Add (value);
 612                                         prop_infos.Add (pi);
 613
 614                                 } else {
 615                                         FieldInfo fi = ((FieldExpr) member).FieldInfo;
 616
 617                                         if (fi.IsInitOnly) {
 618                                                 Error_InvalidNamedArgument (member_name);
 619                                                 return false;
 620                                         }
 621
 622                                         if (!IsValidArgumentType (fi.FieldType)) {
 623                                                 Report.SymbolRelatedToPreviousError (fi);
 624                                                 Error_InvalidNamedAgrumentType (member_name);
 625                                                 return false;
 626                                         }
 627
 628                                         object value;
 629                                         if (!a.Expr.GetAttributableValue (fi.FieldType, out value))
 630                                                 return false;
 631
 632                                         FieldBase fb = TypeManager.GetField (fi);
 633                                         if (fb != null)
 634                                                 obsolete_attr = fb.GetObsoleteAttribute ();
 635                                         else
 636                                                 obsolete_attr = AttributeTester.GetMemberObsoleteAttribute (fi);
 637
 638                                         field_values.Add (value);
 639                                         field_infos.Add (fi);
 640                                 }
 641
 642                                 if (obsolete_attr != null && !Owner.ResolveContext.IsInObsoleteScope)
 643                                         AttributeTester.Report_ObsoleteMessage (obsolete_attr, member.GetSignatureForError (), member.Location);
 644                         }
 645
 646                         prop_info_arr = new PropertyInfo [prop_infos.Count];
 647                         field_info_arr = new FieldInfo [field_infos.Count];
 648                         field_values_arr = new object [field_values.Count];
 649                         prop_values_arr = new object [prop_values.Count];
 650
 651                         field_infos.CopyTo  (field_info_arr, 0);
 652                         field_values.CopyTo (field_values_arr, 0);
 653
 654                         prop_values.CopyTo  (prop_values_arr, 0);
 655                         prop_infos.CopyTo   (prop_info_arr, 0);
 656
 657                         return true;
 658                 }
 659
 660                 /// <summary>
 661                 ///   Get a string containing a list of valid targets for the attribute 'attr'
 662                 /// </summary>
 663                 public string GetValidTargets ()
 664                 {
 665                         StringBuilder sb = new StringBuilder ();
 666                         AttributeTargets targets = GetAttributeUsage ().ValidOn;
 667
 668                         if ((targets & AttributeTargets.Assembly) != 0)
 669                                 sb.Append ("assembly, ");
 670
 671                         if ((targets & AttributeTargets.Module) != 0)
 672                                 sb.Append ("module, ");
 673
 674                         if ((targets & AttributeTargets.Class) != 0)
 675                                 sb.Append ("class, ");
 676
 677                         if ((targets & AttributeTargets.Struct) != 0)
 678                                 sb.Append ("struct, ");
 679
 680                         if ((targets & AttributeTargets.Enum) != 0)
 681                                 sb.Append ("enum, ");
 682
 683                         if ((targets & AttributeTargets.Constructor) != 0)
 684                                 sb.Append ("constructor, ");
 685
 686                         if ((targets & AttributeTargets.Method) != 0)
 687                                 sb.Append ("method, ");
 688
 689                         if ((targets & AttributeTargets.Property) != 0)
 690                                 sb.Append ("property, indexer, ");
 691
 692                         if ((targets & AttributeTargets.Field) != 0)
 693                                 sb.Append ("field, ");
 694
 695                         if ((targets & AttributeTargets.Event) != 0)
 696                                 sb.Append ("event, ");
 697
 698                         if ((targets & AttributeTargets.Interface) != 0)
 699                                 sb.Append ("interface, ");
 700
 701                         if ((targets & AttributeTargets.Parameter) != 0)
 702                                 sb.Append ("parameter, ");
 703
 704                         if ((targets & AttributeTargets.Delegate) != 0)
 705                                 sb.Append ("delegate, ");
 706
 707                         if ((targets & AttributeTargets.ReturnValue) != 0)
 708                                 sb.Append ("return, ");
 709
 710 #if NET_2_0
 711                         if ((targets & AttributeTargets.GenericParameter) != 0)
 712                                 sb.Append ("type parameter, ");
 713 #endif
 714                         return sb.Remove (sb.Length - 2, 2).ToString ();
 715                 }
 716
 717                 /// <summary>
 718                 /// Returns AttributeUsage attribute for this type
 719                 /// </summary>
 720                 AttributeUsageAttribute GetAttributeUsage ()
 721                 {
 722                         AttributeUsageAttribute ua = usage_attr_cache [Type] as AttributeUsageAttribute;
 723                         if (ua != null)
 724                                 return ua;
 725
 726                         Class attr_class = TypeManager.LookupClass (Type);
 727
 728                         if (attr_class == null) {
 729                                 object[] usage_attr = Type.GetCustomAttributes (TypeManager.attribute_usage_type, true);
 730                                 ua = (AttributeUsageAttribute)usage_attr [0];
 731                                 usage_attr_cache.Add (Type, ua);
 732                                 return ua;
 733                         }
 734
 735                         Attribute a = attr_class.OptAttributes == null
 736                                 ? null
 737                                 : attr_class.OptAttributes.Search (TypeManager.attribute_usage_type);
 738
 739                         ua = a == null
 740                                 ? DefaultUsageAttribute
 741                                 : a.GetAttributeUsageAttribute ();
 742
 743                         usage_attr_cache.Add (Type, ua);
 744                         return ua;
 745                 }
 746
 747                 AttributeUsageAttribute GetAttributeUsageAttribute ()
 748                 {
 749                         if (pos_values == null)
 750                                 // TODO: It is not neccessary to call whole Resolve (ApplyAttribute does it now) we need only ctor args.
 751                                 // But because a lot of attribute class code must be rewritten will be better to wait...
 752                                 Resolve ();
 753
 754                         if (resolve_error)
 755                                 return DefaultUsageAttribute;
 756
 757                         AttributeUsageAttribute usage_attribute = new AttributeUsageAttribute ((AttributeTargets)pos_values [0]);
 758
 759                         object field = GetPropertyValue ("AllowMultiple");
 760                         if (field != null)
 761                                 usage_attribute.AllowMultiple = (bool)field;
 762
 763                         field = GetPropertyValue ("Inherited");
 764                         if (field != null)
 765                                 usage_attribute.Inherited = (bool)field;
 766
 767                         return usage_attribute;
 768                 }
 769
 770                 /// <summary>
 771                 /// Returns custom name of indexer
 772                 /// </summary>
 773                 public string GetIndexerAttributeValue ()
 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 ();
 779
 780                         if (resolve_error)
 781                                 return null;
 782
 783                         return pos_values [0] as string;
 784                 }
 785
 786                 /// <summary>
 787                 /// Returns condition of ConditionalAttribute
 788                 /// </summary>
 789                 public string GetConditionalAttributeValue ()
 790                 {
 791                         if (pos_values == null)
 792                                 // TODO: It is not neccessary to call whole Resolve (ApplyAttribute does it now) we need only ctor args.
 793                                 // But because a lot of attribute class code must be rewritten will be better to wait...
 794                                 Resolve ();
 795
 796                         if (resolve_error)
 797                                 return null;
 798
 799                         return (string)pos_values [0];
 800                 }
 801
 802                 /// <summary>
 803                 /// Creates the instance of ObsoleteAttribute from this attribute instance
 804                 /// </summary>
 805                 public ObsoleteAttribute GetObsoleteAttribute ()
 806                 {
 807                         if (pos_values == null)
 808                                 // TODO: It is not neccessary to call whole Resolve (ApplyAttribute does it now) we need only ctor args.
 809                                 // But because a lot of attribute class code must be rewritten will be better to wait...
 810                                 Resolve ();
 811
 812                         if (resolve_error)
 813                                 return null;
 814
 815                         if (pos_values == null || pos_values.Length == 0)
 816                                 return new ObsoleteAttribute ();
 817
 818                         if (pos_values.Length == 1)
 819                                 return new ObsoleteAttribute ((string)pos_values [0]);
 820
 821                         return new ObsoleteAttribute ((string)pos_values [0], (bool)pos_values [1]);
 822                 }
 823
 824                 /// <summary>
 825                 /// Returns value of CLSCompliantAttribute contructor parameter but because the method can be called
 826                 /// before ApplyAttribute. We need to resolve the arguments.
 827                 /// This situation occurs when class deps is differs from Emit order.
 828                 /// </summary>
 829                 public bool GetClsCompliantAttributeValue ()
 830                 {
 831                         if (pos_values == null)
 832                                 // TODO: It is not neccessary to call whole Resolve (ApplyAttribute does it now) we need only ctor args.
 833                                 // But because a lot of attribute class code must be rewritten will be better to wait...
 834                                 Resolve ();
 835
 836                         if (resolve_error)
 837                                 return false;
 838
 839                         return (bool)pos_values [0];
 840                 }
 841
 842                 public Type GetCoClassAttributeValue ()
 843                 {
 844                         if (pos_values == null)
 845                                 Resolve ();
 846
 847                         if (resolve_error)
 848                                 return null;
 849
 850                         return (Type)pos_values [0];
 851                 }
 852
 853                 public bool CheckTarget ()
 854                 {
 855                         string[] valid_targets = Owner.ValidAttributeTargets;
 856                         if (ExplicitTarget == null || ExplicitTarget == valid_targets [0]) {
 857                                 Target = Owner.AttributeTargets;
 858                                 return true;
 859                         }
 860
 861                         // TODO: we can skip the first item
 862                         if (((IList) valid_targets).Contains (ExplicitTarget)) {
 863                                 switch (ExplicitTarget) {
 864                                         case "return": Target = AttributeTargets.ReturnValue; return true;
 865                                         case "param": Target = AttributeTargets.Parameter; return true;
 866                                         case "field": Target = AttributeTargets.Field; return true;
 867                                         case "method": Target = AttributeTargets.Method; return true;
 868                                         case "property": Target = AttributeTargets.Property; return true;
 869                                 }
 870                                 throw new InternalErrorException ("Unknown explicit target: " + ExplicitTarget);
 871                         }
 872
 873                         StringBuilder sb = new StringBuilder ();
 874                         foreach (string s in valid_targets) {
 875                                 sb.Append (s);
 876                                 sb.Append (", ");
 877                         }
 878                         sb.Remove (sb.Length - 2, 2);
 879                         Report.Error (657, Location, "`{0}' is not a valid attribute location for this declaration. " +
 880                                 "Valid attribute locations for this declaration are `{1}'", ExplicitTarget, sb.ToString ());
 881                         return false;
 882                 }
 883
 884                 /// <summary>
 885                 /// Tests permitted SecurityAction for assembly or other types
 886                 /// </summary>
 887                 public bool CheckSecurityActionValidity (bool for_assembly)
 888                 {
 889                         SecurityAction action = GetSecurityActionValue ();
 890
 891                         switch (action) {
 892                         case SecurityAction.Demand:
 893                         case SecurityAction.Assert:
 894                         case SecurityAction.Deny:
 895                         case SecurityAction.PermitOnly:
 896                         case SecurityAction.LinkDemand:
 897                         case SecurityAction.InheritanceDemand:
 898                                 if (!for_assembly)
 899                                         return true;
 900                                 break;
 901
 902                         case SecurityAction.RequestMinimum:
 903                         case SecurityAction.RequestOptional:
 904                         case SecurityAction.RequestRefuse:
 905                                 if (for_assembly)
 906                                         return true;
 907                                 break;
 908
 909                         default:
 910                                 Error_AttributeEmitError ("SecurityAction is out of range");
 911                                 return false;
 912                         }
 913
 914                         Error_AttributeEmitError (String.Concat ("SecurityAction `", action, "' is not valid for this declaration"));
 915                         return false;
 916                 }
 917
 918                 System.Security.Permissions.SecurityAction GetSecurityActionValue ()
 919                 {
 920                         return (SecurityAction)pos_values [0];
 921                 }
 922
 923                 /// <summary>
 924                 /// Creates instance of SecurityAttribute class and add result of CreatePermission method to permission table.
 925                 /// </summary>
 926                 /// <returns></returns>
 927                 public void ExtractSecurityPermissionSet (ListDictionary permissions)
 928                 {
 929                         Type orig_assembly_type = null;
 930
 931                         if (TypeManager.LookupDeclSpace (Type) != null) {
 932                                 if (!RootContext.StdLib) {
 933                                         orig_assembly_type = Type.GetType (Type.FullName);
 934                                 } else {
 935                                         string orig_version_path = Environment.GetEnvironmentVariable ("__SECURITY_BOOTSTRAP_DB");
 936                                         if (orig_version_path == null) {
 937                                                 Error_AttributeEmitError ("security custom attributes can not be referenced from defining assembly");
 938                                                 return;
 939                                         }
 940
 941                                         if (orig_sec_assembly == null) {
 942                                                 string file = Path.Combine (orig_version_path, Driver.OutputFile);
 943                                                 orig_sec_assembly = Assembly.LoadFile (file);
 944                                         }
 945
 946                                         orig_assembly_type = orig_sec_assembly.GetType (Type.FullName, true);
 947                                         if (orig_assembly_type == null) {
 948                                                 Report.Warning (-112, 1, Location, "Self-referenced security attribute `{0}' " +
 949                                                                 "was not found in previous version of assembly");
 950                                                 return;
 951                                         }
 952                                 }
 953                         }
 954
 955                         SecurityAttribute sa;
 956                         // For all non-selfreferencing security attributes we can avoid all hacks
 957                         if (orig_assembly_type == null) {
 958                                 sa = (SecurityAttribute) Activator.CreateInstance (Type, pos_values);
 959
 960                                 if (prop_info_arr != null) {
 961                                         for (int i = 0; i < prop_info_arr.Length; ++i) {
 962                                                 PropertyInfo pi = prop_info_arr [i];
 963                                                 pi.SetValue (sa, prop_values_arr [i], null);
 964                                         }
 965                                 }
 966                         } else {
 967                                 // HACK: All security attributes have same ctor syntax
 968                                 sa = (SecurityAttribute) Activator.CreateInstance (orig_assembly_type, new object[] { GetSecurityActionValue () } );
 969
 970                                 // All types are from newly created assembly but for invocation with old one we need to convert them
 971                                 if (prop_info_arr != null) {
 972                                         for (int i = 0; i < prop_info_arr.Length; ++i) {
 973                                                 PropertyInfo emited_pi = prop_info_arr [i];
 974                                                 PropertyInfo pi = orig_assembly_type.GetProperty (emited_pi.Name, emited_pi.PropertyType);
 975
 976                                                 object old_instance = pi.PropertyType.IsEnum ?
 977                                                         System.Enum.ToObject (pi.PropertyType, prop_values_arr [i]) :
 978                                                         prop_values_arr [i];
 979
 980                                                 pi.SetValue (sa, old_instance, null);
 981                                         }
 982                                 }
 983                         }
 984
 985                         IPermission perm;
 986                         perm = sa.CreatePermission ();
 987                         SecurityAction action = GetSecurityActionValue ();
 988
 989                         // IS is correct because for corlib we are using an instance from old corlib
 990                         if (!(perm is System.Security.CodeAccessPermission)) {
 991                                 switch (action) {
 992                                         case SecurityAction.Demand:
 993                                                 action = (SecurityAction)13;
 994                                                 break;
 995                                         case SecurityAction.LinkDemand:
 996                                                 action = (SecurityAction)14;
 997                                                 break;
 998                                         case SecurityAction.InheritanceDemand:
 999                                                 action = (SecurityAction)15;
1000                                                 break;
1001                                 }
1002                         }
1003
1004                         PermissionSet ps = (PermissionSet)permissions [action];
1005                         if (ps == null) {
1006                                 if (sa is PermissionSetAttribute)
1007                                         ps = new PermissionSet (sa.Unrestricted ? PermissionState.Unrestricted : PermissionState.None);
1008                                 else
1009                                         ps = new PermissionSet (PermissionState.None);
1010
1011                                 permissions.Add (action, ps);
1012                         } else if (!ps.IsUnrestricted () && (sa is PermissionSetAttribute) && sa.Unrestricted) {
1013                                 ps = ps.Union (new PermissionSet (PermissionState.Unrestricted));
1014                                 permissions [action] = ps;
1015                         }
1016                         ps.AddPermission (perm);
1017                 }
1018
1019                 static object GetValue (object value)
1020                 {
1021                         if (value is EnumConstant)
1022                                 return ((EnumConstant) value).GetValue ();
1023                         else
1024                                 return value;
1025                 }
1026
1027                 public object GetPropertyValue (string name)
1028                 {
1029                         if (prop_info_arr == null)
1030                                 return null;
1031
1032                         for (int i = 0; i < prop_info_arr.Length; ++i) {
1033                                 if (prop_info_arr [i].Name == name)
1034                                         return prop_values_arr [i];
1035                         }
1036
1037                         return null;
1038                 }
1039
1040                 object GetFieldValue (string name)
1041                 {
1042                         int i;
1043                         if (field_info_arr == null)
1044                                 return null;
1045                         i = 0;
1046                         foreach (FieldInfo fi in field_info_arr) {
1047                                 if (fi.Name == name)
1048                                         return GetValue (field_values_arr [i]);
1049                                 i++;
1050                         }
1051                         return null;
1052                 }
1053
1054                 //
1055                 // Theoretically, we can get rid of this, since FieldBuilder.SetCustomAttribute()
1056                 // and ParameterBuilder.SetCustomAttribute() are supposed to handle this attribute.
1057                 // However, we can't, since it appears that the .NET 1.1 SRE hangs when given a MarshalAsAttribute.
1058                 //
1059                 public UnmanagedMarshal GetMarshal (Attributable attr)
1060                 {
1061                         UnmanagedType UnmanagedType;
1062                         if (!RootContext.StdLib || pos_values [0].GetType () != typeof (UnmanagedType))
1063                                 UnmanagedType = (UnmanagedType) System.Enum.ToObject (typeof (UnmanagedType), pos_values [0]);
1064                         else
1065                                 UnmanagedType = (UnmanagedType) pos_values [0];
1066
1067                         object value = GetFieldValue ("SizeParamIndex");
1068                         if (value != null && UnmanagedType != UnmanagedType.LPArray) {
1069                                 Error_AttributeEmitError ("SizeParamIndex field is not valid for the specified unmanaged type");
1070                                 return null;
1071                         }
1072
1073                         object o = GetFieldValue ("ArraySubType");
1074                         UnmanagedType array_sub_type = o == null ? (UnmanagedType) 0x50 /* NATIVE_MAX */ : (UnmanagedType) o;
1075
1076                         switch (UnmanagedType) {
1077                         case UnmanagedType.CustomMarshaler: {
1078                                 MethodInfo define_custom = typeof (UnmanagedMarshal).GetMethod ("DefineCustom",
1079                                         BindingFlags.Static | BindingFlags.Public | BindingFlags.NonPublic);
1080                                 if (define_custom == null) {
1081                                         Report.RuntimeMissingSupport (Location, "set marshal info");
1082                                         return null;
1083                                 }
1084
1085                                 object [] args = new object [4];
1086                                 args [0] = GetFieldValue ("MarshalTypeRef");
1087                                 args [1] = GetFieldValue ("MarshalCookie");
1088                                 args [2] = GetFieldValue ("MarshalType");
1089                                 args [3] = Guid.Empty;
1090                                 return (UnmanagedMarshal) define_custom.Invoke (null, args);
1091                         }
1092                         case UnmanagedType.LPArray: {
1093                                 object size_const = GetFieldValue ("SizeConst");
1094                                 object size_param_index = GetFieldValue ("SizeParamIndex");
1095
1096                                 if ((size_const != null) || (size_param_index != null)) {
1097                                         MethodInfo define_array = typeof (UnmanagedMarshal).GetMethod ("DefineLPArrayInternal",
1098                                                 BindingFlags.Static | BindingFlags.Public | BindingFlags.NonPublic);
1099                                         if (define_array == null) {
1100                                                 Report.RuntimeMissingSupport (Location, "set marshal info");
1101                                                 return null;
1102                                         }
1103
1104                                         object [] args = new object [3];
1105                                         args [0] = array_sub_type;
1106                                         args [1] = size_const == null ? -1 : size_const;
1107                                         args [2] = size_param_index == null ? -1 : size_param_index;
1108                                         return (UnmanagedMarshal) define_array.Invoke (null, args);
1109                                 }
1110                                 else
1111                                         return UnmanagedMarshal.DefineLPArray (array_sub_type);
1112                         }
1113                         case UnmanagedType.SafeArray:
1114                                 return UnmanagedMarshal.DefineSafeArray (array_sub_type);
1115
1116                         case UnmanagedType.ByValArray:
1117                                 FieldBase fm = attr as FieldBase;
1118                                 if (fm == null) {
1119                                         Error_AttributeEmitError ("Specified unmanaged type is only valid on fields");
1120                                         return null;
1121                                 }
1122                                 return UnmanagedMarshal.DefineByValArray ((int) GetFieldValue ("SizeConst"));
1123
1124                         case UnmanagedType.ByValTStr:
1125                                 return UnmanagedMarshal.DefineByValTStr ((int) GetFieldValue ("SizeConst"));
1126
1127                         default:
1128                                 return UnmanagedMarshal.DefineUnmanagedMarshal (UnmanagedType);
1129                         }
1130                 }
1131
1132                 public CharSet GetCharSetValue ()
1133                 {
1134                         return (CharSet)System.Enum.Parse (typeof (CharSet), pos_values [0].ToString ());
1135                 }
1136
1137                 public bool IsInternalMethodImplAttribute {
1138                         get {
1139                                 if (Type != TypeManager.methodimpl_attr_type)
1140                                         return false;
1141
1142                                 MethodImplOptions options;
1143                                 if (pos_values[0].GetType () != typeof (MethodImplOptions))
1144                                         options = (MethodImplOptions)System.Enum.ToObject (typeof (MethodImplOptions), pos_values[0]);
1145                                 else
1146                                         options = (MethodImplOptions)pos_values[0];
1147
1148                                 return (options & MethodImplOptions.InternalCall) != 0;
1149                         }
1150                 }
1151
1152                 public LayoutKind GetLayoutKindValue ()
1153                 {
1154                         if (!RootContext.StdLib || pos_values [0].GetType () != typeof (LayoutKind))
1155                                 return (LayoutKind)System.Enum.ToObject (typeof (LayoutKind), pos_values [0]);
1156
1157                         return (LayoutKind)pos_values [0];
1158                 }
1159
1160                 public object GetParameterDefaultValue ()
1161                 {
1162                         return pos_values [0];
1163                 }
1164
1165                 public override bool Equals (object obj)
1166                 {
1167                         Attribute a = obj as Attribute;
1168                         if (a == null)
1169                                 return false;
1170
1171                         return Type == a.Type && Target == a.Target;
1172                 }
1173
1174                 public override int GetHashCode ()
1175                 {
1176                         return base.GetHashCode ();
1177                 }
1178
1179                 /// <summary>
1180                 /// Emit attribute for Attributable symbol
1181                 /// </summary>
1182                 public void Emit (ListDictionary allEmitted)
1183                 {
1184                         CustomAttributeBuilder cb = Resolve ();
1185                         if (cb == null)
1186                                 return;
1187
1188                         AttributeUsageAttribute usage_attr = GetAttributeUsage ();
1189                         if ((usage_attr.ValidOn & Target) == 0) {
1190                                 Report.Error (592, Location, "The attribute `{0}' is not valid on this declaration type. " +
1191                                               "It is valid on `{1}' declarations only",
1192                                         GetSignatureForError (), GetValidTargets ());
1193                                 return;
1194                         }
1195
1196                         try {
1197                                 foreach (Attributable owner in owners)
1198                                         owner.ApplyAttributeBuilder (this, cb);
1199                         }
1200                         catch (Exception e) {
1201                                 Error_AttributeEmitError (e.Message);
1202                                 return;
1203                         }
1204
1205                         if (!usage_attr.AllowMultiple && allEmitted != null) {
1206                                 if (allEmitted.Contains (this)) {
1207                                         ArrayList a = allEmitted [this] as ArrayList;
1208                                         if (a == null) {
1209                                                 a = new ArrayList (2);
1210                                                 allEmitted [this] = a;
1211                                         }
1212                                         a.Add (this);
1213                                 } else {
1214                                         allEmitted.Add (this, null);
1215                                 }
1216                         }
1217
1218                         if (!RootContext.VerifyClsCompliance)
1219                                 return;
1220
1221                         // Here we are testing attribute arguments for array usage (error 3016)
1222                         if (Owner.IsClsComplianceRequired ()) {
1223                                 if (PosArguments != null) {
1224                                         foreach (Argument arg in PosArguments) {
1225                                                 // Type is undefined (was error 246)
1226                                                 if (arg.Type == null)
1227                                                         return;
1228
1229                                                 if (arg.Type.IsArray) {
1230                                                         Report.Error (3016, Location, "Arrays as attribute arguments are not CLS-compliant");
1231                                                         return;
1232                                                 }
1233                                         }
1234                                 }
1235
1236                                 if (NamedArguments == null)
1237                                         return;
1238
1239                                 foreach (DictionaryEntry de in NamedArguments) {
1240                                         Argument arg  = (Argument) de.Value;
1241
1242                                         // Type is undefined (was error 246)
1243                                         if (arg.Type == null)
1244                                                 return;
1245
1246                                         if (arg.Type.IsArray) {
1247                                                 Report.Error (3016, Location, "Arrays as attribute arguments are not CLS-compliant");
1248                                                 return;
1249                                         }
1250                                 }
1251                         }
1252                 }
1253
1254                 private Expression GetValue ()
1255                 {
1256                         if (PosArguments == null || PosArguments.Count < 1)
1257                                 return null;
1258
1259                         return ((Argument) PosArguments [0]).Expr;
1260                 }
1261
1262                 public string GetString ()
1263                 {
1264                         Expression e = GetValue ();
1265                         if (e is StringLiteral)
1266                                 return (e as StringLiteral).Value;
1267                         return null;
1268                 }
1269
1270                 public bool GetBoolean ()
1271                 {
1272                         Expression e = GetValue ();
1273                         if (e is BoolLiteral)
1274                                 return (e as BoolLiteral).Value;
1275                         return false;
1276                 }
1277
1278                 public Type GetArgumentType ()
1279                 {
1280                         TypeOf e = GetValue () as TypeOf;
1281                         if (e == null)
1282                                 return null;
1283                         return e.TypeArgument;
1284                 }
1285         }
1286
1287
1288         /// <summary>
1289         /// For global attributes (assembly, module) we need special handling.
1290         /// Attributes can be located in the several files
1291         /// </summary>
1292         public class GlobalAttribute : Attribute
1293         {
1294                 public readonly NamespaceEntry ns;
1295
1296                 public GlobalAttribute (NamespaceEntry ns, string target,
1297                                         Expression left_expr, string identifier, object[] args, Location loc, bool nameEscaped):
1298                         base (target, left_expr, identifier, args, loc, nameEscaped)
1299                 {
1300                         this.ns = ns;
1301                 }
1302
1303                 void Enter ()
1304                 {
1305                         // RootContext.ToplevelTypes has a single NamespaceEntry which gets overwritten
1306                         // each time a new file is parsed.  However, we need to use the NamespaceEntry
1307                         // in effect where the attribute was used.  Since code elsewhere cannot assume
1308                         // that the NamespaceEntry is right, just overwrite it.
1309                         //
1310                         // Precondition: RootContext.ToplevelTypes == null
1311
1312                         if (RootContext.ToplevelTypes.NamespaceEntry != null)
1313                                 throw new InternalErrorException (Location + " non-null NamespaceEntry");
1314
1315                         RootContext.ToplevelTypes.NamespaceEntry = ns;
1316                 }
1317
1318                 void Leave ()
1319                 {
1320                         RootContext.ToplevelTypes.NamespaceEntry = null;
1321                 }
1322
1323                 protected override TypeExpr ResolveAsTypeTerminal (Expression expr, IResolveContext ec, bool silent)
1324                 {
1325                         try {
1326                                 Enter ();
1327                                 return base.ResolveAsTypeTerminal (expr, ec, silent);
1328                         }
1329                         finally {
1330                                 Leave ();
1331                         }
1332                 }
1333
1334                 protected override ConstructorInfo ResolveConstructor (EmitContext ec)
1335                 {
1336                         try {
1337                                 Enter ();
1338                                 return base.ResolveConstructor (ec);
1339                         }
1340                         finally {
1341                                 Leave ();
1342                         }
1343                 }
1344
1345                 protected override bool ResolveNamedArguments (EmitContext ec)
1346                 {
1347                         try {
1348                                 Enter ();
1349                                 return base.ResolveNamedArguments (ec);
1350                         }
1351                         finally {
1352                                 Leave ();
1353                         }
1354                 }
1355         }
1356
1357         public class Attributes {
1358                 public readonly ArrayList Attrs;
1359
1360                 public Attributes (Attribute a)
1361                 {
1362                         Attrs = new ArrayList ();
1363                         Attrs.Add (a);
1364                 }
1365
1366                 public Attributes (ArrayList attrs)
1367                 {
1368                         Attrs = attrs;
1369                 }
1370
1371                 public void AddAttributes (ArrayList attrs)
1372                 {
1373                         Attrs.AddRange (attrs);
1374                 }
1375
1376                 public void AttachTo (Attributable attributable)
1377                 {
1378                         foreach (Attribute a in Attrs)
1379                                 a.AttachTo (attributable);
1380                 }
1381
1382                 /// <summary>
1383                 /// Checks whether attribute target is valid for the current element
1384                 /// </summary>
1385                 public bool CheckTargets ()
1386                 {
1387                         foreach (Attribute a in Attrs) {
1388                                 if (!a.CheckTarget ())
1389                                         return false;
1390                         }
1391                         return true;
1392                 }
1393
1394                 public Attribute Search (Type t)
1395                 {
1396                         foreach (Attribute a in Attrs) {
1397                                 if (a.ResolveType () == t)
1398                                         return a;
1399                         }
1400                         return null;
1401                 }
1402
1403                 /// <summary>
1404                 /// Returns all attributes of type 't'. Use it when attribute is AllowMultiple = true
1405                 /// </summary>
1406                 public Attribute[] SearchMulti (Type t)
1407                 {
1408                         ArrayList ar = null;
1409
1410                         foreach (Attribute a in Attrs) {
1411                                 if (a.ResolveType () == t) {
1412                                         if (ar == null)
1413                                                 ar = new ArrayList ();
1414                                         ar.Add (a);
1415                                 }
1416                         }
1417
1418                         return ar == null ? null : ar.ToArray (typeof (Attribute)) as Attribute[];
1419                 }
1420
1421                 public void Emit ()
1422                 {
1423                         CheckTargets ();
1424
1425                         ListDictionary ld = Attrs.Count > 1 ? new ListDictionary () : null;
1426
1427                         foreach (Attribute a in Attrs)
1428                                 a.Emit (ld);
1429
1430                         if (ld == null || ld.Count == 0)
1431                                 return;
1432
1433                         foreach (DictionaryEntry d in ld) {
1434                                 if (d.Value == null)
1435                                         continue;
1436
1437                                 foreach (Attribute collision in (ArrayList)d.Value)
1438                                         Report.SymbolRelatedToPreviousError (collision.Location, "");
1439
1440                                 Attribute a = (Attribute)d.Key;
1441                                 Report.Error (579, a.Location, "The attribute `{0}' cannot be applied multiple times", a.GetSignatureForError ());
1442                         }
1443                 }
1444
1445                 public bool Contains (Type t)
1446                 {
1447                         return Search (t) != null;
1448                 }
1449         }
1450
1451         /// <summary>
1452         /// Helper class for attribute verification routine.
1453         /// </summary>
1454         sealed class AttributeTester
1455         {
1456                 static PtrHashtable analyzed_types;
1457                 static PtrHashtable analyzed_types_obsolete;
1458                 static PtrHashtable analyzed_member_obsolete;
1459                 static PtrHashtable analyzed_method_excluded;
1460
1461 #if NET_2_0
1462                 static PtrHashtable fixed_buffer_cache;
1463 #endif
1464
1465                 static object TRUE = new object ();
1466                 static object FALSE = new object ();
1467
1468                 static AttributeTester ()
1469                 {
1470                         Reset ();
1471                 }
1472
1473                 private AttributeTester ()
1474                 {
1475                 }
1476
1477                 public static void Reset ()
1478                 {
1479                         analyzed_types = new PtrHashtable ();
1480                         analyzed_types_obsolete = new PtrHashtable ();
1481                         analyzed_member_obsolete = new PtrHashtable ();
1482                         analyzed_method_excluded = new PtrHashtable ();
1483 #if NET_2_0
1484                         fixed_buffer_cache = new PtrHashtable ();
1485 #endif
1486                 }
1487
1488                 public enum Result {
1489                         Ok,
1490                         RefOutArrayError,
1491                         ArrayArrayError
1492                 }
1493
1494                 /// <summary>
1495                 /// Returns true if parameters of two compared methods are CLS-Compliant.
1496                 /// It tests differing only in ref or out, or in array rank.
1497                 /// </summary>
1498                 public static Result AreOverloadedMethodParamsClsCompliant (Type[] types_a, Type[] types_b)
1499                 {
1500                         if (types_a == null || types_b == null)
1501                                 return Result.Ok;
1502
1503                         if (types_a.Length != types_b.Length)
1504                                 return Result.Ok;
1505
1506                         Result result = Result.Ok;
1507                         for (int i = 0; i < types_b.Length; ++i) {
1508                                 Type aType = types_a [i];
1509                                 Type bType = types_b [i];
1510
1511                                 if (aType.IsArray && bType.IsArray) {
1512                                         Type a_el_type = aType.GetElementType ();
1513                                         Type b_el_type = bType.GetElementType ();
1514                                         if (aType.GetArrayRank () != bType.GetArrayRank () && a_el_type == b_el_type) {
1515                                                 result = Result.RefOutArrayError;
1516                                                 continue;
1517                                         }
1518
1519                                         if (a_el_type.IsArray || b_el_type.IsArray) {
1520                                                 result = Result.ArrayArrayError;
1521                                                 continue;
1522                                         }
1523                                 }
1524
1525                                 Type aBaseType = aType;
1526                                 bool is_either_ref_or_out = false;
1527
1528                                 if (aType.IsByRef || aType.IsPointer) {
1529                                         aBaseType = aType.GetElementType ();
1530                                         is_either_ref_or_out = true;
1531                                 }
1532
1533                                 Type bBaseType = bType;
1534                                 if (bType.IsByRef || bType.IsPointer)
1535                                 {
1536                                         bBaseType = bType.GetElementType ();
1537                                         is_either_ref_or_out = !is_either_ref_or_out;
1538                                 }
1539
1540                                 if (aBaseType != bBaseType)
1541                                         return Result.Ok;
1542
1543                                 if (is_either_ref_or_out)
1544                                         result = Result.RefOutArrayError;
1545                         }
1546                         return result;
1547                 }
1548
1549                 /// <summary>
1550                 /// This method tests the CLS compliance of external types. It doesn't test type visibility.
1551                 /// </summary>
1552                 public static bool IsClsCompliant (Type type)
1553                 {
1554                         if (type == null)
1555                                 return true;
1556
1557                         object type_compliance = analyzed_types[type];
1558                         if (type_compliance != null)
1559                                 return type_compliance == TRUE;
1560
1561                         if (type.IsPointer) {
1562                                 analyzed_types.Add (type, null);
1563                                 return false;
1564                         }
1565
1566                         bool result;
1567                         if (type.IsArray || type.IsByRef)       {
1568                                 result = IsClsCompliant (TypeManager.GetElementType (type));
1569                         } else {
1570                                 result = AnalyzeTypeCompliance (type);
1571                         }
1572                         analyzed_types.Add (type, result ? TRUE : FALSE);
1573                         return result;
1574                 }
1575
1576                 /// <summary>
1577                 /// Returns IFixedBuffer implementation if field is fixed buffer else null.
1578                 /// </summary>
1579                 public static IFixedBuffer GetFixedBuffer (FieldInfo fi)
1580                 {
1581                         // Fixed buffer helper type is generated as value type
1582                         if (!fi.FieldType.IsValueType)
1583                                 return null;
1584
1585                         FieldBase fb = TypeManager.GetField (fi);
1586                         if (fb != null) {
1587                                 return fb as IFixedBuffer;
1588                         }
1589
1590 #if NET_2_0
1591                         object o = fixed_buffer_cache [fi];
1592                         if (o == null) {
1593                                 if (System.Attribute.GetCustomAttribute (fi, TypeManager.fixed_buffer_attr_type) == null) {
1594                                         fixed_buffer_cache.Add (fi, FALSE);
1595                                         return null;
1596                                 }
1597
1598                                 IFixedBuffer iff = new FixedFieldExternal (fi);
1599                                 fixed_buffer_cache.Add (fi, iff);
1600                                 return iff;
1601                         }
1602
1603                         if (o == FALSE)
1604                                 return null;
1605
1606                         return (IFixedBuffer)o;
1607 #else
1608                         return null;
1609 #endif
1610                 }
1611
1612                 public static void VerifyModulesClsCompliance ()
1613                 {
1614                         Module[] modules = RootNamespace.Global.Modules;
1615                         if (modules == null)
1616                                 return;
1617
1618                         // The first module is generated assembly
1619                         for (int i = 1; i < modules.Length; ++i) {
1620                                 Module module = modules [i];
1621                                 if (!IsClsCompliant (module)) {
1622                                         Report.Error (3013, "Added modules must be marked with the CLSCompliant attribute " +
1623                                                       "to match the assembly", module.Name);
1624                                         return;
1625                                 }
1626                         }
1627                 }
1628
1629                 public static Type GetImportedIgnoreCaseClsType (string name)
1630                 {
1631                         foreach (Assembly a in RootNamespace.Global.Assemblies) {
1632                                 Type t = a.GetType (name, false, true);
1633                                 if (t == null)
1634                                         continue;
1635
1636                                 if (IsClsCompliant (t))
1637                                         return t;
1638                         }
1639                         return null;
1640                 }
1641
1642                 static bool IsClsCompliant (ICustomAttributeProvider attribute_provider)
1643                 {
1644                         object[] CompliantAttribute = attribute_provider.GetCustomAttributes (TypeManager.cls_compliant_attribute_type, false);
1645                         if (CompliantAttribute.Length == 0)
1646                                 return false;
1647
1648                         return ((CLSCompliantAttribute)CompliantAttribute[0]).IsCompliant;
1649                 }
1650
1651                 static bool AnalyzeTypeCompliance (Type type)
1652                 {
1653                         type = TypeManager.DropGenericTypeArguments (type);
1654                         DeclSpace ds = TypeManager.LookupDeclSpace (type);
1655                         if (ds != null) {
1656                                 return ds.IsClsComplianceRequired ();
1657                         }
1658
1659                         if (TypeManager.IsGenericParameter (type))
1660                                 return true;
1661
1662                         object[] CompliantAttribute = type.GetCustomAttributes (TypeManager.cls_compliant_attribute_type, false);
1663                         if (CompliantAttribute.Length == 0)
1664                                 return IsClsCompliant (type.Assembly);
1665
1666                         return ((CLSCompliantAttribute)CompliantAttribute[0]).IsCompliant;
1667                 }
1668
1669                 // Registers the core type as we assume that they will never be obsolete which
1670                 // makes things easier for bootstrap and faster (we don't need to query Obsolete attribute).
1671                 public static void RegisterNonObsoleteType (Type type)
1672                 {
1673                         analyzed_types_obsolete [type] = FALSE;
1674                 }
1675
1676                 /// <summary>
1677                 /// Returns instance of ObsoleteAttribute when type is obsolete
1678                 /// </summary>
1679                 public static ObsoleteAttribute GetObsoleteAttribute (Type type)
1680                 {
1681                         object type_obsolete = analyzed_types_obsolete [type];
1682                         if (type_obsolete == FALSE)
1683                                 return null;
1684
1685                         if (type_obsolete != null)
1686                                 return (ObsoleteAttribute)type_obsolete;
1687
1688                         ObsoleteAttribute result = null;
1689                         if (TypeManager.HasElementType (type)) {
1690                                 result = GetObsoleteAttribute (TypeManager.GetElementType (type));
1691                         } else if (TypeManager.IsGenericParameter (type) || TypeManager.IsGenericType (type))
1692                                 return null;
1693                         else {
1694                                 DeclSpace type_ds = TypeManager.LookupDeclSpace (type);
1695
1696                                 // Type is external, we can get attribute directly
1697                                 if (type_ds == null) {
1698                                         object[] attribute = type.GetCustomAttributes (TypeManager.obsolete_attribute_type, false);
1699                                         if (attribute.Length == 1)
1700                                                 result = (ObsoleteAttribute)attribute [0];
1701                                 } else {
1702                                         result = type_ds.GetObsoleteAttribute ();
1703                                 }
1704                         }
1705
1706                         // Cannot use .Add because of corlib bootstrap
1707                         analyzed_types_obsolete [type] = result == null ? FALSE : result;
1708                         return result;
1709                 }
1710
1711                 /// <summary>
1712                 /// Returns instance of ObsoleteAttribute when method is obsolete
1713                 /// </summary>
1714                 public static ObsoleteAttribute GetMethodObsoleteAttribute (MethodBase mb)
1715                 {
1716                         IMethodData mc = TypeManager.GetMethod (mb);
1717                         if (mc != null)
1718                                 return mc.GetObsoleteAttribute ();
1719
1720                         // compiler generated methods are not registered by AddMethod
1721                         if (mb.DeclaringType is TypeBuilder)
1722                                 return null;
1723
1724                         MemberInfo mi = TypeManager.GetPropertyFromAccessor (mb);
1725                         if (mi != null)
1726                                 return GetMemberObsoleteAttribute (mi);
1727
1728                         mi = TypeManager.GetEventFromAccessor (mb);
1729                         if (mi != null)
1730                                 return GetMemberObsoleteAttribute (mi);
1731
1732                         return GetMemberObsoleteAttribute (mb);
1733                 }
1734
1735                 /// <summary>
1736                 /// Returns instance of ObsoleteAttribute when member is obsolete
1737                 /// </summary>
1738                 public static ObsoleteAttribute GetMemberObsoleteAttribute (MemberInfo mi)
1739                 {
1740                         object type_obsolete = analyzed_member_obsolete [mi];
1741                         if (type_obsolete == FALSE)
1742                                 return null;
1743
1744                         if (type_obsolete != null)
1745                                 return (ObsoleteAttribute)type_obsolete;
1746
1747                         if ((mi.DeclaringType is TypeBuilder) || TypeManager.IsGenericType (mi.DeclaringType))
1748                                 return null;
1749
1750                         ObsoleteAttribute oa = System.Attribute.GetCustomAttribute (mi, TypeManager.obsolete_attribute_type, false)
1751                                 as ObsoleteAttribute;
1752                         analyzed_member_obsolete.Add (mi, oa == null ? FALSE : oa);
1753                         return oa;
1754                 }
1755
1756                 /// <summary>
1757                 /// Common method for Obsolete error/warning reporting.
1758                 /// </summary>
1759                 public static void Report_ObsoleteMessage (ObsoleteAttribute oa, string member, Location loc)
1760                 {
1761                         if (oa.IsError) {
1762                                 Report.Error (619, loc, "`{0}' is obsolete: `{1}'", member, oa.Message);
1763                                 return;
1764                         }
1765
1766                         if (oa.Message == null) {
1767                                 Report.Warning (612, 1, loc, "`{0}' is obsolete", member);
1768                                 return;
1769                         }
1770                         Report.Warning (618, 2, loc, "`{0}' is obsolete: `{1}'", member, oa.Message);
1771                 }
1772
1773                 public static bool IsConditionalMethodExcluded (MethodBase mb)
1774                 {
1775                         mb = TypeManager.DropGenericMethodArguments (mb);
1776                         if ((mb is MethodBuilder) || (mb is ConstructorBuilder))
1777                                 return false;
1778
1779                         object excluded = analyzed_method_excluded [mb];
1780                         if (excluded != null)
1781                                 return excluded == TRUE ? true : false;
1782
1783                         ConditionalAttribute[] attrs = mb.GetCustomAttributes (TypeManager.conditional_attribute_type, true)
1784                                 as ConditionalAttribute[];
1785                         if (attrs.Length == 0) {
1786                                 analyzed_method_excluded.Add (mb, FALSE);
1787                                 return false;
1788                         }
1789
1790                         foreach (ConditionalAttribute a in attrs) {
1791                                 if (RootContext.AllDefines.Contains (a.ConditionString)) {
1792                                         analyzed_method_excluded.Add (mb, FALSE);
1793                                         return false;
1794                                 }
1795                         }
1796                         analyzed_method_excluded.Add (mb, TRUE);
1797                         return true;
1798                 }
1799
1800                 /// <summary>
1801                 /// Analyzes class whether it has attribute which has ConditionalAttribute
1802                 /// and its condition is not defined.
1803                 /// </summary>
1804                 public static bool IsAttributeExcluded (Type type)
1805                 {
1806                         if (!type.IsClass)
1807                                 return false;
1808
1809                         Class class_decl = TypeManager.LookupDeclSpace (type) as Class;
1810
1811                         // TODO: add caching
1812                         // TODO: merge all Type bases attribute caching to one cache to save memory
1813                         if (class_decl == null) {
1814                                 object[] attributes = type.GetCustomAttributes (TypeManager.conditional_attribute_type, false);
1815                                 foreach (ConditionalAttribute ca in attributes) {
1816                                         if (RootContext.AllDefines.Contains (ca.ConditionString))
1817                                                 return false;
1818                                 }
1819                                 return attributes.Length > 0;
1820                         }
1821
1822                         return class_decl.IsExcluded ();
1823                 }
1824
1825                 public static Type GetCoClassAttribute (Type type)
1826                 {
1827                         TypeContainer tc = TypeManager.LookupInterface (type);
1828                         if (tc == null) {
1829                                 object[] o = type.GetCustomAttributes (TypeManager.coclass_attr_type, false);
1830                                 if (o.Length < 1)
1831                                         return null;
1832                                 return ((System.Runtime.InteropServices.CoClassAttribute)o[0]).CoClass;
1833                         }
1834
1835                         if (tc.OptAttributes == null)
1836                                 return null;
1837
1838                         Attribute a = tc.OptAttributes.Search (TypeManager.coclass_attr_type);
1839                         if (a == null)
1840                                 return null;
1841
1842                         return a.GetCoClassAttributeValue ();
1843                 }
1844         }
1845 }