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
  25 namespace Mono.CSharp {
  26
  27         /// <summary>
  28         ///   Base class for objects that can have Attributes applied to them.
  29         /// </summary>
  30         public abstract class Attributable {
  31                 /// <summary>
  32                 ///   Attributes for this type
  33                 /// </summary>
  34                 Attributes attributes;
  35
  36                 public Attributable (Attributes attrs)
  37                 {
  38                         attributes = attrs;
  39                 }
  40
  41                 public Attributes OptAttributes
  42                 {
  43                         get {
  44                                 return attributes;
  45                         }
  46                         set {
  47                                 attributes = value;
  48                         }
  49                 }
  50
  51                 /// <summary>
  52                 /// Use member-specific procedure to apply attribute @a in @cb to the entity being built in @builder
  53                 /// </summary>
  54                 public abstract void ApplyAttributeBuilder (Attribute a, CustomAttributeBuilder cb);
  55
  56                 /// <summary>
  57                 /// Returns one AttributeTarget for this element.
  58                 /// </summary>
  59                 public abstract AttributeTargets AttributeTargets { get; }
  60
  61                 public abstract bool IsClsComplianceRequired (DeclSpace ds);
  62
  63                 /// <summary>
  64                 /// Gets list of valid attribute targets for explicit target declaration.
  65                 /// The first array item is default target. Don't break this rule.
  66                 /// </summary>
  67                 public abstract string[] ValidAttributeTargets { get; }
  68         };
  69
  70         public class Attribute {
  71                 public readonly string ExplicitTarget;
  72                 public AttributeTargets Target;
  73
  74                 public readonly string    Name;
  75                 public readonly Expression LeftExpr;
  76                 public readonly string Identifier;
  77
  78                 public readonly ArrayList Arguments;
  79
  80                 public readonly Location Location;
  81
  82                 public Type Type;
  83
  84                 bool resolve_error;
  85
  86                 static AttributeUsageAttribute DefaultUsageAttribute = new AttributeUsageAttribute (AttributeTargets.All);
  87
  88                 // non-null if named args present after Resolve () is called
  89                 PropertyInfo [] prop_info_arr;
  90                 FieldInfo [] field_info_arr;
  91                 object [] field_values_arr;
  92                 object [] prop_values_arr;
  93                 object [] pos_values;
  94
  95                 static PtrHashtable usage_attr_cache = new PtrHashtable ();
  96
  97                 public Attribute (string target, Expression left_expr, string identifier, ArrayList args, Location loc)
  98                 {
  99                         LeftExpr = left_expr;
 100                         Identifier = identifier;
 101                         Name = LeftExpr == null ? identifier : LeftExpr + "." + identifier;
 102                         Arguments = args;
 103                         Location = loc;
 104                         ExplicitTarget = target;
 105                 }
 106
 107                 void Error_InvalidNamedArgument (string name)
 108                 {
 109                         Report.Error (617, Location, "Invalid attribute argument: '{0}'.  Argument must be fields " +
 110                                       "fields which are not readonly, static or const;  or read-write instance properties.",
 111                                       name);
 112                 }
 113
 114                 void Error_InvalidNamedAgrumentType (string name)
 115                 {
 116                         Report.Error (655, Location, "'{0}' is not a valid named attribute argument because its type is not valid attribute type", name);
 117                 }
 118
 119                 static void Error_AttributeArgumentNotValid (string extra, Location loc)
 120                 {
 121                         Report.Error (182, loc,
 122                                       "An attribute argument must be a constant expression, typeof " +
 123                                       "expression or array creation expression" + extra);
 124                 }
 125
 126                 static void Error_AttributeArgumentNotValid (Location loc)
 127                 {
 128                         Error_AttributeArgumentNotValid ("", loc);
 129                 }
 130
 131                 static void Error_TypeParameterInAttribute (Location loc)
 132                 {
 133                         Report.Error (
 134                                 -202, loc, "Can not use a type parameter in an attribute");
 135                 }
 136
 137                 /// <summary>
 138                 /// This is rather hack. We report many emit attribute error with same error to be compatible with
 139                 /// csc. But because csc has to report them this way because error came from ilasm we needn't.
 140                 /// </summary>
 141                 public void Error_AttributeEmitError (string inner)
 142                 {
 143                         Report.Error (647, Location, "Error emitting '{0}' attribute because '{1}'", Name, inner);
 144                 }
 145
 146                 public void Error_InvalidSecurityParent ()
 147                 {
 148                         Error_AttributeEmitError ("it is attached to invalid parent");
 149                 }
 150
 151                 void Error_AttributeConstructorMismatch ()
 152                 {
 153                         Report.Error (-6, Location,
 154                                       "Could not find a constructor for this argument list.");
 155                 }
 156
 157
 158                 protected virtual FullNamedExpression ResolveAsTypeStep (Expression expr, EmitContext ec)
 159                 {
 160                         return expr.ResolveAsTypeStep (ec);
 161                 }
 162
 163                 void ResolvePossibleAttributeTypes (EmitContext ec, out Type t1, out Type t2)
 164                 {
 165                         t1 = null;
 166                         t2 = null;
 167
 168                         FullNamedExpression n1 = null;
 169                         FullNamedExpression n2 = null;
 170                         string IdentifierAttribute = Identifier + "Attribute";
 171                         if (LeftExpr == null) {
 172                                 n1 = ResolveAsTypeStep (new SimpleName (Identifier, Location), ec);
 173
 174                                 // FIXME: Shouldn't do this for quoted attributes: [@A]
 175                                 n2 = ResolveAsTypeStep (new SimpleName (IdentifierAttribute, Location), ec);
 176                         } else {
 177                                 FullNamedExpression l = ResolveAsTypeStep (LeftExpr, ec);
 178                                 if (l == null) {
 179                                         Report.Error (246, Location, "Couldn't find namespace or type '{0}'", LeftExpr);
 180                                         return;
 181                                 }
 182                                 n1 = new MemberAccess (l, Identifier, Location).ResolveNamespaceOrType (ec, true);
 183
 184                                 // FIXME: Shouldn't do this for quoted attributes: [X.@A]
 185                                 n2 = new MemberAccess (l, IdentifierAttribute, Location).ResolveNamespaceOrType (ec, true);
 186                         }
 187
 188                         TypeExpr te1 = n1 == null ? null : n1 as TypeExpr;
 189                         TypeExpr te2 = n2 == null ? null : n2 as TypeExpr;
 190
 191                         if (te1 != null)
 192                                 t1 = te1.ResolveType (ec);
 193                         if (te2 != null)
 194                                 t2 = te2.ResolveType (ec);
 195                 }
 196
 197                 /// <summary>
 198                 ///   Tries to resolve the type of the attribute. Flags an error if it can't, and complain is true.
 199                 /// </summary>
 200                 Type CheckAttributeType (EmitContext ec)
 201                 {
 202                         Type t1, t2;
 203                         ResolvePossibleAttributeTypes (ec, out t1, out t2);
 204
 205                         String err0616 = null;
 206                         if (t1 != null && ! t1.IsSubclassOf (TypeManager.attribute_type)) {
 207                                 t1 = null;
 208                                 err0616 = "'{0}' is not an attribute class";
 209                         }
 210                         if (t2 != null && ! t2.IsSubclassOf (TypeManager.attribute_type)) {
 211                                 t2 = null;
 212                                 err0616 = (err0616 != null)
 213                                         ? "Neither '{0}' nor '{0}Attribute' is an attribute class"
 214                                         : "'{0}Attribute': is not an attribute class";
 215                         }
 216
 217                         if (t1 != null && t2 != null) {
 218                                 Report.Error (1614, Location, "'{0}' is ambiguous; use either '@{0}' or '{0}Attribute'", Name);
 219                                 return null;
 220                         }
 221                         if (t1 != null)
 222                                 return t1;
 223                         if (t2 != null)
 224                                 return t2;
 225                         if (err0616 != null) {
 226                                 Report.Error (616, Location, err0616, Name);
 227                                 return null;
 228                         }
 229
 230                         Report.Error (246, Location,
 231                                       "Could not find attribute '{0}' (are you missing a using directive or an assembly reference ?)",
 232                                       Name);
 233
 234                         resolve_error = true;
 235                         return null;
 236                 }
 237
 238                 public virtual Type ResolveType (EmitContext ec)
 239                 {
 240                         if (Type == null && !resolve_error)
 241                                 Type = CheckAttributeType (ec);
 242                         return Type;
 243                 }
 244
 245                 string GetFullMemberName (string member)
 246                 {
 247                         return Type.FullName + '.' + member;
 248                 }
 249
 250                 //
 251                 // Given an expression, if the expression is a valid attribute-argument-expression
 252                 // returns an object that can be used to encode it, or null on failure.
 253                 //
 254                 public static bool GetAttributeArgumentExpression (Expression e, Location loc, Type arg_type, out object result)
 255                 {
 256                         if (e is EnumConstant) {
 257                                 if (RootContext.StdLib)
 258                                         result = ((EnumConstant)e).GetValueAsEnumType ();
 259                                 else
 260                                         result = ((EnumConstant)e).GetValue ();
 261
 262                                 return true;
 263                         }
 264
 265                         Constant constant = e as Constant;
 266                         if (constant != null) {
 267                                 if (e.Type != arg_type) {
 268                                         constant = Const.ChangeType (loc, constant, arg_type);
 269                                         if (constant == null) {
 270                                                 result = null;
 271                                                 Error_AttributeArgumentNotValid (loc);
 272                                                 return false;
 273                                         }
 274                                 }
 275                                 result = constant.GetValue ();
 276                                 return true;
 277                         } else if (e is TypeOf) {
 278                                 result = ((TypeOf) e).TypeArg;
 279                                 return true;
 280                         } else if (e is ArrayCreation){
 281                                 result =  ((ArrayCreation) e).EncodeAsAttribute ();
 282                                 if (result != null)
 283                                         return true;
 284                         } else if (e is EmptyCast) {
 285                                 Expression child = ((EmptyCast)e).Child;
 286                                 return GetAttributeArgumentExpression (child, loc, child.Type, out result);
 287                         }
 288
 289                         result = null;
 290                         Error_AttributeArgumentNotValid (loc);
 291                         return false;
 292                 }
 293
 294                 bool IsValidArgumentType (Type t)
 295                 {
 296                         return TypeManager.IsPrimitiveType (t) ||
 297                                 (t.IsArray && TypeManager.IsPrimitiveType (t.GetElementType ())) ||
 298                                 TypeManager.IsEnumType (t) ||
 299                                 t == TypeManager.string_type ||
 300                                 t == TypeManager.object_type ||
 301                                 t == TypeManager.type_type;
 302                 }
 303
 304                 // Cache for parameter-less attributes
 305                 static PtrHashtable att_cache = new PtrHashtable ();
 306
 307                 public CustomAttributeBuilder Resolve (EmitContext ec)
 308                 {
 309                         if (resolve_error)
 310                                 return null;
 311
 312                         resolve_error = true;
 313
 314                         if (Type == null) {
 315                                 Type = CheckAttributeType (ec);
 316
 317                                 if (Type == null)
 318                                         return null;
 319                         }
 320
 321                         if (Type.IsAbstract) {
 322                                 Report.Error (653, Location, "Cannot apply attribute class '{0}' because it is abstract", Name);
 323                                 return null;
 324                         }
 325
 326                         if (Arguments == null) {
 327                                 object o = att_cache [Type];
 328                                 if (o != null) {
 329                                         resolve_error = false;
 330                                         return (CustomAttributeBuilder)o;
 331                                 }
 332                         }
 333
 334                         ConstructorInfo ctor = ResolveArguments (ec);
 335                         CustomAttributeBuilder cb;
 336
 337                         try {
 338                                 if (prop_info_arr != null || field_info_arr != null) {
 339                                         cb = new CustomAttributeBuilder (
 340                                                 ctor, pos_values,
 341                                                 prop_info_arr, prop_values_arr,
 342                                                 field_info_arr, field_values_arr);
 343                                 } else {
 344                                         cb = new CustomAttributeBuilder (
 345                                                 ctor, pos_values);
 346
 347                                         if (pos_values.Length == 0)
 348                                                 att_cache.Add (Type, cb);
 349                                 }
 350                         }
 351                         catch (Exception) {
 352                                 Error_AttributeArgumentNotValid (Location);
 353                                 return null;
 354                         }
 355
 356                         resolve_error = false;
 357                         return cb;
 358                 }
 359
 360                 protected virtual ConstructorInfo ResolveArguments (EmitContext ec)
 361                 {
 362                         // Now we extract the positional and named arguments
 363
 364                         ArrayList pos_args = null;
 365                         ArrayList named_args = null;
 366                         int pos_arg_count = 0;
 367                         int named_arg_count = 0;
 368
 369                         if (Arguments != null) {
 370                                 pos_args = (ArrayList) Arguments [0];
 371                                 if (pos_args != null)
 372                                         pos_arg_count = pos_args.Count;
 373                                 if (Arguments.Count > 1) {
 374                                         named_args = (ArrayList) Arguments [1];
 375                                         named_arg_count = named_args.Count;
 376                                 }
 377                         }
 378
 379                         pos_values = new object [pos_arg_count];
 380
 381                         //
 382                         // First process positional arguments
 383                         //
 384
 385                         int i;
 386                         for (i = 0; i < pos_arg_count; i++) {
 387                                 Argument a = (Argument) pos_args [i];
 388                                 Expression e;
 389
 390                                 if (!a.Resolve (ec, Location))
 391                                         return null;
 392
 393                                 e = a.Expr;
 394
 395                                 object val;
 396                                 if (!GetAttributeArgumentExpression (e, Location, a.Type, out val))
 397                                         return null;
 398
 399                                 pos_values [i] = val;
 400
 401                                 if (i == 0 && Type == TypeManager.attribute_usage_type && (int)val == 0) {
 402                                         Report.Error (591, Location, "Invalid value for argument to 'System.AttributeUsage' attribute");
 403                                         return null;
 404                                 }
 405                         }
 406
 407                         //
 408                         // Now process named arguments
 409                         //
 410
 411                         ArrayList field_infos = null;
 412                         ArrayList prop_infos  = null;
 413                         ArrayList field_values = null;
 414                         ArrayList prop_values = null;
 415                         Hashtable seen_names = null;
 416
 417                         if (named_arg_count > 0) {
 418                                 field_infos = new ArrayList ();
 419                                 prop_infos  = new ArrayList ();
 420                                 field_values = new ArrayList ();
 421                                 prop_values = new ArrayList ();
 422
 423                                 seen_names = new Hashtable();
 424                         }
 425
 426                         for (i = 0; i < named_arg_count; i++) {
 427                                 DictionaryEntry de = (DictionaryEntry) named_args [i];
 428                                 string member_name = (string) de.Key;
 429                                 Argument a  = (Argument) de.Value;
 430                                 Expression e;
 431
 432                                 if (seen_names.Contains(member_name)) {
 433                                         Report.Error(643, Location, "'" + member_name + "' duplicate named attribute argument");
 434                                         return null;
 435                                 }
 436                                 seen_names.Add(member_name, 1);
 437
 438                                 if (!a.Resolve (ec, Location))
 439                                         return null;
 440
 441                                 Expression member = Expression.MemberLookup (
 442                                         ec, Type, member_name,
 443                                         MemberTypes.Field | MemberTypes.Property,
 444                                         BindingFlags.Public | BindingFlags.Instance,
 445                                         Location);
 446
 447                                 if (member == null) {
 448                                         member = Expression.MemberLookup (ec, Type, member_name,
 449                                                 MemberTypes.Field | MemberTypes.Property, BindingFlags.NonPublic | BindingFlags.Instance,
 450                                                 Location);
 451
 452                                         if (member != null) {
 453                                                 Report.Error (122, Location, "'{0}' is inaccessible due to its protection level", GetFullMemberName (member_name));
 454                                                 return null;
 455                                         }
 456                                 }
 457
 458                                 if (member == null){
 459                                         Report.Error (117, Location, "Attribute `{0}' does not contain a definition for `{1}'",
 460                                                       Type, member_name);
 461                                         return null;
 462                                 }
 463
 464                                 if (!(member is PropertyExpr || member is FieldExpr)) {
 465                                         Error_InvalidNamedArgument (member_name);
 466                                         return null;
 467                                 }
 468
 469                                 e = a.Expr;
 470                                 if (e is TypeParameterExpr){
 471                                         Error_TypeParameterInAttribute (Location);
 472                                         return null;
 473                                 }
 474
 475                                 if (member is PropertyExpr) {
 476                                         PropertyExpr pe = (PropertyExpr) member;
 477                                         PropertyInfo pi = pe.PropertyInfo;
 478
 479                                         if (!pi.CanWrite || !pi.CanRead) {
 480                                                 Report.SymbolRelatedToPreviousError (pi);
 481                                                 Error_InvalidNamedArgument (member_name);
 482                                                 return null;
 483                                         }
 484
 485                                         if (!IsValidArgumentType (pi.PropertyType)) {
 486                                                 Report.SymbolRelatedToPreviousError (pi);
 487                                                 Error_InvalidNamedAgrumentType (member_name);
 488                                                 return null;
 489                                         }
 490
 491                                         object value;
 492                                         if (!GetAttributeArgumentExpression (e, Location, pi.PropertyType, out value))
 493                                                 return null;
 494
 495                                         prop_values.Add (value);
 496                                         prop_infos.Add (pi);
 497
 498                                 } else if (member is FieldExpr) {
 499                                         FieldExpr fe = (FieldExpr) member;
 500                                         FieldInfo fi = fe.FieldInfo;
 501
 502                                         if (fi.IsInitOnly) {
 503                                                 Error_InvalidNamedArgument (member_name);
 504                                                 return null;
 505                                         }
 506
 507                                         if (!IsValidArgumentType (fi.FieldType)) {
 508                                                 Report.SymbolRelatedToPreviousError (fi);
 509                                                 Error_InvalidNamedAgrumentType (member_name);
 510                                                 return null;
 511                                         }
 512
 513                                         object value;
 514                                         if (!GetAttributeArgumentExpression (e, Location, fi.FieldType, out value))
 515                                                 return null;
 516
 517                                         field_values.Add (value);
 518
 519                                         field_infos.Add (fi);
 520                                 }
 521                         }
 522
 523                         Expression mg = Expression.MemberLookup (
 524                                 ec, Type, ".ctor", MemberTypes.Constructor,
 525                                 BindingFlags.Public | BindingFlags.Instance | BindingFlags.DeclaredOnly,
 526                                 Location);
 527
 528                         if (mg == null) {
 529                                 Error_AttributeConstructorMismatch ();
 530                                 return null;
 531                         }
 532
 533                         MethodBase constructor = Invocation.OverloadResolve (
 534                                 ec, (MethodGroupExpr) mg, pos_args, false, Location);
 535
 536                         if (constructor == null) {
 537                                 return null;
 538                         }
 539
 540
 541                         // Here we do the checks which should be done by corlib or by runtime.
 542                         // However Zoltan doesn't like it and every Mono compiler has to do it again.
 543
 544                         if (Type == TypeManager.guid_attr_type) {
 545                                 try {
 546                                         new Guid ((string)pos_values [0]);
 547                                 }
 548                                 catch (Exception e) {
 549                                         Error_AttributeEmitError (e.Message);
 550                                 }
 551                         }
 552 // TODO: reenable
 553 //                      if (Type == TypeManager.methodimpl_attr_type &&
 554 //                              pos_values.Length == 1 && ((Argument)pos_args [0]).Type == TypeManager.short_type &&
 555 //                              !System.Enum.IsDefined (TypeManager.method_impl_options, pos_values [0])) {
 556 //                                      Error_AttributeEmitError ("Incorrect argument value.");
 557 //                      }
 558
 559                         //
 560                         // Now we perform some checks on the positional args as they
 561                         // cannot be null for a constructor which expects a parameter
 562                         // of type object
 563                         //
 564
 565                         ParameterData pd = TypeManager.GetParameterData (constructor);
 566
 567                         int last_real_param = pd.Count;
 568                         if (pd.HasParams) {
 569                                 // When the params is not filled we need to put one
 570                                 if (last_real_param > pos_arg_count) {
 571                                         object [] new_pos_values = new object [pos_arg_count + 1];
 572                                         pos_values.CopyTo (new_pos_values, 0);
 573                                         new_pos_values [pos_arg_count] = new object [] {} ;
 574                                         pos_values = new_pos_values;
 575                                 }
 576                                 last_real_param--;
 577                         }
 578
 579                         for (int j = 0; j < pos_arg_count; ++j) {
 580                                 Argument a = (Argument) pos_args [j];
 581
 582                                 if (a.Expr is NullLiteral && pd.ParameterType (j) == TypeManager.object_type) {
 583                                         Error_AttributeArgumentNotValid (Location);
 584                                         return null;
 585                                 }
 586
 587                                 object value = pos_values [j];
 588                                 if (value != null && a.Type != value.GetType () && TypeManager.IsPrimitiveType (a.Type)) {
 589                                         bool fail;
 590                                         pos_values [j] = TypeManager.ChangeType (value, a.Type, out fail);
 591                                         if (fail) {
 592                                                 // TODO: Can failed ?
 593                                                 throw new NotImplementedException ();
 594                                         }
 595                                 }
 596
 597                                 if (j < last_real_param)
 598                                         continue;
 599
 600                                 if (j == last_real_param) {
 601                                         object [] array = new object [pos_arg_count - last_real_param];
 602                                         array [0] = pos_values [j];
 603                                         pos_values [j] = array;
 604                                         continue;
 605                                 }
 606
 607                                 object [] params_array = (object []) pos_values [last_real_param];
 608                                 params_array [j - last_real_param] = pos_values [j];
 609                         }
 610
 611                         // Adjust the size of the pos_values if it had params
 612                         if (last_real_param != pos_arg_count) {
 613                                 object [] new_pos_values = new object [last_real_param + 1];
 614                                 Array.Copy (pos_values, new_pos_values, last_real_param + 1);
 615                                 pos_values = new_pos_values;
 616                         }
 617
 618                         if (named_arg_count > 0) {
 619                                 prop_info_arr = new PropertyInfo [prop_infos.Count];
 620                                 field_info_arr = new FieldInfo [field_infos.Count];
 621                                 field_values_arr = new object [field_values.Count];
 622                                 prop_values_arr = new object [prop_values.Count];
 623
 624                                 field_infos.CopyTo  (field_info_arr, 0);
 625                                 field_values.CopyTo (field_values_arr, 0);
 626
 627                                 prop_values.CopyTo  (prop_values_arr, 0);
 628                                 prop_infos.CopyTo   (prop_info_arr, 0);
 629                         }
 630
 631                         return (ConstructorInfo) constructor;
 632                 }
 633
 634                 /// <summary>
 635                 ///   Get a string containing a list of valid targets for the attribute 'attr'
 636                 /// </summary>
 637                 public string GetValidTargets ()
 638                 {
 639                         StringBuilder sb = new StringBuilder ();
 640                         AttributeTargets targets = GetAttributeUsage (null).ValidOn;
 641
 642                         if ((targets & AttributeTargets.Assembly) != 0)
 643                                 sb.Append ("'assembly' ");
 644
 645                         if ((targets & AttributeTargets.Class) != 0)
 646                                 sb.Append ("'class' ");
 647
 648                         if ((targets & AttributeTargets.Constructor) != 0)
 649                                 sb.Append ("'constructor' ");
 650
 651                         if ((targets & AttributeTargets.Delegate) != 0)
 652                                 sb.Append ("'delegate' ");
 653
 654                         if ((targets & AttributeTargets.Enum) != 0)
 655                                 sb.Append ("'enum' ");
 656
 657                         if ((targets & AttributeTargets.Event) != 0)
 658                                 sb.Append ("'event' ");
 659
 660                         if ((targets & AttributeTargets.Field) != 0)
 661                                 sb.Append ("'field' ");
 662
 663                         if ((targets & AttributeTargets.Interface) != 0)
 664                                 sb.Append ("'interface' ");
 665
 666                         if ((targets & AttributeTargets.Method) != 0)
 667                                 sb.Append ("'method' ");
 668
 669                         if ((targets & AttributeTargets.Module) != 0)
 670                                 sb.Append ("'module' ");
 671
 672                         if ((targets & AttributeTargets.Parameter) != 0)
 673                                 sb.Append ("'parameter' ");
 674
 675                         if ((targets & AttributeTargets.Property) != 0)
 676                                 sb.Append ("'property' ");
 677
 678                         if ((targets & AttributeTargets.ReturnValue) != 0)
 679                                 sb.Append ("'return' ");
 680
 681                         if ((targets & AttributeTargets.Struct) != 0)
 682                                 sb.Append ("'struct' ");
 683
 684                         return sb.ToString ();
 685
 686                 }
 687
 688                 /// <summary>
 689                 /// Returns AttributeUsage attribute for this type
 690                 /// </summary>
 691                 AttributeUsageAttribute GetAttributeUsage (EmitContext ec)
 692                 {
 693                         AttributeUsageAttribute ua = usage_attr_cache [Type] as AttributeUsageAttribute;
 694                         if (ua != null)
 695                                 return ua;
 696
 697                         Class attr_class = TypeManager.LookupClass (Type);
 698
 699                         if (attr_class == null) {
 700                                 object[] usage_attr = Type.GetCustomAttributes (TypeManager.attribute_usage_type, true);
 701                                 ua = (AttributeUsageAttribute)usage_attr [0];
 702                                 usage_attr_cache.Add (Type, ua);
 703                                 return ua;
 704                         }
 705
 706                         Attribute a = attr_class.OptAttributes == null
 707                                 ? null
 708                                 : attr_class.OptAttributes.Search (TypeManager.attribute_usage_type, attr_class.EmitContext);
 709
 710                         ua = a == null
 711                                 ? DefaultUsageAttribute
 712                                 : a.GetAttributeUsageAttribute (attr_class.EmitContext);
 713
 714                         usage_attr_cache.Add (Type, ua);
 715                         return ua;
 716                 }
 717
 718                 AttributeUsageAttribute GetAttributeUsageAttribute (EmitContext ec)
 719                 {
 720                         if (pos_values == null)
 721                                 // TODO: It is not neccessary to call whole Resolve (ApplyAttribute does it now) we need only ctor args.
 722                                 // But because a lot of attribute class code must be rewritten will be better to wait...
 723                                 Resolve (ec);
 724
 725                         if (resolve_error)
 726                                 return DefaultUsageAttribute;
 727
 728                         AttributeUsageAttribute usage_attribute = new AttributeUsageAttribute ((AttributeTargets)pos_values [0]);
 729
 730                         object field = GetPropertyValue ("AllowMultiple");
 731                         if (field != null)
 732                                 usage_attribute.AllowMultiple = (bool)field;
 733
 734                         field = GetPropertyValue ("Inherited");
 735                         if (field != null)
 736                                 usage_attribute.Inherited = (bool)field;
 737
 738                         return usage_attribute;
 739                 }
 740
 741                 /// <summary>
 742                 /// Returns custom name of indexer
 743                 /// </summary>
 744                 public string GetIndexerAttributeValue (EmitContext ec)
 745                 {
 746                         if (pos_values == null)
 747                                 // TODO: It is not neccessary to call whole Resolve (ApplyAttribute does it now) we need only ctor args.
 748                                 // But because a lot of attribute class code must be rewritten will be better to wait...
 749                                 Resolve (ec);
 750
 751                         if (resolve_error)
 752                                 return null;
 753
 754                         return pos_values [0] as string;
 755                 }
 756
 757                 /// <summary>
 758                 /// Returns condition of ConditionalAttribute
 759                 /// </summary>
 760                 public string GetConditionalAttributeValue (EmitContext ec)
 761                 {
 762                         if (pos_values == null)
 763                                 // TODO: It is not neccessary to call whole Resolve (ApplyAttribute does it now) we need only ctor args.
 764                                 // But because a lot of attribute class code must be rewritten will be better to wait...
 765                                 Resolve (ec);
 766
 767                         if (resolve_error)
 768                                 return null;
 769
 770                         return (string)pos_values [0];
 771                 }
 772
 773                 /// <summary>
 774                 /// Creates the instance of ObsoleteAttribute from this attribute instance
 775                 /// </summary>
 776                 public ObsoleteAttribute GetObsoleteAttribute (EmitContext ec)
 777                 {
 778                         if (pos_values == null)
 779                                 // TODO: It is not neccessary to call whole Resolve (ApplyAttribute does it now) we need only ctor args.
 780                                 // But because a lot of attribute class code must be rewritten will be better to wait...
 781                                 Resolve (ec);
 782
 783                         if (resolve_error)
 784                                 return null;
 785
 786                         if (pos_values == null || pos_values.Length == 0)
 787                                 return new ObsoleteAttribute ();
 788
 789                         if (pos_values.Length == 1)
 790                                 return new ObsoleteAttribute ((string)pos_values [0]);
 791
 792                         return new ObsoleteAttribute ((string)pos_values [0], (bool)pos_values [1]);
 793                 }
 794
 795                 /// <summary>
 796                 /// Returns value of CLSCompliantAttribute contructor parameter but because the method can be called
 797                 /// before ApplyAttribute. We need to resolve the arguments.
 798                 /// This situation occurs when class deps is differs from Emit order.
 799                 /// </summary>
 800                 public bool GetClsCompliantAttributeValue (EmitContext ec)
 801                 {
 802                         if (pos_values == null)
 803                                 // TODO: It is not neccessary to call whole Resolve (ApplyAttribute does it now) we need only ctor args.
 804                                 // But because a lot of attribute class code must be rewritten will be better to wait...
 805                                 Resolve (ec);
 806
 807                         if (resolve_error)
 808                                 return false;
 809
 810                         return (bool)pos_values [0];
 811                 }
 812
 813                 /// <summary>
 814                 /// Tests permitted SecurityAction for assembly or other types
 815                 /// </summary>
 816                 public bool CheckSecurityActionValidity (bool for_assembly)
 817                 {
 818                         SecurityAction action = GetSecurityActionValue ();
 819
 820                         switch (action) {
 821                         case SecurityAction.Demand:
 822                         case SecurityAction.Assert:
 823                         case SecurityAction.Deny:
 824                         case SecurityAction.PermitOnly:
 825                         case SecurityAction.LinkDemand:
 826                         case SecurityAction.InheritanceDemand:
 827                         case SecurityAction.LinkDemandChoice:
 828                         case SecurityAction.InheritanceDemandChoice:
 829                         case SecurityAction.DemandChoice:
 830                                 if (!for_assembly)
 831                                         return true;
 832                                 break;
 833
 834                         case SecurityAction.RequestMinimum:
 835                         case SecurityAction.RequestOptional:
 836                         case SecurityAction.RequestRefuse:
 837                                 if (for_assembly)
 838                                         return true;
 839                                 break;
 840
 841                         default:
 842                                 Error_AttributeEmitError ("SecurityAction is out of range X");
 843                                 return false;
 844                         }
 845
 846                         Error_AttributeEmitError (String.Concat ("SecurityAction '", action, "' is not valid for this declaration"));
 847                         return false;
 848                 }
 849
 850                 System.Security.Permissions.SecurityAction GetSecurityActionValue ()
 851                 {
 852                         return (SecurityAction)pos_values [0];
 853                 }
 854
 855                 /// <summary>
 856                 /// Creates instance of SecurityAttribute class and add result of CreatePermission method to permission table.
 857                 /// </summary>
 858                 /// <returns></returns>
 859                 public void ExtractSecurityPermissionSet (ListDictionary permissions)
 860                 {
 861                         if (TypeManager.LookupDeclSpace (Type) != null && RootContext.StdLib) {
 862                                 Error_AttributeEmitError ("security custom attributes can not be referenced from defining assembly");
 863                                 return;
 864                         }
 865
 866                         SecurityAttribute sa;
 867                         // For all assemblies except corlib we can avoid all hacks
 868                         if (RootContext.StdLib) {
 869                                 sa = (SecurityAttribute) Activator.CreateInstance (Type, pos_values);
 870
 871                                 if (prop_info_arr != null) {
 872                                         for (int i = 0; i < prop_info_arr.Length; ++i) {
 873                                                 PropertyInfo pi = prop_info_arr [i];
 874                                                 pi.SetValue (sa, prop_values_arr [i], null);
 875                                         }
 876                                 }
 877                         } else {
 878                                 Type temp_type = Type.GetType (Type.FullName);
 879                                 // HACK: All mscorlib attributes have same ctor syntax
 880                                 sa = (SecurityAttribute) Activator.CreateInstance (temp_type, new object[] { GetSecurityActionValue () } );
 881
 882                                 // All types are from newly created corlib but for invocation with old we need to convert them
 883                                 if (prop_info_arr != null) {
 884                                         for (int i = 0; i < prop_info_arr.Length; ++i) {
 885                                                 PropertyInfo emited_pi = prop_info_arr [i];
 886                                                 PropertyInfo pi = temp_type.GetProperty (emited_pi.Name, emited_pi.PropertyType);
 887
 888                                                 object old_instance = pi.PropertyType.IsEnum ?
 889                                                         System.Enum.ToObject (pi.PropertyType, prop_values_arr [i]) :
 890                                                         prop_values_arr [i];
 891
 892                                                 pi.SetValue (sa, old_instance, null);
 893                                         }
 894                                 }
 895                         }
 896
 897                         IPermission perm;
 898                         perm = sa.CreatePermission ();
 899                         SecurityAction action = GetSecurityActionValue ();
 900
 901                         // IS is correct because for corlib we are using an instance from old corlib
 902                         if (!(perm is System.Security.CodeAccessPermission)) {
 903                                 switch (action) {
 904                                         case SecurityAction.Demand:
 905                                                 action = (SecurityAction)13;
 906                                                 break;
 907                                         case SecurityAction.LinkDemand:
 908                                                 action = (SecurityAction)14;
 909                                                 break;
 910                                         case SecurityAction.InheritanceDemand:
 911                                                 action = (SecurityAction)15;
 912                                                 break;
 913                                 }
 914                         }
 915
 916                         PermissionSet ps = (PermissionSet)permissions [action];
 917                         if (ps == null) {
 918                                 if (sa is PermissionSetAttribute)
 919                                         ps = new PermissionSet (sa.Unrestricted ? PermissionState.Unrestricted : PermissionState.None);
 920                                 else
 921                                         ps = new PermissionSet (PermissionState.None);
 922
 923                                 permissions.Add (action, ps);
 924                         } else if (!ps.IsUnrestricted () && (sa is PermissionSetAttribute) && sa.Unrestricted) {
 925                                 ps = ps.Union (new PermissionSet (PermissionState.Unrestricted));
 926                                 permissions [action] = ps;
 927                         }
 928                         ps.AddPermission (perm);
 929                 }
 930
 931                 object GetValue (object value)
 932                 {
 933                         if (value is EnumConstant)
 934                                 return ((EnumConstant) value).GetValue ();
 935                         else
 936                                 return value;
 937                 }
 938
 939                 object GetPropertyValue (string name)
 940                 {
 941                         if (prop_info_arr == null)
 942                                 return null;
 943
 944                         for (int i = 0; i < prop_info_arr.Length; ++i) {
 945                                 if (prop_info_arr [i].Name == name)
 946                                         return prop_values_arr [i];
 947                         }
 948
 949                         return null;
 950                 }
 951
 952                 object GetFieldValue (string name)
 953                 {
 954                         int i;
 955                         if (field_info_arr == null)
 956                                 return null;
 957                         i = 0;
 958                         foreach (FieldInfo fi in field_info_arr) {
 959                                 if (fi.Name == name)
 960                                         return GetValue (field_values_arr [i]);
 961                                 i++;
 962                         }
 963                         return null;
 964                 }
 965
 966                 public UnmanagedMarshal GetMarshal (Attributable attr)
 967                 {
 968                         UnmanagedType UnmanagedType = (UnmanagedType)System.Enum.Parse (typeof (UnmanagedType), pos_values [0].ToString ());
 969
 970                         object value = GetFieldValue ("SizeParamIndex");
 971                         if (value != null && UnmanagedType != UnmanagedType.LPArray) {
 972                                 Error_AttributeEmitError ("SizeParamIndex field is not valid for the specified unmanaged type");
 973                                 return null;
 974                         }
 975
 976                         object o = GetFieldValue ("ArraySubType");
 977                         UnmanagedType array_sub_type = o == null ? UnmanagedType.I4 : (UnmanagedType) o;
 978
 979                         switch (UnmanagedType) {
 980                         case UnmanagedType.CustomMarshaler: {
 981                                 MethodInfo define_custom = typeof (UnmanagedMarshal).GetMethod ("DefineCustom",
 982                                                                        BindingFlags.Static | BindingFlags.Public);
 983                                 if (define_custom == null) {
 984                                         Report.RuntimeMissingSupport (Location, "set marshal info");
 985                                         return null;
 986                                 }
 987
 988                                 object [] args = new object [4];
 989                                 args [0] = GetFieldValue ("MarshalTypeRef");
 990                                 args [1] = GetFieldValue ("MarshalCookie");
 991                                 args [2] = GetFieldValue ("MarshalType");
 992                                 args [3] = Guid.Empty;
 993                                 return (UnmanagedMarshal) define_custom.Invoke (null, args);
 994                         }
 995                         case UnmanagedType.LPArray: {
 996                                 object size_const = GetFieldValue ("SizeConst");
 997                                 object size_param_index = GetFieldValue ("SizeParamIndex");
 998
 999                                 if ((size_const != null) || (size_param_index != null)) {
1000                                         MethodInfo define_array = typeof (UnmanagedMarshal).GetMethod ("DefineLPArrayInternal", BindingFlags.Static | BindingFlags.Public | BindingFlags.NonPublic);
1001                                         if (define_array == null) {
1002                                                 Report.RuntimeMissingSupport (Location, "set marshal info");
1003                                                 return null;
1004                                         }
1005
1006                                         object [] args = new object [3];
1007                                         args [0] = array_sub_type;
1008                                         args [1] = size_const == null ? -1 : size_const;
1009                                         args [2] = size_param_index == null ? -1 : size_param_index;
1010                                         return (UnmanagedMarshal) define_array.Invoke (null, args);
1011                                 }
1012                                 else
1013                                         return UnmanagedMarshal.DefineLPArray (array_sub_type);
1014                         }
1015                         case UnmanagedType.SafeArray:
1016                                 return UnmanagedMarshal.DefineSafeArray (array_sub_type);
1017
1018                         case UnmanagedType.ByValArray:
1019                                 FieldMember fm = attr as FieldMember;
1020                                 if (fm == null) {
1021                                         Error_AttributeEmitError ("Specified unmanaged type is only valid on fields");
1022                                         return null;
1023                                 }
1024                                 return UnmanagedMarshal.DefineByValArray ((int) GetFieldValue ("SizeConst"));
1025
1026                         case UnmanagedType.ByValTStr:
1027                                 return UnmanagedMarshal.DefineByValTStr ((int) GetFieldValue ("SizeConst"));
1028
1029                         default:
1030                                 return UnmanagedMarshal.DefineUnmanagedMarshal (UnmanagedType);
1031                         }
1032                 }
1033
1034                 public CharSet GetCharSetValue ()
1035                 {
1036                         return (CharSet)System.Enum.Parse (typeof (CharSet), pos_values [0].ToString ());
1037                 }
1038
1039                 public MethodImplOptions GetMethodImplOptions ()
1040                 {
1041                         return (MethodImplOptions)System.Enum.Parse (typeof (MethodImplOptions), pos_values [0].ToString ());
1042                 }
1043
1044                 public LayoutKind GetLayoutKindValue ()
1045                 {
1046                         return (LayoutKind)System.Enum.Parse (typeof (LayoutKind), pos_values [0].ToString ());
1047                 }
1048
1049                 /// <summary>
1050                 /// Emit attribute for Attributable symbol
1051                 /// </summary>
1052                 public void Emit (EmitContext ec, Attributable ias, ListDictionary emitted_attr)
1053                 {
1054                         CustomAttributeBuilder cb = Resolve (ec);
1055                         if (cb == null)
1056                                 return;
1057
1058                         AttributeUsageAttribute usage_attr = GetAttributeUsage (ec);
1059                         if ((usage_attr.ValidOn & Target) == 0) {
1060                                 Report.Error (592, Location, "Attribute '{0}' is not valid on this declaration type. It is valid on {1} declarations only.", Name, GetValidTargets ());
1061                                 return;
1062                         }
1063
1064                         try {
1065                                 ias.ApplyAttributeBuilder (this, cb);
1066                         }
1067                         catch (Exception e) {
1068                                 Error_AttributeEmitError (e.Message);
1069                                 return;
1070                         }
1071
1072                         if (!usage_attr.AllowMultiple) {
1073                                 ArrayList emitted_targets = (ArrayList)emitted_attr [Type];
1074                                 if (emitted_targets == null) {
1075                                         emitted_targets = new ArrayList ();
1076                                         emitted_attr.Add (Type, emitted_targets);
1077                                 } else if (emitted_targets.Contains (Target)) {
1078                                 Report.Error (579, Location, "Duplicate '" + Name + "' attribute");
1079                                         return;
1080                                 }
1081                                 emitted_targets.Add (Target);
1082                         }
1083
1084                         if (!RootContext.VerifyClsCompliance)
1085                                 return;
1086
1087                         // Here we are testing attribute arguments for array usage (error 3016)
1088                         if (ias.IsClsComplianceRequired (ec.DeclSpace)) {
1089                                 if (Arguments == null)
1090                                         return;
1091
1092                                 ArrayList pos_args = (ArrayList) Arguments [0];
1093                                 if (pos_args != null) {
1094                                         foreach (Argument arg in pos_args) {
1095                                                 // Type is undefined (was error 246)
1096                                                 if (arg.Type == null)
1097                                                         return;
1098
1099                                                 if (arg.Type.IsArray) {
1100                                                         Report.Error (3016, Location, "Arrays as attribute arguments are not CLS-compliant");
1101                                                         return;
1102                                                 }
1103                                         }
1104                                 }
1105
1106                                 if (Arguments.Count < 2)
1107                                         return;
1108
1109                                 ArrayList named_args = (ArrayList) Arguments [1];
1110                                 foreach (DictionaryEntry de in named_args) {
1111                                         Argument arg  = (Argument) de.Value;
1112
1113                                         // Type is undefined (was error 246)
1114                                         if (arg.Type == null)
1115                                                 return;
1116
1117                                         if (arg.Type.IsArray) {
1118                                                 Report.Error (3016, Location, "Arrays as attribute arguments are not CLS-compliant");
1119                                                 return;
1120                                         }
1121                                 }
1122                         }
1123                 }
1124
1125                 public MethodBuilder DefinePInvokeMethod (EmitContext ec, TypeBuilder builder, string name,
1126                                                           MethodAttributes flags, Type ret_type, Type [] param_types)
1127                 {
1128                         if (pos_values == null)
1129                                 // TODO: It is not neccessary to call whole Resolve (ApplyAttribute does it now) we need only ctor args.
1130                                 // But because a lot of attribute class code must be rewritten will be better to wait...
1131                                 Resolve (ec);
1132
1133                         if (resolve_error)
1134                                 return null;
1135
1136                         string dll_name = (string)pos_values [0];
1137
1138                         // Default settings
1139                         CallingConvention cc = CallingConvention.Winapi;
1140                         CharSet charset = CodeGen.Module.DefaultCharSet;
1141                         bool preserve_sig = true;
1142                         string entry_point = name;
1143                         bool best_fit_mapping = false;
1144                         bool throw_on_unmappable = false;
1145
1146                         bool best_fit_mapping_set = false;
1147                         bool throw_on_unmappable_set = false;
1148
1149                         MethodInfo set_best_fit = null;
1150                         MethodInfo set_throw_on = null;
1151
1152                         if (field_info_arr != null) {
1153                                 int char_set_extra = 0;
1154
1155                                 for (int i = 0; i < field_info_arr.Length; i++) {
1156                                         switch (field_info_arr [i].Name) {
1157                                                 case "BestFitMapping":
1158                                                         best_fit_mapping = (bool) field_values_arr [i];
1159                                                         best_fit_mapping_set = true;
1160                                                         break;
1161                                                 case "CallingConvention":
1162                                                         cc = (CallingConvention) field_values_arr [i];
1163                                                         break;
1164                                                 case "CharSet":
1165                                                         charset = (CharSet) field_values_arr [i];
1166                                                         break;
1167                                                 case "EntryPoint":
1168                                                         entry_point = (string) field_values_arr [i];
1169                                                         break;
1170                                                 case "ExactSpelling":
1171                                                         char_set_extra |= 0x01;
1172                                                         break;
1173                                                 case "PreserveSig":
1174                                                         preserve_sig = (bool) field_values_arr [i];
1175                                                         break;
1176                                                 case "SetLastError":
1177                                                         char_set_extra |= 0x40;
1178                                                         break;
1179                                                 case "ThrowOnUnmappableChar":
1180                                                         throw_on_unmappable = (bool) field_values_arr [i];
1181                                                         throw_on_unmappable_set = true;
1182                                                         break;
1183                                                 default:
1184                                                         throw new InternalErrorException (field_info_arr [i].ToString ());
1185                                         }
1186                                 }
1187                                 charset |= (CharSet)char_set_extra;
1188                         }
1189
1190                         if (throw_on_unmappable_set || best_fit_mapping_set) {
1191                                 set_best_fit = typeof (MethodBuilder).GetMethod ("set_BestFitMapping", BindingFlags.Instance | BindingFlags.Public | BindingFlags.NonPublic);
1192                                 set_throw_on = typeof (MethodBuilder).GetMethod ("set_ThrowOnUnmappableChar", BindingFlags.Instance | BindingFlags.Public | BindingFlags.NonPublic);
1193
1194                                 if ((set_best_fit == null) || (set_throw_on == null)) {
1195                                         Report.Error (-1, Location,
1196                                                                   "The ThrowOnUnmappableChar and BestFitMapping attributes can only be emitted when running on the mono runtime.");
1197                                         return null;
1198                                 }
1199                         }
1200
1201                         try {
1202                                 MethodBuilder mb = builder.DefinePInvokeMethod (
1203                                         name, dll_name, entry_point, flags | MethodAttributes.HideBySig | MethodAttributes.PinvokeImpl,
1204                                         CallingConventions.Standard, ret_type, param_types, cc, charset);
1205
1206                                 if (preserve_sig)
1207                                         mb.SetImplementationFlags (MethodImplAttributes.PreserveSig);
1208
1209                                 if (throw_on_unmappable_set)
1210                                         set_throw_on.Invoke (mb, 0, null, new object [] { throw_on_unmappable }, null);
1211                                 if (best_fit_mapping_set)
1212                                         set_best_fit.Invoke (mb, 0, null, new object [] { best_fit_mapping }, null);
1213
1214                                 return mb;
1215                         }
1216                         catch (ArgumentException e) {
1217                                 Error_AttributeEmitError (e.Message);
1218                                 return null;
1219                         }
1220                 }
1221
1222                 private Expression GetValue ()
1223                 {
1224                         if ((Arguments == null) || (Arguments.Count < 1))
1225                                 return null;
1226                         ArrayList al = (ArrayList) Arguments [0];
1227                         if ((al == null) || (al.Count < 1))
1228                                 return null;
1229                         Argument arg = (Argument) al [0];
1230                         if ((arg == null) || (arg.Expr == null))
1231                                 return null;
1232                         return arg.Expr;
1233                 }
1234
1235                 public string GetString ()
1236                 {
1237                         Expression e = GetValue ();
1238                         if (e is StringLiteral)
1239                                 return (e as StringLiteral).Value;
1240                         return null;
1241                 }
1242
1243                 public bool GetBoolean ()
1244                 {
1245                         Expression e = GetValue ();
1246                         if (e is BoolLiteral)
1247                                 return (e as BoolLiteral).Value;
1248                         return false;
1249                 }
1250         }
1251
1252
1253         /// <summary>
1254         /// For global attributes (assembly, module) we need special handling.
1255         /// Attributes can be located in the several files
1256         /// </summary>
1257         public class GlobalAttribute: Attribute
1258         {
1259                 public readonly NamespaceEntry ns;
1260
1261                 public GlobalAttribute (TypeContainer container, string target,
1262                                         Expression left_expr, string identifier, ArrayList args, Location loc):
1263                         base (target, left_expr, identifier, args, loc)
1264                 {
1265                         ns = container.NamespaceEntry;
1266                 }
1267
1268                 void Enter ()
1269                 {
1270                         // RootContext.Tree.Types has a single NamespaceEntry which gets overwritten
1271                         // each time a new file is parsed.  However, we need to use the NamespaceEntry
1272                         // in effect where the attribute was used.  Since code elsewhere cannot assume
1273                         // that the NamespaceEntry is right, just overwrite it.
1274                         //
1275                         // Precondition: RootContext.Tree.Types == null
1276
1277                         if (RootContext.Tree.Types.NamespaceEntry != null)
1278                                 throw new InternalErrorException (Location + " non-null NamespaceEntry");
1279
1280                         RootContext.Tree.Types.NamespaceEntry = ns;
1281                 }
1282
1283                 void Leave ()
1284                 {
1285                         RootContext.Tree.Types.NamespaceEntry = null;
1286                 }
1287
1288                 protected override FullNamedExpression ResolveAsTypeStep (Expression expr, EmitContext ec)
1289                 {
1290                         try {
1291                                 Enter ();
1292                                 return base.ResolveAsTypeStep (expr, ec);
1293                         }
1294                         finally {
1295                                 Leave ();
1296                         }
1297                 }
1298
1299                 protected override ConstructorInfo ResolveArguments (EmitContext ec)
1300                 {
1301                         try {
1302                                 Enter ();
1303                                 return base.ResolveArguments (ec);
1304                         }
1305                         finally {
1306                                 Leave ();
1307                         }
1308                 }
1309         }
1310
1311         public class Attributes {
1312                 public ArrayList Attrs;
1313
1314                 public Attributes (Attribute a)
1315                 {
1316                         Attrs = new ArrayList ();
1317                         Attrs.Add (a);
1318                 }
1319
1320                 public Attributes (ArrayList attrs)
1321                 {
1322                         Attrs = attrs;
1323                 }
1324
1325                 public void AddAttributes (ArrayList attrs)
1326                 {
1327                         Attrs.AddRange (attrs);
1328                 }
1329
1330                 /// <summary>
1331                 /// Checks whether attribute target is valid for the current element
1332                 /// </summary>
1333                 public bool CheckTargets (Attributable member)
1334                 {
1335                         string[] valid_targets = member.ValidAttributeTargets;
1336                         foreach (Attribute a in Attrs) {
1337                                 if (a.ExplicitTarget == null || a.ExplicitTarget == valid_targets [0]) {
1338                                         a.Target = member.AttributeTargets;
1339                                         continue;
1340                                 }
1341
1342                                 // TODO: we can skip the first item
1343                                 if (((IList) valid_targets).Contains (a.ExplicitTarget)) {
1344                                         switch (a.ExplicitTarget) {
1345                                                 case "return": a.Target = AttributeTargets.ReturnValue; continue;
1346                                                 case "param": a.Target = AttributeTargets.Parameter; continue;
1347                                                 case "field": a.Target = AttributeTargets.Field; continue;
1348                                                 case "method": a.Target = AttributeTargets.Method; continue;
1349                                                 case "property": a.Target = AttributeTargets.Property; continue;
1350                                         }
1351                                         throw new InternalErrorException ("Unknown explicit target: " + a.ExplicitTarget);
1352                                 }
1353
1354                                 StringBuilder sb = new StringBuilder ();
1355                                 foreach (string s in valid_targets) {
1356                                         sb.Append (s);
1357                                         sb.Append (", ");
1358                                 }
1359                                 sb.Remove (sb.Length - 2, 2);
1360                                 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 ());
1361                                 return false;
1362                         }
1363                         return true;
1364                 }
1365
1366                 public Attribute Search (Type t, EmitContext ec)
1367                 {
1368                         foreach (Attribute a in Attrs) {
1369                                 if (a.ResolveType (ec) == t)
1370                                         return a;
1371                         }
1372                         return null;
1373                 }
1374
1375                 /// <summary>
1376                 /// Returns all attributes of type 't'. Use it when attribute is AllowMultiple = true
1377                 /// </summary>
1378                 public Attribute[] SearchMulti (Type t, EmitContext ec)
1379                 {
1380                         ArrayList ar = null;
1381
1382                         foreach (Attribute a in Attrs) {
1383                                 if (a.ResolveType (ec) == t) {
1384                                         if (ar == null)
1385                                                 ar = new ArrayList ();
1386                                         ar.Add (a);
1387                                 }
1388                         }
1389
1390                         return ar == null ? null : ar.ToArray (typeof (Attribute)) as Attribute[];
1391                 }
1392
1393                 public void Emit (EmitContext ec, Attributable ias)
1394                 {
1395                         CheckTargets (ias);
1396
1397                         ListDictionary ld = new ListDictionary ();
1398
1399                         foreach (Attribute a in Attrs)
1400                                 a.Emit (ec, ias, ld);
1401                 }
1402
1403                 public bool Contains (Type t, EmitContext ec)
1404                 {
1405                         return Search (t, ec) != null;
1406                 }
1407         }
1408
1409         /// <summary>
1410         /// Helper class for attribute verification routine.
1411         /// </summary>
1412         sealed class AttributeTester
1413         {
1414                 static PtrHashtable analyzed_types = new PtrHashtable ();
1415                 static PtrHashtable analyzed_types_obsolete = new PtrHashtable ();
1416                 static PtrHashtable analyzed_member_obsolete = new PtrHashtable ();
1417                 static PtrHashtable analyzed_method_excluded = new PtrHashtable ();
1418
1419                 static PtrHashtable fixed_buffer_cache = new PtrHashtable ();
1420
1421                 static object TRUE = new object ();
1422                 static object FALSE = new object ();
1423
1424                 private AttributeTester ()
1425                 {
1426                 }
1427
1428                 public enum Result {
1429                         Ok,
1430                         RefOutArrayError,
1431                         ArrayArrayError
1432                 }
1433
1434                 /// <summary>
1435                 /// Returns true if parameters of two compared methods are CLS-Compliant.
1436                 /// It tests differing only in ref or out, or in array rank.
1437                 /// </summary>
1438                 public static Result AreOverloadedMethodParamsClsCompliant (Type[] types_a, Type[] types_b)
1439                 {
1440                         if (types_a == null || types_b == null)
1441                                 return Result.Ok;
1442
1443                         if (types_a.Length != types_b.Length)
1444                                 return Result.Ok;
1445
1446                         Result result = Result.Ok;
1447                         for (int i = 0; i < types_b.Length; ++i) {
1448                                 Type aType = types_a [i];
1449                                 Type bType = types_b [i];
1450
1451                                 if (aType.IsArray && bType.IsArray) {
1452                                         Type a_el_type = aType.GetElementType ();
1453                                         Type b_el_type = bType.GetElementType ();
1454                                         if (aType.GetArrayRank () != bType.GetArrayRank () && a_el_type == b_el_type) {
1455                                                 result = Result.RefOutArrayError;
1456                                                 continue;
1457                                         }
1458
1459                                         if (a_el_type.IsArray || b_el_type.IsArray) {
1460                                                 result = Result.ArrayArrayError;
1461                                                 continue;
1462                                         }
1463                                 }
1464
1465                                 Type aBaseType = aType;
1466                                 bool is_either_ref_or_out = false;
1467
1468                                 if (aType.IsByRef || aType.IsPointer) {
1469                                         aBaseType = aType.GetElementType ();
1470                                         is_either_ref_or_out = true;
1471                                 }
1472
1473                                 Type bBaseType = bType;
1474                                 if (bType.IsByRef || bType.IsPointer)
1475                                 {
1476                                         bBaseType = bType.GetElementType ();
1477                                         is_either_ref_or_out = !is_either_ref_or_out;
1478                                 }
1479
1480                                 if (aBaseType != bBaseType)
1481                                         return Result.Ok;
1482
1483                                 if (is_either_ref_or_out)
1484                                         result = Result.RefOutArrayError;
1485                         }
1486                         return result;
1487                 }
1488
1489                 /// <summary>
1490                 /// Goes through all parameters and test if they are CLS-Compliant.
1491                 /// </summary>
1492                 public static bool AreParametersCompliant (Parameter[] fixedParameters, Location loc)
1493                 {
1494                         if (fixedParameters == null)
1495                                 return true;
1496
1497                         foreach (Parameter arg in fixedParameters) {
1498                                 if (!AttributeTester.IsClsCompliant (arg.ParameterType)) {
1499                                         Report.Error (3001, loc, "Argument type '{0}' is not CLS-compliant", arg.GetSignatureForError ());
1500                                         return false;
1501                                 }
1502                         }
1503                         return true;
1504                 }
1505
1506
1507                 /// <summary>
1508                 /// This method tests the CLS compliance of external types. It doesn't test type visibility.
1509                 /// </summary>
1510                 public static bool IsClsCompliant (Type type)
1511                 {
1512                         if (type == null)
1513                                 return true;
1514
1515                         object type_compliance = analyzed_types[type];
1516                         if (type_compliance != null)
1517                                 return type_compliance == TRUE;
1518
1519                         if (type.IsPointer) {
1520                                 analyzed_types.Add (type, null);
1521                                 return false;
1522                         }
1523
1524                         bool result;
1525                         if (type.IsArray || type.IsByRef)       {
1526                                 result = IsClsCompliant (TypeManager.GetElementType (type));
1527                         } else {
1528                                 result = AnalyzeTypeCompliance (type);
1529                         }
1530                         analyzed_types.Add (type, result ? TRUE : FALSE);
1531                         return result;
1532                 }
1533
1534                 /// <summary>
1535                 /// Returns IFixedBuffer implementation if field is fixed buffer else null.
1536                 /// </summary>
1537                 public static IFixedBuffer GetFixedBuffer (FieldInfo fi)
1538                 {
1539                         FieldBase fb = TypeManager.GetField (fi);
1540                         if (fb != null) {
1541                                 return fb as IFixedBuffer;
1542                         }
1543
1544                         object o = fixed_buffer_cache [fi];
1545                         if (o == null) {
1546                                 if (System.Attribute.GetCustomAttribute (fi, TypeManager.fixed_buffer_attr_type) == null) {
1547                                         fixed_buffer_cache.Add (fi, FALSE);
1548                                         return null;
1549                                 }
1550
1551                                 IFixedBuffer iff = new FixedFieldExternal (fi);
1552                                 fixed_buffer_cache.Add (fi, iff);
1553                                 return iff;
1554                         }
1555
1556                         if (o == FALSE)
1557                                 return null;
1558
1559                         return (IFixedBuffer)o;
1560                 }
1561
1562                 public static void VerifyModulesClsCompliance ()
1563                 {
1564                         Module[] modules = TypeManager.Modules;
1565                         if (modules == null)
1566                                 return;
1567
1568                         // The first module is generated assembly
1569                         for (int i = 1; i < modules.Length; ++i) {
1570                                 Module module = modules [i];
1571                                 if (!IsClsCompliant (module)) {
1572                                         Report.Error (3013, "Added modules must be marked with the CLSCompliant attribute to match the assembly", module.Name);
1573                                         return;
1574                                 }
1575                         }
1576                 }
1577
1578                 /// <summary>
1579                 /// Tests container name for CLS-Compliant name (differing only in case)
1580                 /// </summary>
1581                 public static void VerifyTopLevelNameClsCompliance ()
1582                 {
1583                         Hashtable locase_table = new Hashtable ();
1584
1585                         // Convert imported type names to lower case and ignore not cls compliant
1586                         foreach (DictionaryEntry de in TypeManager.all_imported_types) {
1587                                 Type t = (Type)de.Value;
1588                                 if (!AttributeTester.IsClsCompliant (t))
1589                                         continue;
1590
1591                                 locase_table.Add (((string)de.Key).ToLower (System.Globalization.CultureInfo.InvariantCulture), t);
1592                         }
1593
1594                         foreach (DictionaryEntry de in RootContext.Tree.AllDecls) {
1595                                 if (!(de.Key is MemberName))
1596                                         throw new InternalErrorException ("");
1597                                 DeclSpace decl = (DeclSpace) de.Value;
1598                                 if (!decl.IsClsComplianceRequired (decl))
1599                                         continue;
1600
1601                                 string lcase = decl.Name.ToLower (System.Globalization.CultureInfo.InvariantCulture);
1602                                 if (!locase_table.Contains (lcase)) {
1603                                         locase_table.Add (lcase, decl);
1604                                         continue;
1605                                 }
1606
1607                                 object conflict = locase_table [lcase];
1608                                 if (conflict is Type)
1609                                         Report.SymbolRelatedToPreviousError ((Type)conflict);
1610                                 else
1611                                         Report.SymbolRelatedToPreviousError ((MemberCore)conflict);
1612
1613                                 Report.Error (3005, decl.Location, "Identifier '{0}' differing only in case is not CLS-compliant", decl.GetSignatureForError ());
1614                         }
1615                 }
1616
1617                 static bool IsClsCompliant (ICustomAttributeProvider attribute_provider)
1618                 {
1619                         object[] CompliantAttribute = attribute_provider.GetCustomAttributes (TypeManager.cls_compliant_attribute_type, false);
1620                         if (CompliantAttribute.Length == 0)
1621                                 return false;
1622
1623                         return ((CLSCompliantAttribute)CompliantAttribute[0]).IsCompliant;
1624                 }
1625
1626                 static bool AnalyzeTypeCompliance (Type type)
1627                 {
1628                         if (type.IsGenericInstance)
1629                                 type = type.GetGenericTypeDefinition ();
1630                         DeclSpace ds = TypeManager.LookupDeclSpace (type);
1631                         if (ds != null)
1632                                 return ds.IsClsComplianceRequired (ds.Parent);
1633
1634                         if (type.IsGenericParameter)
1635                                 return true;
1636
1637                         object[] CompliantAttribute = type.GetCustomAttributes (TypeManager.cls_compliant_attribute_type, false);
1638                         if (CompliantAttribute.Length == 0)
1639                                 return IsClsCompliant (type.Assembly);
1640
1641                         return ((CLSCompliantAttribute)CompliantAttribute[0]).IsCompliant;
1642                 }
1643
1644                 /// <summary>
1645                 /// Returns instance of ObsoleteAttribute when type is obsolete
1646                 /// </summary>
1647                 public static ObsoleteAttribute GetObsoleteAttribute (Type type)
1648                 {
1649                         object type_obsolete = analyzed_types_obsolete [type];
1650                         if (type_obsolete == FALSE)
1651                                 return null;
1652
1653                         if (type_obsolete != null)
1654                                 return (ObsoleteAttribute)type_obsolete;
1655
1656                         ObsoleteAttribute result = null;
1657                         if (type.IsByRef || type.IsArray || type.IsPointer) {
1658                                 result = GetObsoleteAttribute (TypeManager.GetElementType (type));
1659                         } else if (type.IsGenericParameter || type.IsGenericInstance)
1660                                 return null;
1661                         else {
1662                                 DeclSpace type_ds = TypeManager.LookupDeclSpace (type);
1663
1664                                 // Type is external, we can get attribute directly
1665                                 if (type_ds == null) {
1666                                         object[] attribute = type.GetCustomAttributes (TypeManager.obsolete_attribute_type, false);
1667                                         if (attribute.Length == 1)
1668                                                 result = (ObsoleteAttribute)attribute [0];
1669                                 } else {
1670                                         result = type_ds.GetObsoleteAttribute (type_ds);
1671                                 }
1672                         }
1673
1674                         analyzed_types_obsolete.Add (type, result == null ? FALSE : result);
1675                         return result;
1676                 }
1677
1678                 /// <summary>
1679                 /// Returns instance of ObsoleteAttribute when method is obsolete
1680                 /// </summary>
1681                 public static ObsoleteAttribute GetMethodObsoleteAttribute (MethodBase mb)
1682                 {
1683                         IMethodData mc = TypeManager.GetMethod (mb);
1684                         if (mc != null)
1685                                 return mc.GetObsoleteAttribute ();
1686
1687                         // compiler generated methods are not registered by AddMethod
1688                         if (mb.DeclaringType is TypeBuilder)
1689                                 return null;
1690
1691                         PropertyInfo pi = PropertyExpr.AccessorTable [mb] as PropertyInfo;
1692                         if (pi != null)
1693                                 return GetMemberObsoleteAttribute (pi);
1694
1695                         return GetMemberObsoleteAttribute (mb);
1696                 }
1697
1698                 /// <summary>
1699                 /// Returns instance of ObsoleteAttribute when member is obsolete
1700                 /// </summary>
1701                 public static ObsoleteAttribute GetMemberObsoleteAttribute (MemberInfo mi)
1702                 {
1703                         object type_obsolete = analyzed_member_obsolete [mi];
1704                         if (type_obsolete == FALSE)
1705                                 return null;
1706
1707                         if (type_obsolete != null)
1708                                 return (ObsoleteAttribute)type_obsolete;
1709
1710                         if ((mi.DeclaringType is TypeBuilder) || mi.DeclaringType.IsGenericInstance)
1711                                 return null;
1712
1713                         ObsoleteAttribute oa = System.Attribute.GetCustomAttribute (mi, TypeManager.obsolete_attribute_type, false) as ObsoleteAttribute;
1714                         analyzed_member_obsolete.Add (mi, oa == null ? FALSE : oa);
1715                         return oa;
1716                 }
1717
1718                 /// <summary>
1719                 /// Common method for Obsolete error/warning reporting.
1720                 /// </summary>
1721                 public static void Report_ObsoleteMessage (ObsoleteAttribute oa, string member, Location loc)
1722                 {
1723                         if (oa.IsError) {
1724                                 Report.Error (619, loc, "'{0}' is obsolete: '{1}'", member, oa.Message);
1725                                 return;
1726                         }
1727
1728                         if (oa.Message == null) {
1729                                 Report.Warning (612, loc, "'{0}' is obsolete", member);
1730                                 return;
1731                         }
1732                         if (RootContext.WarningLevel >= 2)
1733                                 Report.Warning (618, loc, "'{0}' is obsolete: '{1}'", member, oa.Message);
1734                 }
1735
1736                 public static bool IsConditionalMethodExcluded (MethodBase mb)
1737                 {
1738                         object excluded = analyzed_method_excluded [mb];
1739                         if (excluded != null)
1740                                 return excluded == TRUE ? true : false;
1741
1742                         if (mb.Mono_IsInflatedMethod)
1743                                 return false;
1744
1745                         ConditionalAttribute[] attrs = mb.GetCustomAttributes (TypeManager.conditional_attribute_type, true) as ConditionalAttribute[];
1746                         if (attrs.Length == 0) {
1747                                 analyzed_method_excluded.Add (mb, FALSE);
1748                                 return false;
1749                         }
1750
1751                         foreach (ConditionalAttribute a in attrs) {
1752                                 if (RootContext.AllDefines.Contains (a.ConditionString)) {
1753                                         analyzed_method_excluded.Add (mb, FALSE);
1754                                         return false;
1755                                 }
1756                         }
1757                         analyzed_method_excluded.Add (mb, TRUE);
1758                         return true;
1759                 }
1760
1761                 /// <summary>
1762                 /// Analyzes class whether it has attribute which has ConditionalAttribute
1763                 /// and its condition is not defined.
1764                 /// </summary>
1765                 public static bool IsAttributeExcluded (Type type)
1766                 {
1767                         if (!type.IsClass)
1768                                 return false;
1769
1770                         Class class_decl = TypeManager.LookupDeclSpace (type) as Class;
1771
1772                         // TODO: add caching
1773                         // TODO: merge all Type bases attribute caching to one cache to save memory
1774                         if (class_decl == null) {
1775                                 object[] attributes = type.GetCustomAttributes (TypeManager.conditional_attribute_type, false);
1776                                 foreach (ConditionalAttribute ca in attributes) {
1777                                         if (RootContext.AllDefines.Contains (ca.ConditionString))
1778                                                 return false;
1779                                 }
1780                                 return attributes.Length > 0;
1781                         }
1782
1783                         return class_decl.IsExcluded ();
1784                 }
1785         }
1786 }