mcs/mcs/attribute.cs

   1 //
   2 // attribute.cs: Attribute Handler
   3 //
   4 // Author: Ravi Pratap (ravi@ximian.com)
   5 //         Marek Safar (marek.safar@seznam.cz)
   6 //
   7 // Dual licensed under the terms of the MIT X11 or GNU GPL
   8 //
   9 // Copyright 2001-2003 Ximian, Inc (http://www.ximian.com)
  10 // Copyright 2003-2008 Novell, Inc.
  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 : Expression
  79         {
  80                 public readonly string ExplicitTarget;
  81                 public AttributeTargets Target;
  82
  83                 // TODO: remove this member
  84                 public readonly string    Name;
  85                 public readonly Expression LeftExpr;
  86                 public readonly string Identifier;
  87
  88                 ArrayList PosArguments;
  89                 ArrayList NamedArguments;
  90
  91                 bool resolve_error;
  92                 readonly bool nameEscaped;
  93
  94                 // It can contain more onwers when the attribute is applied to multiple fiels.
  95                 protected Attributable[] owners;
  96
  97                 static readonly AttributeUsageAttribute DefaultUsageAttribute = new AttributeUsageAttribute (AttributeTargets.All);
  98                 static Assembly orig_sec_assembly;
  99                 public static readonly object[] EmptyObject = new object [0];
 100
 101                 // non-null if named args present after Resolve () is called
 102                 PropertyInfo [] prop_info_arr;
 103                 FieldInfo [] field_info_arr;
 104                 object [] field_values_arr;
 105                 object [] prop_values_arr;
 106                 object [] pos_values;
 107
 108                 static PtrHashtable usage_attr_cache;
 109                 // Cache for parameter-less attributes
 110                 static PtrHashtable att_cache;
 111
 112                 public Attribute (string target, Expression left_expr, string identifier, object[] args, Location loc, bool nameEscaped)
 113                 {
 114                         LeftExpr = left_expr;
 115                         Identifier = identifier;
 116                         Name = LeftExpr == null ? identifier : LeftExpr + "." + identifier;
 117                         if (args != null) {
 118                                 PosArguments = (ArrayList)args [0];
 119                                 NamedArguments = (ArrayList)args [1];
 120                         }
 121                         this.loc = loc;
 122                         ExplicitTarget = target;
 123                         this.nameEscaped = nameEscaped;
 124                 }
 125
 126                 public Attribute Clone ()
 127                 {
 128                         Attribute a = new Attribute (ExplicitTarget, LeftExpr, Identifier, null, loc, nameEscaped);
 129                         a.PosArguments = PosArguments;
 130                         a.NamedArguments = NamedArguments;
 131                         return a;
 132                 }
 133
 134                 static Attribute ()
 135                 {
 136                         Reset ();
 137                 }
 138
 139                 public static void Reset ()
 140                 {
 141                         usage_attr_cache = new PtrHashtable ();
 142                         att_cache = new PtrHashtable ();
 143                 }
 144
 145                 public virtual void AttachTo (Attributable owner)
 146                 {
 147                         if (this.owners == null) {
 148                                 this.owners = new Attributable[1] { owner };
 149                                 return;
 150                         }
 151
 152                         // When the same attribute is attached to multiple fiels
 153                         // we use this extra_owners as a list of owners. The attribute
 154                         // then can be removed because will be emitted when first owner
 155                         // is served
 156                         Attributable[] new_array = new Attributable [this.owners.Length + 1];
 157                         owners.CopyTo (new_array, 0);
 158                         new_array [owners.Length] = owner;
 159                         this.owners = new_array;
 160                         owner.OptAttributes = null;
 161                 }
 162
 163                 void Error_InvalidNamedArgument (string name)
 164                 {
 165                         Report.Error (617, Location, "`{0}' is not a valid named attribute argument. Named attribute arguments " +
 166                                       "must be fields which are not readonly, static, const or read-write properties which are " +
 167                                       "public and not static",
 168                               name);
 169                 }
 170
 171                 void Error_InvalidNamedAgrumentType (string name)
 172                 {
 173                         Report.Error (655, Location, "`{0}' is not a valid named attribute argument because it is not a valid " +
 174                                       "attribute parameter type", name);
 175                 }
 176
 177                 public static void Error_AttributeArgumentNotValid (Location loc)
 178                 {
 179                         Report.Error (182, loc,
 180                                       "An attribute argument must be a constant expression, typeof " +
 181                                       "expression or array creation expression");
 182                 }
 183
 184                 static void Error_TypeParameterInAttribute (Location loc)
 185                 {
 186                         Report.Error (
 187                                 -202, loc, "Can not use a type parameter in an attribute");
 188                 }
 189
 190                 public void Error_MissingGuidAttribute ()
 191                 {
 192                         Report.Error (596, Location, "The Guid attribute must be specified with the ComImport attribute");
 193                 }
 194
 195                 public void Error_MisusedExtensionAttribute ()
 196                 {
 197                         Report.Error (1112, Location, "Do not use `{0}' directly. Use parameter modifier `this' instead", GetSignatureForError ());
 198                 }
 199
 200                 /// <summary>
 201                 /// This is rather hack. We report many emit attribute error with same error to be compatible with
 202                 /// csc. But because csc has to report them this way because error came from ilasm we needn't.
 203                 /// </summary>
 204                 public void Error_AttributeEmitError (string inner)
 205                 {
 206                         Report.Error (647, Location, "Error during emitting `{0}' attribute. The reason is `{1}'",
 207                                       TypeManager.CSharpName (Type), inner);
 208                 }
 209
 210                 public void Error_InvalidSecurityParent ()
 211                 {
 212                         Error_AttributeEmitError ("it is attached to invalid parent");
 213                 }
 214
 215                 Attributable Owner {
 216                         get {
 217                                 return owners [0];
 218                         }
 219                 }
 220
 221                 protected virtual TypeExpr ResolveAsTypeTerminal (Expression expr, IResolveContext ec, bool silent)
 222                 {
 223                         return expr.ResolveAsTypeTerminal (ec, silent);
 224                 }
 225
 226                 Type ResolvePossibleAttributeType (string name, bool silent, ref bool is_attr)
 227                 {
 228                         IResolveContext rc = Owner.ResolveContext;
 229
 230                         TypeExpr te;
 231                         if (LeftExpr == null) {
 232                                 te = ResolveAsTypeTerminal (new SimpleName (name, Location), rc, silent);
 233                         } else {
 234                                 te = ResolveAsTypeTerminal (new MemberAccess (LeftExpr, name), rc, silent);
 235                         }
 236
 237                         if (te == null)
 238                                 return null;
 239
 240                         Type t = te.Type;
 241                         if (TypeManager.IsSubclassOf (t, TypeManager.attribute_type)) {
 242                                 is_attr = true;
 243                         } else if (!silent) {
 244                                 Report.SymbolRelatedToPreviousError (t);
 245                                 Report.Error (616, Location, "`{0}': is not an attribute class", TypeManager.CSharpName (t));
 246                         }
 247                         return t;
 248                 }
 249
 250                 /// <summary>
 251                 ///   Tries to resolve the type of the attribute. Flags an error if it can't, and complain is true.
 252                 /// </summary>
 253                 void ResolveAttributeType ()
 254                 {
 255                         bool t1_is_attr = false;
 256                         Type t1 = ResolvePossibleAttributeType (Identifier, true, ref t1_is_attr);
 257
 258                         bool t2_is_attr = false;
 259                         Type t2 = nameEscaped ? null :
 260                                 ResolvePossibleAttributeType (Identifier + "Attribute", true, ref t2_is_attr);
 261
 262                         if (t1_is_attr && t2_is_attr) {
 263                                 Report.Error (1614, Location, "`{0}' is ambiguous between `{0}' and `{0}Attribute'. " +
 264                                               "Use either `@{0}' or `{0}Attribute'", GetSignatureForError ());
 265                                 resolve_error = true;
 266                                 return;
 267                         }
 268
 269                         if (t1_is_attr) {
 270                                 Type = t1;
 271                                 return;
 272                         }
 273
 274                         if (t2_is_attr) {
 275                                 Type = t2;
 276                                 return;
 277                         }
 278
 279                         if (t1 == null && t2 == null)
 280                                 ResolvePossibleAttributeType (Identifier, false, ref t1_is_attr);
 281                         if (t1 != null)
 282                                 ResolvePossibleAttributeType (Identifier, false, ref t1_is_attr);
 283                         if (t2 != null)
 284                                 ResolvePossibleAttributeType (Identifier + "Attribute", false, ref t2_is_attr);
 285
 286                         resolve_error = true;
 287                 }
 288
 289                 public virtual Type ResolveType ()
 290                 {
 291                         if (Type == null && !resolve_error)
 292                                 ResolveAttributeType ();
 293                         return Type;
 294                 }
 295
 296                 public override string GetSignatureForError ()
 297                 {
 298                         if (Type != null)
 299                                 return TypeManager.CSharpName (Type);
 300
 301                         return LeftExpr == null ? Identifier : LeftExpr.GetSignatureForError () + "." + Identifier;
 302                 }
 303
 304                 public bool HasSecurityAttribute {
 305                         get {
 306                                 return TypeManager.security_attr_type != null &&
 307                                 TypeManager.IsSubclassOf (type, TypeManager.security_attr_type);
 308                         }
 309                 }
 310
 311                 public bool IsValidSecurityAttribute ()
 312                 {
 313                         return HasSecurityAttribute && IsSecurityActionValid (false);
 314                 }
 315
 316                 static bool IsValidArgumentType (Type t)
 317                 {
 318                         if (t.IsArray)
 319                                 t = TypeManager.GetElementType (t);
 320
 321                         return t == TypeManager.string_type ||
 322                                 TypeManager.IsPrimitiveType (t) ||
 323                                 TypeManager.IsEnumType (t) ||
 324                                 t == TypeManager.object_type ||
 325                                 t == TypeManager.type_type;
 326                 }
 327
 328                 [Conditional ("GMCS_SOURCE")]
 329                 void ApplyModuleCharSet ()
 330                 {
 331                         if (Type != TypeManager.dllimport_type)
 332                                 return;
 333
 334                         if (!CodeGen.Module.HasDefaultCharSet)
 335                                 return;
 336
 337                         const string CharSetEnumMember = "CharSet";
 338                         if (NamedArguments == null) {
 339                                 NamedArguments = new ArrayList (1);
 340                         } else {
 341                                 foreach (DictionaryEntry de in NamedArguments) {
 342                                         if ((string)de.Key == CharSetEnumMember)
 343                                                 return;
 344                                 }
 345                         }
 346
 347                         NamedArguments.Add (new DictionaryEntry (CharSetEnumMember,
 348                                 new Argument (Constant.CreateConstant (typeof (CharSet), CodeGen.Module.DefaultCharSet, Location))));
 349                 }
 350
 351                 public CustomAttributeBuilder Resolve ()
 352                 {
 353                         if (resolve_error)
 354                                 return null;
 355
 356                         resolve_error = true;
 357
 358                         if (Type == null) {
 359                                 ResolveAttributeType ();
 360                                 if (Type == null)
 361                                         return null;
 362                         }
 363
 364                         if (Type.IsAbstract) {
 365                                 Report.Error (653, Location, "Cannot apply attribute class `{0}' because it is abstract", GetSignatureForError ());
 366                                 return null;
 367                         }
 368
 369                         ObsoleteAttribute obsolete_attr = AttributeTester.GetObsoleteAttribute (Type);
 370                         if (obsolete_attr != null) {
 371                                 AttributeTester.Report_ObsoleteMessage (obsolete_attr, TypeManager.CSharpName (Type), Location);
 372                         }
 373
 374                         if (PosArguments == null && NamedArguments == null) {
 375                                 object o = att_cache [Type];
 376                                 if (o != null) {
 377                                         resolve_error = false;
 378                                         return (CustomAttributeBuilder)o;
 379                                 }
 380                         }
 381
 382                         Attributable owner = Owner;
 383                         DeclSpace ds = owner.ResolveContext as DeclSpace;
 384                         if (ds == null)
 385                                 ds = owner.ResolveContext.DeclContainer;
 386
 387                         EmitContext ec = new EmitContext (owner.ResolveContext, ds, owner.ResolveContext.DeclContainer,
 388                                 Location, null, typeof (Attribute), owner.ResolveContext.DeclContainer.ModFlags, false);
 389                         ec.IsAnonymousMethodAllowed = false;
 390
 391                         ConstructorInfo ctor = ResolveConstructor (ec);
 392                         if (ctor == null) {
 393                                 if (Type is TypeBuilder &&
 394                                     TypeManager.LookupDeclSpace (Type).MemberCache == null)
 395                                         // The attribute type has been DefineType'd, but not Defined.  Let's not treat it as an error.
 396                                         // It'll be resolved again when the attached-to entity is emitted.
 397                                         resolve_error = false;
 398                                 return null;
 399                         }
 400
 401                         ApplyModuleCharSet ();
 402
 403                         CustomAttributeBuilder cb;
 404                         try {
 405                                 // SRE does not allow private ctor but we want to report all source code errors
 406                                 if (ctor.IsPrivate)
 407                                         return null;
 408
 409                                 if (NamedArguments == null) {
 410                                         cb = new CustomAttributeBuilder (ctor, pos_values);
 411
 412                                         if (pos_values.Length == 0)
 413                                                 att_cache.Add (Type, cb);
 414
 415                                         resolve_error = false;
 416                                         return cb;
 417                                 }
 418
 419                                 if (!ResolveNamedArguments (ec)) {
 420                                         return null;
 421                                 }
 422
 423                                 cb = new CustomAttributeBuilder (ctor, pos_values,
 424                                                 prop_info_arr, prop_values_arr,
 425                                                 field_info_arr, field_values_arr);
 426
 427                                 resolve_error = false;
 428                                 return cb;
 429                         }
 430                         catch (Exception) {
 431                                 Error_AttributeArgumentNotValid (Location);
 432                                 return null;
 433                         }
 434                 }
 435
 436                 protected virtual ConstructorInfo ResolveConstructor (EmitContext ec)
 437                 {
 438                         if (PosArguments != null) {
 439                                 for (int i = 0; i < PosArguments.Count; i++) {
 440                                         Argument a = (Argument) PosArguments [i];
 441
 442                                         if (!a.Resolve (ec, Location))
 443                                                 return null;
 444                                 }
 445                         }
 446
 447                         MethodGroupExpr mg = MemberLookupFinal (ec, ec.ContainerType,
 448                                 Type, ".ctor", MemberTypes.Constructor,
 449                                 BindingFlags.Public | BindingFlags.Instance | BindingFlags.DeclaredOnly,
 450                                 Location) as MethodGroupExpr;
 451
 452                         if (mg == null)
 453                                 return null;
 454
 455                         mg = mg.OverloadResolve (ec, ref PosArguments, false, Location);
 456                         if (mg == null)
 457                                 return null;
 458
 459                         ConstructorInfo constructor = (ConstructorInfo)mg;
 460
 461                         // TODO: move to OverloadResolve
 462                         ObsoleteAttribute oa = AttributeTester.GetMethodObsoleteAttribute (constructor);
 463                         if (oa != null && !Owner.ResolveContext.IsInObsoleteScope) {
 464                                 AttributeTester.Report_ObsoleteMessage (oa, mg.GetSignatureForError (), mg.Location);
 465                         }
 466
 467                         if (PosArguments == null) {
 468                                 pos_values = EmptyObject;
 469                                 return constructor;
 470                         }
 471
 472                         AParametersCollection pd = TypeManager.GetParameterData (constructor);
 473
 474                         int pos_arg_count = PosArguments.Count;
 475                         pos_values = new object [pos_arg_count];
 476                         for (int j = 0; j < pos_arg_count; ++j) {
 477                                 Argument a = (Argument) PosArguments [j];
 478
 479                                 if (!a.Expr.GetAttributableValue (ec, a.Type, out pos_values [j]))
 480                                         return null;
 481                         }
 482
 483                         // Here we do the checks which should be done by corlib or by runtime.
 484                         // However Zoltan doesn't like it and every Mono compiler has to do it again.
 485
 486                         if (Type == TypeManager.guid_attr_type) {
 487                                 try {
 488                                         new Guid ((string)pos_values [0]);
 489                                 }
 490                                 catch (Exception e) {
 491                                         Error_AttributeEmitError (e.Message);
 492                                         return null;
 493                                 }
 494                         }
 495
 496                         if (Type == TypeManager.attribute_usage_type && (int)pos_values [0] == 0) {
 497                                 Report.Error (591, Location, "Invalid value for argument to `System.AttributeUsage' attribute");
 498                                 return null;
 499                         }
 500
 501                         if (Type == TypeManager.indexer_name_type || Type == TypeManager.conditional_attribute_type) {
 502                                 string v = pos_values [0] as string;
 503                                 if (!Tokenizer.IsValidIdentifier (v) || Tokenizer.IsKeyword (v)) {
 504                                         Report.Error (633, ((Argument)PosArguments[0]).Expr.Location,
 505                                                 "The argument to the `{0}' attribute must be a valid identifier", GetSignatureForError ());
 506                                         return null;
 507                                 }
 508                         }
 509
 510                         if (Type == TypeManager.methodimpl_attr_type && pos_values.Length == 1 &&
 511                                 pd.Types [0] == TypeManager.short_type &&
 512                                 !System.Enum.IsDefined (typeof (MethodImplOptions), pos_values [0].ToString ())) {
 513                                 Error_AttributeEmitError ("Incorrect argument value.");
 514                                 return null;
 515                         }
 516
 517                         return constructor;
 518                 }
 519
 520                 protected virtual bool ResolveNamedArguments (EmitContext ec)
 521                 {
 522                         int named_arg_count = NamedArguments.Count;
 523
 524                         ArrayList field_infos = new ArrayList (named_arg_count);
 525                         ArrayList prop_infos  = new ArrayList (named_arg_count);
 526                         ArrayList field_values = new ArrayList (named_arg_count);
 527                         ArrayList prop_values = new ArrayList (named_arg_count);
 528
 529                         ArrayList seen_names = new ArrayList(named_arg_count);
 530
 531                         foreach (DictionaryEntry de in NamedArguments) {
 532                                 string member_name = (string) de.Key;
 533
 534                                 if (seen_names.Contains(member_name)) {
 535                                         Report.Error(643, Location, "'" + member_name + "' duplicate named attribute argument");
 536                                         return false;
 537                                 }
 538                                 seen_names.Add(member_name);
 539
 540                                 Argument a = (Argument) de.Value;
 541                                 if (!a.Resolve (ec, Location))
 542                                         return false;
 543
 544                                 Expression member = Expression.MemberLookup (
 545                                         ec.ContainerType, Type, member_name,
 546                                         MemberTypes.Field | MemberTypes.Property,
 547                                         BindingFlags.Public | BindingFlags.Instance,
 548                                         Location);
 549
 550                                 if (member == null) {
 551                                         member = Expression.MemberLookup (ec.ContainerType, Type, member_name,
 552                                                 MemberTypes.Field | MemberTypes.Property, BindingFlags.NonPublic | BindingFlags.Instance,
 553                                                 Location);
 554
 555                                         if (member != null) {
 556                                                 Report.SymbolRelatedToPreviousError (member.Type);
 557                                                 Expression.ErrorIsInaccesible (Location, member.GetSignatureForError ());
 558                                                 return false;
 559                                         }
 560                                 }
 561
 562                                 if (member == null){
 563                                         Expression.Error_TypeDoesNotContainDefinition (Location, Type, member_name);
 564                                         return false;
 565                                 }
 566
 567                                 if (!(member is PropertyExpr || member is FieldExpr)) {
 568                                         Error_InvalidNamedArgument (member_name);
 569                                         return false;
 570                                 }
 571
 572                                 if (a.Expr is TypeParameterExpr){
 573                                         Error_TypeParameterInAttribute (Location);
 574                                         return false;
 575                                 }
 576
 577                                 ObsoleteAttribute obsolete_attr;
 578
 579                                 if (member is PropertyExpr) {
 580                                         PropertyInfo pi = ((PropertyExpr) member).PropertyInfo;
 581
 582                                         if (!pi.CanWrite || !pi.CanRead) {
 583                                                 Report.SymbolRelatedToPreviousError (pi);
 584                                                 Error_InvalidNamedArgument (member_name);
 585                                                 return false;
 586                                         }
 587
 588                                         if (!IsValidArgumentType (member.Type)) {
 589                                                 Report.SymbolRelatedToPreviousError (pi);
 590                                                 Error_InvalidNamedAgrumentType (member_name);
 591                                                 return false;
 592                                         }
 593
 594                                         object value;
 595                                         if (!a.Expr.GetAttributableValue (ec, member.Type, out value))
 596                                                 return false;
 597
 598                                         PropertyBase pb = TypeManager.GetProperty (pi);
 599                                         if (pb != null)
 600                                                 obsolete_attr = pb.GetObsoleteAttribute ();
 601                                         else
 602                                                 obsolete_attr = AttributeTester.GetMemberObsoleteAttribute (pi);
 603
 604                                         prop_values.Add (value);
 605                                         prop_infos.Add (pi);
 606
 607                                 } else {
 608                                         FieldInfo fi = ((FieldExpr) member).FieldInfo;
 609
 610                                         if (fi.IsInitOnly) {
 611                                                 Error_InvalidNamedArgument (member_name);
 612                                                 return false;
 613                                         }
 614
 615                                         if (!IsValidArgumentType (member.Type)) {
 616                                                 Report.SymbolRelatedToPreviousError (fi);
 617                                                 Error_InvalidNamedAgrumentType (member_name);
 618                                                 return false;
 619                                         }
 620
 621                                         object value;
 622                                         if (!a.Expr.GetAttributableValue (ec, member.Type, out value))
 623                                                 return false;
 624
 625                                         FieldBase fb = TypeManager.GetField (fi);
 626                                         if (fb != null)
 627                                                 obsolete_attr = fb.GetObsoleteAttribute ();
 628                                         else
 629                                                 obsolete_attr = AttributeTester.GetMemberObsoleteAttribute (fi);
 630
 631                                         field_values.Add (value);
 632                                         field_infos.Add (fi);
 633                                 }
 634
 635                                 if (obsolete_attr != null && !Owner.ResolveContext.IsInObsoleteScope)
 636                                         AttributeTester.Report_ObsoleteMessage (obsolete_attr, member.GetSignatureForError (), member.Location);
 637                         }
 638
 639                         prop_info_arr = new PropertyInfo [prop_infos.Count];
 640                         field_info_arr = new FieldInfo [field_infos.Count];
 641                         field_values_arr = new object [field_values.Count];
 642                         prop_values_arr = new object [prop_values.Count];
 643
 644                         field_infos.CopyTo  (field_info_arr, 0);
 645                         field_values.CopyTo (field_values_arr, 0);
 646
 647                         prop_values.CopyTo  (prop_values_arr, 0);
 648                         prop_infos.CopyTo   (prop_info_arr, 0);
 649
 650                         return true;
 651                 }
 652
 653                 /// <summary>
 654                 ///   Get a string containing a list of valid targets for the attribute 'attr'
 655                 /// </summary>
 656                 public string GetValidTargets ()
 657                 {
 658                         StringBuilder sb = new StringBuilder ();
 659                         AttributeTargets targets = GetAttributeUsage (Type).ValidOn;
 660
 661                         if ((targets & AttributeTargets.Assembly) != 0)
 662                                 sb.Append ("assembly, ");
 663
 664                         if ((targets & AttributeTargets.Module) != 0)
 665                                 sb.Append ("module, ");
 666
 667                         if ((targets & AttributeTargets.Class) != 0)
 668                                 sb.Append ("class, ");
 669
 670                         if ((targets & AttributeTargets.Struct) != 0)
 671                                 sb.Append ("struct, ");
 672
 673                         if ((targets & AttributeTargets.Enum) != 0)
 674                                 sb.Append ("enum, ");
 675
 676                         if ((targets & AttributeTargets.Constructor) != 0)
 677                                 sb.Append ("constructor, ");
 678
 679                         if ((targets & AttributeTargets.Method) != 0)
 680                                 sb.Append ("method, ");
 681
 682                         if ((targets & AttributeTargets.Property) != 0)
 683                                 sb.Append ("property, indexer, ");
 684
 685                         if ((targets & AttributeTargets.Field) != 0)
 686                                 sb.Append ("field, ");
 687
 688                         if ((targets & AttributeTargets.Event) != 0)
 689                                 sb.Append ("event, ");
 690
 691                         if ((targets & AttributeTargets.Interface) != 0)
 692                                 sb.Append ("interface, ");
 693
 694                         if ((targets & AttributeTargets.Parameter) != 0)
 695                                 sb.Append ("parameter, ");
 696
 697                         if ((targets & AttributeTargets.Delegate) != 0)
 698                                 sb.Append ("delegate, ");
 699
 700                         if ((targets & AttributeTargets.ReturnValue) != 0)
 701                                 sb.Append ("return, ");
 702
 703 #if NET_2_0
 704                         if ((targets & AttributeTargets.GenericParameter) != 0)
 705                                 sb.Append ("type parameter, ");
 706 #endif
 707                         return sb.Remove (sb.Length - 2, 2).ToString ();
 708                 }
 709
 710                 /// <summary>
 711                 /// Returns AttributeUsage attribute based on types hierarchy
 712                 /// </summary>
 713                 static AttributeUsageAttribute GetAttributeUsage (Type type)
 714                 {
 715                         AttributeUsageAttribute ua = usage_attr_cache [type] as AttributeUsageAttribute;
 716                         if (ua != null)
 717                                 return ua;
 718
 719                         Class attr_class = TypeManager.LookupClass (type);
 720
 721                         if (attr_class == null) {
 722                                 object[] usage_attr = type.GetCustomAttributes (TypeManager.attribute_usage_type, true);
 723                                 ua = (AttributeUsageAttribute)usage_attr [0];
 724                                 usage_attr_cache.Add (type, ua);
 725                                 return ua;
 726                         }
 727
 728                         Attribute a = null;
 729                         if (attr_class.OptAttributes != null)
 730                                 a = attr_class.OptAttributes.Search (TypeManager.attribute_usage_type);
 731
 732                         if (a == null) {
 733                                 if (attr_class.TypeBuilder.BaseType != TypeManager.attribute_type)
 734                                         ua = GetAttributeUsage (attr_class.TypeBuilder.BaseType);
 735                                 else
 736                                         ua = DefaultUsageAttribute;
 737                         } else {
 738                                 ua = a.GetAttributeUsageAttribute ();
 739                         }
 740
 741                         usage_attr_cache.Add (type, ua);
 742                         return ua;
 743                 }
 744
 745                 AttributeUsageAttribute GetAttributeUsageAttribute ()
 746                 {
 747                         if (pos_values == null)
 748                                 // TODO: It is not neccessary to call whole Resolve (ApplyAttribute does it now) we need only ctor args.
 749                                 // But because a lot of attribute class code must be rewritten will be better to wait...
 750                                 Resolve ();
 751
 752                         if (resolve_error)
 753                                 return DefaultUsageAttribute;
 754
 755                         AttributeUsageAttribute usage_attribute = new AttributeUsageAttribute ((AttributeTargets)pos_values [0]);
 756
 757                         object field = GetPropertyValue ("AllowMultiple");
 758                         if (field != null)
 759                                 usage_attribute.AllowMultiple = (bool)field;
 760
 761                         field = GetPropertyValue ("Inherited");
 762                         if (field != null)
 763                                 usage_attribute.Inherited = (bool)field;
 764
 765                         return usage_attribute;
 766                 }
 767
 768                 /// <summary>
 769                 /// Returns custom name of indexer
 770                 /// </summary>
 771                 public string GetIndexerAttributeValue ()
 772                 {
 773                         if (pos_values == null)
 774                                 // TODO: It is not neccessary to call whole Resolve (ApplyAttribute does it now) we need only ctor args.
 775                                 // But because a lot of attribute class code must be rewritten will be better to wait...
 776                                 Resolve ();
 777
 778                         if (resolve_error)
 779                                 return null;
 780
 781                         return pos_values [0] as string;
 782                 }
 783
 784                 /// <summary>
 785                 /// Returns condition of ConditionalAttribute
 786                 /// </summary>
 787                 public string GetConditionalAttributeValue ()
 788                 {
 789                         if (pos_values == null)
 790                                 // TODO: It is not neccessary to call whole Resolve (ApplyAttribute does it now) we need only ctor args.
 791                                 // But because a lot of attribute class code must be rewritten will be better to wait...
 792                                 Resolve ();
 793
 794                         if (resolve_error)
 795                                 return null;
 796
 797                         return (string)pos_values [0];
 798                 }
 799
 800                 /// <summary>
 801                 /// Creates the instance of ObsoleteAttribute from this attribute instance
 802                 /// </summary>
 803                 public ObsoleteAttribute GetObsoleteAttribute ()
 804                 {
 805                         if (pos_values == null)
 806                                 // TODO: It is not neccessary to call whole Resolve (ApplyAttribute does it now) we need only ctor args.
 807                                 // But because a lot of attribute class code must be rewritten will be better to wait...
 808                                 Resolve ();
 809
 810                         if (resolve_error)
 811                                 return null;
 812
 813                         if (pos_values == null || pos_values.Length == 0)
 814                                 return new ObsoleteAttribute ();
 815
 816                         if (pos_values.Length == 1)
 817                                 return new ObsoleteAttribute ((string)pos_values [0]);
 818
 819                         return new ObsoleteAttribute ((string)pos_values [0], (bool)pos_values [1]);
 820                 }
 821
 822                 /// <summary>
 823                 /// Returns value of CLSCompliantAttribute contructor parameter but because the method can be called
 824                 /// before ApplyAttribute. We need to resolve the arguments.
 825                 /// This situation occurs when class deps is differs from Emit order.
 826                 /// </summary>
 827                 public bool GetClsCompliantAttributeValue ()
 828                 {
 829                         if (pos_values == null)
 830                                 // TODO: It is not neccessary to call whole Resolve (ApplyAttribute does it now) we need only ctor args.
 831                                 // But because a lot of attribute class code must be rewritten will be better to wait...
 832                                 Resolve ();
 833
 834                         if (resolve_error)
 835                                 return false;
 836
 837                         return (bool)pos_values [0];
 838                 }
 839
 840                 public Type GetCoClassAttributeValue ()
 841                 {
 842                         if (pos_values == null)
 843                                 Resolve ();
 844
 845                         if (resolve_error)
 846                                 return null;
 847
 848                         return (Type)pos_values [0];
 849                 }
 850
 851                 public bool CheckTarget ()
 852                 {
 853                         string[] valid_targets = Owner.ValidAttributeTargets;
 854                         if (ExplicitTarget == null || ExplicitTarget == valid_targets [0]) {
 855                                 Target = Owner.AttributeTargets;
 856                                 return true;
 857                         }
 858
 859                         // TODO: we can skip the first item
 860                         if (((IList) valid_targets).Contains (ExplicitTarget)) {
 861                                 switch (ExplicitTarget) {
 862                                         case "return": Target = AttributeTargets.ReturnValue; return true;
 863                                         case "param": Target = AttributeTargets.Parameter; return true;
 864                                         case "field": Target = AttributeTargets.Field; return true;
 865                                         case "method": Target = AttributeTargets.Method; return true;
 866                                         case "property": Target = AttributeTargets.Property; return true;
 867                                 }
 868                                 throw new InternalErrorException ("Unknown explicit target: " + ExplicitTarget);
 869                         }
 870
 871                         StringBuilder sb = new StringBuilder ();
 872                         foreach (string s in valid_targets) {
 873                                 sb.Append (s);
 874                                 sb.Append (", ");
 875                         }
 876                         sb.Remove (sb.Length - 2, 2);
 877                         Report.Error (657, Location, "`{0}' is not a valid attribute location for this declaration. " +
 878                                 "Valid attribute locations for this declaration are `{1}'", ExplicitTarget, sb.ToString ());
 879                         return false;
 880                 }
 881
 882                 /// <summary>
 883                 /// Tests permitted SecurityAction for assembly or other types
 884                 /// </summary>
 885                 protected virtual bool IsSecurityActionValid (bool for_assembly)
 886                 {
 887                         SecurityAction action = GetSecurityActionValue ();
 888
 889                         switch (action) {
 890                         case SecurityAction.Demand:
 891                         case SecurityAction.Assert:
 892                         case SecurityAction.Deny:
 893                         case SecurityAction.PermitOnly:
 894                         case SecurityAction.LinkDemand:
 895                         case SecurityAction.InheritanceDemand:
 896                                 if (!for_assembly)
 897                                         return true;
 898                                 break;
 899
 900                         case SecurityAction.RequestMinimum:
 901                         case SecurityAction.RequestOptional:
 902                         case SecurityAction.RequestRefuse:
 903                                 if (for_assembly)
 904                                         return true;
 905                                 break;
 906
 907                         default:
 908                                 Error_AttributeEmitError ("SecurityAction is out of range");
 909                                 return false;
 910                         }
 911
 912                         Error_AttributeEmitError (String.Concat ("SecurityAction `", action, "' is not valid for this declaration"));
 913                         return false;
 914                 }
 915
 916                 System.Security.Permissions.SecurityAction GetSecurityActionValue ()
 917                 {
 918                         return (SecurityAction)pos_values [0];
 919                 }
 920
 921                 /// <summary>
 922                 /// Creates instance of SecurityAttribute class and add result of CreatePermission method to permission table.
 923                 /// </summary>
 924                 /// <returns></returns>
 925                 public void ExtractSecurityPermissionSet (ListDictionary permissions)
 926                 {
 927                         Type orig_assembly_type = null;
 928
 929                         if (TypeManager.LookupDeclSpace (Type) != null) {
 930                                 if (!RootContext.StdLib) {
 931                                         orig_assembly_type = Type.GetType (Type.FullName);
 932                                 } else {
 933                                         string orig_version_path = Environment.GetEnvironmentVariable ("__SECURITY_BOOTSTRAP_DB");
 934                                         if (orig_version_path == null) {
 935                                                 Error_AttributeEmitError ("security custom attributes can not be referenced from defining assembly");
 936                                                 return;
 937                                         }
 938
 939                                         if (orig_sec_assembly == null) {
 940                                                 string file = Path.Combine (orig_version_path, Driver.OutputFile);
 941                                                 orig_sec_assembly = Assembly.LoadFile (file);
 942                                         }
 943
 944                                         orig_assembly_type = orig_sec_assembly.GetType (Type.FullName, true);
 945                                         if (orig_assembly_type == null) {
 946                                                 Report.Warning (-112, 1, Location, "Self-referenced security attribute `{0}' " +
 947                                                                 "was not found in previous version of assembly");
 948                                                 return;
 949                                         }
 950                                 }
 951                         }
 952
 953                         SecurityAttribute sa;
 954                         // For all non-selfreferencing security attributes we can avoid all hacks
 955                         if (orig_assembly_type == null) {
 956                                 sa = (SecurityAttribute) Activator.CreateInstance (Type, pos_values);
 957
 958                                 if (prop_info_arr != null) {
 959                                         for (int i = 0; i < prop_info_arr.Length; ++i) {
 960                                                 PropertyInfo pi = prop_info_arr [i];
 961                                                 pi.SetValue (sa, prop_values_arr [i], null);
 962                                         }
 963                                 }
 964                         } else {
 965                                 // HACK: All security attributes have same ctor syntax
 966                                 sa = (SecurityAttribute) Activator.CreateInstance (orig_assembly_type, new object[] { GetSecurityActionValue () } );
 967
 968                                 // All types are from newly created assembly but for invocation with old one we need to convert them
 969                                 if (prop_info_arr != null) {
 970                                         for (int i = 0; i < prop_info_arr.Length; ++i) {
 971                                                 PropertyInfo emited_pi = prop_info_arr [i];
 972                                                 // FIXME: We are missing return type filter
 973                                                 // TODO: pi can be null
 974                                                 PropertyInfo pi = orig_assembly_type.GetProperty (emited_pi.Name);
 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                 public object GetPropertyValue (string name)
1020                 {
1021                         if (prop_info_arr == null)
1022                                 return null;
1023
1024                         for (int i = 0; i < prop_info_arr.Length; ++i) {
1025                                 if (prop_info_arr [i].Name == name)
1026                                         return prop_values_arr [i];
1027                         }
1028
1029                         return null;
1030                 }
1031
1032                 //
1033                 // Theoretically, we can get rid of this, since FieldBuilder.SetCustomAttribute()
1034                 // and ParameterBuilder.SetCustomAttribute() are supposed to handle this attribute.
1035                 // However, we can't, since it appears that the .NET 1.1 SRE hangs when given a MarshalAsAttribute.
1036                 //
1037 #if !NET_2_0
1038                 public UnmanagedMarshal GetMarshal (Attributable attr)
1039                 {
1040                         UnmanagedType UnmanagedType;
1041                         if (!RootContext.StdLib || pos_values [0].GetType () != typeof (UnmanagedType))
1042                                 UnmanagedType = (UnmanagedType) System.Enum.ToObject (typeof (UnmanagedType), pos_values [0]);
1043                         else
1044                                 UnmanagedType = (UnmanagedType) pos_values [0];
1045
1046                         object value = GetFieldValue ("SizeParamIndex");
1047                         if (value != null && UnmanagedType != UnmanagedType.LPArray) {
1048                                 Error_AttributeEmitError ("SizeParamIndex field is not valid for the specified unmanaged type");
1049                                 return null;
1050                         }
1051
1052                         object o = GetFieldValue ("ArraySubType");
1053                         UnmanagedType array_sub_type = o == null ? (UnmanagedType) 0x50 /* NATIVE_MAX */ : (UnmanagedType) o;
1054
1055                         switch (UnmanagedType) {
1056                         case UnmanagedType.CustomMarshaler: {
1057                                 MethodInfo define_custom = typeof (UnmanagedMarshal).GetMethod ("DefineCustom",
1058                                         BindingFlags.Static | BindingFlags.Public | BindingFlags.NonPublic);
1059                                 if (define_custom == null) {
1060                                         Report.RuntimeMissingSupport (Location, "set marshal info");
1061                                         return null;
1062                                 }
1063
1064                                 object [] args = new object [4];
1065                                 args [0] = GetFieldValue ("MarshalTypeRef");
1066                                 args [1] = GetFieldValue ("MarshalCookie");
1067                                 args [2] = GetFieldValue ("MarshalType");
1068                                 args [3] = Guid.Empty;
1069                                 return (UnmanagedMarshal) define_custom.Invoke (null, args);
1070                         }
1071                         case UnmanagedType.LPArray: {
1072                                 object size_const = GetFieldValue ("SizeConst");
1073                                 object size_param_index = GetFieldValue ("SizeParamIndex");
1074
1075                                 if ((size_const != null) || (size_param_index != null)) {
1076                                         MethodInfo define_array = typeof (UnmanagedMarshal).GetMethod ("DefineLPArrayInternal",
1077                                                 BindingFlags.Static | BindingFlags.Public | BindingFlags.NonPublic);
1078                                         if (define_array == null) {
1079                                                 Report.RuntimeMissingSupport (Location, "set marshal info");
1080                                                 return null;
1081                                         }
1082
1083                                         object [] args = new object [3];
1084                                         args [0] = array_sub_type;
1085                                         args [1] = size_const == null ? -1 : size_const;
1086                                         args [2] = size_param_index == null ? -1 : size_param_index;
1087                                         return (UnmanagedMarshal) define_array.Invoke (null, args);
1088                                 }
1089                                 else
1090                                         return UnmanagedMarshal.DefineLPArray (array_sub_type);
1091                         }
1092                         case UnmanagedType.SafeArray:
1093                                 return UnmanagedMarshal.DefineSafeArray (array_sub_type);
1094
1095                         case UnmanagedType.ByValArray:
1096                                 FieldBase fm = attr as FieldBase;
1097                                 if (fm == null) {
1098                                         Error_AttributeEmitError ("Specified unmanaged type is only valid on fields");
1099                                         return null;
1100                                 }
1101                                 return UnmanagedMarshal.DefineByValArray ((int) GetFieldValue ("SizeConst"));
1102
1103                         case UnmanagedType.ByValTStr:
1104                                 return UnmanagedMarshal.DefineByValTStr ((int) GetFieldValue ("SizeConst"));
1105
1106                         default:
1107                                 return UnmanagedMarshal.DefineUnmanagedMarshal (UnmanagedType);
1108                         }
1109                 }
1110
1111                 object GetFieldValue (string name)
1112                 {
1113                         int i;
1114                         if (field_info_arr == null)
1115                                 return null;
1116                         i = 0;
1117                         foreach (FieldInfo fi in field_info_arr) {
1118                                 if (fi.Name == name)
1119                                         return GetValue (field_values_arr [i]);
1120                                 i++;
1121                         }
1122                         return null;
1123                 }
1124
1125                 static object GetValue (object value)
1126                 {
1127                         if (value is EnumConstant)
1128                                 return ((EnumConstant) value).GetValue ();
1129                         else
1130                                 return value;
1131                 }
1132
1133 #endif
1134
1135                 public CharSet GetCharSetValue ()
1136                 {
1137                         return (CharSet)System.Enum.Parse (typeof (CharSet), pos_values [0].ToString ());
1138                 }
1139
1140                 public bool IsInternalMethodImplAttribute {
1141                         get {
1142                                 if (Type != TypeManager.methodimpl_attr_type)
1143                                         return false;
1144
1145                                 MethodImplOptions options;
1146                                 if (pos_values[0].GetType () != typeof (MethodImplOptions))
1147                                         options = (MethodImplOptions)System.Enum.ToObject (typeof (MethodImplOptions), pos_values[0]);
1148                                 else
1149                                         options = (MethodImplOptions)pos_values[0];
1150
1151                                 return (options & MethodImplOptions.InternalCall) != 0;
1152                         }
1153                 }
1154
1155                 public LayoutKind GetLayoutKindValue ()
1156                 {
1157                         if (!RootContext.StdLib || pos_values [0].GetType () != typeof (LayoutKind))
1158                                 return (LayoutKind)System.Enum.ToObject (typeof (LayoutKind), pos_values [0]);
1159
1160                         return (LayoutKind)pos_values [0];
1161                 }
1162
1163                 public object GetParameterDefaultValue ()
1164                 {
1165                         return pos_values [0];
1166                 }
1167
1168                 public override bool Equals (object obj)
1169                 {
1170                         Attribute a = obj as Attribute;
1171                         if (a == null)
1172                                 return false;
1173
1174                         return Type == a.Type && Target == a.Target;
1175                 }
1176
1177                 public override int GetHashCode ()
1178                 {
1179                         return base.GetHashCode ();
1180                 }
1181
1182                 /// <summary>
1183                 /// Emit attribute for Attributable symbol
1184                 /// </summary>
1185                 public void Emit (ListDictionary allEmitted)
1186                 {
1187                         CustomAttributeBuilder cb = Resolve ();
1188                         if (cb == null)
1189                                 return;
1190
1191                         AttributeUsageAttribute usage_attr = GetAttributeUsage (Type);
1192                         if ((usage_attr.ValidOn & Target) == 0) {
1193                                 Report.Error (592, Location, "The attribute `{0}' is not valid on this declaration type. " +
1194                                               "It is valid on `{1}' declarations only",
1195                                         GetSignatureForError (), GetValidTargets ());
1196                                 return;
1197                         }
1198
1199                         try {
1200                                 foreach (Attributable owner in owners)
1201                                         owner.ApplyAttributeBuilder (this, cb);
1202                         }
1203                         catch (Exception e) {
1204                                 Error_AttributeEmitError (e.Message);
1205                                 return;
1206                         }
1207
1208                         if (!usage_attr.AllowMultiple && allEmitted != null) {
1209                                 if (allEmitted.Contains (this)) {
1210                                         ArrayList a = allEmitted [this] as ArrayList;
1211                                         if (a == null) {
1212                                                 a = new ArrayList (2);
1213                                                 allEmitted [this] = a;
1214                                         }
1215                                         a.Add (this);
1216                                 } else {
1217                                         allEmitted.Add (this, null);
1218                                 }
1219                         }
1220
1221                         if (!RootContext.VerifyClsCompliance)
1222                                 return;
1223
1224                         // Here we are testing attribute arguments for array usage (error 3016)
1225                         if (Owner.IsClsComplianceRequired ()) {
1226                                 if (PosArguments != null) {
1227                                         foreach (Argument arg in PosArguments) {
1228                                                 // Type is undefined (was error 246)
1229                                                 if (arg.Type == null)
1230                                                         return;
1231
1232                                                 if (arg.Type.IsArray) {
1233                                                         Report.Warning (3016, 1, Location, "Arrays as attribute arguments are not CLS-compliant");
1234                                                         return;
1235                                                 }
1236                                         }
1237                                 }
1238
1239                                 if (NamedArguments == null)
1240                                         return;
1241
1242                                 foreach (DictionaryEntry de in NamedArguments) {
1243                                         Argument arg  = (Argument) de.Value;
1244
1245                                         // Type is undefined (was error 246)
1246                                         if (arg.Type == null)
1247                                                 return;
1248
1249                                         if (arg.Type.IsArray) {
1250                                                 Report.Warning (3016, 1, Location, "Arrays as attribute arguments are not CLS-compliant");
1251                                                 return;
1252                                         }
1253                                 }
1254                         }
1255                 }
1256
1257                 private Expression GetValue ()
1258                 {
1259                         if (PosArguments == null || PosArguments.Count < 1)
1260                                 return null;
1261
1262                         return ((Argument) PosArguments [0]).Expr;
1263                 }
1264
1265                 public string GetString ()
1266                 {
1267                         Expression e = GetValue ();
1268                         if (e is StringConstant)
1269                                 return ((StringConstant)e).Value;
1270                         return null;
1271                 }
1272
1273                 public bool GetBoolean ()
1274                 {
1275                         Expression e = GetValue ();
1276                         if (e is BoolConstant)
1277                                 return ((BoolConstant)e).Value;
1278                         return false;
1279                 }
1280
1281                 public Type GetArgumentType ()
1282                 {
1283                         TypeOf e = GetValue () as TypeOf;
1284                         if (e == null)
1285                                 return null;
1286                         return e.TypeArgument;
1287                 }
1288
1289                 public override Expression CreateExpressionTree (EmitContext ec)
1290                 {
1291                         throw new NotSupportedException ("ET");
1292                 }
1293
1294                 public override Expression DoResolve (EmitContext ec)
1295                 {
1296                         throw new NotImplementedException ();
1297                 }
1298
1299                 public override void Emit (EmitContext ec)
1300                 {
1301                         throw new NotImplementedException ();
1302                 }
1303         }
1304
1305
1306         /// <summary>
1307         /// For global attributes (assembly, module) we need special handling.
1308         /// Attributes can be located in the several files
1309         /// </summary>
1310         public class GlobalAttribute : Attribute
1311         {
1312                 public readonly NamespaceEntry ns;
1313
1314                 public GlobalAttribute (NamespaceEntry ns, string target,
1315                                         Expression left_expr, string identifier, object[] args, Location loc, bool nameEscaped):
1316                         base (target, left_expr, identifier, args, loc, nameEscaped)
1317                 {
1318                         this.ns = ns;
1319                         this.owners = new Attributable[1];
1320                 }
1321
1322                 public override void AttachTo (Attributable owner)
1323                 {
1324                         if (ExplicitTarget == "assembly") {
1325                                 owners [0] = CodeGen.Assembly;
1326                                 return;
1327                         }
1328                         if (ExplicitTarget == "module") {
1329                                 owners [0] = CodeGen.Module;
1330                                 return;
1331                         }
1332                         throw new NotImplementedException ("Unknown global explicit target " + ExplicitTarget);
1333                 }
1334
1335                 void Enter ()
1336                 {
1337                         // RootContext.ToplevelTypes has a single NamespaceEntry which gets overwritten
1338                         // each time a new file is parsed.  However, we need to use the NamespaceEntry
1339                         // in effect where the attribute was used.  Since code elsewhere cannot assume
1340                         // that the NamespaceEntry is right, just overwrite it.
1341                         //
1342                         // Precondition: RootContext.ToplevelTypes == null
1343
1344                         if (RootContext.ToplevelTypes.NamespaceEntry != null)
1345                                 throw new InternalErrorException (Location + " non-null NamespaceEntry");
1346
1347                         RootContext.ToplevelTypes.NamespaceEntry = ns;
1348                 }
1349
1350                 protected override bool IsSecurityActionValid (bool for_assembly)
1351                 {
1352                         return base.IsSecurityActionValid (true);
1353                 }
1354
1355                 void Leave ()
1356                 {
1357                         RootContext.ToplevelTypes.NamespaceEntry = null;
1358                 }
1359
1360                 protected override TypeExpr ResolveAsTypeTerminal (Expression expr, IResolveContext ec, bool silent)
1361                 {
1362                         try {
1363                                 Enter ();
1364                                 return base.ResolveAsTypeTerminal (expr, ec, silent);
1365                         }
1366                         finally {
1367                                 Leave ();
1368                         }
1369                 }
1370
1371                 protected override ConstructorInfo ResolveConstructor (EmitContext ec)
1372                 {
1373                         try {
1374                                 Enter ();
1375                                 return base.ResolveConstructor (ec);
1376                         }
1377                         finally {
1378                                 Leave ();
1379                         }
1380                 }
1381
1382                 protected override bool ResolveNamedArguments (EmitContext ec)
1383                 {
1384                         try {
1385                                 Enter ();
1386                                 return base.ResolveNamedArguments (ec);
1387                         }
1388                         finally {
1389                                 Leave ();
1390                         }
1391                 }
1392         }
1393
1394         public class Attributes {
1395                 public readonly ArrayList Attrs;
1396
1397                 public Attributes (Attribute a)
1398                 {
1399                         Attrs = new ArrayList ();
1400                         Attrs.Add (a);
1401                 }
1402
1403                 public Attributes (ArrayList attrs)
1404                 {
1405                         Attrs = attrs;
1406                 }
1407
1408                 public void AddAttributes (ArrayList attrs)
1409                 {
1410                         Attrs.AddRange (attrs);
1411                 }
1412
1413                 public void AttachTo (Attributable attributable)
1414                 {
1415                         foreach (Attribute a in Attrs)
1416                                 a.AttachTo (attributable);
1417                 }
1418
1419                 public Attributes Clone ()
1420                 {
1421                         ArrayList al = new ArrayList (Attrs.Count);
1422                         foreach (Attribute a in Attrs)
1423                                 al.Add (a.Clone ());
1424
1425                         return new Attributes (al);
1426                 }
1427
1428                 /// <summary>
1429                 /// Checks whether attribute target is valid for the current element
1430                 /// </summary>
1431                 public bool CheckTargets ()
1432                 {
1433                         foreach (Attribute a in Attrs) {
1434                                 if (!a.CheckTarget ())
1435                                         return false;
1436                         }
1437                         return true;
1438                 }
1439
1440                 public Attribute Search (Type t)
1441                 {
1442                         foreach (Attribute a in Attrs) {
1443                                 if (a.ResolveType () == t)
1444                                         return a;
1445                         }
1446                         return null;
1447                 }
1448
1449                 /// <summary>
1450                 /// Returns all attributes of type 't'. Use it when attribute is AllowMultiple = true
1451                 /// </summary>
1452                 public Attribute[] SearchMulti (Type t)
1453                 {
1454                         ArrayList ar = null;
1455
1456                         foreach (Attribute a in Attrs) {
1457                                 if (a.ResolveType () == t) {
1458                                         if (ar == null)
1459                                                 ar = new ArrayList ();
1460                                         ar.Add (a);
1461                                 }
1462                         }
1463
1464                         return ar == null ? null : ar.ToArray (typeof (Attribute)) as Attribute[];
1465                 }
1466
1467                 public void Emit ()
1468                 {
1469                         CheckTargets ();
1470
1471                         ListDictionary ld = Attrs.Count > 1 ? new ListDictionary () : null;
1472
1473                         foreach (Attribute a in Attrs)
1474                                 a.Emit (ld);
1475
1476                         if (ld == null || ld.Count == 0)
1477                                 return;
1478
1479                         foreach (DictionaryEntry d in ld) {
1480                                 if (d.Value == null)
1481                                         continue;
1482
1483                                 foreach (Attribute collision in (ArrayList)d.Value)
1484                                         Report.SymbolRelatedToPreviousError (collision.Location, "");
1485
1486                                 Attribute a = (Attribute)d.Key;
1487                                 Report.Error (579, a.Location, "The attribute `{0}' cannot be applied multiple times",
1488                                         a.GetSignatureForError ());
1489                         }
1490                 }
1491
1492                 public bool Contains (Type t)
1493                 {
1494                         return Search (t) != null;
1495                 }
1496         }
1497
1498         /// <summary>
1499         /// Helper class for attribute verification routine.
1500         /// </summary>
1501         sealed class AttributeTester
1502         {
1503                 static PtrHashtable analyzed_types;
1504                 static PtrHashtable analyzed_types_obsolete;
1505                 static PtrHashtable analyzed_member_obsolete;
1506                 static PtrHashtable analyzed_method_excluded;
1507                 static PtrHashtable fixed_buffer_cache;
1508
1509                 static object TRUE = new object ();
1510                 static object FALSE = new object ();
1511
1512                 static AttributeTester ()
1513                 {
1514                         Reset ();
1515                 }
1516
1517                 private AttributeTester ()
1518                 {
1519                 }
1520
1521                 public static void Reset ()
1522                 {
1523                         analyzed_types = new PtrHashtable ();
1524                         analyzed_types_obsolete = new PtrHashtable ();
1525                         analyzed_member_obsolete = new PtrHashtable ();
1526                         analyzed_method_excluded = new PtrHashtable ();
1527                         fixed_buffer_cache = new PtrHashtable ();
1528                 }
1529
1530                 public enum Result {
1531                         Ok,
1532                         RefOutArrayError,
1533                         ArrayArrayError
1534                 }
1535
1536                 /// <summary>
1537                 /// Returns true if parameters of two compared methods are CLS-Compliant.
1538                 /// It tests differing only in ref or out, or in array rank.
1539                 /// </summary>
1540                 public static Result AreOverloadedMethodParamsClsCompliant (AParametersCollection pa, AParametersCollection pb)
1541                 {
1542                         Type [] types_a = pa.Types;
1543                         Type [] types_b = pb.Types;
1544                         if (types_a == null || types_b == null)
1545                                 return Result.Ok;
1546
1547                         if (types_a.Length != types_b.Length)
1548                                 return Result.Ok;
1549
1550                         Result result = Result.Ok;
1551                         for (int i = 0; i < types_b.Length; ++i) {
1552                                 Type aType = types_a [i];
1553                                 Type bType = types_b [i];
1554
1555                                 if (aType.IsArray && bType.IsArray) {
1556                                         Type a_el_type = aType.GetElementType ();
1557                                         Type b_el_type = bType.GetElementType ();
1558                                         if (aType.GetArrayRank () != bType.GetArrayRank () && a_el_type == b_el_type) {
1559                                                 result = Result.RefOutArrayError;
1560                                                 continue;
1561                                         }
1562
1563                                         if (a_el_type.IsArray || b_el_type.IsArray) {
1564                                                 result = Result.ArrayArrayError;
1565                                                 continue;
1566                                         }
1567                                 }
1568
1569                                 if (aType != bType)
1570                                         return Result.Ok;
1571
1572                                 if (pa.FixedParameters [i].ModFlags != pb.FixedParameters [i].ModFlags)
1573                                         result = Result.RefOutArrayError;
1574                         }
1575                         return result;
1576                 }
1577
1578                 /// <summary>
1579                 /// This method tests the CLS compliance of external types. It doesn't test type visibility.
1580                 /// </summary>
1581                 public static bool IsClsCompliant (Type type)
1582                 {
1583                         if (type == null)
1584                                 return true;
1585
1586                         object type_compliance = analyzed_types[type];
1587                         if (type_compliance != null)
1588                                 return type_compliance == TRUE;
1589
1590                         if (type.IsPointer) {
1591                                 analyzed_types.Add (type, FALSE);
1592                                 return false;
1593                         }
1594
1595                         bool result;
1596                         if (type.IsArray) {
1597                                 result = IsClsCompliant (TypeManager.GetElementType (type));
1598                         } else if (TypeManager.IsNullableType (type)) {
1599                                 result = IsClsCompliant (TypeManager.GetTypeArguments (type) [0]);
1600                         } else {
1601                                 result = AnalyzeTypeCompliance (type);
1602                         }
1603                         analyzed_types.Add (type, result ? TRUE : FALSE);
1604                         return result;
1605                 }
1606
1607                 /// <summary>
1608                 /// Returns IFixedBuffer implementation if field is fixed buffer else null.
1609                 /// </summary>
1610                 public static IFixedBuffer GetFixedBuffer (FieldInfo fi)
1611                 {
1612                         // Fixed buffer helper type is generated as value type
1613                         if (!fi.FieldType.IsValueType)
1614                                 return null;
1615
1616                         FieldBase fb = TypeManager.GetField (fi);
1617                         if (fb != null) {
1618                                 return fb as IFixedBuffer;
1619                         }
1620
1621                         if (TypeManager.GetConstant (fi) != null)
1622                                 return null;
1623
1624                         object o = fixed_buffer_cache [fi];
1625                         if (o == null) {
1626                                 if (TypeManager.fixed_buffer_attr_type == null)
1627                                         return null;
1628
1629                                 if (!fi.IsDefined (TypeManager.fixed_buffer_attr_type, false)) {
1630                                         fixed_buffer_cache.Add (fi, FALSE);
1631                                         return null;
1632                                 }
1633
1634                                 IFixedBuffer iff = new FixedFieldExternal (fi);
1635                                 fixed_buffer_cache.Add (fi, iff);
1636                                 return iff;
1637                         }
1638
1639                         if (o == FALSE)
1640                                 return null;
1641
1642                         return (IFixedBuffer)o;
1643                 }
1644
1645                 public static void VerifyModulesClsCompliance ()
1646                 {
1647                         Module[] modules = RootNamespace.Global.Modules;
1648                         if (modules == null)
1649                                 return;
1650
1651                         // The first module is generated assembly
1652                         for (int i = 1; i < modules.Length; ++i) {
1653                                 Module module = modules [i];
1654                                 if (!GetClsCompliantAttributeValue (module, null)) {
1655                                         Report.Error (3013, "Added modules must be marked with the CLSCompliant attribute " +
1656                                                       "to match the assembly", module.Name);
1657                                         return;
1658                                 }
1659                         }
1660                 }
1661
1662                 public static Type GetImportedIgnoreCaseClsType (string name)
1663                 {
1664                         foreach (Assembly a in RootNamespace.Global.Assemblies) {
1665                                 Type t = a.GetType (name, false, true);
1666                                 if (t == null)
1667                                         continue;
1668
1669                                 if (IsClsCompliant (t))
1670                                         return t;
1671                         }
1672                         return null;
1673                 }
1674
1675                 static bool GetClsCompliantAttributeValue (ICustomAttributeProvider attribute_provider, Assembly a)
1676                 {
1677                         if (TypeManager.cls_compliant_attribute_type == null)
1678                                 return false;
1679
1680                         object[] cls_attr = attribute_provider.GetCustomAttributes (TypeManager.cls_compliant_attribute_type, false);
1681                         if (cls_attr.Length == 0) {
1682                                 if (a == null)
1683                                         return false;
1684
1685                                 return GetClsCompliantAttributeValue (a, null);
1686                         }
1687
1688                         return ((CLSCompliantAttribute)cls_attr [0]).IsCompliant;
1689                 }
1690
1691                 static bool AnalyzeTypeCompliance (Type type)
1692                 {
1693                         type = TypeManager.DropGenericTypeArguments (type);
1694                         DeclSpace ds = TypeManager.LookupDeclSpace (type);
1695                         if (ds != null) {
1696                                 return ds.IsClsComplianceRequired ();
1697                         }
1698
1699                         if (TypeManager.IsGenericParameter (type))
1700                                 return true;
1701
1702                         return GetClsCompliantAttributeValue (type, type.Assembly);
1703                 }
1704
1705                 /// <summary>
1706                 /// Returns instance of ObsoleteAttribute when type is obsolete
1707                 /// </summary>
1708                 public static ObsoleteAttribute GetObsoleteAttribute (Type type)
1709                 {
1710                         object type_obsolete = analyzed_types_obsolete [type];
1711                         if (type_obsolete == FALSE)
1712                                 return null;
1713
1714                         if (type_obsolete != null)
1715                                 return (ObsoleteAttribute)type_obsolete;
1716
1717                         ObsoleteAttribute result = null;
1718                         if (TypeManager.HasElementType (type)) {
1719                                 result = GetObsoleteAttribute (TypeManager.GetElementType (type));
1720                         } else if (TypeManager.IsGenericParameter (type) || TypeManager.IsGenericType (type))
1721                                 return null;
1722                         else {
1723                                 DeclSpace type_ds = TypeManager.LookupDeclSpace (type);
1724
1725                                 // Type is external, we can get attribute directly
1726                                 if (type_ds == null) {
1727                                         if (TypeManager.obsolete_attribute_type != null) {
1728                                                 object [] attribute = type.GetCustomAttributes (TypeManager.obsolete_attribute_type, false);
1729                                                 if (attribute.Length == 1)
1730                                                         result = (ObsoleteAttribute) attribute [0];
1731                                         }
1732                                 } else {
1733                                         result = type_ds.GetObsoleteAttribute ();
1734                                 }
1735                         }
1736
1737                         // Cannot use .Add because of corlib bootstrap
1738                         analyzed_types_obsolete [type] = result == null ? FALSE : result;
1739                         return result;
1740                 }
1741
1742                 /// <summary>
1743                 /// Returns instance of ObsoleteAttribute when method is obsolete
1744                 /// </summary>
1745                 public static ObsoleteAttribute GetMethodObsoleteAttribute (MethodBase mb)
1746                 {
1747                         IMethodData mc = TypeManager.GetMethod (mb);
1748                         if (mc != null)
1749                                 return mc.GetObsoleteAttribute ();
1750
1751                         // compiler generated methods are not registered by AddMethod
1752                         if (mb.DeclaringType is TypeBuilder)
1753                                 return null;
1754
1755                         MemberInfo mi = TypeManager.GetPropertyFromAccessor (mb);
1756                         if (mi != null)
1757                                 return GetMemberObsoleteAttribute (mi);
1758
1759                         mi = TypeManager.GetEventFromAccessor (mb);
1760                         if (mi != null)
1761                                 return GetMemberObsoleteAttribute (mi);
1762
1763                         return GetMemberObsoleteAttribute (mb);
1764                 }
1765
1766                 /// <summary>
1767                 /// Returns instance of ObsoleteAttribute when member is obsolete
1768                 /// </summary>
1769                 public static ObsoleteAttribute GetMemberObsoleteAttribute (MemberInfo mi)
1770                 {
1771                         object type_obsolete = analyzed_member_obsolete [mi];
1772                         if (type_obsolete == FALSE)
1773                                 return null;
1774
1775                         if (type_obsolete != null)
1776                                 return (ObsoleteAttribute)type_obsolete;
1777
1778                         if ((mi.DeclaringType is TypeBuilder) || TypeManager.IsGenericType (mi.DeclaringType))
1779                                 return null;
1780
1781                         if (TypeManager.obsolete_attribute_type == null)
1782                                 return null;
1783
1784                         ObsoleteAttribute oa = System.Attribute.GetCustomAttribute (mi, TypeManager.obsolete_attribute_type, false)
1785                                 as ObsoleteAttribute;
1786                         analyzed_member_obsolete.Add (mi, oa == null ? FALSE : oa);
1787                         return oa;
1788                 }
1789
1790                 /// <summary>
1791                 /// Common method for Obsolete error/warning reporting.
1792                 /// </summary>
1793                 public static void Report_ObsoleteMessage (ObsoleteAttribute oa, string member, Location loc)
1794                 {
1795                         if (oa.IsError) {
1796                                 Report.Error (619, loc, "`{0}' is obsolete: `{1}'", member, oa.Message);
1797                                 return;
1798                         }
1799
1800                         if (oa.Message == null || oa.Message.Length == 0) {
1801                                 Report.Warning (612, 1, loc, "`{0}' is obsolete", member);
1802                                 return;
1803                         }
1804                         Report.Warning (618, 2, loc, "`{0}' is obsolete: `{1}'", member, oa.Message);
1805                 }
1806
1807                 public static bool IsConditionalMethodExcluded (MethodBase mb, Location loc)
1808                 {
1809                         object excluded = analyzed_method_excluded [mb];
1810                         if (excluded != null)
1811                                 return excluded == TRUE ? true : false;
1812
1813                         if (TypeManager.conditional_attribute_type == null)
1814                                 return false;
1815
1816                         ConditionalAttribute[] attrs = mb.GetCustomAttributes (TypeManager.conditional_attribute_type, true)
1817                                 as ConditionalAttribute[];
1818                         if (attrs.Length == 0) {
1819                                 analyzed_method_excluded.Add (mb, FALSE);
1820                                 return false;
1821                         }
1822
1823                         foreach (ConditionalAttribute a in attrs) {
1824                                 if (loc.CompilationUnit.IsConditionalDefined (a.ConditionString)) {
1825                                         analyzed_method_excluded.Add (mb, FALSE);
1826                                         return false;
1827                                 }
1828                         }
1829
1830                         analyzed_method_excluded.Add (mb, TRUE);
1831                         return true;
1832                 }
1833
1834                 /// <summary>
1835                 /// Analyzes class whether it has attribute which has ConditionalAttribute
1836                 /// and its condition is not defined.
1837                 /// </summary>
1838                 public static bool IsAttributeExcluded (Type type, Location loc)
1839                 {
1840                         if (!type.IsClass)
1841                                 return false;
1842
1843                         Class class_decl = TypeManager.LookupDeclSpace (type) as Class;
1844
1845                         // TODO: add caching
1846                         // TODO: merge all Type bases attribute caching to one cache to save memory
1847                         if (class_decl == null && TypeManager.conditional_attribute_type != null) {
1848                                 object[] attributes = type.GetCustomAttributes (TypeManager.conditional_attribute_type, false);
1849                                 foreach (ConditionalAttribute ca in attributes) {
1850                                         if (loc.CompilationUnit.IsConditionalDefined (ca.ConditionString))
1851                                                 return false;
1852                                 }
1853                                 return attributes.Length > 0;
1854                         }
1855
1856                         return class_decl.IsExcluded ();
1857                 }
1858
1859                 public static Type GetCoClassAttribute (Type type)
1860                 {
1861                         TypeContainer tc = TypeManager.LookupInterface (type);
1862                         if (tc == null) {
1863                                 if (TypeManager.coclass_attr_type == null)
1864                                         return null;
1865
1866                                 object[] o = type.GetCustomAttributes (TypeManager.coclass_attr_type, false);
1867                                 if (o.Length < 1)
1868                                         return null;
1869                                 return ((System.Runtime.InteropServices.CoClassAttribute)o[0]).CoClass;
1870                         }
1871
1872                         if (tc.OptAttributes == null || TypeManager.coclass_attr_type == null)
1873                                 return null;
1874
1875                         Attribute a = tc.OptAttributes.Search (TypeManager.coclass_attr_type);
1876                         if (a == null)
1877                                 return null;
1878
1879                         return a.GetCoClassAttributeValue ();
1880                 }
1881         }
1882 }