mcs/mcs/attribute.cs

   1 //
   2 // attribute.cs: Attribute Handler
   3 //
   4 // Author: Ravi Pratap (ravi@ximian.com)
   5 //         Marek Safar (marek.safar@seznam.cz)
   6 //
   7 // Licensed under the terms of the GNU GPL
   8 //
   9 // (C) 2001 Ximian, Inc (http://www.ximian.com)
  10 //
  11 //
  12
  13 using System;
  14 using System.Diagnostics;
  15 using System.Collections;
  16 using System.Collections.Specialized;
  17 using System.Reflection;
  18 using System.Reflection.Emit;
  19 using System.Runtime.InteropServices;
  20 using System.Runtime.CompilerServices;
  21 using System.Security;
  22 using System.Security.Permissions;
  23 using System.Text;
  24 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                 Attributes attributes;
  36
  37                 public Attributable (Attributes attrs)
  38                 {
  39                         attributes = attrs;
  40                 }
  41
  42                 public Attributes OptAttributes
  43                 {
  44                         get {
  45                                 return attributes;
  46                         }
  47                         set {
  48                                 attributes = value;
  49                         }
  50                 }
  51
  52                 /// <summary>
  53                 /// Use member-specific procedure to apply attribute @a in @cb to the entity being built in @builder
  54                 /// </summary>
  55                 public abstract void ApplyAttributeBuilder (Attribute a, CustomAttributeBuilder cb);
  56
  57                 /// <summary>
  58                 /// Returns one AttributeTarget for this element.
  59                 /// </summary>
  60                 public abstract AttributeTargets AttributeTargets { get; }
  61
  62                 public abstract bool IsClsCompliaceRequired (DeclSpace ds);
  63
  64                 /// <summary>
  65                 /// Gets list of valid attribute targets for explicit target declaration.
  66                 /// The first array item is default target. Don't break this rule.
  67                 /// </summary>
  68                 public abstract string[] ValidAttributeTargets { get; }
  69         };
  70
  71         public class Attribute {
  72                 public readonly string ExplicitTarget;
  73                 public AttributeTargets Target;
  74
  75                 // TODO: remove this member
  76                 public readonly string    Name;
  77                 public readonly Expression LeftExpr;
  78                 public readonly string Identifier;
  79
  80                 public readonly ArrayList Arguments;
  81
  82                 public readonly Location Location;
  83
  84                 public Type Type;
  85
  86                 bool resolve_error;
  87
  88                 readonly bool nameEscaped;
  89
  90                 static AttributeUsageAttribute DefaultUsageAttribute = new AttributeUsageAttribute (AttributeTargets.All);
  91                 static Assembly orig_sec_assembly;
  92
  93                 // non-null if named args present after Resolve () is called
  94                 PropertyInfo [] prop_info_arr;
  95                 FieldInfo [] field_info_arr;
  96                 object [] field_values_arr;
  97                 object [] prop_values_arr;
  98                 object [] pos_values;
  99
 100                 static PtrHashtable usage_attr_cache = new PtrHashtable ();
 101
 102                 public Attribute (string target, Expression left_expr, string identifier, ArrayList args, Location loc, bool nameEscaped)
 103                 {
 104                         LeftExpr = left_expr;
 105                         Identifier = identifier;
 106                         Name = LeftExpr == null ? identifier : LeftExpr + "." + identifier;
 107                         Arguments = args;
 108                         Location = loc;
 109                         ExplicitTarget = target;
 110                         this.nameEscaped = nameEscaped;
 111                 }
 112
 113                 void Error_InvalidNamedArgument (string name)
 114                 {
 115                         Report.Error (617, Location, "`{0}' is not a valid named attribute argument. Named attribute arguments must be fields which are not readonly, static, const or read-write properties which are public and not static",
 116                               name);
 117                 }
 118
 119                 void Error_InvalidNamedAgrumentType (string name)
 120                 {
 121                         Report.Error (655, Location, "`{0}' is not a valid named attribute argument because it is not a valid attribute parameter type", name);
 122                 }
 123
 124                 static void Error_AttributeArgumentNotValid (string extra, Location loc)
 125                 {
 126                         Report.Error (182, loc,
 127                                       "An attribute argument must be a constant expression, typeof " +
 128                                       "expression or array creation expression" + extra);
 129                 }
 130
 131                 static void Error_AttributeArgumentNotValid (Location loc)
 132                 {
 133                         Error_AttributeArgumentNotValid ("", loc);
 134                 }
 135
 136
 137                 /// <summary>
 138                 /// This is rather hack. We report many emit attribute error with same error to be compatible with
 139                 /// csc. But because csc has to report them this way because error came from ilasm we needn't.
 140                 /// </summary>
 141                 public void Error_AttributeEmitError (string inner)
 142                 {
 143                         Report.Error (647, Location, "Error during emitting `{0}' attribute. The reason is `{1}'", TypeManager.CSharpName (Type), inner);
 144                 }
 145
 146                 public void Error_InvalidSecurityParent ()
 147                 {
 148                         Error_AttributeEmitError ("it is attached to invalid parent");
 149                 }
 150
 151                 protected virtual FullNamedExpression ResolveAsTypeTerminal (Expression expr, EmitContext ec, bool silent)
 152                 {
 153                         return expr.ResolveAsTypeTerminal (ec, silent);
 154                 }
 155
 156                 protected virtual FullNamedExpression ResolveAsTypeStep (Expression expr, EmitContext ec, bool silent)
 157                 {
 158                         return expr.ResolveAsTypeStep (ec, silent);
 159                 }
 160
 161                 Type ResolvePossibleAttributeType (EmitContext ec, string name, bool silent, ref bool is_attr)
 162                 {
 163                         FullNamedExpression fn;
 164                         if (LeftExpr == null) {
 165                                 fn = ResolveAsTypeTerminal (new SimpleName (name, Location), ec, silent);
 166                         } else {
 167                                 fn = ResolveAsTypeStep (LeftExpr, ec, silent);
 168                                 if (fn == null)
 169                                         return null;
 170                                 fn = new MemberAccess (fn, name, Location).ResolveAsTypeTerminal (ec, silent);
 171                         }
 172
 173                         TypeExpr te = fn as TypeExpr;
 174                         if (te == null)
 175                                 return null;
 176
 177                         Type t = te.Type;
 178                         if (t.IsSubclassOf (TypeManager.attribute_type)) {
 179                                 is_attr = true;
 180                         } else if (!silent) {
 181                                 Report.SymbolRelatedToPreviousError (t);
 182                                 Report.Error (616, Location, "`{0}': is not an attribute class", TypeManager.CSharpName (t));
 183                         }
 184                         return t;
 185                 }
 186
 187                 /// <summary>
 188                 ///   Tries to resolve the type of the attribute. Flags an error if it can't, and complain is true.
 189                 /// </summary>
 190                 void ResolveAttributeType (EmitContext ec)
 191                 {
 192                         bool t1_is_attr = false;
 193                         Type t1 = ResolvePossibleAttributeType (ec, Identifier, true, ref t1_is_attr);
 194
 195                         bool t2_is_attr = false;
 196                         Type t2 = nameEscaped ? null :
 197                                 ResolvePossibleAttributeType (ec, Identifier + "Attribute", true, ref t2_is_attr);
 198
 199                         if (t1_is_attr && t2_is_attr) {
 200                                 Report.Error (1614, Location, "`{0}' is ambiguous between `{0}' and `{0}Attribute'. Use either `@{0}' or `{0}Attribute'", GetSignatureForError ());
 201                                 resolve_error = true;
 202                                 return;
 203                         }
 204
 205                         if (t1_is_attr) {
 206                                 Type = t1;
 207                                 return;
 208                         }
 209
 210                         if (t2_is_attr) {
 211                                 Type = t2;
 212                                 return;
 213                         }
 214
 215                         if (t1 == null && t2 == null)
 216                                 ResolvePossibleAttributeType (ec, Identifier, false, ref t1_is_attr);
 217                         if (t1 != null)
 218                                 ResolvePossibleAttributeType (ec, Identifier, false, ref t1_is_attr);
 219                         if (t2 != null)
 220                                 ResolvePossibleAttributeType (ec, Identifier + "Attribute", false, ref t2_is_attr);
 221
 222                         resolve_error = true;
 223                 }
 224
 225                 public virtual Type ResolveType (EmitContext ec)
 226                 {
 227                         if (Type == null && !resolve_error)
 228                                 ResolveAttributeType (ec);
 229                         return Type;
 230                 }
 231
 232                 public string GetSignatureForError ()
 233                 {
 234                         return LeftExpr == null ? Identifier : LeftExpr.GetSignatureForError () + "." + Identifier;
 235                 }
 236
 237                 //
 238                 // Given an expression, if the expression is a valid attribute-argument-expression
 239                 // returns an object that can be used to encode it, or null on failure.
 240                 //
 241                 public static bool GetAttributeArgumentExpression (Expression e, Location loc, Type arg_type, out object result)
 242                 {
 243                         Constant constant = e as Constant;
 244                         if (constant != null) {
 245                                 constant = constant.ToType (arg_type, loc);
 246                                 if (constant == null) {
 247                                         result = null;
 248                                         return false;
 249                                 }
 250                                 result = constant.GetTypedValue ();
 251                                 return true;
 252                         } else if (e is TypeOf) {
 253                                 result = ((TypeOf) e).TypeArg;
 254                                 return true;
 255                         } else if (e is ArrayCreation){
 256                                 result =  ((ArrayCreation) e).EncodeAsAttribute ();
 257                                 if (result != null)
 258                                         return true;
 259                         } else if (e is EmptyCast) {
 260                                 Expression child = ((EmptyCast)e).Child;
 261                                 return GetAttributeArgumentExpression (child, loc, child.Type, out result);
 262                         } else if (e is As) {
 263                                 As as_e = (As) e;
 264                                 return GetAttributeArgumentExpression (as_e.Expr, loc, as_e.ProbeType.Type, out result);
 265                         }
 266
 267                         result = null;
 268                         Error_AttributeArgumentNotValid (loc);
 269                         return false;
 270                 }
 271
 272                 bool IsValidArgumentType (Type t)
 273                 {
 274                         if (t.IsArray)
 275                                 t = t.GetElementType ();
 276
 277                         return TypeManager.IsPrimitiveType (t) ||
 278                                 TypeManager.IsEnumType (t) ||
 279                                 t == TypeManager.string_type ||
 280                                 t == TypeManager.object_type ||
 281                                 t == TypeManager.type_type;
 282                 }
 283
 284                 // Cache for parameter-less attributes
 285                 static PtrHashtable att_cache = new PtrHashtable ();
 286
 287                 public CustomAttributeBuilder Resolve (EmitContext ec)
 288                 {
 289                         if (resolve_error)
 290                                 return null;
 291
 292                         resolve_error = true;
 293
 294                         if (Type == null) {
 295                                 ResolveAttributeType (ec);
 296                                 if (Type == null)
 297                                         return null;
 298                         }
 299
 300                         if (Type.IsAbstract) {
 301                                 Report.Error (653, Location, "Cannot apply attribute class `{0}' because it is abstract", GetSignatureForError ());
 302                                 return null;
 303                         }
 304
 305                         ObsoleteAttribute obsolete_attr = AttributeTester.GetObsoleteAttribute (Type);
 306                         if (obsolete_attr != null) {
 307                                 AttributeTester.Report_ObsoleteMessage (obsolete_attr, TypeManager.CSharpName (Type), Location);
 308                         }
 309
 310                         if (Arguments == null) {
 311                                 object o = att_cache [Type];
 312                                 if (o != null) {
 313                                         resolve_error = false;
 314                                         return (CustomAttributeBuilder)o;
 315                                 }
 316                         }
 317
 318                         ConstructorInfo ctor = ResolveArguments (ec);
 319                         if (ctor == null)
 320                                 return null;
 321
 322                         CustomAttributeBuilder cb;
 323
 324                         try {
 325                                 if (prop_info_arr != null || field_info_arr != null) {
 326                                         cb = new CustomAttributeBuilder (
 327                                                 ctor, pos_values,
 328                                                 prop_info_arr, prop_values_arr,
 329                                                 field_info_arr, field_values_arr);
 330                                 } else {
 331                                         cb = new CustomAttributeBuilder (
 332                                                 ctor, pos_values);
 333
 334                                         if (pos_values.Length == 0)
 335                                                 att_cache.Add (Type, cb);
 336                                 }
 337                         }
 338                         catch (Exception) {
 339                                 Error_AttributeArgumentNotValid (Location);
 340                                 return null;
 341                         }
 342
 343                         resolve_error = false;
 344                         return cb;
 345                 }
 346
 347                 protected virtual ConstructorInfo ResolveArguments (EmitContext ec)
 348                 {
 349                         // Now we extract the positional and named arguments
 350
 351                         ArrayList pos_args = null;
 352                         ArrayList named_args = null;
 353                         int pos_arg_count = 0;
 354                         int named_arg_count = 0;
 355
 356                         if (Arguments != null) {
 357                                 pos_args = (ArrayList) Arguments [0];
 358                                 if (pos_args != null)
 359                                         pos_arg_count = pos_args.Count;
 360                                 if (Arguments.Count > 1) {
 361                                         named_args = (ArrayList) Arguments [1];
 362                                         named_arg_count = named_args.Count;
 363                                 }
 364                         }
 365
 366                         pos_values = new object [pos_arg_count];
 367
 368                         //
 369                         // First process positional arguments
 370                         //
 371
 372                         int i;
 373                         for (i = 0; i < pos_arg_count; i++) {
 374                                 Argument a = (Argument) pos_args [i];
 375                                 Expression e;
 376
 377                                 if (!a.Resolve (ec, Location))
 378                                         return null;
 379
 380                                 e = a.Expr;
 381
 382                                 object val;
 383                                 if (!GetAttributeArgumentExpression (e, Location, a.Type, out val))
 384                                         return null;
 385
 386                                 pos_values [i] = val;
 387
 388                                 if (i == 0 && Type == TypeManager.attribute_usage_type && (int)val == 0) {
 389                                         Report.Error (591, Location, "Invalid value for argument to 'System.AttributeUsage' attribute");
 390                                         return null;
 391                                 }
 392                         }
 393
 394                         //
 395                         // Now process named arguments
 396                         //
 397
 398                         ArrayList field_infos = null;
 399                         ArrayList prop_infos  = null;
 400                         ArrayList field_values = null;
 401                         ArrayList prop_values = null;
 402                         Hashtable seen_names = null;
 403
 404                         if (named_arg_count > 0) {
 405                                 field_infos = new ArrayList ();
 406                                 prop_infos  = new ArrayList ();
 407                                 field_values = new ArrayList ();
 408                                 prop_values = new ArrayList ();
 409
 410                                 seen_names = new Hashtable();
 411                         }
 412
 413                         for (i = 0; i < named_arg_count; i++) {
 414                                 DictionaryEntry de = (DictionaryEntry) named_args [i];
 415                                 string member_name = (string) de.Key;
 416                                 Argument a  = (Argument) de.Value;
 417                                 Expression e;
 418
 419                                 if (seen_names.Contains(member_name)) {
 420                                         Report.Error(643, Location, "'" + member_name + "' duplicate named attribute argument");
 421                                         return null;
 422                                 }
 423                                 seen_names.Add(member_name, 1);
 424
 425                                 if (!a.Resolve (ec, Location))
 426                                         return null;
 427
 428                                 Expression member = Expression.MemberLookup (
 429                                         ec, Type, member_name,
 430                                         MemberTypes.Field | MemberTypes.Property,
 431                                         BindingFlags.Public | BindingFlags.Instance,
 432                                         Location);
 433
 434                                 if (member == null) {
 435                                         member = Expression.MemberLookup (ec, Type, member_name,
 436                                                 MemberTypes.Field | MemberTypes.Property, BindingFlags.NonPublic | BindingFlags.Instance,
 437                                                 Location);
 438
 439                                         if (member != null) {
 440                                                 Expression.ErrorIsInaccesible (Location, member.GetSignatureForError ());
 441                                                 return null;
 442                                         }
 443                                 }
 444
 445                                 if (member == null){
 446                                         Report.Error (117, Location, "`{0}' does not contain a definition for `{1}'",
 447                                                       Type, member_name);
 448                                         return null;
 449                                 }
 450
 451                                 if (!(member is PropertyExpr || member is FieldExpr)) {
 452                                         Error_InvalidNamedArgument (member_name);
 453                                         return null;
 454                                 }
 455
 456                                 e = a.Expr;
 457                                 if (member is PropertyExpr) {
 458                                         PropertyExpr pe = (PropertyExpr) member;
 459                                         PropertyInfo pi = pe.PropertyInfo;
 460
 461                                         if (!pi.CanWrite || !pi.CanRead) {
 462                                                 Report.SymbolRelatedToPreviousError (pi);
 463                                                 Error_InvalidNamedArgument (member_name);
 464                                                 return null;
 465                                         }
 466
 467                                         if (!IsValidArgumentType (pi.PropertyType)) {
 468                                                 Report.SymbolRelatedToPreviousError (pi);
 469                                                 Error_InvalidNamedAgrumentType (member_name);
 470                                                 return null;
 471                                         }
 472
 473                                         object value;
 474                                         if (!GetAttributeArgumentExpression (e, Location, pi.PropertyType, out value))
 475                                                 return null;
 476
 477                                         prop_values.Add (value);
 478                                         prop_infos.Add (pi);
 479
 480                                 } else if (member is FieldExpr) {
 481                                         FieldExpr fe = (FieldExpr) member;
 482                                         FieldInfo fi = fe.FieldInfo;
 483
 484                                         if (fi.IsInitOnly) {
 485                                                 Error_InvalidNamedArgument (member_name);
 486                                                 return null;
 487                                         }
 488
 489                                         if (!IsValidArgumentType (fi.FieldType)) {
 490                                                 Report.SymbolRelatedToPreviousError (fi);
 491                                                 Error_InvalidNamedAgrumentType (member_name);
 492                                                 return null;
 493                                         }
 494
 495                                         object value;
 496                                         if (!GetAttributeArgumentExpression (e, Location, fi.FieldType, out value))
 497                                                 return null;
 498
 499                                         field_values.Add (value);
 500                                         field_infos.Add (fi);
 501                                 }
 502                         }
 503
 504                         Expression mg = Expression.MemberLookup (
 505                                 ec, Type, ".ctor", MemberTypes.Constructor,
 506                                 BindingFlags.Public | BindingFlags.Instance | BindingFlags.DeclaredOnly,
 507                                 Location);
 508
 509                         MethodBase constructor = Invocation.OverloadResolve (
 510                                 ec, (MethodGroupExpr) mg, pos_args, false, Location);
 511
 512                         if (constructor == null) {
 513                                 return null;
 514                         }
 515
 516
 517                         // Here we do the checks which should be done by corlib or by runtime.
 518                         // However Zoltan doesn't like it and every Mono compiler has to do it again.
 519
 520                         if (Type == TypeManager.guid_attr_type) {
 521                                 try {
 522                                         new Guid ((string)pos_values [0]);
 523                                 }
 524                                 catch (Exception e) {
 525                                         Error_AttributeEmitError (e.Message);
 526                                 }
 527                         }
 528 // TODO: reenable
 529 //                      if (Type == TypeManager.methodimpl_attr_type &&
 530 //                              pos_values.Length == 1 && ((Argument)pos_args [0]).Type == TypeManager.short_type &&
 531 //                              !System.Enum.IsDefined (TypeManager.method_impl_options, pos_values [0])) {
 532 //                                      Error_AttributeEmitError ("Incorrect argument value.");
 533 //                      }
 534
 535                         //
 536                         // Now we perform some checks on the positional args as they
 537                         // cannot be null for a constructor which expects a parameter
 538                         // of type object
 539                         //
 540
 541                         ParameterData pd = TypeManager.GetParameterData (constructor);
 542
 543                         int last_real_param = pd.Count;
 544                         if (pd.HasParams) {
 545                                 // When the params is not filled we need to put one
 546                                 if (last_real_param > pos_arg_count) {
 547                                         object [] new_pos_values = new object [pos_arg_count + 1];
 548                                         pos_values.CopyTo (new_pos_values, 0);
 549                                         new_pos_values [pos_arg_count] = new object [] {} ;
 550                                         pos_values = new_pos_values;
 551                                 }
 552                                 last_real_param--;
 553                         }
 554
 555                         for (int j = 0; j < pos_arg_count; ++j) {
 556                                 Argument a = (Argument) pos_args [j];
 557
 558                                 if (a.Expr is NullLiteral && pd.ParameterType (j) == TypeManager.object_type) {
 559                                         Error_AttributeArgumentNotValid (Location);
 560                                         return null;
 561                                 }
 562
 563                                 object value = pos_values [j];
 564                                 if (value != null && a.Type != value.GetType () && TypeManager.IsPrimitiveType (a.Type)) {
 565                                         bool fail;
 566                                         pos_values [j] = TypeManager.ChangeType (value, a.Type, out fail);
 567                                         if (fail) {
 568                                                 // TODO: Can failed ?
 569                                                 throw new NotImplementedException ();
 570                                         }
 571                                 }
 572
 573                                 if (j < last_real_param)
 574                                         continue;
 575
 576                                 if (j == last_real_param) {
 577                                         object [] array = new object [pos_arg_count - last_real_param];
 578                                         array [0] = pos_values [j];
 579                                         pos_values [j] = array;
 580                                         continue;
 581                                 }
 582
 583                                 object [] params_array = (object []) pos_values [last_real_param];
 584                                 params_array [j - last_real_param] = pos_values [j];
 585                         }
 586
 587                         // Adjust the size of the pos_values if it had params
 588                         if (last_real_param != pos_arg_count) {
 589                                 object [] new_pos_values = new object [last_real_param + 1];
 590                                 Array.Copy (pos_values, new_pos_values, last_real_param + 1);
 591                                 pos_values = new_pos_values;
 592                         }
 593
 594                         if (named_arg_count > 0) {
 595                                 prop_info_arr = new PropertyInfo [prop_infos.Count];
 596                                 field_info_arr = new FieldInfo [field_infos.Count];
 597                                 field_values_arr = new object [field_values.Count];
 598                                 prop_values_arr = new object [prop_values.Count];
 599
 600                                 field_infos.CopyTo  (field_info_arr, 0);
 601                                 field_values.CopyTo (field_values_arr, 0);
 602
 603                                 prop_values.CopyTo  (prop_values_arr, 0);
 604                                 prop_infos.CopyTo   (prop_info_arr, 0);
 605                         }
 606
 607                         return (ConstructorInfo) constructor;
 608                 }
 609
 610                 /// <summary>
 611                 ///   Get a string containing a list of valid targets for the attribute 'attr'
 612                 /// </summary>
 613                 public string GetValidTargets ()
 614                 {
 615                         StringBuilder sb = new StringBuilder ();
 616                         AttributeTargets targets = GetAttributeUsage (null).ValidOn;
 617
 618                         if ((targets & AttributeTargets.Assembly) != 0)
 619                                 sb.Append ("assembly, ");
 620
 621                         if ((targets & AttributeTargets.Module) != 0)
 622                                 sb.Append ("module, ");
 623
 624                         if ((targets & AttributeTargets.Class) != 0)
 625                                 sb.Append ("class, ");
 626
 627                         if ((targets & AttributeTargets.Struct) != 0)
 628                                 sb.Append ("struct, ");
 629
 630                         if ((targets & AttributeTargets.Enum) != 0)
 631                                 sb.Append ("enum, ");
 632
 633                         if ((targets & AttributeTargets.Constructor) != 0)
 634                                 sb.Append ("constructor, ");
 635
 636                         if ((targets & AttributeTargets.Method) != 0)
 637                                 sb.Append ("method, ");
 638
 639                         if ((targets & AttributeTargets.Property) != 0)
 640                                 sb.Append ("property, indexer, ");
 641
 642                         if ((targets & AttributeTargets.Field) != 0)
 643                                 sb.Append ("field, ");
 644
 645                         if ((targets & AttributeTargets.Event) != 0)
 646                                 sb.Append ("event, ");
 647
 648                         if ((targets & AttributeTargets.Interface) != 0)
 649                                 sb.Append ("interface, ");
 650
 651                         if ((targets & AttributeTargets.Parameter) != 0)
 652                                 sb.Append ("parameter, ");
 653
 654                         if ((targets & AttributeTargets.Delegate) != 0)
 655                                 sb.Append ("delegate, ");
 656
 657                         if ((targets & AttributeTargets.ReturnValue) != 0)
 658                                 sb.Append ("return, ");
 659
 660 #if NET_2_0
 661                         if ((targets & AttributeTargets.GenericParameter) != 0)
 662                                 sb.Append ("type parameter, ");
 663 #endif
 664                         return sb.Remove (sb.Length - 2, 2).ToString ();
 665                 }
 666
 667                 /// <summary>
 668                 /// Returns AttributeUsage attribute for this type
 669                 /// </summary>
 670                 AttributeUsageAttribute GetAttributeUsage (EmitContext ec)
 671                 {
 672                         AttributeUsageAttribute ua = usage_attr_cache [Type] as AttributeUsageAttribute;
 673                         if (ua != null)
 674                                 return ua;
 675
 676                         Class attr_class = TypeManager.LookupClass (Type);
 677
 678                         if (attr_class == null) {
 679                                 object[] usage_attr = Type.GetCustomAttributes (TypeManager.attribute_usage_type, true);
 680                                 ua = (AttributeUsageAttribute)usage_attr [0];
 681                                 usage_attr_cache.Add (Type, ua);
 682                                 return ua;
 683                         }
 684
 685                         Attribute a = attr_class.OptAttributes == null
 686                                 ? null
 687                                 : attr_class.OptAttributes.Search (TypeManager.attribute_usage_type, attr_class.EmitContext);
 688
 689                         ua = a == null
 690                                 ? DefaultUsageAttribute
 691                                 : a.GetAttributeUsageAttribute (attr_class.EmitContext);
 692
 693                         usage_attr_cache.Add (Type, ua);
 694                         return ua;
 695                 }
 696
 697                 AttributeUsageAttribute GetAttributeUsageAttribute (EmitContext ec)
 698                 {
 699                         if (pos_values == null)
 700                                 // TODO: It is not neccessary to call whole Resolve (ApplyAttribute does it now) we need only ctor args.
 701                                 // But because a lot of attribute class code must be rewritten will be better to wait...
 702                                 Resolve (ec);
 703
 704                         if (resolve_error)
 705                                 return DefaultUsageAttribute;
 706
 707                         AttributeUsageAttribute usage_attribute = new AttributeUsageAttribute ((AttributeTargets)pos_values [0]);
 708
 709                         object field = GetPropertyValue ("AllowMultiple");
 710                         if (field != null)
 711                                 usage_attribute.AllowMultiple = (bool)field;
 712
 713                         field = GetPropertyValue ("Inherited");
 714                         if (field != null)
 715                                 usage_attribute.Inherited = (bool)field;
 716
 717                         return usage_attribute;
 718                 }
 719
 720                 /// <summary>
 721                 /// Returns custom name of indexer
 722                 /// </summary>
 723                 public string GetIndexerAttributeValue (EmitContext ec)
 724                 {
 725                         if (pos_values == null)
 726                                 // TODO: It is not neccessary to call whole Resolve (ApplyAttribute does it now) we need only ctor args.
 727                                 // But because a lot of attribute class code must be rewritten will be better to wait...
 728                                 Resolve (ec);
 729
 730                         if (resolve_error)
 731                                 return null;
 732
 733                         return pos_values [0] as string;
 734                 }
 735
 736                 /// <summary>
 737                 /// Returns condition of ConditionalAttribute
 738                 /// </summary>
 739                 public string GetConditionalAttributeValue (EmitContext ec)
 740                 {
 741                         if (pos_values == null)
 742                                 // TODO: It is not neccessary to call whole Resolve (ApplyAttribute does it now) we need only ctor args.
 743                                 // But because a lot of attribute class code must be rewritten will be better to wait...
 744                                 Resolve (ec);
 745
 746                         if (resolve_error)
 747                                 return null;
 748
 749                         return (string)pos_values [0];
 750                 }
 751
 752                 /// <summary>
 753                 /// Creates the instance of ObsoleteAttribute from this attribute instance
 754                 /// </summary>
 755                 public ObsoleteAttribute GetObsoleteAttribute (EmitContext ec)
 756                 {
 757                         if (pos_values == null)
 758                                 // TODO: It is not neccessary to call whole Resolve (ApplyAttribute does it now) we need only ctor args.
 759                                 // But because a lot of attribute class code must be rewritten will be better to wait...
 760                                 Resolve (ec);
 761
 762                         if (resolve_error)
 763                                 return null;
 764
 765                         if (pos_values == null || pos_values.Length == 0)
 766                                 return new ObsoleteAttribute ();
 767
 768                         if (pos_values.Length == 1)
 769                                 return new ObsoleteAttribute ((string)pos_values [0]);
 770
 771                         return new ObsoleteAttribute ((string)pos_values [0], (bool)pos_values [1]);
 772                 }
 773
 774                 /// <summary>
 775                 /// Returns value of CLSCompliantAttribute contructor parameter but because the method can be called
 776                 /// before ApplyAttribute. We need to resolve the arguments.
 777                 /// This situation occurs when class deps is differs from Emit order.
 778                 /// </summary>
 779                 public bool GetClsCompliantAttributeValue (EmitContext ec)
 780                 {
 781                         if (pos_values == null)
 782                                 // TODO: It is not neccessary to call whole Resolve (ApplyAttribute does it now) we need only ctor args.
 783                                 // But because a lot of attribute class code must be rewritten will be better to wait...
 784                                 Resolve (ec);
 785
 786                         if (resolve_error)
 787                                 return false;
 788
 789                         return (bool)pos_values [0];
 790                 }
 791
 792                 /// <summary>
 793                 /// Tests permitted SecurityAction for assembly or other types
 794                 /// </summary>
 795                 public bool CheckSecurityActionValidity (bool for_assembly)
 796                 {
 797                         SecurityAction action  = GetSecurityActionValue ();
 798
 799                         if ((action == SecurityAction.RequestMinimum || action == SecurityAction.RequestOptional || action == SecurityAction.RequestRefuse) && for_assembly)
 800                                 return true;
 801
 802                         if (!for_assembly) {
 803                                 if (action < SecurityAction.Demand || action > SecurityAction.InheritanceDemand) {
 804                                         Error_AttributeEmitError ("SecurityAction is out of range");
 805                                         return false;
 806                                 }
 807
 808                                 if ((action != SecurityAction.RequestMinimum && action != SecurityAction.RequestOptional && action != SecurityAction.RequestRefuse) && !for_assembly)
 809                                         return true;
 810                         }
 811
 812                         Error_AttributeEmitError (String.Concat ("SecurityAction '", action, "' is not valid for this declaration"));
 813                         return false;
 814                 }
 815
 816                 System.Security.Permissions.SecurityAction GetSecurityActionValue ()
 817                 {
 818                         return (SecurityAction)pos_values [0];
 819                 }
 820
 821                 /// <summary>
 822                 /// Creates instance of SecurityAttribute class and add result of CreatePermission method to permission table.
 823                 /// </summary>
 824                 /// <returns></returns>
 825                 public void ExtractSecurityPermissionSet (ListDictionary permissions)
 826                 {
 827                         Type orig_assembly_type = null;
 828
 829                         if (TypeManager.LookupDeclSpace (Type) != null) {
 830                                 if (!RootContext.StdLib) {
 831                                         orig_assembly_type = Type.GetType (Type.FullName);
 832                                 } else {
 833                                         string orig_version_path = Environment.GetEnvironmentVariable ("__SECURITY_BOOTSTRAP_DB");
 834                                         if (orig_version_path == null) {
 835                                                 Error_AttributeEmitError ("security custom attributes can not be referenced from defining assembly");
 836                                                 return;
 837                                         }
 838
 839                                         if (orig_sec_assembly == null) {
 840                                                 string file = Path.Combine (orig_version_path, Driver.OutputFile);
 841                                                 orig_sec_assembly = Assembly.LoadFile (file);
 842                                         }
 843
 844                                         orig_assembly_type = orig_sec_assembly.GetType (Type.FullName, true);
 845                                         if (orig_assembly_type == null) {
 846                                                 Report.Warning (-112, 1, Location, "Self-referenced security attribute `{0}' was not found in previous version of assembly");
 847                                                 return;
 848                                         }
 849                                 }
 850                         }
 851
 852                         SecurityAttribute sa;
 853                         // For all non-selfreferencing security attributes we can avoid all hacks
 854                         if (orig_assembly_type == null) {
 855                                 sa = (SecurityAttribute) Activator.CreateInstance (Type, pos_values);
 856
 857                                 if (prop_info_arr != null) {
 858                                         for (int i = 0; i < prop_info_arr.Length; ++i) {
 859                                                 PropertyInfo pi = prop_info_arr [i];
 860                                                 pi.SetValue (sa, prop_values_arr [i], null);
 861                                         }
 862                                 }
 863                         } else {
 864                                 // HACK: All security attributes have same ctor syntax
 865                                 sa = (SecurityAttribute) Activator.CreateInstance (orig_assembly_type, new object[] { GetSecurityActionValue () } );
 866
 867                                 // All types are from newly created assembly but for invocation with old one we need to convert them
 868                                 if (prop_info_arr != null) {
 869                                         for (int i = 0; i < prop_info_arr.Length; ++i) {
 870                                                 PropertyInfo emited_pi = prop_info_arr [i];
 871                                                 PropertyInfo pi = orig_assembly_type.GetProperty (emited_pi.Name, emited_pi.PropertyType);
 872
 873                                                 object old_instance = pi.PropertyType.IsEnum ?
 874                                                         System.Enum.ToObject (pi.PropertyType, prop_values_arr [i]) :
 875                                                         prop_values_arr [i];
 876
 877                                                 pi.SetValue (sa, old_instance, null);
 878                                         }
 879                                 }
 880                         }
 881
 882                         IPermission perm;
 883                         perm = sa.CreatePermission ();
 884                         SecurityAction action = GetSecurityActionValue ();
 885
 886                         // IS is correct because for corlib we are using an instance from old corlib
 887                         if (!(perm is System.Security.CodeAccessPermission)) {
 888                                 switch (action) {
 889                                         case SecurityAction.Demand:
 890                                                 action = (SecurityAction)13;
 891                                                 break;
 892                                         case SecurityAction.LinkDemand:
 893                                                 action = (SecurityAction)14;
 894                                                 break;
 895                                         case SecurityAction.InheritanceDemand:
 896                                                 action = (SecurityAction)15;
 897                                                 break;
 898                                 }
 899                         }
 900
 901                         PermissionSet ps = (PermissionSet)permissions [action];
 902                         if (ps == null) {
 903                                 if (sa is PermissionSetAttribute)
 904                                         ps = new PermissionSet (sa.Unrestricted ? PermissionState.Unrestricted : PermissionState.None);
 905                                 else
 906                                         ps = new PermissionSet (PermissionState.None);
 907
 908                                 permissions.Add (action, ps);
 909                         } else if (!ps.IsUnrestricted () && (sa is PermissionSetAttribute) && sa.Unrestricted) {
 910                                 ps = ps.Union (new PermissionSet (PermissionState.Unrestricted));
 911                                 permissions [action] = ps;
 912                         }
 913                         ps.AddPermission (perm);
 914                 }
 915
 916                 object GetValue (object value)
 917                 {
 918                         if (value is EnumConstant)
 919                                 return ((EnumConstant) value).GetValue ();
 920                         else
 921                                 return value;
 922                 }
 923
 924                 object GetPropertyValue (string name)
 925                 {
 926                         if (prop_info_arr == null)
 927                                 return null;
 928
 929                         for (int i = 0; i < prop_info_arr.Length; ++i) {
 930                                 if (prop_info_arr [i].Name == name)
 931                                         return prop_values_arr [i];
 932                         }
 933
 934                         return null;
 935                 }
 936
 937                 object GetFieldValue (string name)
 938                 {
 939                         int i;
 940                         if (field_info_arr == null)
 941                                 return null;
 942                         i = 0;
 943                         foreach (FieldInfo fi in field_info_arr) {
 944                                 if (fi.Name == name)
 945                                         return GetValue (field_values_arr [i]);
 946                                 i++;
 947                         }
 948                         return null;
 949                 }
 950
 951                 //
 952                 // Theoretically, we can get rid of this, since FieldBuilder.SetCustomAttribute()
 953                 // and ParameterBuilder.SetCustomAttribute() are supposed to handle this attribute.
 954                 // However, we can't, since it appears that the .NET 1.1 SRE hangs when given a MarshalAsAttribute.
 955                 //
 956                 public UnmanagedMarshal GetMarshal (Attributable attr)
 957                 {
 958                         UnmanagedType UnmanagedType;
 959                         if (!RootContext.StdLib || pos_values [0].GetType () != typeof (UnmanagedType))
 960                                 UnmanagedType = (UnmanagedType) System.Enum.ToObject (typeof (UnmanagedType), pos_values [0]);
 961                         else
 962                                 UnmanagedType = (UnmanagedType) pos_values [0];
 963
 964                         object value = GetFieldValue ("SizeParamIndex");
 965                         if (value != null && UnmanagedType != UnmanagedType.LPArray) {
 966                                 Error_AttributeEmitError ("SizeParamIndex field is not valid for the specified unmanaged type");
 967                                 return null;
 968                         }
 969
 970                         object o = GetFieldValue ("ArraySubType");
 971                         UnmanagedType array_sub_type = o == null ? (UnmanagedType) 0x50 /* NATIVE_MAX */ : (UnmanagedType) o;
 972
 973                         switch (UnmanagedType) {
 974                         case UnmanagedType.CustomMarshaler: {
 975                                 MethodInfo define_custom = typeof (UnmanagedMarshal).GetMethod ("DefineCustom",
 976                                         BindingFlags.Static | BindingFlags.Public | BindingFlags.NonPublic);
 977                                 if (define_custom == null) {
 978                                         Report.RuntimeMissingSupport (Location, "set marshal info");
 979                                         return null;
 980                                 }
 981
 982                                 object [] args = new object [4];
 983                                 args [0] = GetFieldValue ("MarshalTypeRef");
 984                                 args [1] = GetFieldValue ("MarshalCookie");
 985                                 args [2] = GetFieldValue ("MarshalType");
 986                                 args [3] = Guid.Empty;
 987                                 return (UnmanagedMarshal) define_custom.Invoke (null, args);
 988                         }
 989                         case UnmanagedType.LPArray: {
 990                                 object size_const = GetFieldValue ("SizeConst");
 991                                 object size_param_index = GetFieldValue ("SizeParamIndex");
 992
 993                                 if ((size_const != null) || (size_param_index != null)) {
 994                                         MethodInfo define_array = typeof (UnmanagedMarshal).GetMethod ("DefineLPArrayInternal",
 995                                                 BindingFlags.Static | BindingFlags.Public | BindingFlags.NonPublic);
 996                                         if (define_array == null) {
 997                                                 Report.RuntimeMissingSupport (Location, "set marshal info");
 998                                                 return null;
 999                                         }
1000
1001                                         object [] args = new object [3];
1002                                         args [0] = array_sub_type;
1003                                         args [1] = size_const == null ? -1 : size_const;
1004                                         args [2] = size_param_index == null ? -1 : size_param_index;
1005                                         return (UnmanagedMarshal) define_array.Invoke (null, args);
1006                                 }
1007                                 else
1008                                         return UnmanagedMarshal.DefineLPArray (array_sub_type);
1009                         }
1010                         case UnmanagedType.SafeArray:
1011                                 return UnmanagedMarshal.DefineSafeArray (array_sub_type);
1012
1013                         case UnmanagedType.ByValArray:
1014                                 FieldMember fm = attr as FieldMember;
1015                                 if (fm == null) {
1016                                         Error_AttributeEmitError ("Specified unmanaged type is only valid on fields");
1017                                         return null;
1018                                 }
1019                                 return UnmanagedMarshal.DefineByValArray ((int) GetFieldValue ("SizeConst"));
1020
1021                         case UnmanagedType.ByValTStr:
1022                                 return UnmanagedMarshal.DefineByValTStr ((int) GetFieldValue ("SizeConst"));
1023
1024                         default:
1025                                 return UnmanagedMarshal.DefineUnmanagedMarshal (UnmanagedType);
1026                         }
1027                 }
1028
1029                 public CharSet GetCharSetValue ()
1030                 {
1031                         return (CharSet)System.Enum.Parse (typeof (CharSet), pos_values [0].ToString ());
1032                 }
1033
1034                 public MethodImplOptions GetMethodImplOptions ()
1035                 {
1036                         if (pos_values [0].GetType () != typeof (MethodImplOptions))
1037                                 return (MethodImplOptions)System.Enum.ToObject (typeof (MethodImplOptions), pos_values [0]);
1038                         return (MethodImplOptions)pos_values [0];
1039                 }
1040
1041                 public LayoutKind GetLayoutKindValue ()
1042                 {
1043                         if (!RootContext.StdLib || pos_values [0].GetType () != typeof (LayoutKind))
1044                                 return (LayoutKind)System.Enum.ToObject (typeof (LayoutKind), pos_values [0]);
1045
1046                         return (LayoutKind)pos_values [0];
1047                 }
1048
1049                 /// <summary>
1050                 /// Emit attribute for Attributable symbol
1051                 /// </summary>
1052                 public void Emit (EmitContext ec, Attributable ias, ListDictionary emitted_attr)
1053                 {
1054                         CustomAttributeBuilder cb = Resolve (ec);
1055                         if (cb == null)
1056                                 return;
1057
1058                         AttributeUsageAttribute usage_attr = GetAttributeUsage (ec);
1059                         if ((usage_attr.ValidOn & Target) == 0) {
1060                                 Report.Error (592, Location, "Attribute `{0}' is not valid on this declaration type. It is valid on `{1}' declarations only",
1061                                         GetSignatureForError (), GetValidTargets ());
1062                                 return;
1063                         }
1064
1065                         try {
1066                                 ias.ApplyAttributeBuilder (this, cb);
1067                         }
1068                         catch (Exception e) {
1069                                 Error_AttributeEmitError (e.Message);
1070                                 return;
1071                         }
1072
1073                         if (!usage_attr.AllowMultiple) {
1074                                 ArrayList emitted_targets = (ArrayList)emitted_attr [Type];
1075                                 if (emitted_targets == null) {
1076                                         emitted_targets = new ArrayList ();
1077                                         emitted_attr.Add (Type, emitted_targets);
1078                                 } else if (emitted_targets.Contains (Target)) {
1079                                         Report.Error (579, Location, "Duplicate `{0}' attribute", GetSignatureForError ());
1080                                         return;
1081                                 }
1082                                 emitted_targets.Add (Target);
1083                         }
1084
1085                         if (!RootContext.VerifyClsCompliance)
1086                                 return;
1087
1088                         // Here we are testing attribute arguments for array usage (error 3016)
1089                         if (ias.IsClsCompliaceRequired (ec.DeclSpace)) {
1090                                 if (Arguments == null)
1091                                         return;
1092
1093                                 ArrayList pos_args = (ArrayList) Arguments [0];
1094                                 if (pos_args != null) {
1095                                         foreach (Argument arg in pos_args) {
1096                                                 // Type is undefined (was error 246)
1097                                                 if (arg.Type == null)
1098                                                         return;
1099
1100                                                 if (arg.Type.IsArray) {
1101                                                         Report.Error (3016, Location, "Arrays as attribute arguments are not CLS-compliant");
1102                                                         return;
1103                                                 }
1104                                         }
1105                                 }
1106
1107                                 if (Arguments.Count < 2)
1108                                         return;
1109
1110                                 ArrayList named_args = (ArrayList) Arguments [1];
1111                                 foreach (DictionaryEntry de in named_args) {
1112                                         Argument arg  = (Argument) de.Value;
1113
1114                                         // Type is undefined (was error 246)
1115                                         if (arg.Type == null)
1116                                                 return;
1117
1118                                         if (arg.Type.IsArray) {
1119                                                 Report.Error (3016, Location, "Arrays as attribute arguments are not CLS-compliant");
1120                                                 return;
1121                                         }
1122                                 }
1123                         }
1124                 }
1125
1126                 public MethodBuilder DefinePInvokeMethod (EmitContext ec, TypeBuilder builder, string name,
1127                                                           MethodAttributes flags, Type ret_type, Type [] param_types)
1128                 {
1129                         if (pos_values == null)
1130                                 // TODO: It is not neccessary to call whole Resolve (ApplyAttribute does it now) we need only ctor args.
1131                                 // But because a lot of attribute class code must be rewritten will be better to wait...
1132                                 Resolve (ec);
1133
1134                         if (resolve_error)
1135                                 return null;
1136
1137                         string dll_name = (string)pos_values [0];
1138
1139                         // Default settings
1140                         CallingConvention cc = CallingConvention.Winapi;
1141                         CharSet charset = CodeGen.Module.DefaultCharSet;
1142                         bool preserve_sig = true;
1143                         string entry_point = name;
1144                         bool best_fit_mapping = false;
1145                         bool throw_on_unmappable = false;
1146                         bool exact_spelling = false;
1147                         bool set_last_error = false;
1148
1149                         bool best_fit_mapping_set = false;
1150                         bool throw_on_unmappable_set = false;
1151                         bool exact_spelling_set = false;
1152                         bool set_last_error_set = false;
1153
1154                         MethodInfo set_best_fit = null;
1155                         MethodInfo set_throw_on = null;
1156                         MethodInfo set_exact_spelling = null;
1157                         MethodInfo set_set_last_error = null;
1158
1159                         if (field_info_arr != null) {
1160
1161                                 for (int i = 0; i < field_info_arr.Length; i++) {
1162                                         switch (field_info_arr [i].Name) {
1163                                                 case "BestFitMapping":
1164                                                         best_fit_mapping = (bool) field_values_arr [i];
1165                                                         best_fit_mapping_set = true;
1166                                                         break;
1167                                                 case "CallingConvention":
1168                                                         cc = (CallingConvention) field_values_arr [i];
1169                                                         break;
1170                                                 case "CharSet":
1171                                                         charset = (CharSet) field_values_arr [i];
1172                                                         break;
1173                                                 case "EntryPoint":
1174                                                         entry_point = (string) field_values_arr [i];
1175                                                         break;
1176                                                 case "ExactSpelling":
1177                                                         exact_spelling = (bool) field_values_arr [i];
1178                                                         exact_spelling_set = true;
1179                                                         break;
1180                                                 case "PreserveSig":
1181                                                         preserve_sig = (bool) field_values_arr [i];
1182                                                         break;
1183                                                 case "SetLastError":
1184                                                         set_last_error = (bool) field_values_arr [i];
1185                                                         set_last_error_set = true;
1186                                                         break;
1187                                                 case "ThrowOnUnmappableChar":
1188                                                         throw_on_unmappable = (bool) field_values_arr [i];
1189                                                         throw_on_unmappable_set = true;
1190                                                         break;
1191                                                 default:
1192                                                         throw new InternalErrorException (field_info_arr [i].ToString ());
1193                                         }
1194                                 }
1195                         }
1196
1197                         if (throw_on_unmappable_set || best_fit_mapping_set || exact_spelling_set || set_last_error_set) {
1198                                 set_best_fit = typeof (MethodBuilder).GetMethod ("set_BestFitMapping", BindingFlags.Instance | BindingFlags.Public | BindingFlags.NonPublic);
1199                                 set_throw_on = typeof (MethodBuilder).GetMethod ("set_ThrowOnUnmappableChar", BindingFlags.Instance | BindingFlags.Public | BindingFlags.NonPublic);
1200                                 set_exact_spelling = typeof (MethodBuilder).GetMethod ("set_ExactSpelling", BindingFlags.Instance | BindingFlags.Public | BindingFlags.NonPublic);
1201                                 set_set_last_error = typeof (MethodBuilder).GetMethod ("set_SetLastError", BindingFlags.Instance | BindingFlags.Public | BindingFlags.NonPublic);
1202
1203                                 if ((set_best_fit == null) || (set_throw_on == null) || (set_exact_spelling == null) || (set_set_last_error == null)) {
1204                                         Report.Error (-1, Location,
1205                                                                   "The ThrowOnUnmappableChar, BestFitMapping, SetLastError, and ExactSpelling attributes can only be emitted when running on the mono runtime.");
1206                                         return null;
1207                                 }
1208                         }
1209
1210                         try {
1211                                 MethodBuilder mb = builder.DefinePInvokeMethod (
1212                                         name, dll_name, entry_point, flags | MethodAttributes.HideBySig | MethodAttributes.PinvokeImpl,
1213                                         CallingConventions.Standard, ret_type, param_types, cc, charset);
1214
1215                                 if (preserve_sig)
1216                                         mb.SetImplementationFlags (MethodImplAttributes.PreserveSig);
1217
1218                                 if (throw_on_unmappable_set)
1219                                         set_throw_on.Invoke (mb, 0, null, new object [] { throw_on_unmappable }, null);
1220                                 if (best_fit_mapping_set)
1221                                         set_best_fit.Invoke (mb, 0, null, new object [] { best_fit_mapping }, null);
1222                                 if (exact_spelling_set)
1223                                         set_exact_spelling.Invoke  (mb, 0, null, new object [] { exact_spelling }, null);
1224                                 if (set_last_error_set)
1225                                         set_set_last_error.Invoke  (mb, 0, null, new object [] { set_last_error }, null);
1226
1227                                 return mb;
1228                         }
1229                         catch (ArgumentException e) {
1230                                 Error_AttributeEmitError (e.Message);
1231                                 return null;
1232                         }
1233                 }
1234
1235                 private Expression GetValue ()
1236                 {
1237                         if ((Arguments == null) || (Arguments.Count < 1))
1238                                 return null;
1239                         ArrayList al = (ArrayList) Arguments [0];
1240                         if ((al == null) || (al.Count < 1))
1241                                 return null;
1242                         Argument arg = (Argument) al [0];
1243                         if ((arg == null) || (arg.Expr == null))
1244                                 return null;
1245                         return arg.Expr;
1246                 }
1247
1248                 public string GetString ()
1249                 {
1250                         Expression e = GetValue ();
1251                         if (e is StringLiteral)
1252                                 return (e as StringLiteral).Value;
1253                         return null;
1254                 }
1255
1256                 public bool GetBoolean ()
1257                 {
1258                         Expression e = GetValue ();
1259                         if (e is BoolLiteral)
1260                                 return (e as BoolLiteral).Value;
1261                         return false;
1262                 }
1263         }
1264
1265
1266         /// <summary>
1267         /// For global attributes (assembly, module) we need special handling.
1268         /// Attributes can be located in the several files
1269         /// </summary>
1270         public class GlobalAttribute: Attribute
1271         {
1272                 public readonly NamespaceEntry ns;
1273
1274                 public GlobalAttribute (TypeContainer container, string target,
1275                                         Expression left_expr, string identifier, ArrayList args, Location loc, bool nameEscaped):
1276                         base (target, left_expr, identifier, args, loc, nameEscaped)
1277                 {
1278                         ns = container.NamespaceEntry;
1279                 }
1280
1281                 void Enter ()
1282                 {
1283                         // RootContext.Tree.Types has a single NamespaceEntry which gets overwritten
1284                         // each time a new file is parsed.  However, we need to use the NamespaceEntry
1285                         // in effect where the attribute was used.  Since code elsewhere cannot assume
1286                         // that the NamespaceEntry is right, just overwrite it.
1287                         //
1288                         // Precondition: RootContext.Tree.Types == null
1289
1290                         if (RootContext.Tree.Types.NamespaceEntry != null)
1291                                 throw new InternalErrorException (Location + " non-null NamespaceEntry");
1292
1293                         RootContext.Tree.Types.NamespaceEntry = ns;
1294                 }
1295
1296                 void Leave ()
1297                 {
1298                         RootContext.Tree.Types.NamespaceEntry = null;
1299                 }
1300
1301                 protected override FullNamedExpression ResolveAsTypeStep (Expression expr, EmitContext ec, bool silent)
1302                 {
1303                         try {
1304                                 Enter ();
1305                                 return base.ResolveAsTypeStep (expr, ec, silent);
1306                         }
1307                         finally {
1308                                 Leave ();
1309                         }
1310                 }
1311
1312
1313                 protected override FullNamedExpression ResolveAsTypeTerminal (Expression expr, EmitContext ec, bool silent)
1314                 {
1315                         try {
1316                                 Enter ();
1317                                 return base.ResolveAsTypeTerminal (expr, ec, silent);
1318                         }
1319                         finally {
1320                                 Leave ();
1321                         }
1322                 }
1323
1324                 protected override ConstructorInfo ResolveArguments (EmitContext ec)
1325                 {
1326                         try {
1327                                 Enter ();
1328                                 return base.ResolveArguments (ec);
1329                         }
1330                         finally {
1331                                 Leave ();
1332                         }
1333                 }
1334         }
1335
1336         public class Attributes {
1337                 public ArrayList Attrs;
1338
1339                 public Attributes (Attribute a)
1340                 {
1341                         Attrs = new ArrayList ();
1342                         Attrs.Add (a);
1343                 }
1344
1345                 public Attributes (ArrayList attrs)
1346                 {
1347                         Attrs = attrs;
1348                 }
1349
1350                 public void AddAttributes (ArrayList attrs)
1351                 {
1352                         Attrs.AddRange (attrs);
1353                 }
1354
1355                 /// <summary>
1356                 /// Checks whether attribute target is valid for the current element
1357                 /// </summary>
1358                 public bool CheckTargets (Attributable member)
1359                 {
1360                         string[] valid_targets = member.ValidAttributeTargets;
1361                         foreach (Attribute a in Attrs) {
1362                                 if (a.ExplicitTarget == null || a.ExplicitTarget == valid_targets [0]) {
1363                                         a.Target = member.AttributeTargets;
1364                                         continue;
1365                                 }
1366
1367                                 // TODO: we can skip the first item
1368                                 if (((IList) valid_targets).Contains (a.ExplicitTarget)) {
1369                                         switch (a.ExplicitTarget) {
1370                                                 case "return": a.Target = AttributeTargets.ReturnValue; continue;
1371                                                 case "param": a.Target = AttributeTargets.Parameter; continue;
1372                                                 case "field": a.Target = AttributeTargets.Field; continue;
1373                                                 case "method": a.Target = AttributeTargets.Method; continue;
1374                                                 case "property": a.Target = AttributeTargets.Property; continue;
1375                                         }
1376                                         throw new InternalErrorException ("Unknown explicit target: " + a.ExplicitTarget);
1377                                 }
1378
1379                                 StringBuilder sb = new StringBuilder ();
1380                                 foreach (string s in valid_targets) {
1381                                         sb.Append (s);
1382                                         sb.Append (", ");
1383                                 }
1384                                 sb.Remove (sb.Length - 2, 2);
1385                                 Report.Error (657, a.Location, "`{0}' is not a valid attribute location for this declaration. Valid attribute locations for this declaration are `{1}'", a.ExplicitTarget, sb.ToString ());
1386                                 return false;
1387                         }
1388                         return true;
1389                 }
1390
1391                 public Attribute Search (Type t, EmitContext ec)
1392                 {
1393                         foreach (Attribute a in Attrs) {
1394                                 if (a.ResolveType (ec) == t)
1395                                         return a;
1396                         }
1397                         return null;
1398                 }
1399
1400                 /// <summary>
1401                 /// Returns all attributes of type 't'. Use it when attribute is AllowMultiple = true
1402                 /// </summary>
1403                 public Attribute[] SearchMulti (Type t, EmitContext ec)
1404                 {
1405                         ArrayList ar = null;
1406
1407                         foreach (Attribute a in Attrs) {
1408                                 if (a.ResolveType (ec) == t) {
1409                                         if (ar == null)
1410                                                 ar = new ArrayList ();
1411                                         ar.Add (a);
1412                                 }
1413                         }
1414
1415                         return ar == null ? null : ar.ToArray (typeof (Attribute)) as Attribute[];
1416                 }
1417
1418                 public void Emit (EmitContext ec, Attributable ias)
1419                 {
1420                         CheckTargets (ias);
1421
1422                         ListDictionary ld = new ListDictionary ();
1423
1424                         foreach (Attribute a in Attrs)
1425                                 a.Emit (ec, ias, ld);
1426                 }
1427
1428                 public bool Contains (Type t, EmitContext ec)
1429                 {
1430                         return Search (t, ec) != null;
1431                 }
1432         }
1433
1434         /// <summary>
1435         /// Helper class for attribute verification routine.
1436         /// </summary>
1437         sealed class AttributeTester
1438         {
1439                 static PtrHashtable analyzed_types = new PtrHashtable ();
1440                 static PtrHashtable analyzed_types_obsolete = new PtrHashtable ();
1441                 static PtrHashtable analyzed_member_obsolete = new PtrHashtable ();
1442                 static PtrHashtable analyzed_method_excluded = new PtrHashtable ();
1443
1444 #if NET_2_0
1445                 static PtrHashtable fixed_buffer_cache = new PtrHashtable ();
1446 #endif
1447
1448                 static object TRUE = new object ();
1449                 static object FALSE = new object ();
1450
1451                 private AttributeTester ()
1452                 {
1453                 }
1454
1455                 public enum Result {
1456                         Ok,
1457                         RefOutArrayError,
1458                         ArrayArrayError
1459                 }
1460
1461                 /// <summary>
1462                 /// Returns true if parameters of two compared methods are CLS-Compliant.
1463                 /// It tests differing only in ref or out, or in array rank.
1464                 /// </summary>
1465                 public static Result AreOverloadedMethodParamsClsCompliant (Type[] types_a, Type[] types_b)
1466                 {
1467                         if (types_a == null || types_b == null)
1468                                 return Result.Ok;
1469
1470                         if (types_a.Length != types_b.Length)
1471                                 return Result.Ok;
1472
1473                         Result result = Result.Ok;
1474                         for (int i = 0; i < types_b.Length; ++i) {
1475                                 Type aType = types_a [i];
1476                                 Type bType = types_b [i];
1477
1478                                 if (aType.IsArray && bType.IsArray) {
1479                                         Type a_el_type = aType.GetElementType ();
1480                                         Type b_el_type = bType.GetElementType ();
1481                                         if (aType.GetArrayRank () != bType.GetArrayRank () && a_el_type == b_el_type) {
1482                                                 result = Result.RefOutArrayError;
1483                                                 continue;
1484                                         }
1485
1486                                         if (a_el_type.IsArray || b_el_type.IsArray) {
1487                                                 result = Result.ArrayArrayError;
1488                                                 continue;
1489                                         }
1490                                 }
1491
1492                                 Type aBaseType = aType;
1493                                 bool is_either_ref_or_out = false;
1494
1495                                 if (aType.IsByRef || aType.IsPointer) {
1496                                         aBaseType = aType.GetElementType ();
1497                                         is_either_ref_or_out = true;
1498                                 }
1499
1500                                 Type bBaseType = bType;
1501                                 if (bType.IsByRef || bType.IsPointer)
1502                                 {
1503                                         bBaseType = bType.GetElementType ();
1504                                         is_either_ref_or_out = !is_either_ref_or_out;
1505                                 }
1506
1507                                 if (aBaseType != bBaseType)
1508                                         return Result.Ok;
1509
1510                                 if (is_either_ref_or_out)
1511                                         result = Result.RefOutArrayError;
1512                         }
1513                         return result;
1514                 }
1515
1516                 /// <summary>
1517                 /// Goes through all parameters and test if they are CLS-Compliant.
1518                 /// </summary>
1519                 public static bool AreParametersCompliant (Parameter[] fixedParameters, Location loc)
1520                 {
1521                         if (fixedParameters == null)
1522                                 return true;
1523
1524                         foreach (Parameter arg in fixedParameters) {
1525                                 if (!AttributeTester.IsClsCompliant (arg.ParameterType)) {
1526                                         Report.Error (3001, loc, "Argument type `{0}' is not CLS-compliant", arg.GetSignatureForError ());
1527                                         return false;
1528                                 }
1529                         }
1530                         return true;
1531                 }
1532
1533
1534                 /// <summary>
1535                 /// This method tests the CLS compliance of external types. It doesn't test type visibility.
1536                 /// </summary>
1537                 public static bool IsClsCompliant (Type type)
1538                 {
1539                         if (type == null)
1540                                 return true;
1541
1542                         object type_compliance = analyzed_types[type];
1543                         if (type_compliance != null)
1544                                 return type_compliance == TRUE;
1545
1546                         if (type.IsPointer) {
1547                                 analyzed_types.Add (type, null);
1548                                 return false;
1549                         }
1550
1551                         bool result;
1552                         if (type.IsArray || type.IsByRef)       {
1553                                 result = IsClsCompliant (TypeManager.GetElementType (type));
1554                         } else {
1555                                 result = AnalyzeTypeCompliance (type);
1556                         }
1557                         analyzed_types.Add (type, result ? TRUE : FALSE);
1558                         return result;
1559                 }
1560
1561                 /// <summary>
1562                 /// Returns IFixedBuffer implementation if field is fixed buffer else null.
1563                 /// </summary>
1564                 public static IFixedBuffer GetFixedBuffer (FieldInfo fi)
1565                 {
1566                         FieldBase fb = TypeManager.GetField (fi);
1567                         if (fb != null) {
1568                                 return fb as IFixedBuffer;
1569                         }
1570
1571 #if NET_2_0
1572                         object o = fixed_buffer_cache [fi];
1573                         if (o == null) {
1574                                 if (System.Attribute.GetCustomAttribute (fi, TypeManager.fixed_buffer_attr_type) == null) {
1575                                         fixed_buffer_cache.Add (fi, FALSE);
1576                                         return null;
1577                                 }
1578
1579                                 IFixedBuffer iff = new FixedFieldExternal (fi);
1580                                 fixed_buffer_cache.Add (fi, iff);
1581                                 return iff;
1582                         }
1583
1584                         if (o == FALSE)
1585                                 return null;
1586
1587                         return (IFixedBuffer)o;
1588 #else
1589                         return null;
1590 #endif
1591                 }
1592
1593                 public static void VerifyModulesClsCompliance ()
1594                 {
1595                         Module[] modules = TypeManager.Modules;
1596                         if (modules == null)
1597                                 return;
1598
1599                         // The first module is generated assembly
1600                         for (int i = 1; i < modules.Length; ++i) {
1601                                 Module module = modules [i];
1602                                 if (!IsClsCompliant (module)) {
1603                                         Report.Error (3013, "Added modules must be marked with the CLSCompliant attribute to match the assembly", module.Name);
1604                                         return;
1605                                 }
1606                         }
1607                 }
1608
1609                 public static Type GetImportedIgnoreCaseClsType (string name)
1610                 {
1611                         foreach (Assembly a in TypeManager.GetAssemblies ()) {
1612                                 Type t = a.GetType (name, false, true);
1613                                 if (t == null)
1614                                         continue;
1615
1616                                 if (IsClsCompliant (t))
1617                                         return t;
1618                         }
1619                         return null;
1620                 }
1621
1622                 static bool IsClsCompliant (ICustomAttributeProvider attribute_provider)
1623                 {
1624                         object[] CompliantAttribute = attribute_provider.GetCustomAttributes (TypeManager.cls_compliant_attribute_type, false);
1625                         if (CompliantAttribute.Length == 0)
1626                                 return false;
1627
1628                         return ((CLSCompliantAttribute)CompliantAttribute[0]).IsCompliant;
1629                 }
1630
1631                 static bool AnalyzeTypeCompliance (Type type)
1632                 {
1633                         DeclSpace ds = TypeManager.LookupDeclSpace (type);
1634                         if (ds != null) {
1635                                 return ds.IsClsCompliaceRequired (ds.Parent);
1636                         }
1637
1638                         object[] CompliantAttribute = type.GetCustomAttributes (TypeManager.cls_compliant_attribute_type, false);
1639                         if (CompliantAttribute.Length == 0)
1640                                 return IsClsCompliant (type.Assembly);
1641
1642                         return ((CLSCompliantAttribute)CompliantAttribute[0]).IsCompliant;
1643                 }
1644
1645                 /// <summary>
1646                 /// Returns instance of ObsoleteAttribute when type is obsolete
1647                 /// </summary>
1648                 public static ObsoleteAttribute GetObsoleteAttribute (Type type)
1649                 {
1650                         object type_obsolete = analyzed_types_obsolete [type];
1651                         if (type_obsolete == FALSE)
1652                                 return null;
1653
1654                         if (type_obsolete != null)
1655                                 return (ObsoleteAttribute)type_obsolete;
1656
1657                         ObsoleteAttribute result = null;
1658                         if (type.IsByRef || type.IsArray || type.IsPointer) {
1659                                 result = GetObsoleteAttribute (TypeManager.GetElementType (type));
1660                         } else {
1661                                 DeclSpace type_ds = TypeManager.LookupDeclSpace (type);
1662
1663                                 // Type is external, we can get attribute directly
1664                                 if (type_ds == null) {
1665                                         object[] attribute = type.GetCustomAttributes (TypeManager.obsolete_attribute_type, false);
1666                                         if (attribute.Length == 1)
1667                                                 result = (ObsoleteAttribute)attribute [0];
1668                                 } else {
1669                                         result = type_ds.GetObsoleteAttribute ();
1670                                 }
1671                         }
1672
1673                         analyzed_types_obsolete.Add (type, result == null ? FALSE : result);
1674                         return result;
1675                 }
1676
1677                 /// <summary>
1678                 /// Returns instance of ObsoleteAttribute when method is obsolete
1679                 /// </summary>
1680                 public static ObsoleteAttribute GetMethodObsoleteAttribute (MethodBase mb)
1681                 {
1682                         IMethodData mc = TypeManager.GetMethod (mb);
1683                         if (mc != null)
1684                                 return mc.GetObsoleteAttribute ();
1685
1686                         // compiler generated methods are not registered by AddMethod
1687                         if (mb.DeclaringType is TypeBuilder)
1688                                 return null;
1689
1690                         if (mb.IsSpecialName) {
1691                                 PropertyInfo pi = PropertyExpr.AccessorTable [mb] as PropertyInfo;
1692                                 if (pi != null) {
1693                                         // FIXME: This is buggy as properties from this assembly are included as well
1694                                         return null;
1695                                         //return GetMemberObsoleteAttribute (pi);
1696                                 }
1697                         }
1698
1699                         return GetMemberObsoleteAttribute (mb);
1700                 }
1701
1702                 /// <summary>
1703                 /// Returns instance of ObsoleteAttribute when member is obsolete
1704                 /// </summary>
1705                 public static ObsoleteAttribute GetMemberObsoleteAttribute (MemberInfo mi)
1706                 {
1707                         object type_obsolete = analyzed_member_obsolete [mi];
1708                         if (type_obsolete == FALSE)
1709                                 return null;
1710
1711                         if (type_obsolete != null)
1712                                 return (ObsoleteAttribute)type_obsolete;
1713
1714                         ObsoleteAttribute oa = System.Attribute.GetCustomAttribute (mi, TypeManager.obsolete_attribute_type, false) as ObsoleteAttribute;
1715                         analyzed_member_obsolete.Add (mi, oa == null ? FALSE : oa);
1716                         return oa;
1717                 }
1718
1719                 /// <summary>
1720                 /// Common method for Obsolete error/warning reporting.
1721                 /// </summary>
1722                 public static void Report_ObsoleteMessage (ObsoleteAttribute oa, string member, Location loc)
1723                 {
1724                         if (oa.IsError) {
1725                                 Report.Error (619, loc, "`{0}' is obsolete: `{1}'", member, oa.Message);
1726                                 return;
1727                         }
1728
1729                         if (oa.Message == null) {
1730                                 Report.Warning (612, loc, "`{0}' is obsolete", member);
1731                                 return;
1732                         }
1733                         if (RootContext.WarningLevel >= 2)
1734                                 Report.Warning (618, loc, "`{0}' is obsolete: `{1}'", member, oa.Message);
1735                 }
1736
1737                 public static bool IsConditionalMethodExcluded (MethodBase mb)
1738                 {
1739                         object excluded = analyzed_method_excluded [mb];
1740                         if (excluded != null)
1741                                 return excluded == TRUE ? true : false;
1742
1743                         ConditionalAttribute[] attrs = mb.GetCustomAttributes (TypeManager.conditional_attribute_type, true) as ConditionalAttribute[];
1744                         if (attrs.Length == 0) {
1745                                 analyzed_method_excluded.Add (mb, FALSE);
1746                                 return false;
1747                         }
1748
1749                         foreach (ConditionalAttribute a in attrs) {
1750                                 if (RootContext.AllDefines.Contains (a.ConditionString)) {
1751                                         analyzed_method_excluded.Add (mb, FALSE);
1752                                         return false;
1753                                 }
1754                         }
1755                         analyzed_method_excluded.Add (mb, TRUE);
1756                         return true;
1757                 }
1758
1759                 /// <summary>
1760                 /// Analyzes class whether it has attribute which has ConditionalAttribute
1761                 /// and its condition is not defined.
1762                 /// </summary>
1763                 public static bool IsAttributeExcluded (Type type)
1764                 {
1765                         if (!type.IsClass)
1766                                 return false;
1767
1768                         Class class_decl = TypeManager.LookupDeclSpace (type) as Class;
1769
1770                         // TODO: add caching
1771                         // TODO: merge all Type bases attribute caching to one cache to save memory
1772                         if (class_decl == null) {
1773                                 object[] attributes = type.GetCustomAttributes (TypeManager.conditional_attribute_type, false);
1774                                 foreach (ConditionalAttribute ca in attributes) {
1775                                         if (RootContext.AllDefines.Contains (ca.ConditionString))
1776                                                 return false;
1777                                 }
1778                                 return attributes.Length > 0;
1779                         }
1780
1781                         return class_decl.IsExcluded ();
1782                 }
1783         }
1784 }