mcs/gmcs/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 IsClsComplianceRequired (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                 static void Error_TypeParameterInAttribute (Location loc)
 137                 {
 138                         Report.Error (
 139                                 -202, loc, "Can not use a type parameter in an attribute");
 140                 }
 141
 142                 /// <summary>
 143                 /// This is rather hack. We report many emit attribute error with same error to be compatible with
 144                 /// csc. But because csc has to report them this way because error came from ilasm we needn't.
 145                 /// </summary>
 146                 public void Error_AttributeEmitError (string inner)
 147                 {
 148                         Report.Error (647, Location, "Error during emitting `{0}' attribute. The reason is `{1}'", TypeManager.CSharpName (Type), inner);
 149                 }
 150
 151                 public void Error_InvalidSecurityParent ()
 152                 {
 153                         Error_AttributeEmitError ("it is attached to invalid parent");
 154                 }
 155
 156                 protected virtual FullNamedExpression ResolveAsTypeTerminal (Expression expr, EmitContext ec, bool silent)
 157                 {
 158                         return expr.ResolveAsTypeTerminal (ec, silent);
 159                 }
 160
 161                 protected virtual FullNamedExpression ResolveAsTypeStep (Expression expr, EmitContext ec, bool silent)
 162                 {
 163                         return expr.ResolveAsTypeStep (ec, silent);
 164                 }
 165
 166                 Type ResolvePossibleAttributeType (EmitContext ec, string name, bool silent, ref bool is_attr)
 167                 {
 168                         FullNamedExpression fn;
 169                         if (LeftExpr == null) {
 170                                 fn = ResolveAsTypeTerminal (new SimpleName (name, Location), ec, silent);
 171                         } else {
 172                                 fn = ResolveAsTypeStep (LeftExpr, ec, silent);
 173                                 if (fn == null)
 174                                         return null;
 175                                 fn = new MemberAccess (fn, name, Location).ResolveAsTypeTerminal (ec, silent);
 176                         }
 177
 178                         TypeExpr te = fn as TypeExpr;
 179                         if (te == null)
 180                                 return null;
 181
 182                         Type t = te.Type;
 183                         if (t.IsSubclassOf (TypeManager.attribute_type)) {
 184                                 is_attr = true;
 185                         } else if (!silent) {
 186                                 Report.SymbolRelatedToPreviousError (t);
 187                                 Report.Error (616, Location, "`{0}': is not an attribute class", TypeManager.CSharpName (t));
 188                         }
 189                         return t;
 190                 }
 191
 192                 /// <summary>
 193                 ///   Tries to resolve the type of the attribute. Flags an error if it can't, and complain is true.
 194                 /// </summary>
 195                 void ResolveAttributeType (EmitContext ec)
 196                 {
 197                         bool t1_is_attr = false;
 198                         Type t1 = ResolvePossibleAttributeType (ec, Identifier, true, ref t1_is_attr);
 199                         // FIXME: Shouldn't do this for quoted attributes: [@A]
 200                         bool t2_is_attr = false;
 201                         Type t2 = ResolvePossibleAttributeType (ec, Identifier + "Attribute", true, ref t2_is_attr);
 202
 203                         if (t1_is_attr && t2_is_attr && !nameEscaped) {
 204                                 Report.Error (1614, Location, "`{0}' is ambiguous between `{0}' and `{0}Attribute'. Use either `@{0}' or `{0}Attribute'", GetSignatureForError ());
 205                                 resolve_error = true;
 206                                 return;
 207                         }
 208                         if (t1_is_attr) {
 209                                 Type = t1;
 210                                 return;
 211                         }
 212
 213                         if (t2_is_attr) {
 214                                 Type = t2;
 215                                 return;
 216                         }
 217
 218                         if (t1 == null && t2 == null)
 219                                 ResolvePossibleAttributeType (ec, Identifier, false, ref t1_is_attr);
 220                         if (t1 != null)
 221                                 ResolvePossibleAttributeType (ec, Identifier, false, ref t1_is_attr);
 222                         if (t2 != null)
 223                                 ResolvePossibleAttributeType (ec, Identifier + "Attribute", false, ref t2_is_attr);
 224                         resolve_error = true;
 225                 }
 226
 227                 public virtual Type ResolveType (EmitContext ec)
 228                 {
 229                         if (Type == null && !resolve_error)
 230                                 ResolveAttributeType (ec);
 231                         return Type;
 232                 }
 233
 234                 public string GetSignatureForError ()
 235                 {
 236                         return LeftExpr == null ? Identifier : LeftExpr.GetSignatureForError () + "." + Identifier;
 237                 }
 238
 239                 //
 240                 // Given an expression, if the expression is a valid attribute-argument-expression
 241                 // returns an object that can be used to encode it, or null on failure.
 242                 //
 243                 public static bool GetAttributeArgumentExpression (Expression e, Location loc, Type arg_type, out object result)
 244                 {
 245                         if (e is EnumConstant) {
 246                                 if (RootContext.StdLib)
 247                                         result = ((EnumConstant)e).GetValueAsEnumType ();
 248                                 else
 249                                         result = ((EnumConstant)e).GetValue ();
 250
 251                                 return true;
 252                         }
 253
 254                         Constant constant = e as Constant;
 255                         if (constant != null) {
 256                                 if (e.Type != arg_type) {
 257                                         constant = Const.ChangeType (loc, constant, arg_type);
 258                                         if (constant == null) {
 259                                                 result = null;
 260                                                 Error_AttributeArgumentNotValid (loc);
 261                                                 return false;
 262                                         }
 263                                 }
 264                                 result = constant.GetValue ();
 265                                 return true;
 266                         } else if (e is TypeOf) {
 267                                 result = ((TypeOf) e).TypeArg;
 268                                 return true;
 269                         } else if (e is ArrayCreation){
 270                                 result =  ((ArrayCreation) e).EncodeAsAttribute ();
 271                                 if (result != null)
 272                                         return true;
 273                         } else if (e is EmptyCast) {
 274                                 Expression child = ((EmptyCast)e).Child;
 275                                 return GetAttributeArgumentExpression (child, loc, child.Type, out result);
 276                         }
 277
 278                         result = null;
 279                         Error_AttributeArgumentNotValid (loc);
 280                         return false;
 281                 }
 282
 283                 bool IsValidArgumentType (Type t)
 284                 {
 285                         return TypeManager.IsPrimitiveType (t) ||
 286                                 (t.IsArray && TypeManager.IsPrimitiveType (t.GetElementType ())) ||
 287                                 TypeManager.IsEnumType (t) ||
 288                                 t == TypeManager.string_type ||
 289                                 t == TypeManager.object_type ||
 290                                 t == TypeManager.type_type;
 291                 }
 292
 293                 // Cache for parameter-less attributes
 294                 static PtrHashtable att_cache = new PtrHashtable ();
 295
 296                 public CustomAttributeBuilder Resolve (EmitContext ec)
 297                 {
 298                         if (resolve_error)
 299                                 return null;
 300
 301                         resolve_error = true;
 302
 303                         if (Type == null) {
 304                                 ResolveAttributeType (ec);
 305                                 if (Type == null)
 306                                         return null;
 307                         }
 308
 309                         if (Type.IsAbstract) {
 310                                 Report.Error (653, Location, "Cannot apply attribute class `{0}' because it is abstract", GetSignatureForError ());
 311                                 return null;
 312                         }
 313
 314                         if (Arguments == null) {
 315                                 object o = att_cache [Type];
 316                                 if (o != null) {
 317                                         resolve_error = false;
 318                                         return (CustomAttributeBuilder)o;
 319                                 }
 320                         }
 321
 322                         ConstructorInfo ctor = ResolveArguments (ec);
 323                         if (ctor == null)
 324                                 return null;
 325
 326                         CustomAttributeBuilder cb;
 327
 328                         try {
 329                                 if (prop_info_arr != null || field_info_arr != null) {
 330                                         cb = new CustomAttributeBuilder (
 331                                                 ctor, pos_values,
 332                                                 prop_info_arr, prop_values_arr,
 333                                                 field_info_arr, field_values_arr);
 334                                 } else {
 335                                         cb = new CustomAttributeBuilder (
 336                                                 ctor, pos_values);
 337
 338                                         if (pos_values.Length == 0)
 339                                                 att_cache.Add (Type, cb);
 340                                 }
 341                         }
 342                         catch (Exception) {
 343                                 Error_AttributeArgumentNotValid (Location);
 344                                 return null;
 345                         }
 346
 347                         resolve_error = false;
 348                         return cb;
 349                 }
 350
 351                 protected virtual ConstructorInfo ResolveArguments (EmitContext ec)
 352                 {
 353                         // Now we extract the positional and named arguments
 354
 355                         ArrayList pos_args = null;
 356                         ArrayList named_args = null;
 357                         int pos_arg_count = 0;
 358                         int named_arg_count = 0;
 359
 360                         if (Arguments != null) {
 361                                 pos_args = (ArrayList) Arguments [0];
 362                                 if (pos_args != null)
 363                                         pos_arg_count = pos_args.Count;
 364                                 if (Arguments.Count > 1) {
 365                                         named_args = (ArrayList) Arguments [1];
 366                                         named_arg_count = named_args.Count;
 367                                 }
 368                         }
 369
 370                         pos_values = new object [pos_arg_count];
 371
 372                         //
 373                         // First process positional arguments
 374                         //
 375
 376                         int i;
 377                         for (i = 0; i < pos_arg_count; i++) {
 378                                 Argument a = (Argument) pos_args [i];
 379                                 Expression e;
 380
 381                                 if (!a.Resolve (ec, Location))
 382                                         return null;
 383
 384                                 e = a.Expr;
 385
 386                                 object val;
 387                                 if (!GetAttributeArgumentExpression (e, Location, a.Type, out val))
 388                                         return null;
 389
 390                                 pos_values [i] = val;
 391
 392                                 if (i == 0 && Type == TypeManager.attribute_usage_type && (int)val == 0) {
 393                                         Report.Error (591, Location, "Invalid value for argument to 'System.AttributeUsage' attribute");
 394                                         return null;
 395                                 }
 396                         }
 397
 398                         //
 399                         // Now process named arguments
 400                         //
 401
 402                         ArrayList field_infos = null;
 403                         ArrayList prop_infos  = null;
 404                         ArrayList field_values = null;
 405                         ArrayList prop_values = null;
 406                         Hashtable seen_names = null;
 407
 408                         if (named_arg_count > 0) {
 409                                 field_infos = new ArrayList ();
 410                                 prop_infos  = new ArrayList ();
 411                                 field_values = new ArrayList ();
 412                                 prop_values = new ArrayList ();
 413
 414                                 seen_names = new Hashtable();
 415                         }
 416
 417                         for (i = 0; i < named_arg_count; i++) {
 418                                 DictionaryEntry de = (DictionaryEntry) named_args [i];
 419                                 string member_name = (string) de.Key;
 420                                 Argument a  = (Argument) de.Value;
 421                                 Expression e;
 422
 423                                 if (seen_names.Contains(member_name)) {
 424                                         Report.Error(643, Location, "'" + member_name + "' duplicate named attribute argument");
 425                                         return null;
 426                                 }
 427                                 seen_names.Add(member_name, 1);
 428
 429                                 if (!a.Resolve (ec, Location))
 430                                         return null;
 431
 432                                 Expression member = Expression.MemberLookup (
 433                                         ec, Type, member_name,
 434                                         MemberTypes.Field | MemberTypes.Property,
 435                                         BindingFlags.Public | BindingFlags.Instance,
 436                                         Location);
 437
 438                                 if (member == null) {
 439                                         member = Expression.MemberLookup (ec, Type, member_name,
 440                                                 MemberTypes.Field | MemberTypes.Property, BindingFlags.NonPublic | BindingFlags.Instance,
 441                                                 Location);
 442
 443                                         if (member != null) {
 444                                                 Expression.ErrorIsInaccesible (Location, member.GetSignatureForError ());
 445                                                 return null;
 446                                         }
 447                                 }
 448
 449                                 if (member == null){
 450                                         Report.Error (117, Location, "`{0}' does not contain a definition for `{1}'",
 451                                                       Type, member_name);
 452                                         return null;
 453                                 }
 454
 455                                 if (!(member is PropertyExpr || member is FieldExpr)) {
 456                                         Error_InvalidNamedArgument (member_name);
 457                                         return null;
 458                                 }
 459
 460                                 e = a.Expr;
 461                                 if (e is TypeParameterExpr){
 462                                         Error_TypeParameterInAttribute (Location);
 463                                         return null;
 464                                 }
 465
 466                                 if (member is PropertyExpr) {
 467                                         PropertyExpr pe = (PropertyExpr) member;
 468                                         PropertyInfo pi = pe.PropertyInfo;
 469
 470                                         if (!pi.CanWrite || !pi.CanRead) {
 471                                                 Report.SymbolRelatedToPreviousError (pi);
 472                                                 Error_InvalidNamedArgument (member_name);
 473                                                 return null;
 474                                         }
 475
 476                                         if (!IsValidArgumentType (pi.PropertyType)) {
 477                                                 Report.SymbolRelatedToPreviousError (pi);
 478                                                 Error_InvalidNamedAgrumentType (member_name);
 479                                                 return null;
 480                                         }
 481
 482                                         object value;
 483                                         if (!GetAttributeArgumentExpression (e, Location, pi.PropertyType, out value))
 484                                                 return null;
 485
 486                                         prop_values.Add (value);
 487                                         prop_infos.Add (pi);
 488
 489                                 } else if (member is FieldExpr) {
 490                                         FieldExpr fe = (FieldExpr) member;
 491                                         FieldInfo fi = fe.FieldInfo;
 492
 493                                         if (fi.IsInitOnly) {
 494                                                 Error_InvalidNamedArgument (member_name);
 495                                                 return null;
 496                                         }
 497
 498                                         if (!IsValidArgumentType (fi.FieldType)) {
 499                                                 Report.SymbolRelatedToPreviousError (fi);
 500                                                 Error_InvalidNamedAgrumentType (member_name);
 501                                                 return null;
 502                                         }
 503
 504                                         object value;
 505                                         if (!GetAttributeArgumentExpression (e, Location, fi.FieldType, out value))
 506                                                 return null;
 507
 508                                         field_values.Add (value);
 509
 510                                         field_infos.Add (fi);
 511                                 }
 512                         }
 513
 514                         Expression mg = Expression.MemberLookup (
 515                                 ec, Type, ".ctor", MemberTypes.Constructor,
 516                                 BindingFlags.Public | BindingFlags.Instance | BindingFlags.DeclaredOnly,
 517                                 Location);
 518
 519                         MethodBase constructor = Invocation.OverloadResolve (
 520                                 ec, (MethodGroupExpr) mg, pos_args, false, Location);
 521
 522                         if (constructor == null) {
 523                                 return null;
 524                         }
 525
 526
 527                         // Here we do the checks which should be done by corlib or by runtime.
 528                         // However Zoltan doesn't like it and every Mono compiler has to do it again.
 529
 530                         if (Type == TypeManager.guid_attr_type) {
 531                                 try {
 532                                         new Guid ((string)pos_values [0]);
 533                                 }
 534                                 catch (Exception e) {
 535                                         Error_AttributeEmitError (e.Message);
 536                                 }
 537                         }
 538 // TODO: reenable
 539 //                      if (Type == TypeManager.methodimpl_attr_type &&
 540 //                              pos_values.Length == 1 && ((Argument)pos_args [0]).Type == TypeManager.short_type &&
 541 //                              !System.Enum.IsDefined (TypeManager.method_impl_options, pos_values [0])) {
 542 //                                      Error_AttributeEmitError ("Incorrect argument value.");
 543 //                      }
 544
 545                         //
 546                         // Now we perform some checks on the positional args as they
 547                         // cannot be null for a constructor which expects a parameter
 548                         // of type object
 549                         //
 550
 551                         ParameterData pd = TypeManager.GetParameterData (constructor);
 552
 553                         int last_real_param = pd.Count;
 554                         if (pd.HasParams) {
 555                                 // When the params is not filled we need to put one
 556                                 if (last_real_param > pos_arg_count) {
 557                                         object [] new_pos_values = new object [pos_arg_count + 1];
 558                                         pos_values.CopyTo (new_pos_values, 0);
 559                                         new_pos_values [pos_arg_count] = new object [] {} ;
 560                                         pos_values = new_pos_values;
 561                                 }
 562                                 last_real_param--;
 563                         }
 564
 565                         for (int j = 0; j < pos_arg_count; ++j) {
 566                                 Argument a = (Argument) pos_args [j];
 567
 568                                 if (a.Expr is NullLiteral && pd.ParameterType (j) == TypeManager.object_type) {
 569                                         Error_AttributeArgumentNotValid (Location);
 570                                         return null;
 571                                 }
 572
 573                                 object value = pos_values [j];
 574                                 if (value != null && a.Type != value.GetType () && TypeManager.IsPrimitiveType (a.Type)) {
 575                                         bool fail;
 576                                         pos_values [j] = TypeManager.ChangeType (value, a.Type, out fail);
 577                                         if (fail) {
 578                                                 // TODO: Can failed ?
 579                                                 throw new NotImplementedException ();
 580                                         }
 581                                 }
 582
 583                                 if (j < last_real_param)
 584                                         continue;
 585
 586                                 if (j == last_real_param) {
 587                                         object [] array = new object [pos_arg_count - last_real_param];
 588                                         array [0] = pos_values [j];
 589                                         pos_values [j] = array;
 590                                         continue;
 591                                 }
 592
 593                                 object [] params_array = (object []) pos_values [last_real_param];
 594                                 params_array [j - last_real_param] = pos_values [j];
 595                         }
 596
 597                         // Adjust the size of the pos_values if it had params
 598                         if (last_real_param != pos_arg_count) {
 599                                 object [] new_pos_values = new object [last_real_param + 1];
 600                                 Array.Copy (pos_values, new_pos_values, last_real_param + 1);
 601                                 pos_values = new_pos_values;
 602                         }
 603
 604                         if (named_arg_count > 0) {
 605                                 prop_info_arr = new PropertyInfo [prop_infos.Count];
 606                                 field_info_arr = new FieldInfo [field_infos.Count];
 607                                 field_values_arr = new object [field_values.Count];
 608                                 prop_values_arr = new object [prop_values.Count];
 609
 610                                 field_infos.CopyTo  (field_info_arr, 0);
 611                                 field_values.CopyTo (field_values_arr, 0);
 612
 613                                 prop_values.CopyTo  (prop_values_arr, 0);
 614                                 prop_infos.CopyTo   (prop_info_arr, 0);
 615                         }
 616
 617                         return (ConstructorInfo) constructor;
 618                 }
 619
 620                 /// <summary>
 621                 ///   Get a string containing a list of valid targets for the attribute 'attr'
 622                 /// </summary>
 623                 public string GetValidTargets ()
 624                 {
 625                         StringBuilder sb = new StringBuilder ();
 626                         AttributeTargets targets = GetAttributeUsage (null).ValidOn;
 627
 628                         if ((targets & AttributeTargets.Assembly) != 0)
 629                                 sb.Append ("assembly, ");
 630
 631                         if ((targets & AttributeTargets.Module) != 0)
 632                                 sb.Append ("module, ");
 633
 634                         if ((targets & AttributeTargets.Class) != 0)
 635                                 sb.Append ("class, ");
 636
 637                         if ((targets & AttributeTargets.Struct) != 0)
 638                                 sb.Append ("struct, ");
 639
 640                         if ((targets & AttributeTargets.Enum) != 0)
 641                                 sb.Append ("enum, ");
 642
 643                         if ((targets & AttributeTargets.Constructor) != 0)
 644                                 sb.Append ("constructor, ");
 645
 646                         if ((targets & AttributeTargets.Method) != 0)
 647                                 sb.Append ("method, ");
 648
 649                         if ((targets & AttributeTargets.Property) != 0)
 650                                 sb.Append ("property, indexer, ");
 651
 652                         if ((targets & AttributeTargets.Field) != 0)
 653                                 sb.Append ("field, ");
 654
 655                         if ((targets & AttributeTargets.Event) != 0)
 656                                 sb.Append ("event, ");
 657
 658                         if ((targets & AttributeTargets.Interface) != 0)
 659                                 sb.Append ("interface, ");
 660
 661                         if ((targets & AttributeTargets.Parameter) != 0)
 662                                 sb.Append ("parameter, ");
 663
 664                         if ((targets & AttributeTargets.Delegate) != 0)
 665                                 sb.Append ("delegate, ");
 666
 667                         if ((targets & AttributeTargets.ReturnValue) != 0)
 668                                 sb.Append ("return, ");
 669
 670                         if ((targets & AttributeTargets.GenericParameter) != 0)
 671                                 sb.Append ("type parameter, ");
 672                         return sb.Remove (sb.Length - 2, 2).ToString ();
 673                 }
 674
 675                 /// <summary>
 676                 /// Returns AttributeUsage attribute for this type
 677                 /// </summary>
 678                 AttributeUsageAttribute GetAttributeUsage (EmitContext ec)
 679                 {
 680                         AttributeUsageAttribute ua = usage_attr_cache [Type] as AttributeUsageAttribute;
 681                         if (ua != null)
 682                                 return ua;
 683
 684                         Class attr_class = TypeManager.LookupClass (Type);
 685
 686                         if (attr_class == null) {
 687                                 object[] usage_attr = Type.GetCustomAttributes (TypeManager.attribute_usage_type, true);
 688                                 ua = (AttributeUsageAttribute)usage_attr [0];
 689                                 usage_attr_cache.Add (Type, ua);
 690                                 return ua;
 691                         }
 692
 693                         Attribute a = attr_class.OptAttributes == null
 694                                 ? null
 695                                 : attr_class.OptAttributes.Search (TypeManager.attribute_usage_type, attr_class.EmitContext);
 696
 697                         ua = a == null
 698                                 ? DefaultUsageAttribute
 699                                 : a.GetAttributeUsageAttribute (attr_class.EmitContext);
 700
 701                         usage_attr_cache.Add (Type, ua);
 702                         return ua;
 703                 }
 704
 705                 AttributeUsageAttribute GetAttributeUsageAttribute (EmitContext ec)
 706                 {
 707                         if (pos_values == null)
 708                                 // TODO: It is not neccessary to call whole Resolve (ApplyAttribute does it now) we need only ctor args.
 709                                 // But because a lot of attribute class code must be rewritten will be better to wait...
 710                                 Resolve (ec);
 711
 712                         if (resolve_error)
 713                                 return DefaultUsageAttribute;
 714
 715                         AttributeUsageAttribute usage_attribute = new AttributeUsageAttribute ((AttributeTargets)pos_values [0]);
 716
 717                         object field = GetPropertyValue ("AllowMultiple");
 718                         if (field != null)
 719                                 usage_attribute.AllowMultiple = (bool)field;
 720
 721                         field = GetPropertyValue ("Inherited");
 722                         if (field != null)
 723                                 usage_attribute.Inherited = (bool)field;
 724
 725                         return usage_attribute;
 726                 }
 727
 728                 /// <summary>
 729                 /// Returns custom name of indexer
 730                 /// </summary>
 731                 public string GetIndexerAttributeValue (EmitContext ec)
 732                 {
 733                         if (pos_values == null)
 734                                 // TODO: It is not neccessary to call whole Resolve (ApplyAttribute does it now) we need only ctor args.
 735                                 // But because a lot of attribute class code must be rewritten will be better to wait...
 736                                 Resolve (ec);
 737
 738                         if (resolve_error)
 739                                 return null;
 740
 741                         return pos_values [0] as string;
 742                 }
 743
 744                 /// <summary>
 745                 /// Returns condition of ConditionalAttribute
 746                 /// </summary>
 747                 public string GetConditionalAttributeValue (EmitContext ec)
 748                 {
 749                         if (pos_values == null)
 750                                 // TODO: It is not neccessary to call whole Resolve (ApplyAttribute does it now) we need only ctor args.
 751                                 // But because a lot of attribute class code must be rewritten will be better to wait...
 752                                 Resolve (ec);
 753
 754                         if (resolve_error)
 755                                 return null;
 756
 757                         return (string)pos_values [0];
 758                 }
 759
 760                 /// <summary>
 761                 /// Creates the instance of ObsoleteAttribute from this attribute instance
 762                 /// </summary>
 763                 public ObsoleteAttribute GetObsoleteAttribute (EmitContext ec)
 764                 {
 765                         if (pos_values == null)
 766                                 // TODO: It is not neccessary to call whole Resolve (ApplyAttribute does it now) we need only ctor args.
 767                                 // But because a lot of attribute class code must be rewritten will be better to wait...
 768                                 Resolve (ec);
 769
 770                         if (resolve_error)
 771                                 return null;
 772
 773                         if (pos_values == null || pos_values.Length == 0)
 774                                 return new ObsoleteAttribute ();
 775
 776                         if (pos_values.Length == 1)
 777                                 return new ObsoleteAttribute ((string)pos_values [0]);
 778
 779                         return new ObsoleteAttribute ((string)pos_values [0], (bool)pos_values [1]);
 780                 }
 781
 782                 /// <summary>
 783                 /// Returns value of CLSCompliantAttribute contructor parameter but because the method can be called
 784                 /// before ApplyAttribute. We need to resolve the arguments.
 785                 /// This situation occurs when class deps is differs from Emit order.
 786                 /// </summary>
 787                 public bool GetClsCompliantAttributeValue (EmitContext ec)
 788                 {
 789                         if (pos_values == null)
 790                                 // TODO: It is not neccessary to call whole Resolve (ApplyAttribute does it now) we need only ctor args.
 791                                 // But because a lot of attribute class code must be rewritten will be better to wait...
 792                                 Resolve (ec);
 793
 794                         if (resolve_error)
 795                                 return false;
 796
 797                         return (bool)pos_values [0];
 798                 }
 799
 800                 /// <summary>
 801                 /// Tests permitted SecurityAction for assembly or other types
 802                 /// </summary>
 803                 public bool CheckSecurityActionValidity (bool for_assembly)
 804                 {
 805                         SecurityAction action = GetSecurityActionValue ();
 806
 807                         switch (action) {
 808                         case SecurityAction.Demand:
 809                         case SecurityAction.Assert:
 810                         case SecurityAction.Deny:
 811                         case SecurityAction.PermitOnly:
 812                         case SecurityAction.LinkDemand:
 813                         case SecurityAction.InheritanceDemand:
 814                                 if (!for_assembly)
 815                                         return true;
 816                                 break;
 817
 818                         case SecurityAction.RequestMinimum:
 819                         case SecurityAction.RequestOptional:
 820                         case SecurityAction.RequestRefuse:
 821                                 if (for_assembly)
 822                                         return true;
 823                                 break;
 824
 825                         default:
 826                                 Error_AttributeEmitError ("SecurityAction is out of range X");
 827                                 return false;
 828                         }
 829
 830                         Error_AttributeEmitError (String.Concat ("SecurityAction '", action, "' is not valid for this declaration"));
 831                         return false;
 832                 }
 833
 834                 System.Security.Permissions.SecurityAction GetSecurityActionValue ()
 835                 {
 836                         return (SecurityAction)pos_values [0];
 837                 }
 838
 839                 /// <summary>
 840                 /// Creates instance of SecurityAttribute class and add result of CreatePermission method to permission table.
 841                 /// </summary>
 842                 /// <returns></returns>
 843                 public void ExtractSecurityPermissionSet (ListDictionary permissions)
 844                 {
 845                         Type orig_assembly_type = null;
 846
 847                         if (TypeManager.LookupDeclSpace (Type) != null) {
 848                                 if (!RootContext.StdLib) {
 849                                         orig_assembly_type = Type.GetType (Type.FullName);
 850                                 } else {
 851                                         string orig_version_path = Environment.GetEnvironmentVariable ("__SECURITY_BOOTSTRAP_DB");
 852                                         if (orig_version_path == null) {
 853                                                 Error_AttributeEmitError ("security custom attributes can not be referenced from defining assembly");
 854                                                 return;
 855                                         }
 856
 857                                         if (orig_sec_assembly == null) {
 858                                                 string file = Path.Combine (orig_version_path, Driver.OutputFile);
 859                                                 orig_sec_assembly = Assembly.LoadFile (file);
 860                                         }
 861
 862                                         orig_assembly_type = orig_sec_assembly.GetType (Type.FullName, true);
 863                                         if (orig_assembly_type == null) {
 864                                                 Report.Warning (-112, 1, Location, "Self-referenced security attribute `{0}' was not found in previous version of assembly");
 865                                                 return;
 866                                         }
 867                                 }
 868                         }
 869
 870                         SecurityAttribute sa;
 871                         // For all non-selfreferencing security attributes we can avoid all hacks
 872                         if (orig_assembly_type == null) {
 873                                 sa = (SecurityAttribute) Activator.CreateInstance (Type, pos_values);
 874
 875                                 if (prop_info_arr != null) {
 876                                         for (int i = 0; i < prop_info_arr.Length; ++i) {
 877                                                 PropertyInfo pi = prop_info_arr [i];
 878                                                 pi.SetValue (sa, prop_values_arr [i], null);
 879                                         }
 880                                 }
 881                         } else {
 882                                 // HACK: All security attributes have same ctor syntax
 883                                 sa = (SecurityAttribute) Activator.CreateInstance (orig_assembly_type, new object[] { GetSecurityActionValue () } );
 884
 885                                 // All types are from newly created assembly but for invocation with old one we need to convert them
 886                                 if (prop_info_arr != null) {
 887                                         for (int i = 0; i < prop_info_arr.Length; ++i) {
 888                                                 PropertyInfo emited_pi = prop_info_arr [i];
 889                                                 PropertyInfo pi = orig_assembly_type.GetProperty (emited_pi.Name, emited_pi.PropertyType);
 890
 891                                                 object old_instance = pi.PropertyType.IsEnum ?
 892                                                         System.Enum.ToObject (pi.PropertyType, prop_values_arr [i]) :
 893                                                         prop_values_arr [i];
 894
 895                                                 pi.SetValue (sa, old_instance, null);
 896                                         }
 897                                 }
 898                         }
 899
 900                         IPermission perm;
 901                         perm = sa.CreatePermission ();
 902                         SecurityAction action = GetSecurityActionValue ();
 903
 904                         // IS is correct because for corlib we are using an instance from old corlib
 905                         if (!(perm is System.Security.CodeAccessPermission)) {
 906                                 switch (action) {
 907                                         case SecurityAction.Demand:
 908                                                 action = (SecurityAction)13;
 909                                                 break;
 910                                         case SecurityAction.LinkDemand:
 911                                                 action = (SecurityAction)14;
 912                                                 break;
 913                                         case SecurityAction.InheritanceDemand:
 914                                                 action = (SecurityAction)15;
 915                                                 break;
 916                                 }
 917                         }
 918
 919                         PermissionSet ps = (PermissionSet)permissions [action];
 920                         if (ps == null) {
 921                                 if (sa is PermissionSetAttribute)
 922                                         ps = new PermissionSet (sa.Unrestricted ? PermissionState.Unrestricted : PermissionState.None);
 923                                 else
 924                                         ps = new PermissionSet (PermissionState.None);
 925
 926                                 permissions.Add (action, ps);
 927                         } else if (!ps.IsUnrestricted () && (sa is PermissionSetAttribute) && sa.Unrestricted) {
 928                                 ps = ps.Union (new PermissionSet (PermissionState.Unrestricted));
 929                                 permissions [action] = ps;
 930                         }
 931                         ps.AddPermission (perm);
 932                 }
 933
 934                 object GetValue (object value)
 935                 {
 936                         if (value is EnumConstant)
 937                                 return ((EnumConstant) value).GetValue ();
 938                         else
 939                                 return value;
 940                 }
 941
 942                 object GetPropertyValue (string name)
 943                 {
 944                         if (prop_info_arr == null)
 945                                 return null;
 946
 947                         for (int i = 0; i < prop_info_arr.Length; ++i) {
 948                                 if (prop_info_arr [i].Name == name)
 949                                         return prop_values_arr [i];
 950                         }
 951
 952                         return null;
 953                 }
 954
 955                 object GetFieldValue (string name)
 956                 {
 957                         int i;
 958                         if (field_info_arr == null)
 959                                 return null;
 960                         i = 0;
 961                         foreach (FieldInfo fi in field_info_arr) {
 962                                 if (fi.Name == name)
 963                                         return GetValue (field_values_arr [i]);
 964                                 i++;
 965                         }
 966                         return null;
 967                 }
 968
 969                 public UnmanagedMarshal GetMarshal (Attributable attr)
 970                 {
 971                         UnmanagedType UnmanagedType = (UnmanagedType)System.Enum.Parse (typeof (UnmanagedType), pos_values [0].ToString ());
 972
 973                         object value = GetFieldValue ("SizeParamIndex");
 974                         if (value != null && UnmanagedType != UnmanagedType.LPArray) {
 975                                 Error_AttributeEmitError ("SizeParamIndex field is not valid for the specified unmanaged type");
 976                                 return null;
 977                         }
 978
 979                         object o = GetFieldValue ("ArraySubType");
 980                         UnmanagedType array_sub_type = o == null ? UnmanagedType.I4 : (UnmanagedType) o;
 981
 982                         switch (UnmanagedType) {
 983                         case UnmanagedType.CustomMarshaler: {
 984                                 MethodInfo define_custom = typeof (UnmanagedMarshal).GetMethod ("DefineCustom",
 985                                                                        BindingFlags.Static | BindingFlags.Public);
 986                                 if (define_custom == null) {
 987                                         Report.RuntimeMissingSupport (Location, "set marshal info");
 988                                         return null;
 989                                 }
 990
 991                                 object [] args = new object [4];
 992                                 args [0] = GetFieldValue ("MarshalTypeRef");
 993                                 args [1] = GetFieldValue ("MarshalCookie");
 994                                 args [2] = GetFieldValue ("MarshalType");
 995                                 args [3] = Guid.Empty;
 996                                 return (UnmanagedMarshal) define_custom.Invoke (null, args);
 997                         }
 998                         case UnmanagedType.LPArray: {
 999                                 object size_const = GetFieldValue ("SizeConst");
1000                                 object size_param_index = GetFieldValue ("SizeParamIndex");
1001
1002                                 if ((size_const != null) || (size_param_index != null)) {
1003                                         MethodInfo define_array = typeof (UnmanagedMarshal).GetMethod ("DefineLPArrayInternal", BindingFlags.Static | BindingFlags.Public | BindingFlags.NonPublic);
1004                                         if (define_array == null) {
1005                                                 Report.RuntimeMissingSupport (Location, "set marshal info");
1006                                                 return null;
1007                                         }
1008
1009                                         object [] args = new object [3];
1010                                         args [0] = array_sub_type;
1011                                         args [1] = size_const == null ? -1 : size_const;
1012                                         args [2] = size_param_index == null ? -1 : size_param_index;
1013                                         return (UnmanagedMarshal) define_array.Invoke (null, args);
1014                                 }
1015                                 else
1016                                         return UnmanagedMarshal.DefineLPArray (array_sub_type);
1017                         }
1018                         case UnmanagedType.SafeArray:
1019                                 return UnmanagedMarshal.DefineSafeArray (array_sub_type);
1020
1021                         case UnmanagedType.ByValArray:
1022                                 FieldMember fm = attr as FieldMember;
1023                                 if (fm == null) {
1024                                         Error_AttributeEmitError ("Specified unmanaged type is only valid on fields");
1025                                         return null;
1026                                 }
1027                                 return UnmanagedMarshal.DefineByValArray ((int) GetFieldValue ("SizeConst"));
1028
1029                         case UnmanagedType.ByValTStr:
1030                                 return UnmanagedMarshal.DefineByValTStr ((int) GetFieldValue ("SizeConst"));
1031
1032                         default:
1033                                 return UnmanagedMarshal.DefineUnmanagedMarshal (UnmanagedType);
1034                         }
1035                 }
1036
1037                 public CharSet GetCharSetValue ()
1038                 {
1039                         return (CharSet)System.Enum.Parse (typeof (CharSet), pos_values [0].ToString ());
1040                 }
1041
1042                 public MethodImplOptions GetMethodImplOptions ()
1043                 {
1044                         return (MethodImplOptions)System.Enum.Parse (typeof (MethodImplOptions), pos_values [0].ToString ());
1045                 }
1046
1047                 public LayoutKind GetLayoutKindValue ()
1048                 {
1049                         return (LayoutKind)System.Enum.Parse (typeof (LayoutKind), pos_values [0].ToString ());
1050                 }
1051
1052                 /// <summary>
1053                 /// Emit attribute for Attributable symbol
1054                 /// </summary>
1055                 public void Emit (EmitContext ec, Attributable ias, ListDictionary emitted_attr)
1056                 {
1057                         CustomAttributeBuilder cb = Resolve (ec);
1058                         if (cb == null)
1059                                 return;
1060
1061                         AttributeUsageAttribute usage_attr = GetAttributeUsage (ec);
1062                         if ((usage_attr.ValidOn & Target) == 0) {
1063                                 Report.Error (592, Location, "Attribute `{0}' is not valid on this declaration type. It is valid on `{1}' declarations only",
1064                                         GetSignatureForError (), GetValidTargets ());
1065                                 return;
1066                         }
1067
1068                         try {
1069                                 ias.ApplyAttributeBuilder (this, cb);
1070                         }
1071                         catch (Exception e) {
1072                                 Error_AttributeEmitError (e.Message);
1073                                 return;
1074                         }
1075
1076                         if (!usage_attr.AllowMultiple) {
1077                                 ArrayList emitted_targets = (ArrayList)emitted_attr [Type];
1078                                 if (emitted_targets == null) {
1079                                         emitted_targets = new ArrayList ();
1080                                         emitted_attr.Add (Type, emitted_targets);
1081                                 } else if (emitted_targets.Contains (Target)) {
1082                                         Report.Error (579, Location, "Duplicate `{0}' attribute", GetSignatureForError ());
1083                                         return;
1084                                 }
1085                                 emitted_targets.Add (Target);
1086                         }
1087
1088                         if (!RootContext.VerifyClsCompliance)
1089                                 return;
1090
1091                         // Here we are testing attribute arguments for array usage (error 3016)
1092                         if (ias.IsClsComplianceRequired (ec.DeclSpace)) {
1093                                 if (Arguments == null)
1094                                         return;
1095
1096                                 ArrayList pos_args = (ArrayList) Arguments [0];
1097                                 if (pos_args != null) {
1098                                         foreach (Argument arg in pos_args) {
1099                                                 // Type is undefined (was error 246)
1100                                                 if (arg.Type == null)
1101                                                         return;
1102
1103                                                 if (arg.Type.IsArray) {
1104                                                         Report.Error (3016, Location, "Arrays as attribute arguments are not CLS-compliant");
1105                                                         return;
1106                                                 }
1107                                         }
1108                                 }
1109
1110                                 if (Arguments.Count < 2)
1111                                         return;
1112
1113                                 ArrayList named_args = (ArrayList) Arguments [1];
1114                                 foreach (DictionaryEntry de in named_args) {
1115                                         Argument arg  = (Argument) de.Value;
1116
1117                                         // Type is undefined (was error 246)
1118                                         if (arg.Type == null)
1119                                                 return;
1120
1121                                         if (arg.Type.IsArray) {
1122                                                 Report.Error (3016, Location, "Arrays as attribute arguments are not CLS-compliant");
1123                                                 return;
1124                                         }
1125                                 }
1126                         }
1127                 }
1128
1129                 public MethodBuilder DefinePInvokeMethod (EmitContext ec, TypeBuilder builder, string name,
1130                                                           MethodAttributes flags, Type ret_type, Type [] param_types)
1131                 {
1132                         if (pos_values == null)
1133                                 // TODO: It is not neccessary to call whole Resolve (ApplyAttribute does it now) we need only ctor args.
1134                                 // But because a lot of attribute class code must be rewritten will be better to wait...
1135                                 Resolve (ec);
1136
1137                         if (resolve_error)
1138                                 return null;
1139
1140                         string dll_name = (string)pos_values [0];
1141
1142                         // Default settings
1143                         CallingConvention cc = CallingConvention.Winapi;
1144                         CharSet charset = CodeGen.Module.DefaultCharSet;
1145                         bool preserve_sig = true;
1146                         string entry_point = name;
1147                         bool best_fit_mapping = false;
1148                         bool throw_on_unmappable = false;
1149                         bool exact_spelling = false;
1150                         bool set_last_error = false;
1151
1152                         bool best_fit_mapping_set = false;
1153                         bool throw_on_unmappable_set = false;
1154                         bool exact_spelling_set = false;
1155                         bool set_last_error_set = false;
1156
1157                         MethodInfo set_best_fit = null;
1158                         MethodInfo set_throw_on = null;
1159                         MethodInfo set_exact_spelling = null;
1160                         MethodInfo set_set_last_error = null;
1161
1162                         if (field_info_arr != null) {
1163
1164                                 for (int i = 0; i < field_info_arr.Length; i++) {
1165                                         switch (field_info_arr [i].Name) {
1166                                                 case "BestFitMapping":
1167                                                         best_fit_mapping = (bool) field_values_arr [i];
1168                                                         best_fit_mapping_set = true;
1169                                                         break;
1170                                                 case "CallingConvention":
1171                                                         cc = (CallingConvention) field_values_arr [i];
1172                                                         break;
1173                                                 case "CharSet":
1174                                                         charset = (CharSet) field_values_arr [i];
1175                                                         break;
1176                                                 case "EntryPoint":
1177                                                         entry_point = (string) field_values_arr [i];
1178                                                         break;
1179                                                 case "ExactSpelling":
1180                                                         exact_spelling = (bool) field_values_arr [i];
1181                                                         exact_spelling_set = true;
1182                                                         break;
1183                                                 case "PreserveSig":
1184                                                         preserve_sig = (bool) field_values_arr [i];
1185                                                         break;
1186                                                 case "SetLastError":
1187                                                         set_last_error = (bool) field_values_arr [i];
1188                                                         set_last_error_set = true;
1189                                                         break;
1190                                                 case "ThrowOnUnmappableChar":
1191                                                         throw_on_unmappable = (bool) field_values_arr [i];
1192                                                         throw_on_unmappable_set = true;
1193                                                         break;
1194                                                 default:
1195                                                         throw new InternalErrorException (field_info_arr [i].ToString ());
1196                                         }
1197                                 }
1198                         }
1199
1200                         if (throw_on_unmappable_set || best_fit_mapping_set || exact_spelling_set || set_last_error_set) {
1201                                 set_best_fit = typeof (MethodBuilder).GetMethod ("set_BestFitMapping", BindingFlags.Instance | BindingFlags.Public | BindingFlags.NonPublic);
1202                                 set_throw_on = typeof (MethodBuilder).GetMethod ("set_ThrowOnUnmappableChar", BindingFlags.Instance | BindingFlags.Public | BindingFlags.NonPublic);
1203                                 set_exact_spelling = typeof (MethodBuilder).GetMethod ("set_ExactSpelling", BindingFlags.Instance | BindingFlags.Public | BindingFlags.NonPublic);
1204                                 set_set_last_error = typeof (MethodBuilder).GetMethod ("set_SetLastError", BindingFlags.Instance | BindingFlags.Public | BindingFlags.NonPublic);
1205
1206                                 if ((set_best_fit == null) || (set_throw_on == null) || (set_exact_spelling == null) || (set_set_last_error == null)) {
1207                                         Report.Error (-1, Location,
1208                                                                   "The ThrowOnUnmappableChar, BestFitMapping, SetLastError, and ExactSpelling attributes can only be emitted when running on the mono runtime.");
1209                                         return null;
1210                                 }
1211                         }
1212
1213                         try {
1214                                 MethodBuilder mb = builder.DefinePInvokeMethod (
1215                                         name, dll_name, entry_point, flags | MethodAttributes.HideBySig | MethodAttributes.PinvokeImpl,
1216                                         CallingConventions.Standard, ret_type, param_types, cc, charset);
1217
1218                                 if (preserve_sig)
1219                                         mb.SetImplementationFlags (MethodImplAttributes.PreserveSig);
1220
1221                                 if (throw_on_unmappable_set)
1222                                         set_throw_on.Invoke (mb, 0, null, new object [] { throw_on_unmappable }, null);
1223                                 if (best_fit_mapping_set)
1224                                         set_best_fit.Invoke (mb, 0, null, new object [] { best_fit_mapping }, null);
1225                                 if (exact_spelling_set)
1226                                         set_exact_spelling.Invoke  (mb, 0, null, new object [] { exact_spelling }, null);
1227                                 if (set_last_error_set)
1228                                         set_set_last_error.Invoke  (mb, 0, null, new object [] { set_last_error }, null);
1229
1230                                 return mb;
1231                         }
1232                         catch (ArgumentException e) {
1233                                 Error_AttributeEmitError (e.Message);
1234                                 return null;
1235                         }
1236                 }
1237
1238                 private Expression GetValue ()
1239                 {
1240                         if ((Arguments == null) || (Arguments.Count < 1))
1241                                 return null;
1242                         ArrayList al = (ArrayList) Arguments [0];
1243                         if ((al == null) || (al.Count < 1))
1244                                 return null;
1245                         Argument arg = (Argument) al [0];
1246                         if ((arg == null) || (arg.Expr == null))
1247                                 return null;
1248                         return arg.Expr;
1249                 }
1250
1251                 public string GetString ()
1252                 {
1253                         Expression e = GetValue ();
1254                         if (e is StringLiteral)
1255                                 return (e as StringLiteral).Value;
1256                         return null;
1257                 }
1258
1259                 public bool GetBoolean ()
1260                 {
1261                         Expression e = GetValue ();
1262                         if (e is BoolLiteral)
1263                                 return (e as BoolLiteral).Value;
1264                         return false;
1265                 }
1266         }
1267
1268
1269         /// <summary>
1270         /// For global attributes (assembly, module) we need special handling.
1271         /// Attributes can be located in the several files
1272         /// </summary>
1273         public class GlobalAttribute: Attribute
1274         {
1275                 public readonly NamespaceEntry ns;
1276
1277                 public GlobalAttribute (TypeContainer container, string target,
1278                                         Expression left_expr, string identifier, ArrayList args, Location loc, bool nameEscaped):
1279                         base (target, left_expr, identifier, args, loc, nameEscaped)
1280                 {
1281                         ns = container.NamespaceEntry;
1282                 }
1283
1284                 void Enter ()
1285                 {
1286                         // RootContext.Tree.Types has a single NamespaceEntry which gets overwritten
1287                         // each time a new file is parsed.  However, we need to use the NamespaceEntry
1288                         // in effect where the attribute was used.  Since code elsewhere cannot assume
1289                         // that the NamespaceEntry is right, just overwrite it.
1290                         //
1291                         // Precondition: RootContext.Tree.Types == null
1292
1293                         if (RootContext.Tree.Types.NamespaceEntry != null)
1294                                 throw new InternalErrorException (Location + " non-null NamespaceEntry");
1295
1296                         RootContext.Tree.Types.NamespaceEntry = ns;
1297                 }
1298
1299                 void Leave ()
1300                 {
1301                         RootContext.Tree.Types.NamespaceEntry = null;
1302                 }
1303
1304                 protected override FullNamedExpression ResolveAsTypeStep (Expression expr, EmitContext ec, bool silent)
1305                 {
1306                         try {
1307                                 Enter ();
1308                                 return base.ResolveAsTypeStep (expr, ec, silent);
1309                         }
1310                         finally {
1311                                 Leave ();
1312                         }
1313                 }
1314
1315
1316                 protected override FullNamedExpression ResolveAsTypeTerminal (Expression expr, EmitContext ec, bool silent)
1317                 {
1318                         try {
1319                                 Enter ();
1320                                 return base.ResolveAsTypeTerminal (expr, ec, silent);
1321                         }
1322                         finally {
1323                                 Leave ();
1324                         }
1325                 }
1326
1327                 protected override ConstructorInfo ResolveArguments (EmitContext ec)
1328                 {
1329                         try {
1330                                 Enter ();
1331                                 return base.ResolveArguments (ec);
1332                         }
1333                         finally {
1334                                 Leave ();
1335                         }
1336                 }
1337         }
1338
1339         public class Attributes {
1340                 public ArrayList Attrs;
1341
1342                 public Attributes (Attribute a)
1343                 {
1344                         Attrs = new ArrayList ();
1345                         Attrs.Add (a);
1346                 }
1347
1348                 public Attributes (ArrayList attrs)
1349                 {
1350                         Attrs = attrs;
1351                 }
1352
1353                 public void AddAttributes (ArrayList attrs)
1354                 {
1355                         Attrs.AddRange (attrs);
1356                 }
1357
1358                 /// <summary>
1359                 /// Checks whether attribute target is valid for the current element
1360                 /// </summary>
1361                 public bool CheckTargets (Attributable member)
1362                 {
1363                         string[] valid_targets = member.ValidAttributeTargets;
1364                         foreach (Attribute a in Attrs) {
1365                                 if (a.ExplicitTarget == null || a.ExplicitTarget == valid_targets [0]) {
1366                                         a.Target = member.AttributeTargets;
1367                                         continue;
1368                                 }
1369
1370                                 // TODO: we can skip the first item
1371                                 if (((IList) valid_targets).Contains (a.ExplicitTarget)) {
1372                                         switch (a.ExplicitTarget) {
1373                                                 case "return": a.Target = AttributeTargets.ReturnValue; continue;
1374                                                 case "param": a.Target = AttributeTargets.Parameter; continue;
1375                                                 case "field": a.Target = AttributeTargets.Field; continue;
1376                                                 case "method": a.Target = AttributeTargets.Method; continue;
1377                                                 case "property": a.Target = AttributeTargets.Property; continue;
1378                                         }
1379                                         throw new InternalErrorException ("Unknown explicit target: " + a.ExplicitTarget);
1380                                 }
1381
1382                                 StringBuilder sb = new StringBuilder ();
1383                                 foreach (string s in valid_targets) {
1384                                         sb.Append (s);
1385                                         sb.Append (", ");
1386                                 }
1387                                 sb.Remove (sb.Length - 2, 2);
1388                                 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 ());
1389                                 return false;
1390                         }
1391                         return true;
1392                 }
1393
1394                 public Attribute Search (Type t, EmitContext ec)
1395                 {
1396                         foreach (Attribute a in Attrs) {
1397                                 if (a.ResolveType (ec) == t)
1398                                         return a;
1399                         }
1400                         return null;
1401                 }
1402
1403                 /// <summary>
1404                 /// Returns all attributes of type 't'. Use it when attribute is AllowMultiple = true
1405                 /// </summary>
1406                 public Attribute[] SearchMulti (Type t, EmitContext ec)
1407                 {
1408                         ArrayList ar = null;
1409
1410                         foreach (Attribute a in Attrs) {
1411                                 if (a.ResolveType (ec) == t) {
1412                                         if (ar == null)
1413                                                 ar = new ArrayList ();
1414                                         ar.Add (a);
1415                                 }
1416                         }
1417
1418                         return ar == null ? null : ar.ToArray (typeof (Attribute)) as Attribute[];
1419                 }
1420
1421                 public void Emit (EmitContext ec, Attributable ias)
1422                 {
1423                         CheckTargets (ias);
1424
1425                         ListDictionary ld = new ListDictionary ();
1426
1427                         foreach (Attribute a in Attrs)
1428                                 a.Emit (ec, ias, ld);
1429                 }
1430
1431                 public bool Contains (Type t, EmitContext ec)
1432                 {
1433                         return Search (t, ec) != null;
1434                 }
1435         }
1436
1437         /// <summary>
1438         /// Helper class for attribute verification routine.
1439         /// </summary>
1440         sealed class AttributeTester
1441         {
1442                 static PtrHashtable analyzed_types = new PtrHashtable ();
1443                 static PtrHashtable analyzed_types_obsolete = new PtrHashtable ();
1444                 static PtrHashtable analyzed_member_obsolete = new PtrHashtable ();
1445                 static PtrHashtable analyzed_method_excluded = new PtrHashtable ();
1446
1447                 static PtrHashtable fixed_buffer_cache = new PtrHashtable ();
1448
1449                 static object TRUE = new object ();
1450                 static object FALSE = new object ();
1451
1452                 private AttributeTester ()
1453                 {
1454                 }
1455
1456                 public enum Result {
1457                         Ok,
1458                         RefOutArrayError,
1459                         ArrayArrayError
1460                 }
1461
1462                 /// <summary>
1463                 /// Returns true if parameters of two compared methods are CLS-Compliant.
1464                 /// It tests differing only in ref or out, or in array rank.
1465                 /// </summary>
1466                 public static Result AreOverloadedMethodParamsClsCompliant (Type[] types_a, Type[] types_b)
1467                 {
1468                         if (types_a == null || types_b == null)
1469                                 return Result.Ok;
1470
1471                         if (types_a.Length != types_b.Length)
1472                                 return Result.Ok;
1473
1474                         Result result = Result.Ok;
1475                         for (int i = 0; i < types_b.Length; ++i) {
1476                                 Type aType = types_a [i];
1477                                 Type bType = types_b [i];
1478
1479                                 if (aType.IsArray && bType.IsArray) {
1480                                         Type a_el_type = aType.GetElementType ();
1481                                         Type b_el_type = bType.GetElementType ();
1482                                         if (aType.GetArrayRank () != bType.GetArrayRank () && a_el_type == b_el_type) {
1483                                                 result = Result.RefOutArrayError;
1484                                                 continue;
1485                                         }
1486
1487                                         if (a_el_type.IsArray || b_el_type.IsArray) {
1488                                                 result = Result.ArrayArrayError;
1489                                                 continue;
1490                                         }
1491                                 }
1492
1493                                 Type aBaseType = aType;
1494                                 bool is_either_ref_or_out = false;
1495
1496                                 if (aType.IsByRef || aType.IsPointer) {
1497                                         aBaseType = aType.GetElementType ();
1498                                         is_either_ref_or_out = true;
1499                                 }
1500
1501                                 Type bBaseType = bType;
1502                                 if (bType.IsByRef || bType.IsPointer)
1503                                 {
1504                                         bBaseType = bType.GetElementType ();
1505                                         is_either_ref_or_out = !is_either_ref_or_out;
1506                                 }
1507
1508                                 if (aBaseType != bBaseType)
1509                                         return Result.Ok;
1510
1511                                 if (is_either_ref_or_out)
1512                                         result = Result.RefOutArrayError;
1513                         }
1514                         return result;
1515                 }
1516
1517                 /// <summary>
1518                 /// Goes through all parameters and test if they are CLS-Compliant.
1519                 /// </summary>
1520                 public static bool AreParametersCompliant (Parameter[] fixedParameters, Location loc)
1521                 {
1522                         if (fixedParameters == null)
1523                                 return true;
1524
1525                         foreach (Parameter arg in fixedParameters) {
1526                                 if (!AttributeTester.IsClsCompliant (arg.ParameterType)) {
1527                                         Report.Error (3001, loc, "Argument type `{0}' is not CLS-compliant", arg.GetSignatureForError ());
1528                                         return false;
1529                                 }
1530                         }
1531                         return true;
1532                 }
1533
1534
1535                 /// <summary>
1536                 /// This method tests the CLS compliance of external types. It doesn't test type visibility.
1537                 /// </summary>
1538                 public static bool IsClsCompliant (Type type)
1539                 {
1540                         if (type == null)
1541                                 return true;
1542
1543                         object type_compliance = analyzed_types[type];
1544                         if (type_compliance != null)
1545                                 return type_compliance == TRUE;
1546
1547                         if (type.IsPointer) {
1548                                 analyzed_types.Add (type, null);
1549                                 return false;
1550                         }
1551
1552                         bool result;
1553                         if (type.IsArray || type.IsByRef)       {
1554                                 result = IsClsCompliant (TypeManager.GetElementType (type));
1555                         } else {
1556                                 result = AnalyzeTypeCompliance (type);
1557                         }
1558                         analyzed_types.Add (type, result ? TRUE : FALSE);
1559                         return result;
1560                 }
1561
1562                 /// <summary>
1563                 /// Returns IFixedBuffer implementation if field is fixed buffer else null.
1564                 /// </summary>
1565                 public static IFixedBuffer GetFixedBuffer (FieldInfo fi)
1566                 {
1567                         FieldBase fb = TypeManager.GetField (fi);
1568                         if (fb != null) {
1569                                 return fb as IFixedBuffer;
1570                         }
1571
1572                         object o = fixed_buffer_cache [fi];
1573                         if (o == null) {
1574                                 if (System.Attribute.GetCustomAttribute (fi, TypeManager.fixed_buffer_attr_type) == null) {
1575                                         fixed_buffer_cache.Add (fi, FALSE);
1576                                         return null;
1577                                 }
1578
1579                                 IFixedBuffer iff = new FixedFieldExternal (fi);
1580                                 fixed_buffer_cache.Add (fi, iff);
1581                                 return iff;
1582                         }
1583
1584                         if (o == FALSE)
1585                                 return null;
1586
1587                         return (IFixedBuffer)o;
1588                 }
1589
1590                 public static void VerifyModulesClsCompliance ()
1591                 {
1592                         Module[] modules = TypeManager.Modules;
1593                         if (modules == null)
1594                                 return;
1595
1596                         // The first module is generated assembly
1597                         for (int i = 1; i < modules.Length; ++i) {
1598                                 Module module = modules [i];
1599                                 if (!IsClsCompliant (module)) {
1600                                         Report.Error (3013, "Added modules must be marked with the CLSCompliant attribute to match the assembly", module.Name);
1601                                         return;
1602                                 }
1603                         }
1604                 }
1605
1606                 public static Type GetImportedIgnoreCaseClsType (string name)
1607                 {
1608                         foreach (Assembly a in TypeManager.GetAssemblies ()) {
1609                                 Type t = a.GetType (name, false, true);
1610                                 if (t == null)
1611                                         continue;
1612
1613                                 if (IsClsCompliant (t))
1614                                         return t;
1615                         }
1616                         return null;
1617                 }
1618
1619                 static bool IsClsCompliant (ICustomAttributeProvider attribute_provider)
1620                 {
1621                         object[] CompliantAttribute = attribute_provider.GetCustomAttributes (TypeManager.cls_compliant_attribute_type, false);
1622                         if (CompliantAttribute.Length == 0)
1623                                 return false;
1624
1625                         return ((CLSCompliantAttribute)CompliantAttribute[0]).IsCompliant;
1626                 }
1627
1628                 static bool AnalyzeTypeCompliance (Type type)
1629                 {
1630                         if (type.IsGenericInstance)
1631                                 type = type.GetGenericTypeDefinition ();
1632                         DeclSpace ds = TypeManager.LookupDeclSpace (type);
1633                         if (ds != null)
1634                                 return ds.IsClsComplianceRequired (ds);
1635
1636                         if (type.IsGenericParameter)
1637                                 return true;
1638
1639                         object[] CompliantAttribute = type.GetCustomAttributes (TypeManager.cls_compliant_attribute_type, false);
1640                         if (CompliantAttribute.Length == 0)
1641                                 return IsClsCompliant (type.Assembly);
1642
1643                         return ((CLSCompliantAttribute)CompliantAttribute[0]).IsCompliant;
1644                 }
1645
1646                 /// <summary>
1647                 /// Returns instance of ObsoleteAttribute when type is obsolete
1648                 /// </summary>
1649                 public static ObsoleteAttribute GetObsoleteAttribute (Type type)
1650                 {
1651                         object type_obsolete = analyzed_types_obsolete [type];
1652                         if (type_obsolete == FALSE)
1653                                 return null;
1654
1655                         if (type_obsolete != null)
1656                                 return (ObsoleteAttribute)type_obsolete;
1657
1658                         ObsoleteAttribute result = null;
1659                         if (type.IsByRef || type.IsArray || type.IsPointer) {
1660                                 result = GetObsoleteAttribute (TypeManager.GetElementType (type));
1661                         } else if (type.IsGenericParameter || type.IsGenericInstance)
1662                                 return null;
1663                         else {
1664                                 DeclSpace type_ds = TypeManager.LookupDeclSpace (type);
1665
1666                                 // Type is external, we can get attribute directly
1667                                 if (type_ds == null) {
1668                                         object[] attribute = type.GetCustomAttributes (TypeManager.obsolete_attribute_type, false);
1669                                         if (attribute.Length == 1)
1670                                                 result = (ObsoleteAttribute)attribute [0];
1671                                 } else {
1672                                         result = type_ds.GetObsoleteAttribute (type_ds);
1673                                 }
1674                         }
1675
1676                         analyzed_types_obsolete.Add (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                         PropertyInfo pi = PropertyExpr.AccessorTable [mb] as PropertyInfo;
1694                         if (pi != null)
1695                                 return GetMemberObsoleteAttribute (pi);
1696
1697                         return GetMemberObsoleteAttribute (mb);
1698                 }
1699
1700                 /// <summary>
1701                 /// Returns instance of ObsoleteAttribute when member is obsolete
1702                 /// </summary>
1703                 public static ObsoleteAttribute GetMemberObsoleteAttribute (MemberInfo mi)
1704                 {
1705                         object type_obsolete = analyzed_member_obsolete [mi];
1706                         if (type_obsolete == FALSE)
1707                                 return null;
1708
1709                         if (type_obsolete != null)
1710                                 return (ObsoleteAttribute)type_obsolete;
1711
1712                         if ((mi.DeclaringType is TypeBuilder) || mi.DeclaringType.IsGenericInstance)
1713                                 return null;
1714
1715                         ObsoleteAttribute oa = System.Attribute.GetCustomAttribute (mi, TypeManager.obsolete_attribute_type, false) as ObsoleteAttribute;
1716                         analyzed_member_obsolete.Add (mi, oa == null ? FALSE : oa);
1717                         return oa;
1718                 }
1719
1720                 /// <summary>
1721                 /// Common method for Obsolete error/warning reporting.
1722                 /// </summary>
1723                 public static void Report_ObsoleteMessage (ObsoleteAttribute oa, string member, Location loc)
1724                 {
1725                         if (oa.IsError) {
1726                                 Report.Error (619, loc, "`{0}' is obsolete: `{1}'", member, oa.Message);
1727                                 return;
1728                         }
1729
1730                         if (oa.Message == null) {
1731                                 Report.Warning (612, loc, "`{0}' is obsolete", member);
1732                                 return;
1733                         }
1734                         if (RootContext.WarningLevel >= 2)
1735                                 Report.Warning (618, loc, "`{0}' is obsolete: `{1}'", member, oa.Message);
1736                 }
1737
1738                 public static bool IsConditionalMethodExcluded (MethodBase mb)
1739                 {
1740                         object excluded = analyzed_method_excluded [mb];
1741                         if (excluded != null)
1742                                 return excluded == TRUE ? true : false;
1743
1744                         if (mb.Mono_IsInflatedMethod)
1745                                 return false;
1746
1747                         ConditionalAttribute[] attrs = mb.GetCustomAttributes (TypeManager.conditional_attribute_type, true) as ConditionalAttribute[];
1748                         if (attrs.Length == 0) {
1749                                 analyzed_method_excluded.Add (mb, FALSE);
1750                                 return false;
1751                         }
1752
1753                         foreach (ConditionalAttribute a in attrs) {
1754                                 if (RootContext.AllDefines.Contains (a.ConditionString)) {
1755                                         analyzed_method_excluded.Add (mb, FALSE);
1756                                         return false;
1757                                 }
1758                         }
1759                         analyzed_method_excluded.Add (mb, TRUE);
1760                         return true;
1761                 }
1762
1763                 /// <summary>
1764                 /// Analyzes class whether it has attribute which has ConditionalAttribute
1765                 /// and its condition is not defined.
1766                 /// </summary>
1767                 public static bool IsAttributeExcluded (Type type)
1768                 {
1769                         if (!type.IsClass)
1770                                 return false;
1771
1772                         Class class_decl = TypeManager.LookupDeclSpace (type) as Class;
1773
1774                         // TODO: add caching
1775                         // TODO: merge all Type bases attribute caching to one cache to save memory
1776                         if (class_decl == null) {
1777                                 object[] attributes = type.GetCustomAttributes (TypeManager.conditional_attribute_type, false);
1778                                 foreach (ConditionalAttribute ca in attributes) {
1779                                         if (RootContext.AllDefines.Contains (ca.ConditionString))
1780                                                 return false;
1781                                 }
1782                                 return attributes.Length > 0;
1783                         }
1784
1785                         return class_decl.IsExcluded ();
1786                 }
1787         }
1788 }