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                                         return null;
 527                                 }
 528                         }
 529
 530                         if (Type == TypeManager.methodimpl_attr_type &&
 531                                 pos_values.Length == 1 && ((Argument)pos_args [0]).Type == TypeManager.short_type &&
 532                                 !System.Enum.IsDefined (typeof (MethodImplOptions), pos_values [0])) {
 533                                         Error_AttributeEmitError ("Incorrect argument value.");
 534                                 return null;
 535                         }
 536
 537                         //
 538                         // Now we perform some checks on the positional args as they
 539                         // cannot be null for a constructor which expects a parameter
 540                         // of type object
 541                         //
 542
 543                         ParameterData pd = TypeManager.GetParameterData (constructor);
 544
 545                         int last_real_param = pd.Count;
 546                         if (pd.HasParams) {
 547                                 // When the params is not filled we need to put one
 548                                 if (last_real_param > pos_arg_count) {
 549                                         object [] new_pos_values = new object [pos_arg_count + 1];
 550                                         pos_values.CopyTo (new_pos_values, 0);
 551                                         new_pos_values [pos_arg_count] = new object [] {} ;
 552                                         pos_values = new_pos_values;
 553                                 }
 554                                 last_real_param--;
 555                         }
 556
 557                         for (int j = 0; j < pos_arg_count; ++j) {
 558                                 Argument a = (Argument) pos_args [j];
 559
 560                                 if (a.Expr is NullLiteral && pd.ParameterType (j) == TypeManager.object_type) {
 561                                         Error_AttributeArgumentNotValid (Location);
 562                                         return null;
 563                                 }
 564
 565                                 object value = pos_values [j];
 566                                 if (value != null && a.Type != value.GetType () && TypeManager.IsPrimitiveType (a.Type)) {
 567                                         bool fail;
 568                                         pos_values [j] = TypeManager.ChangeType (value, a.Type, out fail);
 569                                         if (fail) {
 570                                                 // TODO: Can failed ?
 571                                                 throw new NotImplementedException ();
 572                                         }
 573                                 }
 574
 575                                 if (j < last_real_param)
 576                                         continue;
 577
 578                                 if (j == last_real_param) {
 579                                         object [] array = new object [pos_arg_count - last_real_param];
 580                                         array [0] = pos_values [j];
 581                                         pos_values [j] = array;
 582                                         continue;
 583                                 }
 584
 585                                 object [] params_array = (object []) pos_values [last_real_param];
 586                                 params_array [j - last_real_param] = pos_values [j];
 587                         }
 588
 589                         // Adjust the size of the pos_values if it had params
 590                         if (last_real_param != pos_arg_count) {
 591                                 object [] new_pos_values = new object [last_real_param + 1];
 592                                 Array.Copy (pos_values, new_pos_values, last_real_param + 1);
 593                                 pos_values = new_pos_values;
 594                         }
 595
 596                         if (named_arg_count > 0) {
 597                                 prop_info_arr = new PropertyInfo [prop_infos.Count];
 598                                 field_info_arr = new FieldInfo [field_infos.Count];
 599                                 field_values_arr = new object [field_values.Count];
 600                                 prop_values_arr = new object [prop_values.Count];
 601
 602                                 field_infos.CopyTo  (field_info_arr, 0);
 603                                 field_values.CopyTo (field_values_arr, 0);
 604
 605                                 prop_values.CopyTo  (prop_values_arr, 0);
 606                                 prop_infos.CopyTo   (prop_info_arr, 0);
 607                         }
 608
 609                         return (ConstructorInfo) constructor;
 610                 }
 611
 612                 /// <summary>
 613                 ///   Get a string containing a list of valid targets for the attribute 'attr'
 614                 /// </summary>
 615                 public string GetValidTargets ()
 616                 {
 617                         StringBuilder sb = new StringBuilder ();
 618                         AttributeTargets targets = GetAttributeUsage (null).ValidOn;
 619
 620                         if ((targets & AttributeTargets.Assembly) != 0)
 621                                 sb.Append ("assembly, ");
 622
 623                         if ((targets & AttributeTargets.Module) != 0)
 624                                 sb.Append ("module, ");
 625
 626                         if ((targets & AttributeTargets.Class) != 0)
 627                                 sb.Append ("class, ");
 628
 629                         if ((targets & AttributeTargets.Struct) != 0)
 630                                 sb.Append ("struct, ");
 631
 632                         if ((targets & AttributeTargets.Enum) != 0)
 633                                 sb.Append ("enum, ");
 634
 635                         if ((targets & AttributeTargets.Constructor) != 0)
 636                                 sb.Append ("constructor, ");
 637
 638                         if ((targets & AttributeTargets.Method) != 0)
 639                                 sb.Append ("method, ");
 640
 641                         if ((targets & AttributeTargets.Property) != 0)
 642                                 sb.Append ("property, indexer, ");
 643
 644                         if ((targets & AttributeTargets.Field) != 0)
 645                                 sb.Append ("field, ");
 646
 647                         if ((targets & AttributeTargets.Event) != 0)
 648                                 sb.Append ("event, ");
 649
 650                         if ((targets & AttributeTargets.Interface) != 0)
 651                                 sb.Append ("interface, ");
 652
 653                         if ((targets & AttributeTargets.Parameter) != 0)
 654                                 sb.Append ("parameter, ");
 655
 656                         if ((targets & AttributeTargets.Delegate) != 0)
 657                                 sb.Append ("delegate, ");
 658
 659                         if ((targets & AttributeTargets.ReturnValue) != 0)
 660                                 sb.Append ("return, ");
 661
 662 #if NET_2_0
 663                         if ((targets & AttributeTargets.GenericParameter) != 0)
 664                                 sb.Append ("type parameter, ");
 665 #endif
 666                         return sb.Remove (sb.Length - 2, 2).ToString ();
 667                 }
 668
 669                 /// <summary>
 670                 /// Returns AttributeUsage attribute for this type
 671                 /// </summary>
 672                 AttributeUsageAttribute GetAttributeUsage (EmitContext ec)
 673                 {
 674                         AttributeUsageAttribute ua = usage_attr_cache [Type] as AttributeUsageAttribute;
 675                         if (ua != null)
 676                                 return ua;
 677
 678                         Class attr_class = TypeManager.LookupClass (Type);
 679
 680                         if (attr_class == null) {
 681                                 object[] usage_attr = Type.GetCustomAttributes (TypeManager.attribute_usage_type, true);
 682                                 ua = (AttributeUsageAttribute)usage_attr [0];
 683                                 usage_attr_cache.Add (Type, ua);
 684                                 return ua;
 685                         }
 686
 687                         Attribute a = attr_class.OptAttributes == null
 688                                 ? null
 689                                 : attr_class.OptAttributes.Search (TypeManager.attribute_usage_type, attr_class.EmitContext);
 690
 691                         ua = a == null
 692                                 ? DefaultUsageAttribute
 693                                 : a.GetAttributeUsageAttribute (attr_class.EmitContext);
 694
 695                         usage_attr_cache.Add (Type, ua);
 696                         return ua;
 697                 }
 698
 699                 AttributeUsageAttribute GetAttributeUsageAttribute (EmitContext ec)
 700                 {
 701                         if (pos_values == null)
 702                                 // TODO: It is not neccessary to call whole Resolve (ApplyAttribute does it now) we need only ctor args.
 703                                 // But because a lot of attribute class code must be rewritten will be better to wait...
 704                                 Resolve (ec);
 705
 706                         if (resolve_error)
 707                                 return DefaultUsageAttribute;
 708
 709                         AttributeUsageAttribute usage_attribute = new AttributeUsageAttribute ((AttributeTargets)pos_values [0]);
 710
 711                         object field = GetPropertyValue ("AllowMultiple");
 712                         if (field != null)
 713                                 usage_attribute.AllowMultiple = (bool)field;
 714
 715                         field = GetPropertyValue ("Inherited");
 716                         if (field != null)
 717                                 usage_attribute.Inherited = (bool)field;
 718
 719                         return usage_attribute;
 720                 }
 721
 722                 /// <summary>
 723                 /// Returns custom name of indexer
 724                 /// </summary>
 725                 public string GetIndexerAttributeValue (EmitContext ec)
 726                 {
 727                         if (pos_values == null)
 728                                 // TODO: It is not neccessary to call whole Resolve (ApplyAttribute does it now) we need only ctor args.
 729                                 // But because a lot of attribute class code must be rewritten will be better to wait...
 730                                 Resolve (ec);
 731
 732                         if (resolve_error)
 733                                 return null;
 734
 735                         return pos_values [0] as string;
 736                 }
 737
 738                 /// <summary>
 739                 /// Returns condition of ConditionalAttribute
 740                 /// </summary>
 741                 public string GetConditionalAttributeValue (EmitContext ec)
 742                 {
 743                         if (pos_values == null)
 744                                 // TODO: It is not neccessary to call whole Resolve (ApplyAttribute does it now) we need only ctor args.
 745                                 // But because a lot of attribute class code must be rewritten will be better to wait...
 746                                 Resolve (ec);
 747
 748                         if (resolve_error)
 749                                 return null;
 750
 751                         return (string)pos_values [0];
 752                 }
 753
 754                 /// <summary>
 755                 /// Creates the instance of ObsoleteAttribute from this attribute instance
 756                 /// </summary>
 757                 public ObsoleteAttribute GetObsoleteAttribute (EmitContext ec)
 758                 {
 759                         if (pos_values == null)
 760                                 // TODO: It is not neccessary to call whole Resolve (ApplyAttribute does it now) we need only ctor args.
 761                                 // But because a lot of attribute class code must be rewritten will be better to wait...
 762                                 Resolve (ec);
 763
 764                         if (resolve_error)
 765                                 return null;
 766
 767                         if (pos_values == null || pos_values.Length == 0)
 768                                 return new ObsoleteAttribute ();
 769
 770                         if (pos_values.Length == 1)
 771                                 return new ObsoleteAttribute ((string)pos_values [0]);
 772
 773                         return new ObsoleteAttribute ((string)pos_values [0], (bool)pos_values [1]);
 774                 }
 775
 776                 /// <summary>
 777                 /// Returns value of CLSCompliantAttribute contructor parameter but because the method can be called
 778                 /// before ApplyAttribute. We need to resolve the arguments.
 779                 /// This situation occurs when class deps is differs from Emit order.
 780                 /// </summary>
 781                 public bool GetClsCompliantAttributeValue (EmitContext ec)
 782                 {
 783                         if (pos_values == null)
 784                                 // TODO: It is not neccessary to call whole Resolve (ApplyAttribute does it now) we need only ctor args.
 785                                 // But because a lot of attribute class code must be rewritten will be better to wait...
 786                                 Resolve (ec);
 787
 788                         if (resolve_error)
 789                                 return false;
 790
 791                         return (bool)pos_values [0];
 792                 }
 793
 794                 /// <summary>
 795                 /// Tests permitted SecurityAction for assembly or other types
 796                 /// </summary>
 797                 public bool CheckSecurityActionValidity (bool for_assembly)
 798                 {
 799                         SecurityAction action  = GetSecurityActionValue ();
 800
 801                         if ((action == SecurityAction.RequestMinimum || action == SecurityAction.RequestOptional || action == SecurityAction.RequestRefuse) && for_assembly)
 802                                 return true;
 803
 804                         if (!for_assembly) {
 805                                 if (action < SecurityAction.Demand || action > SecurityAction.InheritanceDemand) {
 806                                         Error_AttributeEmitError ("SecurityAction is out of range");
 807                                         return false;
 808                                 }
 809
 810                                 if ((action != SecurityAction.RequestMinimum && action != SecurityAction.RequestOptional && action != SecurityAction.RequestRefuse) && !for_assembly)
 811                                         return true;
 812                         }
 813
 814                         Error_AttributeEmitError (String.Concat ("SecurityAction '", action, "' is not valid for this declaration"));
 815                         return false;
 816                 }
 817
 818                 System.Security.Permissions.SecurityAction GetSecurityActionValue ()
 819                 {
 820                         return (SecurityAction)pos_values [0];
 821                 }
 822
 823                 /// <summary>
 824                 /// Creates instance of SecurityAttribute class and add result of CreatePermission method to permission table.
 825                 /// </summary>
 826                 /// <returns></returns>
 827                 public void ExtractSecurityPermissionSet (ListDictionary permissions)
 828                 {
 829                         Type orig_assembly_type = null;
 830
 831                         if (TypeManager.LookupDeclSpace (Type) != null) {
 832                                 if (!RootContext.StdLib) {
 833                                         orig_assembly_type = Type.GetType (Type.FullName);
 834                                 } else {
 835                                         string orig_version_path = Environment.GetEnvironmentVariable ("__SECURITY_BOOTSTRAP_DB");
 836                                         if (orig_version_path == null) {
 837                                                 Error_AttributeEmitError ("security custom attributes can not be referenced from defining assembly");
 838                                                 return;
 839                                         }
 840
 841                                         if (orig_sec_assembly == null) {
 842                                                 string file = Path.Combine (orig_version_path, Driver.OutputFile);
 843                                                 orig_sec_assembly = Assembly.LoadFile (file);
 844                                         }
 845
 846                                         orig_assembly_type = orig_sec_assembly.GetType (Type.FullName, true);
 847                                         if (orig_assembly_type == null) {
 848                                                 Report.Warning (-112, 1, Location, "Self-referenced security attribute `{0}' was not found in previous version of assembly");
 849                                                 return;
 850                                         }
 851                                 }
 852                         }
 853
 854                         SecurityAttribute sa;
 855                         // For all non-selfreferencing security attributes we can avoid all hacks
 856                         if (orig_assembly_type == null) {
 857                                 sa = (SecurityAttribute) Activator.CreateInstance (Type, pos_values);
 858
 859                                 if (prop_info_arr != null) {
 860                                         for (int i = 0; i < prop_info_arr.Length; ++i) {
 861                                                 PropertyInfo pi = prop_info_arr [i];
 862                                                 pi.SetValue (sa, prop_values_arr [i], null);
 863                                         }
 864                                 }
 865                         } else {
 866                                 // HACK: All security attributes have same ctor syntax
 867                                 sa = (SecurityAttribute) Activator.CreateInstance (orig_assembly_type, new object[] { GetSecurityActionValue () } );
 868
 869                                 // All types are from newly created assembly but for invocation with old one we need to convert them
 870                                 if (prop_info_arr != null) {
 871                                         for (int i = 0; i < prop_info_arr.Length; ++i) {
 872                                                 PropertyInfo emited_pi = prop_info_arr [i];
 873                                                 PropertyInfo pi = orig_assembly_type.GetProperty (emited_pi.Name, emited_pi.PropertyType);
 874
 875                                                 object old_instance = pi.PropertyType.IsEnum ?
 876                                                         System.Enum.ToObject (pi.PropertyType, prop_values_arr [i]) :
 877                                                         prop_values_arr [i];
 878
 879                                                 pi.SetValue (sa, old_instance, null);
 880                                         }
 881                                 }
 882                         }
 883
 884                         IPermission perm;
 885                         perm = sa.CreatePermission ();
 886                         SecurityAction action = GetSecurityActionValue ();
 887
 888                         // IS is correct because for corlib we are using an instance from old corlib
 889                         if (!(perm is System.Security.CodeAccessPermission)) {
 890                                 switch (action) {
 891                                         case SecurityAction.Demand:
 892                                                 action = (SecurityAction)13;
 893                                                 break;
 894                                         case SecurityAction.LinkDemand:
 895                                                 action = (SecurityAction)14;
 896                                                 break;
 897                                         case SecurityAction.InheritanceDemand:
 898                                                 action = (SecurityAction)15;
 899                                                 break;
 900                                 }
 901                         }
 902
 903                         PermissionSet ps = (PermissionSet)permissions [action];
 904                         if (ps == null) {
 905                                 if (sa is PermissionSetAttribute)
 906                                         ps = new PermissionSet (sa.Unrestricted ? PermissionState.Unrestricted : PermissionState.None);
 907                                 else
 908                                         ps = new PermissionSet (PermissionState.None);
 909
 910                                 permissions.Add (action, ps);
 911                         } else if (!ps.IsUnrestricted () && (sa is PermissionSetAttribute) && sa.Unrestricted) {
 912                                 ps = ps.Union (new PermissionSet (PermissionState.Unrestricted));
 913                                 permissions [action] = ps;
 914                         }
 915                         ps.AddPermission (perm);
 916                 }
 917
 918                 object GetValue (object value)
 919                 {
 920                         if (value is EnumConstant)
 921                                 return ((EnumConstant) value).GetValue ();
 922                         else
 923                                 return value;
 924                 }
 925
 926                 object GetPropertyValue (string name)
 927                 {
 928                         if (prop_info_arr == null)
 929                                 return null;
 930
 931                         for (int i = 0; i < prop_info_arr.Length; ++i) {
 932                                 if (prop_info_arr [i].Name == name)
 933                                         return prop_values_arr [i];
 934                         }
 935
 936                         return null;
 937                 }
 938
 939                 object GetFieldValue (string name)
 940                 {
 941                         int i;
 942                         if (field_info_arr == null)
 943                                 return null;
 944                         i = 0;
 945                         foreach (FieldInfo fi in field_info_arr) {
 946                                 if (fi.Name == name)
 947                                         return GetValue (field_values_arr [i]);
 948                                 i++;
 949                         }
 950                         return null;
 951                 }
 952
 953                 //
 954                 // Theoretically, we can get rid of this, since FieldBuilder.SetCustomAttribute()
 955                 // and ParameterBuilder.SetCustomAttribute() are supposed to handle this attribute.
 956                 // However, we can't, since it appears that the .NET 1.1 SRE hangs when given a MarshalAsAttribute.
 957                 //
 958                 public UnmanagedMarshal GetMarshal (Attributable attr)
 959                 {
 960                         UnmanagedType UnmanagedType;
 961                         if (!RootContext.StdLib || pos_values [0].GetType () != typeof (UnmanagedType))
 962                                 UnmanagedType = (UnmanagedType) System.Enum.ToObject (typeof (UnmanagedType), pos_values [0]);
 963                         else
 964                                 UnmanagedType = (UnmanagedType) pos_values [0];
 965
 966                         object value = GetFieldValue ("SizeParamIndex");
 967                         if (value != null && UnmanagedType != UnmanagedType.LPArray) {
 968                                 Error_AttributeEmitError ("SizeParamIndex field is not valid for the specified unmanaged type");
 969                                 return null;
 970                         }
 971
 972                         object o = GetFieldValue ("ArraySubType");
 973                         UnmanagedType array_sub_type = o == null ? (UnmanagedType) 0x50 /* NATIVE_MAX */ : (UnmanagedType) o;
 974
 975                         switch (UnmanagedType) {
 976                         case UnmanagedType.CustomMarshaler: {
 977                                 MethodInfo define_custom = typeof (UnmanagedMarshal).GetMethod ("DefineCustom",
 978                                         BindingFlags.Static | BindingFlags.Public | BindingFlags.NonPublic);
 979                                 if (define_custom == null) {
 980                                         Report.RuntimeMissingSupport (Location, "set marshal info");
 981                                         return null;
 982                                 }
 983
 984                                 object [] args = new object [4];
 985                                 args [0] = GetFieldValue ("MarshalTypeRef");
 986                                 args [1] = GetFieldValue ("MarshalCookie");
 987                                 args [2] = GetFieldValue ("MarshalType");
 988                                 args [3] = Guid.Empty;
 989                                 return (UnmanagedMarshal) define_custom.Invoke (null, args);
 990                         }
 991                         case UnmanagedType.LPArray: {
 992                                 object size_const = GetFieldValue ("SizeConst");
 993                                 object size_param_index = GetFieldValue ("SizeParamIndex");
 994
 995                                 if ((size_const != null) || (size_param_index != null)) {
 996                                         MethodInfo define_array = typeof (UnmanagedMarshal).GetMethod ("DefineLPArrayInternal",
 997                                                 BindingFlags.Static | BindingFlags.Public | BindingFlags.NonPublic);
 998                                         if (define_array == null) {
 999                                                 Report.RuntimeMissingSupport (Location, "set marshal info");
1000                                                 return null;
1001                                         }
1002
1003                                         object [] args = new object [3];
1004                                         args [0] = array_sub_type;
1005                                         args [1] = size_const == null ? -1 : size_const;
1006                                         args [2] = size_param_index == null ? -1 : size_param_index;
1007                                         return (UnmanagedMarshal) define_array.Invoke (null, args);
1008                                 }
1009                                 else
1010                                         return UnmanagedMarshal.DefineLPArray (array_sub_type);
1011                         }
1012                         case UnmanagedType.SafeArray:
1013                                 return UnmanagedMarshal.DefineSafeArray (array_sub_type);
1014
1015                         case UnmanagedType.ByValArray:
1016                                 FieldMember fm = attr as FieldMember;
1017                                 if (fm == null) {
1018                                         Error_AttributeEmitError ("Specified unmanaged type is only valid on fields");
1019                                         return null;
1020                                 }
1021                                 return UnmanagedMarshal.DefineByValArray ((int) GetFieldValue ("SizeConst"));
1022
1023                         case UnmanagedType.ByValTStr:
1024                                 return UnmanagedMarshal.DefineByValTStr ((int) GetFieldValue ("SizeConst"));
1025
1026                         default:
1027                                 return UnmanagedMarshal.DefineUnmanagedMarshal (UnmanagedType);
1028                         }
1029                 }
1030
1031                 public CharSet GetCharSetValue ()
1032                 {
1033                         return (CharSet)System.Enum.Parse (typeof (CharSet), pos_values [0].ToString ());
1034                 }
1035
1036                 public MethodImplOptions GetMethodImplOptions ()
1037                 {
1038                         if (pos_values [0].GetType () != typeof (MethodImplOptions))
1039                                 return (MethodImplOptions)System.Enum.ToObject (typeof (MethodImplOptions), pos_values [0]);
1040                         return (MethodImplOptions)pos_values [0];
1041                 }
1042
1043                 public LayoutKind GetLayoutKindValue ()
1044                 {
1045                         if (!RootContext.StdLib || pos_values [0].GetType () != typeof (LayoutKind))
1046                                 return (LayoutKind)System.Enum.ToObject (typeof (LayoutKind), pos_values [0]);
1047
1048                         return (LayoutKind)pos_values [0];
1049                 }
1050
1051                 /// <summary>
1052                 /// Emit attribute for Attributable symbol
1053                 /// </summary>
1054                 public void Emit (EmitContext ec, Attributable ias, ListDictionary emitted_attr)
1055                 {
1056                         CustomAttributeBuilder cb = Resolve (ec);
1057                         if (cb == null)
1058                                 return;
1059
1060                         AttributeUsageAttribute usage_attr = GetAttributeUsage (ec);
1061                         if ((usage_attr.ValidOn & Target) == 0) {
1062                                 Report.Error (592, Location, "Attribute `{0}' is not valid on this declaration type. It is valid on `{1}' declarations only",
1063                                         GetSignatureForError (), GetValidTargets ());
1064                                 return;
1065                         }
1066
1067                         try {
1068                                 ias.ApplyAttributeBuilder (this, cb);
1069                         }
1070                         catch (Exception e) {
1071                                 Error_AttributeEmitError (e.Message);
1072                                 return;
1073                         }
1074
1075                         if (!usage_attr.AllowMultiple) {
1076                                 ArrayList emitted_targets = (ArrayList)emitted_attr [Type];
1077                                 if (emitted_targets == null) {
1078                                         emitted_targets = new ArrayList ();
1079                                         emitted_attr.Add (Type, emitted_targets);
1080                                 } else if (emitted_targets.Contains (Target)) {
1081                                         Report.Error (579, Location, "Duplicate `{0}' attribute", GetSignatureForError ());
1082                                         return;
1083                                 }
1084                                 emitted_targets.Add (Target);
1085                         }
1086
1087                         if (!RootContext.VerifyClsCompliance)
1088                                 return;
1089
1090                         // Here we are testing attribute arguments for array usage (error 3016)
1091                         if (ias.IsClsCompliaceRequired (ec.DeclSpace)) {
1092                                 if (Arguments == null)
1093                                         return;
1094
1095                                 ArrayList pos_args = (ArrayList) Arguments [0];
1096                                 if (pos_args != null) {
1097                                         foreach (Argument arg in pos_args) {
1098                                                 // Type is undefined (was error 246)
1099                                                 if (arg.Type == null)
1100                                                         return;
1101
1102                                                 if (arg.Type.IsArray) {
1103                                                         Report.Error (3016, Location, "Arrays as attribute arguments are not CLS-compliant");
1104                                                         return;
1105                                                 }
1106                                         }
1107                                 }
1108
1109                                 if (Arguments.Count < 2)
1110                                         return;
1111
1112                                 ArrayList named_args = (ArrayList) Arguments [1];
1113                                 foreach (DictionaryEntry de in named_args) {
1114                                         Argument arg  = (Argument) de.Value;
1115
1116                                         // Type is undefined (was error 246)
1117                                         if (arg.Type == null)
1118                                                 return;
1119
1120                                         if (arg.Type.IsArray) {
1121                                                 Report.Error (3016, Location, "Arrays as attribute arguments are not CLS-compliant");
1122                                                 return;
1123                                         }
1124                                 }
1125                         }
1126                 }
1127
1128                 public MethodBuilder DefinePInvokeMethod (EmitContext ec, TypeBuilder builder, string name,
1129                                                           MethodAttributes flags, Type ret_type, Type [] param_types)
1130                 {
1131                         if (pos_values == null)
1132                                 // TODO: It is not neccessary to call whole Resolve (ApplyAttribute does it now) we need only ctor args.
1133                                 // But because a lot of attribute class code must be rewritten will be better to wait...
1134                                 Resolve (ec);
1135
1136                         if (resolve_error)
1137                                 return null;
1138
1139                         string dll_name = (string)pos_values [0];
1140
1141                         // Default settings
1142                         CallingConvention cc = CallingConvention.Winapi;
1143                         CharSet charset = CodeGen.Module.DefaultCharSet;
1144                         bool preserve_sig = true;
1145                         string entry_point = name;
1146                         bool best_fit_mapping = false;
1147                         bool throw_on_unmappable = false;
1148                         bool exact_spelling = false;
1149                         bool set_last_error = false;
1150
1151                         bool best_fit_mapping_set = false;
1152                         bool throw_on_unmappable_set = false;
1153                         bool exact_spelling_set = false;
1154                         bool set_last_error_set = false;
1155
1156                         MethodInfo set_best_fit = null;
1157                         MethodInfo set_throw_on = null;
1158                         MethodInfo set_exact_spelling = null;
1159                         MethodInfo set_set_last_error = null;
1160
1161                         if (field_info_arr != null) {
1162
1163                                 for (int i = 0; i < field_info_arr.Length; i++) {
1164                                         switch (field_info_arr [i].Name) {
1165                                                 case "BestFitMapping":
1166                                                         best_fit_mapping = (bool) field_values_arr [i];
1167                                                         best_fit_mapping_set = true;
1168                                                         break;
1169                                                 case "CallingConvention":
1170                                                         cc = (CallingConvention) field_values_arr [i];
1171                                                         break;
1172                                                 case "CharSet":
1173                                                         charset = (CharSet) field_values_arr [i];
1174                                                         break;
1175                                                 case "EntryPoint":
1176                                                         entry_point = (string) field_values_arr [i];
1177                                                         break;
1178                                                 case "ExactSpelling":
1179                                                         exact_spelling = (bool) field_values_arr [i];
1180                                                         exact_spelling_set = true;
1181                                                         break;
1182                                                 case "PreserveSig":
1183                                                         preserve_sig = (bool) field_values_arr [i];
1184                                                         break;
1185                                                 case "SetLastError":
1186                                                         set_last_error = (bool) field_values_arr [i];
1187                                                         set_last_error_set = true;
1188                                                         break;
1189                                                 case "ThrowOnUnmappableChar":
1190                                                         throw_on_unmappable = (bool) field_values_arr [i];
1191                                                         throw_on_unmappable_set = true;
1192                                                         break;
1193                                                 default:
1194                                                         throw new InternalErrorException (field_info_arr [i].ToString ());
1195                                         }
1196                                 }
1197                         }
1198
1199                         if (throw_on_unmappable_set || best_fit_mapping_set || exact_spelling_set || set_last_error_set) {
1200                                 set_best_fit = typeof (MethodBuilder).GetMethod ("set_BestFitMapping", BindingFlags.Instance | BindingFlags.Public | BindingFlags.NonPublic);
1201                                 set_throw_on = typeof (MethodBuilder).GetMethod ("set_ThrowOnUnmappableChar", BindingFlags.Instance | BindingFlags.Public | BindingFlags.NonPublic);
1202                                 set_exact_spelling = typeof (MethodBuilder).GetMethod ("set_ExactSpelling", BindingFlags.Instance | BindingFlags.Public | BindingFlags.NonPublic);
1203                                 set_set_last_error = typeof (MethodBuilder).GetMethod ("set_SetLastError", BindingFlags.Instance | BindingFlags.Public | BindingFlags.NonPublic);
1204
1205                                 if ((set_best_fit == null) || (set_throw_on == null) || (set_exact_spelling == null) || (set_set_last_error == null)) {
1206                                         Report.Error (-1, Location,
1207                                                                   "The ThrowOnUnmappableChar, BestFitMapping, SetLastError, and ExactSpelling attributes can only be emitted when running on the mono runtime.");
1208                                         return null;
1209                                 }
1210                         }
1211
1212                         try {
1213                                 MethodBuilder mb = builder.DefinePInvokeMethod (
1214                                         name, dll_name, entry_point, flags | MethodAttributes.HideBySig | MethodAttributes.PinvokeImpl,
1215                                         CallingConventions.Standard, ret_type, param_types, cc, charset);
1216
1217                                 if (preserve_sig)
1218                                         mb.SetImplementationFlags (MethodImplAttributes.PreserveSig);
1219
1220                                 if (throw_on_unmappable_set)
1221                                         set_throw_on.Invoke (mb, 0, null, new object [] { throw_on_unmappable }, null);
1222                                 if (best_fit_mapping_set)
1223                                         set_best_fit.Invoke (mb, 0, null, new object [] { best_fit_mapping }, null);
1224                                 if (exact_spelling_set)
1225                                         set_exact_spelling.Invoke  (mb, 0, null, new object [] { exact_spelling }, null);
1226                                 if (set_last_error_set)
1227                                         set_set_last_error.Invoke  (mb, 0, null, new object [] { set_last_error }, null);
1228
1229                                 return mb;
1230                         }
1231                         catch (ArgumentException e) {
1232                                 Error_AttributeEmitError (e.Message);
1233                                 return null;
1234                         }
1235                 }
1236
1237                 private Expression GetValue ()
1238                 {
1239                         if ((Arguments == null) || (Arguments.Count < 1))
1240                                 return null;
1241                         ArrayList al = (ArrayList) Arguments [0];
1242                         if ((al == null) || (al.Count < 1))
1243                                 return null;
1244                         Argument arg = (Argument) al [0];
1245                         if ((arg == null) || (arg.Expr == null))
1246                                 return null;
1247                         return arg.Expr;
1248                 }
1249
1250                 public string GetString ()
1251                 {
1252                         Expression e = GetValue ();
1253                         if (e is StringLiteral)
1254                                 return (e as StringLiteral).Value;
1255                         return null;
1256                 }
1257
1258                 public bool GetBoolean ()
1259                 {
1260                         Expression e = GetValue ();
1261                         if (e is BoolLiteral)
1262                                 return (e as BoolLiteral).Value;
1263                         return false;
1264                 }
1265         }
1266
1267
1268         /// <summary>
1269         /// For global attributes (assembly, module) we need special handling.
1270         /// Attributes can be located in the several files
1271         /// </summary>
1272         public class GlobalAttribute: Attribute
1273         {
1274                 public readonly NamespaceEntry ns;
1275
1276                 public GlobalAttribute (TypeContainer container, string target,
1277                                         Expression left_expr, string identifier, ArrayList args, Location loc, bool nameEscaped):
1278                         base (target, left_expr, identifier, args, loc, nameEscaped)
1279                 {
1280                         ns = container.NamespaceEntry;
1281                 }
1282
1283                 void Enter ()
1284                 {
1285                         // RootContext.Tree.Types has a single NamespaceEntry which gets overwritten
1286                         // each time a new file is parsed.  However, we need to use the NamespaceEntry
1287                         // in effect where the attribute was used.  Since code elsewhere cannot assume
1288                         // that the NamespaceEntry is right, just overwrite it.
1289                         //
1290                         // Precondition: RootContext.Tree.Types == null
1291
1292                         if (RootContext.Tree.Types.NamespaceEntry != null)
1293                                 throw new InternalErrorException (Location + " non-null NamespaceEntry");
1294
1295                         RootContext.Tree.Types.NamespaceEntry = ns;
1296                 }
1297
1298                 void Leave ()
1299                 {
1300                         RootContext.Tree.Types.NamespaceEntry = null;
1301                 }
1302
1303                 protected override FullNamedExpression ResolveAsTypeStep (Expression expr, EmitContext ec, bool silent)
1304                 {
1305                         try {
1306                                 Enter ();
1307                                 return base.ResolveAsTypeStep (expr, ec, silent);
1308                         }
1309                         finally {
1310                                 Leave ();
1311                         }
1312                 }
1313
1314
1315                 protected override FullNamedExpression ResolveAsTypeTerminal (Expression expr, EmitContext ec, bool silent)
1316                 {
1317                         try {
1318                                 Enter ();
1319                                 return base.ResolveAsTypeTerminal (expr, ec, silent);
1320                         }
1321                         finally {
1322                                 Leave ();
1323                         }
1324                 }
1325
1326                 protected override ConstructorInfo ResolveArguments (EmitContext ec)
1327                 {
1328                         try {
1329                                 Enter ();
1330                                 return base.ResolveArguments (ec);
1331                         }
1332                         finally {
1333                                 Leave ();
1334                         }
1335                 }
1336         }
1337
1338         public class Attributes {
1339                 public ArrayList Attrs;
1340
1341                 public Attributes (Attribute a)
1342                 {
1343                         Attrs = new ArrayList ();
1344                         Attrs.Add (a);
1345                 }
1346
1347                 public Attributes (ArrayList attrs)
1348                 {
1349                         Attrs = attrs;
1350                 }
1351
1352                 public void AddAttributes (ArrayList attrs)
1353                 {
1354                         Attrs.AddRange (attrs);
1355                 }
1356
1357                 /// <summary>
1358                 /// Checks whether attribute target is valid for the current element
1359                 /// </summary>
1360                 public bool CheckTargets (Attributable member)
1361                 {
1362                         string[] valid_targets = member.ValidAttributeTargets;
1363                         foreach (Attribute a in Attrs) {
1364                                 if (a.ExplicitTarget == null || a.ExplicitTarget == valid_targets [0]) {
1365                                         a.Target = member.AttributeTargets;
1366                                         continue;
1367                                 }
1368
1369                                 // TODO: we can skip the first item
1370                                 if (((IList) valid_targets).Contains (a.ExplicitTarget)) {
1371                                         switch (a.ExplicitTarget) {
1372                                                 case "return": a.Target = AttributeTargets.ReturnValue; continue;
1373                                                 case "param": a.Target = AttributeTargets.Parameter; continue;
1374                                                 case "field": a.Target = AttributeTargets.Field; continue;
1375                                                 case "method": a.Target = AttributeTargets.Method; continue;
1376                                                 case "property": a.Target = AttributeTargets.Property; continue;
1377                                         }
1378                                         throw new InternalErrorException ("Unknown explicit target: " + a.ExplicitTarget);
1379                                 }
1380
1381                                 StringBuilder sb = new StringBuilder ();
1382                                 foreach (string s in valid_targets) {
1383                                         sb.Append (s);
1384                                         sb.Append (", ");
1385                                 }
1386                                 sb.Remove (sb.Length - 2, 2);
1387                                 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 ());
1388                                 return false;
1389                         }
1390                         return true;
1391                 }
1392
1393                 public Attribute Search (Type t, EmitContext ec)
1394                 {
1395                         foreach (Attribute a in Attrs) {
1396                                 if (a.ResolveType (ec) == t)
1397                                         return a;
1398                         }
1399                         return null;
1400                 }
1401
1402                 /// <summary>
1403                 /// Returns all attributes of type 't'. Use it when attribute is AllowMultiple = true
1404                 /// </summary>
1405                 public Attribute[] SearchMulti (Type t, EmitContext ec)
1406                 {
1407                         ArrayList ar = null;
1408
1409                         foreach (Attribute a in Attrs) {
1410                                 if (a.ResolveType (ec) == t) {
1411                                         if (ar == null)
1412                                                 ar = new ArrayList ();
1413                                         ar.Add (a);
1414                                 }
1415                         }
1416
1417                         return ar == null ? null : ar.ToArray (typeof (Attribute)) as Attribute[];
1418                 }
1419
1420                 public void Emit (EmitContext ec, Attributable ias)
1421                 {
1422                         CheckTargets (ias);
1423
1424                         ListDictionary ld = new ListDictionary ();
1425
1426                         foreach (Attribute a in Attrs)
1427                                 a.Emit (ec, ias, ld);
1428                 }
1429
1430                 public bool Contains (Type t, EmitContext ec)
1431                 {
1432                         return Search (t, ec) != null;
1433                 }
1434         }
1435
1436         /// <summary>
1437         /// Helper class for attribute verification routine.
1438         /// </summary>
1439         sealed class AttributeTester
1440         {
1441                 static PtrHashtable analyzed_types = new PtrHashtable ();
1442                 static PtrHashtable analyzed_types_obsolete = new PtrHashtable ();
1443                 static PtrHashtable analyzed_member_obsolete = new PtrHashtable ();
1444                 static PtrHashtable analyzed_method_excluded = new PtrHashtable ();
1445
1446 #if NET_2_0
1447                 static PtrHashtable fixed_buffer_cache = new PtrHashtable ();
1448 #endif
1449
1450                 static object TRUE = new object ();
1451                 static object FALSE = new object ();
1452
1453                 private AttributeTester ()
1454                 {
1455                 }
1456
1457                 public enum Result {
1458                         Ok,
1459                         RefOutArrayError,
1460                         ArrayArrayError
1461                 }
1462
1463                 /// <summary>
1464                 /// Returns true if parameters of two compared methods are CLS-Compliant.
1465                 /// It tests differing only in ref or out, or in array rank.
1466                 /// </summary>
1467                 public static Result AreOverloadedMethodParamsClsCompliant (Type[] types_a, Type[] types_b)
1468                 {
1469                         if (types_a == null || types_b == null)
1470                                 return Result.Ok;
1471
1472                         if (types_a.Length != types_b.Length)
1473                                 return Result.Ok;
1474
1475                         Result result = Result.Ok;
1476                         for (int i = 0; i < types_b.Length; ++i) {
1477                                 Type aType = types_a [i];
1478                                 Type bType = types_b [i];
1479
1480                                 if (aType.IsArray && bType.IsArray) {
1481                                         Type a_el_type = aType.GetElementType ();
1482                                         Type b_el_type = bType.GetElementType ();
1483                                         if (aType.GetArrayRank () != bType.GetArrayRank () && a_el_type == b_el_type) {
1484                                                 result = Result.RefOutArrayError;
1485                                                 continue;
1486                                         }
1487
1488                                         if (a_el_type.IsArray || b_el_type.IsArray) {
1489                                                 result = Result.ArrayArrayError;
1490                                                 continue;
1491                                         }
1492                                 }
1493
1494                                 Type aBaseType = aType;
1495                                 bool is_either_ref_or_out = false;
1496
1497                                 if (aType.IsByRef || aType.IsPointer) {
1498                                         aBaseType = aType.GetElementType ();
1499                                         is_either_ref_or_out = true;
1500                                 }
1501
1502                                 Type bBaseType = bType;
1503                                 if (bType.IsByRef || bType.IsPointer)
1504                                 {
1505                                         bBaseType = bType.GetElementType ();
1506                                         is_either_ref_or_out = !is_either_ref_or_out;
1507                                 }
1508
1509                                 if (aBaseType != bBaseType)
1510                                         return Result.Ok;
1511
1512                                 if (is_either_ref_or_out)
1513                                         result = Result.RefOutArrayError;
1514                         }
1515                         return result;
1516                 }
1517
1518                 /// <summary>
1519                 /// Goes through all parameters and test if they are CLS-Compliant.
1520                 /// </summary>
1521                 public static bool AreParametersCompliant (Parameter[] fixedParameters, Location loc)
1522                 {
1523                         if (fixedParameters == null)
1524                                 return true;
1525
1526                         foreach (Parameter arg in fixedParameters) {
1527                                 if (!AttributeTester.IsClsCompliant (arg.ParameterType)) {
1528                                         Report.Error (3001, loc, "Argument type `{0}' is not CLS-compliant", arg.GetSignatureForError ());
1529                                         return false;
1530                                 }
1531                         }
1532                         return true;
1533                 }
1534
1535
1536                 /// <summary>
1537                 /// This method tests the CLS compliance of external types. It doesn't test type visibility.
1538                 /// </summary>
1539                 public static bool IsClsCompliant (Type type)
1540                 {
1541                         if (type == null)
1542                                 return true;
1543
1544                         object type_compliance = analyzed_types[type];
1545                         if (type_compliance != null)
1546                                 return type_compliance == TRUE;
1547
1548                         if (type.IsPointer) {
1549                                 analyzed_types.Add (type, null);
1550                                 return false;
1551                         }
1552
1553                         bool result;
1554                         if (type.IsArray || type.IsByRef)       {
1555                                 result = IsClsCompliant (TypeManager.GetElementType (type));
1556                         } else {
1557                                 result = AnalyzeTypeCompliance (type);
1558                         }
1559                         analyzed_types.Add (type, result ? TRUE : FALSE);
1560                         return result;
1561                 }
1562
1563                 /// <summary>
1564                 /// Returns IFixedBuffer implementation if field is fixed buffer else null.
1565                 /// </summary>
1566                 public static IFixedBuffer GetFixedBuffer (FieldInfo fi)
1567                 {
1568                         FieldBase fb = TypeManager.GetField (fi);
1569                         if (fb != null) {
1570                                 return fb as IFixedBuffer;
1571                         }
1572
1573 #if NET_2_0
1574                         object o = fixed_buffer_cache [fi];
1575                         if (o == null) {
1576                                 if (System.Attribute.GetCustomAttribute (fi, TypeManager.fixed_buffer_attr_type) == null) {
1577                                         fixed_buffer_cache.Add (fi, FALSE);
1578                                         return null;
1579                                 }
1580
1581                                 IFixedBuffer iff = new FixedFieldExternal (fi);
1582                                 fixed_buffer_cache.Add (fi, iff);
1583                                 return iff;
1584                         }
1585
1586                         if (o == FALSE)
1587                                 return null;
1588
1589                         return (IFixedBuffer)o;
1590 #else
1591                         return null;
1592 #endif
1593                 }
1594
1595                 public static void VerifyModulesClsCompliance ()
1596                 {
1597                         Module[] modules = TypeManager.Modules;
1598                         if (modules == null)
1599                                 return;
1600
1601                         // The first module is generated assembly
1602                         for (int i = 1; i < modules.Length; ++i) {
1603                                 Module module = modules [i];
1604                                 if (!IsClsCompliant (module)) {
1605                                         Report.Error (3013, "Added modules must be marked with the CLSCompliant attribute to match the assembly", module.Name);
1606                                         return;
1607                                 }
1608                         }
1609                 }
1610
1611                 public static Type GetImportedIgnoreCaseClsType (string name)
1612                 {
1613                         foreach (Assembly a in TypeManager.GetAssemblies ()) {
1614                                 Type t = a.GetType (name, false, true);
1615                                 if (t == null)
1616                                         continue;
1617
1618                                 if (IsClsCompliant (t))
1619                                         return t;
1620                         }
1621                         return null;
1622                 }
1623
1624                 static bool IsClsCompliant (ICustomAttributeProvider attribute_provider)
1625                 {
1626                         object[] CompliantAttribute = attribute_provider.GetCustomAttributes (TypeManager.cls_compliant_attribute_type, false);
1627                         if (CompliantAttribute.Length == 0)
1628                                 return false;
1629
1630                         return ((CLSCompliantAttribute)CompliantAttribute[0]).IsCompliant;
1631                 }
1632
1633                 static bool AnalyzeTypeCompliance (Type type)
1634                 {
1635                         DeclSpace ds = TypeManager.LookupDeclSpace (type);
1636                         if (ds != null) {
1637                                 return ds.IsClsCompliaceRequired (ds.Parent);
1638                         }
1639
1640                         object[] CompliantAttribute = type.GetCustomAttributes (TypeManager.cls_compliant_attribute_type, false);
1641                         if (CompliantAttribute.Length == 0)
1642                                 return IsClsCompliant (type.Assembly);
1643
1644                         return ((CLSCompliantAttribute)CompliantAttribute[0]).IsCompliant;
1645                 }
1646
1647                 /// <summary>
1648                 /// Returns instance of ObsoleteAttribute when type is obsolete
1649                 /// </summary>
1650                 public static ObsoleteAttribute GetObsoleteAttribute (Type type)
1651                 {
1652                         object type_obsolete = analyzed_types_obsolete [type];
1653                         if (type_obsolete == FALSE)
1654                                 return null;
1655
1656                         if (type_obsolete != null)
1657                                 return (ObsoleteAttribute)type_obsolete;
1658
1659                         ObsoleteAttribute result = null;
1660                         if (type.IsByRef || type.IsArray || type.IsPointer) {
1661                                 result = GetObsoleteAttribute (TypeManager.GetElementType (type));
1662                         } else {
1663                                 DeclSpace type_ds = TypeManager.LookupDeclSpace (type);
1664
1665                                 // Type is external, we can get attribute directly
1666                                 if (type_ds == null) {
1667                                         object[] attribute = type.GetCustomAttributes (TypeManager.obsolete_attribute_type, false);
1668                                         if (attribute.Length == 1)
1669                                                 result = (ObsoleteAttribute)attribute [0];
1670                                 } else {
1671                                         result = type_ds.GetObsoleteAttribute ();
1672                                 }
1673                         }
1674
1675                         // Cannot use .Add because of corlib bootstrap
1676                         analyzed_types_obsolete [type] = result == null ? FALSE : result;
1677                         return result;
1678                 }
1679
1680                 /// <summary>
1681                 /// Returns instance of ObsoleteAttribute when method is obsolete
1682                 /// </summary>
1683                 public static ObsoleteAttribute GetMethodObsoleteAttribute (MethodBase mb)
1684                 {
1685                         IMethodData mc = TypeManager.GetMethod (mb);
1686                         if (mc != null)
1687                                 return mc.GetObsoleteAttribute ();
1688
1689                         // compiler generated methods are not registered by AddMethod
1690                         if (mb.DeclaringType is TypeBuilder)
1691                                 return null;
1692
1693                         if (mb.IsSpecialName) {
1694                                 PropertyInfo pi = PropertyExpr.AccessorTable [mb] as PropertyInfo;
1695                                 if (pi != null) {
1696                                         // FIXME: This is buggy as properties from this assembly are included as well
1697                                         return null;
1698                                         //return GetMemberObsoleteAttribute (pi);
1699                                 }
1700                         }
1701
1702                         return GetMemberObsoleteAttribute (mb);
1703                 }
1704
1705                 /// <summary>
1706                 /// Returns instance of ObsoleteAttribute when member is obsolete
1707                 /// </summary>
1708                 public static ObsoleteAttribute GetMemberObsoleteAttribute (MemberInfo mi)
1709                 {
1710                         object type_obsolete = analyzed_member_obsolete [mi];
1711                         if (type_obsolete == FALSE)
1712                                 return null;
1713
1714                         if (type_obsolete != null)
1715                                 return (ObsoleteAttribute)type_obsolete;
1716
1717                         ObsoleteAttribute oa = System.Attribute.GetCustomAttribute (mi, TypeManager.obsolete_attribute_type, false) as ObsoleteAttribute;
1718                         analyzed_member_obsolete.Add (mi, oa == null ? FALSE : oa);
1719                         return oa;
1720                 }
1721
1722                 /// <summary>
1723                 /// Common method for Obsolete error/warning reporting.
1724                 /// </summary>
1725                 public static void Report_ObsoleteMessage (ObsoleteAttribute oa, string member, Location loc)
1726                 {
1727                         if (oa.IsError) {
1728                                 Report.Error (619, loc, "`{0}' is obsolete: `{1}'", member, oa.Message);
1729                                 return;
1730                         }
1731
1732                         if (oa.Message == null) {
1733                                 Report.Warning (612, loc, "`{0}' is obsolete", member);
1734                                 return;
1735                         }
1736                         if (RootContext.WarningLevel >= 2)
1737                                 Report.Warning (618, loc, "`{0}' is obsolete: `{1}'", member, oa.Message);
1738                 }
1739
1740                 public static bool IsConditionalMethodExcluded (MethodBase mb)
1741                 {
1742                         object excluded = analyzed_method_excluded [mb];
1743                         if (excluded != null)
1744                                 return excluded == TRUE ? true : false;
1745
1746                         ConditionalAttribute[] attrs = mb.GetCustomAttributes (TypeManager.conditional_attribute_type, true) as ConditionalAttribute[];
1747                         if (attrs.Length == 0) {
1748                                 analyzed_method_excluded.Add (mb, FALSE);
1749                                 return false;
1750                         }
1751
1752                         foreach (ConditionalAttribute a in attrs) {
1753                                 if (RootContext.AllDefines.Contains (a.ConditionString)) {
1754                                         analyzed_method_excluded.Add (mb, FALSE);
1755                                         return false;
1756                                 }
1757                         }
1758                         analyzed_method_excluded.Add (mb, TRUE);
1759                         return true;
1760                 }
1761
1762                 /// <summary>
1763                 /// Analyzes class whether it has attribute which has ConditionalAttribute
1764                 /// and its condition is not defined.
1765                 /// </summary>
1766                 public static bool IsAttributeExcluded (Type type)
1767                 {
1768                         if (!type.IsClass)
1769                                 return false;
1770
1771                         Class class_decl = TypeManager.LookupDeclSpace (type) as Class;
1772
1773                         // TODO: add caching
1774                         // TODO: merge all Type bases attribute caching to one cache to save memory
1775                         if (class_decl == null) {
1776                                 object[] attributes = type.GetCustomAttributes (TypeManager.conditional_attribute_type, false);
1777                                 foreach (ConditionalAttribute ca in attributes) {
1778                                         if (RootContext.AllDefines.Contains (ca.ConditionString))
1779                                                 return false;
1780                                 }
1781                                 return attributes.Length > 0;
1782                         }
1783
1784                         return class_decl.IsExcluded ();
1785                 }
1786         }
1787 }