mcs/mcs/attribute.cs

   1 //
   2 // attribute.cs: Attribute Handler
   3 //
   4 // Author: Ravi Pratap (ravi@ximian.com)
   5 //
   6 // Licensed under the terms of the GNU GPL
   7 //
   8 // (C) 2001 Ximian, Inc (http://www.ximian.com)
   9 //
  10 //
  11
  12 using System;
  13 using System.Diagnostics;
  14 using System.Collections;
  15 using System.Collections.Specialized;
  16 using System.Reflection;
  17 using System.Reflection.Emit;
  18 using System.Runtime.InteropServices;
  19 using System.Runtime.CompilerServices;
  20 using System.Text;
  21
  22 namespace Mono.CSharp {
  23
  24         /// <summary>
  25         ///   Base class for objects that can have Attributes applied to them.
  26         /// </summary>
  27         public abstract class Attributable {
  28                 /// <summary>
  29                 ///   Attributes for this type
  30                 /// </summary>
  31                 Attributes attributes;
  32
  33                 public Attributable(Attributes attrs)
  34                 {
  35                         attributes = attrs;
  36                         if (attributes != null)
  37                                 attributes.CheckTargets (ValidAttributeTargets);
  38                 }
  39
  40                 public Attributes OptAttributes
  41                 {
  42                         get {
  43                                 return attributes;
  44                         }
  45                         set {
  46                                 attributes = value;
  47                                 if (attributes != null)
  48                                         attributes.CheckTargets (ValidAttributeTargets);
  49                         }
  50                 }
  51
  52                 /// <summary>
  53                 /// Use member-specific procedure to apply attribute @a in @cb to the entity being built in @builder
  54                 /// </summary>
  55                 public abstract void ApplyAttributeBuilder (Attribute a, CustomAttributeBuilder cb);
  56
  57                 /// <summary>
  58                 /// Returns combination of enabled AttributeTargets
  59                 /// </summary>
  60                 public abstract AttributeTargets AttributeTargets { get; }
  61
  62                 public abstract bool IsClsCompliaceRequired (DeclSpace ds);
  63
  64                 /// <summary>
  65                 /// Gets list of valid attribute targets for explicit target declaration.
  66                 /// The first array item is default target. Don't break this rule.
  67                 /// </summary>
  68                 protected abstract string[] ValidAttributeTargets { get; }
  69         };
  70
  71         public class Attribute {
  72                 public string Target;
  73                 public readonly string    Name;
  74                 public readonly ArrayList Arguments;
  75
  76                 public readonly Location Location;
  77
  78                 public Type Type;
  79
  80                 // Is non-null if type is AttributeUsageAttribute
  81                 AttributeUsageAttribute usage_attribute;
  82
  83                 public AttributeUsageAttribute UsageAttribute {
  84                         get {
  85                                 return usage_attribute;
  86                         }
  87                 }
  88
  89                 MethodImplOptions ImplOptions;
  90                 UnmanagedType     UnmanagedType;
  91                 CustomAttributeBuilder cb;
  92
  93                 // non-null if named args present after Resolve () is called
  94                 PropertyInfo [] prop_info_arr;
  95                 FieldInfo [] field_info_arr;
  96                 object [] field_values_arr;
  97                 object [] prop_values_arr;
  98                 object [] pos_values;
  99
 100                 static PtrHashtable usage_attr_cache = new PtrHashtable ();
 101
 102                 public Attribute (string target, string name, ArrayList args, Location loc)
 103                 {
 104                         Name = name;
 105                         Arguments = args;
 106                         Location = loc;
 107                         Target = target;
 108                 }
 109
 110                 void Error_InvalidNamedArgument (string name)
 111                 {
 112                         Report.Error (617, Location, "'" + name + "' is not a valid named attribute " +
 113                                       "argument. Named attribute arguments must be fields which are not " +
 114                                       "readonly, static or const, or properties with a set accessor which "+
 115                                       "are not static.");
 116                 }
 117
 118                 static void Error_AttributeArgumentNotValid (Location loc)
 119                 {
 120                         Report.Error (182, loc,
 121                                       "An attribute argument must be a constant expression, typeof " +
 122                                       "expression or array creation expression");
 123                 }
 124
 125                 void Error_AttributeConstructorMismatch ()
 126                 {
 127                         Report.Error (-6, Location,
 128                                       "Could not find a constructor for this argument list.");
 129                 }
 130
 131                 /// <summary>
 132                 ///   Tries to resolve the type of the attribute. Flags an error if it can't, and complain is true.
 133                 /// </summary>
 134                 protected virtual Type CheckAttributeType (EmitContext ec, bool complain)
 135                 {
 136                         Type t1 = RootContext.LookupType (ec.DeclSpace, Name, true, Location);
 137
 138                         // FIXME: Shouldn't do this for quoted attributes: [@A]
 139                         Type t2 = RootContext.LookupType (ec.DeclSpace, Name + "Attribute", true, Location);
 140
 141                         String err0616 = null;
 142
 143                         if (t1 != null && ! t1.IsSubclassOf (TypeManager.attribute_type)) {
 144                                 t1 = null;
 145                                 err0616 = "'" + Name + "': is not an attribute class";
 146                         }
 147                         if (t2 != null && ! t2.IsSubclassOf (TypeManager.attribute_type)) {
 148                                 t2 = null;
 149                                 err0616 = (err0616 != null)
 150                                         ? "Neither '" + Name + "' nor '" + Name + "Attribute' is an attribute class"
 151                                         : "'" + Name + "Attribute': is not an attribute class";
 152                         }
 153
 154                         if (t1 != null && t2 != null) {
 155                                 Report.Error(1614, Location, "'" + Name + "': is ambiguous; "
 156                                              + " use either '@" + Name + "' or '" + Name + "Attribute'");
 157                                 return null;
 158                         }
 159                         if (t1 != null)
 160                                 return t1;
 161                         if (t2 != null)
 162                                 return t2;
 163
 164                         if (err0616 != null) {
 165                                 Report.Error (616, Location, err0616);
 166                                 return null;
 167                         }
 168
 169                         if (complain)
 170                                 Report.Error (246, Location,
 171                                               "Could not find attribute '" + Name
 172                                               + "' (are you missing a using directive or an assembly reference ?)");
 173                         return null;
 174                 }
 175
 176                 public Type ResolveType (EmitContext ec, bool complain)
 177                 {
 178                         if (Type == null)
 179                                 Type = CheckAttributeType (ec, complain);
 180                         return Type;
 181                 }
 182
 183                 /// <summary>
 184                 ///   Validates the guid string
 185                 /// </summary>
 186                 bool ValidateGuid (string guid)
 187                 {
 188                         try {
 189                                 new Guid (guid);
 190                                 return true;
 191                         } catch {
 192                                 Report.Error (647, Location, "Format of GUID is invalid: " + guid);
 193                                 return false;
 194                         }
 195                 }
 196
 197                 string GetFullMemberName (string member)
 198                 {
 199                         return Type.FullName + '.' + member;
 200                 }
 201
 202                 //
 203                 // Given an expression, if the expression is a valid attribute-argument-expression
 204                 // returns an object that can be used to encode it, or null on failure.
 205                 //
 206                 public static bool GetAttributeArgumentExpression (Expression e, Location loc, out object result)
 207                 {
 208                         if (e is Constant) {
 209                                 result = ((Constant) e).GetValue ();
 210                                 return true;
 211                         } else if (e is TypeOf) {
 212                                 result = ((TypeOf) e).TypeArg;
 213                                 return true;
 214                         } else if (e is ArrayCreation){
 215                                 result =  ((ArrayCreation) e).EncodeAsAttribute ();
 216                                 if (result != null)
 217                                         return true;
 218                         } else if (e is EmptyCast) {
 219                                 result = e;
 220                                 if (((EmptyCast) e).Child is Constant) {
 221                                         result = ((Constant) ((EmptyCast)e).Child).GetValue();
 222                                 }
 223                                 return true;
 224                         }
 225
 226                         result = null;
 227                         Error_AttributeArgumentNotValid (loc);
 228                         return false;
 229                 }
 230
 231                 public CustomAttributeBuilder Resolve (EmitContext ec)
 232                 {
 233                         Type oldType = Type;
 234
 235                         // Sanity check.
 236                         Type = CheckAttributeType (ec, true);
 237                         if (oldType == null && Type == null)
 238                                 return null;
 239                         if (oldType != null && oldType != Type) {
 240                                 Report.Error (-6, Location,
 241                                               "Attribute {0} resolved to different types at different times: {1} vs. {2}",
 242                                               Name, oldType, Type);
 243                                 return null;
 244                         }
 245
 246                         bool MethodImplAttr = false;
 247                         bool MarshalAsAttr = false;
 248                         bool GuidAttr = false;
 249                         bool usage_attr = false;
 250
 251                         bool DoCompares = true;
 252
 253                         //
 254                         // If we are a certain special attribute, we
 255                         // set the information accordingly
 256                         //
 257
 258                         if (Type == TypeManager.attribute_usage_type)
 259                                 usage_attr = true;
 260                         else if (Type == TypeManager.methodimpl_attr_type)
 261                                 MethodImplAttr = true;
 262                         else if (Type == TypeManager.marshal_as_attr_type)
 263                                 MarshalAsAttr = true;
 264                         else if (Type == TypeManager.guid_attr_type)
 265                                 GuidAttr = true;
 266                         else
 267                                 DoCompares = false;
 268
 269                         // Now we extract the positional and named arguments
 270
 271                         ArrayList pos_args = new ArrayList ();
 272                         ArrayList named_args = new ArrayList ();
 273                         int pos_arg_count = 0;
 274
 275                         if (Arguments != null) {
 276                                 pos_args = (ArrayList) Arguments [0];
 277                                 if (pos_args != null)
 278                                         pos_arg_count = pos_args.Count;
 279                                 if (Arguments.Count > 1)
 280                                         named_args = (ArrayList) Arguments [1];
 281                         }
 282
 283                         pos_values = new object [pos_arg_count];
 284
 285                         //
 286                         // First process positional arguments
 287                         //
 288
 289                         int i;
 290                         for (i = 0; i < pos_arg_count; i++) {
 291                                 Argument a = (Argument) pos_args [i];
 292                                 Expression e;
 293
 294                                 if (!a.Resolve (ec, Location))
 295                                         return null;
 296
 297                                 e = a.Expr;
 298
 299                                 object val;
 300                                 if (!GetAttributeArgumentExpression (e, Location, out val))
 301                                         return null;
 302
 303                                 pos_values [i] = val;
 304                                 if (DoCompares){
 305                                         if (usage_attr)
 306                                                 usage_attribute = new AttributeUsageAttribute ((AttributeTargets) pos_values [0]);
 307                                         else if (MethodImplAttr)
 308                                                 this.ImplOptions = (MethodImplOptions) pos_values [0];
 309                                         else if (GuidAttr){
 310                                                 //
 311                                                 // we will later check the validity of the type
 312                                                 //
 313                                                 if (pos_values [0] is string){
 314                                                         if (!ValidateGuid ((string) pos_values [0]))
 315                                                                 return null;
 316                                                 }
 317
 318                                         } else if (MarshalAsAttr)
 319                                                 this.UnmanagedType =
 320                                                 (System.Runtime.InteropServices.UnmanagedType) pos_values [0];
 321                                 }
 322                         }
 323
 324                         //
 325                         // Now process named arguments
 326                         //
 327
 328                         ArrayList field_infos = null;
 329                         ArrayList prop_infos  = null;
 330                         ArrayList field_values = null;
 331                         ArrayList prop_values = null;
 332
 333                         if (named_args.Count > 0) {
 334                                 field_infos = new ArrayList ();
 335                                 prop_infos  = new ArrayList ();
 336                                 field_values = new ArrayList ();
 337                                 prop_values = new ArrayList ();
 338                         }
 339
 340                         Hashtable seen_names = new Hashtable();
 341
 342                         for (i = 0; i < named_args.Count; i++) {
 343                                 DictionaryEntry de = (DictionaryEntry) named_args [i];
 344                                 string member_name = (string) de.Key;
 345                                 Argument a  = (Argument) de.Value;
 346                                 Expression e;
 347
 348                                 if (seen_names.Contains(member_name)) {
 349                                         Report.Error(643, Location, "'" + member_name + "' duplicate named attribute argument");
 350                                         return null;
 351                                 }
 352                                 seen_names.Add(member_name, 1);
 353
 354                                 if (!a.Resolve (ec, Location))
 355                                         return null;
 356
 357                                 Expression member = Expression.MemberLookup (
 358                                         ec, Type, member_name,
 359                                         MemberTypes.Field | MemberTypes.Property,
 360                                         BindingFlags.Public | BindingFlags.Instance,
 361                                         Location);
 362
 363                                 if (member == null) {
 364                                         member = Expression.MemberLookup (ec, Type, member_name,
 365                                                 MemberTypes.Field | MemberTypes.Property, BindingFlags.NonPublic | BindingFlags.Instance,
 366                                                 Location);
 367
 368                                         if (member != null) {
 369                                                 Report.Error_T (122, Location, GetFullMemberName (member_name));
 370                                                 return null;
 371                                         }
 372                                 }
 373
 374                                 if (member == null || !(member is PropertyExpr || member is FieldExpr)) {
 375                                         Error_InvalidNamedArgument (member_name);
 376                                         return null;
 377                                 }
 378
 379                                 e = a.Expr;
 380                                 if (member is PropertyExpr) {
 381                                         PropertyExpr pe = (PropertyExpr) member;
 382                                         PropertyInfo pi = pe.PropertyInfo;
 383
 384                                         if (!pi.CanWrite) {
 385                                                 Error_InvalidNamedArgument (member_name);
 386                                                 return null;
 387                                         }
 388
 389                                         Constant c = e as Constant;
 390                                         if (c != null) {
 391                                                 if (c.Type != pi.PropertyType) {
 392                                                         c = Const.ChangeType (Location, c, pi.PropertyType);
 393                                                         if (c == null)
 394                                                                 return null;
 395                                                 }
 396
 397                                                 object o = c.GetValue ();
 398                                                 prop_values.Add (o);
 399
 400                                                 if (usage_attribute != null) {
 401                                                         if (member_name == "AllowMultiple")
 402                                                                 usage_attribute.AllowMultiple = (bool) o;
 403                                                         if (member_name == "Inherited")
 404                                                                 usage_attribute.Inherited = (bool) o;
 405                                                 }
 406
 407                                         } else if (e is TypeOf) {
 408                                                 prop_values.Add (((TypeOf) e).TypeArg);
 409                                         } else if (e is ArrayCreation) {
 410                                                 prop_values.Add (((ArrayCreation) e).EncodeAsAttribute());
 411                                         } else {
 412                                                 Error_AttributeArgumentNotValid (Location);
 413                                                 return null;
 414                                         }
 415
 416                                         prop_infos.Add (pi);
 417
 418                                 } else if (member is FieldExpr) {
 419                                         FieldExpr fe = (FieldExpr) member;
 420                                         FieldInfo fi = fe.FieldInfo;
 421
 422                                         if (fi.IsInitOnly) {
 423                                                 Error_InvalidNamedArgument (member_name);
 424                                                 return null;
 425                                         }
 426
 427                                         //
 428                                         // Handle charset here, and set the TypeAttributes
 429
 430                                         Constant c = e as Constant;
 431                                         if (c != null) {
 432                                                 if (c.Type != fi.FieldType) {
 433                                                         c = Const.ChangeType (Location, c, fi.FieldType);
 434                                                         if (c == null)
 435                                                                 return null;
 436                                                 }
 437
 438                                                 object value = c.GetValue ();
 439                                                 field_values.Add (value);
 440                                         } else if (e is TypeOf) {
 441                                                 field_values.Add (((TypeOf) e).TypeArg);
 442                                         } else {
 443                                                 Error_AttributeArgumentNotValid (Location);
 444                                                 return null;
 445                                         }
 446
 447                                         field_infos.Add (fi);
 448                                 }
 449                         }
 450
 451                         Expression mg = Expression.MemberLookup (
 452                                 ec, Type, ".ctor", MemberTypes.Constructor,
 453                                 BindingFlags.Public | BindingFlags.Instance | BindingFlags.DeclaredOnly,
 454                                 Location);
 455
 456                         if (mg == null) {
 457                                 Error_AttributeConstructorMismatch ();
 458                                 return null;
 459                         }
 460
 461                         MethodBase constructor = Invocation.OverloadResolve (
 462                                 ec, (MethodGroupExpr) mg, pos_args, Location);
 463
 464                         if (constructor == null) {
 465                                 Error_AttributeConstructorMismatch ();
 466                                 return null;
 467                         }
 468
 469                         //
 470                         // Now we perform some checks on the positional args as they
 471                         // cannot be null for a constructor which expects a parameter
 472                         // of type object
 473                         //
 474
 475                         ParameterData pd = Invocation.GetParameterData (constructor);
 476
 477                         int group_in_params_array = Int32.MaxValue;
 478                         int pc = pd.Count;
 479                         if (pc > 0 && pd.ParameterModifier (pc-1) == Parameter.Modifier.PARAMS)
 480                                 group_in_params_array = pc-1;
 481
 482                         for (int j = 0; j < pos_arg_count; ++j) {
 483                                 Argument a = (Argument) pos_args [j];
 484
 485                                 if (a.Expr is NullLiteral && pd.ParameterType (j) == TypeManager.object_type) {
 486                                         Error_AttributeArgumentNotValid (Location);
 487                                         return null;
 488                                 }
 489
 490                                 if (j < group_in_params_array)
 491                                         continue;
 492
 493                                 if (j == group_in_params_array){
 494                                         object v = pos_values [j];
 495                                         int count = pos_arg_count - j;
 496
 497                                         object [] array = new object [count];
 498                                         pos_values [j] = array;
 499                                         array [0] = v;
 500                                 } else {
 501                                         object [] array = (object []) pos_values [group_in_params_array];
 502
 503                                         array [j - group_in_params_array] = pos_values [j];
 504                                 }
 505                         }
 506
 507                         //
 508                         // Adjust the size of the pos_values if it had params
 509                         //
 510                         if (group_in_params_array != Int32.MaxValue){
 511                                 int argc = group_in_params_array+1;
 512                                 object [] new_pos_values = new object [argc];
 513
 514                                 for (int p = 0; p < argc; p++)
 515                                         new_pos_values [p] = pos_values [p];
 516                                 pos_values = new_pos_values;
 517                         }
 518
 519                         try {
 520                                 if (named_args.Count > 0) {
 521                                         prop_info_arr = new PropertyInfo [prop_infos.Count];
 522                                         field_info_arr = new FieldInfo [field_infos.Count];
 523                                         field_values_arr = new object [field_values.Count];
 524                                         prop_values_arr = new object [prop_values.Count];
 525
 526                                         field_infos.CopyTo  (field_info_arr, 0);
 527                                         field_values.CopyTo (field_values_arr, 0);
 528
 529                                         prop_values.CopyTo  (prop_values_arr, 0);
 530                                         prop_infos.CopyTo   (prop_info_arr, 0);
 531
 532                                         cb = new CustomAttributeBuilder (
 533                                                 (ConstructorInfo) constructor, pos_values,
 534                                                 prop_info_arr, prop_values_arr,
 535                                                 field_info_arr, field_values_arr);
 536                                 }
 537                                 else
 538                                         cb = new CustomAttributeBuilder (
 539                                                 (ConstructorInfo) constructor, pos_values);
 540                         } catch (NullReferenceException) {
 541                                 //
 542                                 // Don't know what to do here
 543                                 //
 544                                 Report.Warning (
 545                                         -101, Location, "NullReferenceException while trying to create attribute." +
 546                                         "Something's wrong!");
 547                         } catch (Exception e) {
 548                                 //
 549                                 // Sample:
 550                                 // using System.ComponentModel;
 551                                 // [DefaultValue (CollectionChangeAction.Add)]
 552                                 // class X { static void Main () {} }
 553                                 //
 554                                 Report.Warning (
 555                                         -23, Location, "The compiler can not encode this attribute in .NET due to a bug in the .NET runtime. Try the Mono runtime. The exception was: " + e.Message);
 556                         }
 557
 558                         return cb;
 559                 }
 560
 561                 /// <summary>
 562                 ///   Get a string containing a list of valid targets for the attribute 'attr'
 563                 /// </summary>
 564                 static string GetValidTargets (Attribute attr)
 565                 {
 566                         StringBuilder sb = new StringBuilder ();
 567                         AttributeTargets targets = attr.GetAttributeUsage ().ValidOn;
 568
 569                         if ((targets & AttributeTargets.Assembly) != 0)
 570                                 sb.Append ("'assembly' ");
 571
 572                         if ((targets & AttributeTargets.Class) != 0)
 573                                 sb.Append ("'class' ");
 574
 575                         if ((targets & AttributeTargets.Constructor) != 0)
 576                                 sb.Append ("'constructor' ");
 577
 578                         if ((targets & AttributeTargets.Delegate) != 0)
 579                                 sb.Append ("'delegate' ");
 580
 581                         if ((targets & AttributeTargets.Enum) != 0)
 582                                 sb.Append ("'enum' ");
 583
 584                         if ((targets & AttributeTargets.Event) != 0)
 585                                 sb.Append ("'event' ");
 586
 587                         if ((targets & AttributeTargets.Field) != 0)
 588                                 sb.Append ("'field' ");
 589
 590                         if ((targets & AttributeTargets.Interface) != 0)
 591                                 sb.Append ("'interface' ");
 592
 593                         if ((targets & AttributeTargets.Method) != 0)
 594                                 sb.Append ("'method' ");
 595
 596                         if ((targets & AttributeTargets.Module) != 0)
 597                                 sb.Append ("'module' ");
 598
 599                         if ((targets & AttributeTargets.Parameter) != 0)
 600                                 sb.Append ("'parameter' ");
 601
 602                         if ((targets & AttributeTargets.Property) != 0)
 603                                 sb.Append ("'property' ");
 604
 605                         if ((targets & AttributeTargets.ReturnValue) != 0)
 606                                 sb.Append ("'return' ");
 607
 608                         if ((targets & AttributeTargets.Struct) != 0)
 609                                 sb.Append ("'struct' ");
 610
 611                         return sb.ToString ();
 612
 613                 }
 614
 615                 public static void Error_AttributeNotValidForElement (Attribute a, Location loc)
 616                 {
 617                         Report.Error (
 618                                 592, loc, "Attribute '" + a.Name +
 619                                 "' is not valid on this declaration type. " +
 620                                 "It is valid on " + GetValidTargets (a) + "declarations only.");
 621                 }
 622
 623
 624                 /// <summary>
 625                 /// Returns AttributeUsage attribute for this type
 626                 /// </summary>
 627                 public AttributeUsageAttribute GetAttributeUsage ()
 628                 {
 629                         AttributeUsageAttribute ua = usage_attr_cache [Type] as AttributeUsageAttribute;
 630                         if (ua != null)
 631                                 return ua;
 632
 633                         Class attr_class = TypeManager.LookupClass (Type);
 634
 635                         if (attr_class == null) {
 636                                 object[] usage_attr = Type.GetCustomAttributes (TypeManager.attribute_usage_type, true);
 637                                 ua = (AttributeUsageAttribute)usage_attr [0];
 638                                 usage_attr_cache.Add (Type, ua);
 639                                 return ua;
 640                         }
 641
 642                         return attr_class.AttributeUsage;
 643                 }
 644
 645
 646                 //
 647                 // This pulls the condition name out of a Conditional attribute
 648                 //
 649                 public string Conditional_GetConditionName ()
 650                 {
 651                         //
 652                         // So we have a Conditional, pull the data out.
 653                         //
 654                         if (Arguments == null || Arguments [0] == null){
 655                                 Error_AttributeConstructorMismatch ();
 656                                 return null;
 657                         }
 658
 659                         ArrayList pos_args = (ArrayList) Arguments [0];
 660                         if (pos_args.Count != 1){
 661                                 Error_AttributeConstructorMismatch ();
 662                                 return null;
 663                         }
 664
 665                         Argument arg = (Argument) pos_args [0];
 666                         if (!(arg.Expr is StringConstant)){
 667                                 Error_AttributeConstructorMismatch ();
 668                                 return null;
 669                         }
 670
 671                         return ((StringConstant) arg.Expr).Value;
 672                 }
 673
 674                 public string IndexerName_GetIndexerName (EmitContext ec)
 675                 {
 676                         if (Arguments == null || Arguments [0] == null){
 677                                 Error_AttributeConstructorMismatch ();
 678                                 return null;
 679                         }
 680                         ArrayList pos_args = (ArrayList) Arguments [0];
 681                         if (pos_args.Count != 1) {
 682                                 Error_AttributeConstructorMismatch ();
 683                                 return null;
 684                         }
 685
 686                         Argument arg = (Argument) pos_args [0];
 687                         if (!arg.Resolve (ec, Location))
 688                                 return null;
 689
 690                         StringConstant sc = arg.Expr as StringConstant;
 691                         if (sc == null){
 692                                 Error_AttributeConstructorMismatch ();
 693                                 return null;
 694                         }
 695
 696                         return sc.Value;
 697                 }
 698
 699                 /// <summary>
 700                 /// Creates the instance of ObsoleteAttribute from this attribute instance
 701                 /// </summary>
 702                 public ObsoleteAttribute GetObsoleteAttribute (DeclSpace ds)
 703                 {
 704                         if (pos_values == null) {
 705                                 EmitContext ec = new EmitContext (ds, ds, Location, null, null, 0, false);
 706
 707                                 // TODO: It is not neccessary to call whole Resolve (ApplyAttribute does it now) we need only ctor args.
 708                                 // But because a lot of attribute class code must be rewritten will be better to wait...
 709                                 Resolve (ec);
 710                         }
 711
 712                         // Some error occurred
 713                         if (pos_values == null)
 714                                 return null;
 715
 716                         if (pos_values.Length == 0)
 717                                 return new ObsoleteAttribute ();
 718
 719                         if (pos_values.Length == 1)
 720                                 return new ObsoleteAttribute ((string)pos_values [0]);
 721
 722                         return new ObsoleteAttribute ((string)pos_values [0], (bool)pos_values [1]);
 723                 }
 724
 725                 /// <summary>
 726                 /// Returns value of CLSCompliantAttribute contructor parameter but because the method can be called
 727                 /// before ApplyAttribute. We need to resolve the arguments.
 728                 /// This situation occurs when class deps is differs from Emit order.
 729                 /// </summary>
 730                 public bool GetClsCompliantAttributeValue (DeclSpace ds)
 731                 {
 732                         if (pos_values == null) {
 733                                 EmitContext ec = new EmitContext (ds, ds, Location, null, null, 0, false);
 734
 735                                 // TODO: It is not neccessary to call whole Resolve (ApplyAttribute does it now) we need only ctor args.
 736                                 // But because a lot of attribute class code must be rewritten will be better to wait...
 737                                 Resolve (ec);
 738                         }
 739
 740                         // Some error occurred
 741                         if (pos_values [0] == null)
 742                                 return false;
 743
 744                         return (bool)pos_values [0];
 745                 }
 746
 747                 public object GetPositionalValue (int i)
 748                 {
 749                         return (pos_values == null) ? null : pos_values[i];
 750                 }
 751
 752                 object GetFieldValue (string name)
 753                 {
 754                         int i;
 755                         if (field_info_arr == null)
 756                                 return null;
 757                         i = 0;
 758                         foreach (FieldInfo fi in field_info_arr) {
 759                                 if (fi.Name == name)
 760                                         return field_values_arr [i];
 761                                 i++;
 762                         }
 763                         return null;
 764                 }
 765
 766                 public UnmanagedMarshal GetMarshal ()
 767                 {
 768                         object o = GetFieldValue ("ArraySubType");
 769                         UnmanagedType array_sub_type = o == null ? UnmanagedType.I4 : (UnmanagedType) o;
 770
 771                         switch (UnmanagedType) {
 772                         case UnmanagedType.CustomMarshaler:
 773                                 MethodInfo define_custom = typeof (UnmanagedMarshal).GetMethod ("DefineCustom",
 774                                                                        BindingFlags.Static | BindingFlags.Public);
 775                                 if (define_custom == null)
 776                                         return null;
 777
 778                                 object [] args = new object [4];
 779                                 args [0] = GetFieldValue ("MarshalTypeRef");
 780                                 args [1] = GetFieldValue ("MarshalCookie");
 781                                 args [2] = GetFieldValue ("MarshalType");
 782                                 args [3] = Guid.Empty;
 783                                 return (UnmanagedMarshal) define_custom.Invoke (null, args);
 784
 785                         case UnmanagedType.LPArray:
 786                                 return UnmanagedMarshal.DefineLPArray (array_sub_type);
 787
 788                         case UnmanagedType.SafeArray:
 789                                 return UnmanagedMarshal.DefineSafeArray (array_sub_type);
 790
 791                         case UnmanagedType.ByValArray:
 792                                 return UnmanagedMarshal.DefineByValArray ((int) GetFieldValue ("SizeConst"));
 793
 794                         case UnmanagedType.ByValTStr:
 795                                 return UnmanagedMarshal.DefineByValTStr ((int) GetFieldValue ("SizeConst"));
 796
 797                         default:
 798                                 return UnmanagedMarshal.DefineUnmanagedMarshal (UnmanagedType);
 799                         }
 800                 }
 801
 802                 public bool IsInternalCall
 803                 {
 804                         get { return ImplOptions == MethodImplOptions.InternalCall; }
 805                 }
 806
 807                 /// <summary>
 808                 /// Emit attribute for Attributable symbol
 809                 /// </summary>
 810                 public void Emit (EmitContext ec, Attributable ias, ListDictionary emitted_attr)
 811                 {
 812                         CustomAttributeBuilder cb = Resolve (ec);
 813                         if (cb == null)
 814                                 return;
 815
 816                         AttributeUsageAttribute usage_attr = GetAttributeUsage ();
 817                         if ((usage_attr.ValidOn & ias.AttributeTargets) == 0) {
 818                                 Error_AttributeNotValidForElement (this, Location);
 819                                 return;
 820                         }
 821
 822                         ias.ApplyAttributeBuilder (this, cb);
 823
 824                         if (!usage_attr.AllowMultiple && emitted_attr.Contains (Target)) {
 825                                 Report.Error (579, Location, "Duplicate '" + Name + "' attribute");
 826                         }
 827
 828                         emitted_attr [Type] = Target;
 829
 830                         // Here we are testing attribute arguments for array usage (error 3016)
 831                         if (ias.IsClsCompliaceRequired (ec.DeclSpace)) {
 832                                 if (Arguments == null)
 833                                         return;
 834
 835                                 ArrayList pos_args = (ArrayList) Arguments [0];
 836                                 if (pos_args != null) {
 837                                         foreach (Argument arg in pos_args) {
 838                                                 // Type is undefined (was error 246)
 839                                                 if (arg.Type == null)
 840                                                         return;
 841
 842                                                 if (arg.Type.IsArray) {
 843                                                         Report.Error_T (3016, Location);
 844                                                         return;
 845                                                 }
 846                                         }
 847                                 }
 848
 849                                 if (Arguments.Count < 2)
 850                                         return;
 851
 852                                 ArrayList named_args = (ArrayList) Arguments [1];
 853                                 foreach (DictionaryEntry de in named_args) {
 854                                         Argument arg  = (Argument) de.Value;
 855
 856                                         // Type is undefined (was error 246)
 857                                         if (arg.Type == null)
 858                                                 return;
 859
 860                                         if (arg.Type.IsArray) {
 861                                                 Report.Error_T (3016, Location);
 862                                                 return;
 863                                         }
 864                                 }
 865                         }
 866                 }
 867
 868                 public object GetValue (EmitContext ec, Constant c, Type target)
 869                 {
 870                         if (Convert.ImplicitConversionExists (ec, c, target))
 871                                 return c.GetValue ();
 872
 873                         Convert.Error_CannotImplicitConversion (Location, c.Type, target);
 874                         return null;
 875                 }
 876
 877                 public MethodBuilder DefinePInvokeMethod (EmitContext ec, TypeBuilder builder, string name,
 878                                                           MethodAttributes flags, Type ret_type, Type [] param_types)
 879                 {
 880                         //
 881                         // We extract from the attribute the information we need
 882                         //
 883
 884                         if (Arguments == null) {
 885                                 Console.WriteLine ("Internal error : this is not supposed to happen !");
 886                                 return null;
 887                         }
 888
 889                         ResolveType (ec, true);
 890                         if (Type == null)
 891                                 return null;
 892
 893                         ArrayList named_args = new ArrayList ();
 894
 895                         ArrayList pos_args = (ArrayList) Arguments [0];
 896                         if (Arguments.Count > 1)
 897                                 named_args = (ArrayList) Arguments [1];
 898
 899
 900                         string dll_name = null;
 901
 902                         Argument tmp = (Argument) pos_args [0];
 903
 904                         if (!tmp.Resolve (ec, Location))
 905                                 return null;
 906
 907                         if (tmp.Expr is Constant)
 908                                 dll_name = (string) ((Constant) tmp.Expr).GetValue ();
 909                         else {
 910                                 Error_AttributeArgumentNotValid (Location);
 911                                 return null;
 912                         }
 913
 914                         // Now we process the named arguments
 915                         CallingConvention cc = CallingConvention.Winapi;
 916                         CharSet charset = CharSet.Ansi;
 917                         bool preserve_sig = true;
 918 #if FIXME
 919                         bool exact_spelling = false;
 920 #endif
 921                         bool set_last_err = false;
 922                         string entry_point = null;
 923
 924                         for (int i = 0; i < named_args.Count; i++) {
 925
 926                                 DictionaryEntry de = (DictionaryEntry) named_args [i];
 927
 928                                 string member_name = (string) de.Key;
 929                                 Argument a  = (Argument) de.Value;
 930
 931                                 if (!a.Resolve (ec, Location))
 932                                         return null;
 933
 934                                 Expression member = Expression.MemberLookup (
 935                                         ec, Type, member_name,
 936                                         MemberTypes.Field | MemberTypes.Property,
 937                                         BindingFlags.Public | BindingFlags.Instance,
 938                                         Location);
 939
 940                                 if (member == null || !(member is FieldExpr)) {
 941                                         Error_InvalidNamedArgument (member_name);
 942                                         return null;
 943                                 }
 944
 945                                 if (member is FieldExpr) {
 946                                         FieldExpr fe = (FieldExpr) member;
 947                                         FieldInfo fi = fe.FieldInfo;
 948
 949                                         if (fi.IsInitOnly) {
 950                                                 Error_InvalidNamedArgument (member_name);
 951                                                 return null;
 952                                         }
 953
 954                                         if (a.Expr is Constant) {
 955                                                 Constant c = (Constant) a.Expr;
 956
 957                                                 try {
 958                                                         if (member_name == "CallingConvention"){
 959                                                                 object val = GetValue (ec, c, typeof (CallingConvention));
 960                                                                 if (val == null)
 961                                                                         return null;
 962                                                                 cc = (CallingConvention) val;
 963                                                         } else if (member_name == "CharSet"){
 964                                                                 charset = (CharSet) c.GetValue ();
 965                                                         } else if (member_name == "EntryPoint")
 966                                                                 entry_point = (string) c.GetValue ();
 967                                                         else if (member_name == "SetLastError")
 968                                                                 set_last_err = (bool) c.GetValue ();
 969 #if FIXME
 970                                                         else if (member_name == "ExactSpelling")
 971                                                                 exact_spelling = (bool) c.GetValue ();
 972 #endif
 973                                                         else if (member_name == "PreserveSig")
 974                                                                 preserve_sig = (bool) c.GetValue ();
 975                                                 } catch (InvalidCastException){
 976                                                         Error_InvalidNamedArgument (member_name);
 977                                                         Error_AttributeArgumentNotValid (Location);
 978                                                 }
 979                                         } else {
 980                                                 Error_AttributeArgumentNotValid (Location);
 981                                                 return null;
 982                                         }
 983
 984                                 }
 985                         }
 986
 987                         if (entry_point == null)
 988                                 entry_point = name;
 989                         if (set_last_err)
 990                                 charset = (CharSet)((int)charset | 0x40);
 991
 992                         MethodBuilder mb = builder.DefinePInvokeMethod (
 993                                 name, dll_name, entry_point, flags | MethodAttributes.HideBySig,
 994                                 CallingConventions.Standard,
 995                                 ret_type,
 996                                 param_types,
 997                                 cc,
 998                                 charset);
 999
1000                         if (preserve_sig)
1001                                 mb.SetImplementationFlags (MethodImplAttributes.PreserveSig);
1002
1003                         return mb;
1004                 }
1005
1006                 private Expression GetValue ()
1007                 {
1008                         if ((Arguments == null) || (Arguments.Count < 1))
1009                                 return null;
1010                         ArrayList al = (ArrayList) Arguments [0];
1011                         if ((al == null) || (al.Count < 1))
1012                                 return null;
1013                         Argument arg = (Argument) al [0];
1014                         if ((arg == null) || (arg.Expr == null))
1015                                 return null;
1016                         return arg.Expr;
1017                 }
1018
1019                 public string GetString ()
1020                 {
1021                         Expression e = GetValue ();
1022                         if (e is StringLiteral)
1023                                 return (e as StringLiteral).Value;
1024                         return null;
1025                 }
1026
1027                 public bool GetBoolean ()
1028                 {
1029                         Expression e = GetValue ();
1030                         if (e is BoolLiteral)
1031                                 return (e as BoolLiteral).Value;
1032                         return false;
1033                 }
1034         }
1035
1036
1037         /// <summary>
1038         /// For global attributes (assembly, module) we need special handling.
1039         /// Attributes can be located in the several files
1040         /// </summary>
1041         public class GlobalAttribute: Attribute
1042         {
1043                 public readonly NamespaceEntry ns;
1044
1045                 public GlobalAttribute (TypeContainer container, string target, string name, ArrayList args, Location loc):
1046                         base (target, name, args, loc)
1047                 {
1048                         ns = container.NamespaceEntry;
1049                 }
1050
1051                 protected override Type CheckAttributeType (EmitContext ec, bool complain)
1052                 {
1053                         NamespaceEntry old = ec.DeclSpace.NamespaceEntry;
1054                         if (old == null || old.NS == null || old.NS == Namespace.Root)
1055                                 ec.DeclSpace.NamespaceEntry = ns;
1056                         return base.CheckAttributeType (ec, complain);
1057                 }
1058         }
1059
1060         public class Attributes {
1061                 public ArrayList Attrs;
1062
1063                 public Attributes (Attribute a)
1064                 {
1065                         Attrs = new ArrayList ();
1066                         Attrs.Add (a);
1067                 }
1068
1069                 public Attributes (ArrayList attrs)
1070                 {
1071                         Attrs = attrs;
1072                 }
1073
1074                 public void AddAttributes (ArrayList attrs)
1075                 {
1076                         Attrs.AddRange (attrs);
1077                 }
1078
1079                 /// <summary>
1080                 /// Checks whether attribute target is valid for the current element
1081                 /// </summary>
1082                 public void CheckTargets (string[] possible_targets)
1083                 {
1084                         foreach (Attribute a in Attrs) {
1085                                 if (a.Target == null) {
1086                                         a.Target = possible_targets [0];
1087                                         continue;
1088                                 }
1089
1090                                 if (((IList) possible_targets).Contains (a.Target))
1091                                         continue;
1092
1093                                 StringBuilder sb = new StringBuilder ();
1094                                 foreach (string s in possible_targets) {
1095                                         sb.Append (s);
1096                                         sb.Append (", ");
1097                                 }
1098                                 sb.Remove (sb.Length - 2, 2);
1099                                 Report.Error_T (657, a.Location, a.Target, sb.ToString ());
1100                         }
1101                 }
1102
1103                 private Attribute Search (Type t, EmitContext ec, bool complain)
1104                 {
1105                         foreach (Attribute a in Attrs) {
1106                                 if (a.ResolveType (ec, false) == t)
1107                                         return a;
1108                         }
1109                         return null;
1110                 }
1111
1112                 public Attribute Search (Type t, EmitContext ec)
1113                 {
1114                         return Search (t, ec, true);
1115                 }
1116
1117                 public void Emit (EmitContext ec, Attributable ias)
1118                 {
1119                         ListDictionary ld = new ListDictionary ();
1120
1121                         foreach (Attribute a in Attrs)
1122                                 a.Emit (ec, ias, ld);
1123                 }
1124
1125                 public bool Contains (Type t, EmitContext ec)
1126                 {
1127                         return Search (t, ec) != null;
1128                 }
1129
1130                 public Attribute GetClsCompliantAttribute (EmitContext ec)
1131                 {
1132                         return Search (TypeManager.cls_compliant_attribute_type, ec, false);
1133                 }
1134
1135                 /// <summary>
1136                 /// Pulls the IndexerName attribute from an Indexer if it exists.
1137                 /// </summary>
1138                 public string ScanForIndexerName (EmitContext ec)
1139                 {
1140                         Attribute a = Search (TypeManager.indexer_name_type, ec);
1141                         if (a == null)
1142                                 return null;
1143
1144                         // Remove the attribute from the list
1145                         //TODO: It is very close to hack and it can crash here
1146                         Attrs.Remove (a);
1147
1148                         return a.IndexerName_GetIndexerName (ec);
1149                 }
1150
1151         }
1152
1153         /// <summary>
1154         /// Helper class for attribute verification routine.
1155         /// </summary>
1156         sealed class AttributeTester
1157         {
1158                 static PtrHashtable analyzed_types = new PtrHashtable ();
1159                 static PtrHashtable analyzed_member_obsolete = new PtrHashtable ();
1160
1161                 private AttributeTester ()
1162                 {
1163                 }
1164
1165                 /// <summary>
1166                 /// Returns true if parameters of two compared methods are CLS-Compliant.
1167                 /// It tests differing only in ref or out, or in array rank.
1168                 /// </summary>
1169                 public static bool AreOverloadedMethodParamsClsCompliant (Type[] types_a, Type[] types_b)
1170                 {
1171                         if (types_a == null || types_b == null)
1172                                 return true;
1173
1174                         if (types_a.Length != types_b.Length)
1175                                 return true;
1176
1177                         for (int i = 0; i < types_b.Length; ++i) {
1178                                 Type aType = types_a [i];
1179                                 Type bType = types_b [i];
1180
1181                                 if (aType.IsArray && bType.IsArray && aType.GetArrayRank () != bType.GetArrayRank () && aType.GetElementType () == bType.GetElementType ()) {
1182                                         return false;
1183                                 }
1184
1185                                 Type aBaseType = aType;
1186                                 bool is_either_ref_or_out = false;
1187
1188                                 if (aType.IsByRef || aType.IsPointer) {
1189                                         aBaseType = aType.GetElementType ();
1190                                         is_either_ref_or_out = true;
1191                                 }
1192
1193                                 Type bBaseType = bType;
1194                                 if (bType.IsByRef || bType.IsPointer)
1195                                 {
1196                                         bBaseType = bType.GetElementType ();
1197                                         is_either_ref_or_out = !is_either_ref_or_out;
1198                                 }
1199
1200                                 if (aBaseType != bBaseType)
1201                                         continue;
1202
1203                                 if (is_either_ref_or_out)
1204                                         return false;
1205                         }
1206                         return true;
1207                 }
1208
1209                 /// <summary>
1210                 /// Goes through all parameters and test if they are CLS-Compliant.
1211                 /// </summary>
1212                 public static bool AreParametersCompliant (Parameter[] fixedParameters, Location loc)
1213                 {
1214                         if (fixedParameters == null)
1215                                 return true;
1216
1217                         foreach (Parameter arg in fixedParameters) {
1218                                 if (!AttributeTester.IsClsCompliant (arg.ParameterType)) {
1219                                         Report.Error_T (3001, loc, arg.GetSignatureForError ());
1220                                         return false;
1221                                 }
1222                         }
1223                         return true;
1224                 }
1225
1226
1227                 /// <summary>
1228                 /// This method tests the CLS compliance of external types. It doesn't test type visibility.
1229                 /// </summary>
1230                 public static bool IsClsCompliant (Type type)
1231                 {
1232                         if (type == null)
1233                                 return true;
1234
1235                         object type_compliance = analyzed_types[type];
1236                         if (type_compliance != null)
1237                                 return type_compliance == TRUE;
1238
1239                         if (type.IsPointer) {
1240                                 analyzed_types.Add (type, null);
1241                                 return false;
1242                         }
1243
1244                         bool result;
1245                         if (type.IsArray || type.IsByRef)       {
1246                                 result = IsClsCompliant (TypeManager.GetElementType (type));
1247                         } else {
1248                                 result = AnalyzeTypeCompliance (type);
1249                         }
1250                         analyzed_types.Add (type, result ? TRUE : FALSE);
1251                         return result;
1252                 }
1253
1254                 static object TRUE = new object ();
1255                 static object FALSE = new object ();
1256
1257                 /// <summary>
1258                 /// Non-hierarchical CLS Compliance analyzer
1259                 /// </summary>
1260                 public static bool IsComplianceRequired (MemberInfo mi, DeclSpace ds)
1261                 {
1262                         DeclSpace temp_ds = TypeManager.LookupDeclSpace (mi.DeclaringType);
1263
1264                         // Type is external, we can get attribute directly
1265                         if (temp_ds == null) {
1266                                 object[] cls_attribute = mi.GetCustomAttributes (TypeManager.cls_compliant_attribute_type, false);
1267                                 return (cls_attribute.Length == 1 && ((CLSCompliantAttribute)cls_attribute[0]).IsCompliant);
1268                         }
1269
1270                         string tmp_name;
1271                         // Interface doesn't store full name
1272                         if (temp_ds is Interface)
1273                                 tmp_name = mi.Name;
1274                         else
1275                                 tmp_name = String.Concat (temp_ds.Name, ".", mi.Name);
1276
1277                         MemberCore mc = temp_ds.GetDefinition (tmp_name) as MemberCore;
1278                         return mc.IsClsCompliaceRequired (ds);
1279                 }
1280
1281                 public static void VerifyModulesClsCompliance ()
1282                 {
1283                         Module[] modules = TypeManager.Modules;
1284                         if (modules == null)
1285                                 return;
1286
1287                         // The first module is generated assembly
1288                         for (int i = 1; i < modules.Length; ++i) {
1289                                 Module module = modules [i];
1290                                 if (!IsClsCompliant (module)) {
1291                                         Report.Error_T (3013, module.Name);
1292                                         return;
1293                                 }
1294                         }
1295                 }
1296
1297                 static bool IsClsCompliant (ICustomAttributeProvider attribute_provider)
1298                 {
1299                         object[] CompliantAttribute = attribute_provider.GetCustomAttributes (TypeManager.cls_compliant_attribute_type, false);
1300                         if (CompliantAttribute.Length == 0)
1301                                 return false;
1302
1303                         return ((CLSCompliantAttribute)CompliantAttribute[0]).IsCompliant;
1304                 }
1305
1306                 static bool AnalyzeTypeCompliance (Type type)
1307                 {
1308                         DeclSpace ds = TypeManager.LookupDeclSpace (type);
1309                         if (ds != null) {
1310                                 return ds.IsClsCompliaceRequired (ds.Parent);
1311                         }
1312
1313                         object[] CompliantAttribute = type.GetCustomAttributes (TypeManager.cls_compliant_attribute_type, false);
1314                         if (CompliantAttribute.Length == 0)
1315                                 return IsClsCompliant (type.Assembly);
1316
1317                         return ((CLSCompliantAttribute)CompliantAttribute[0]).IsCompliant;
1318                 }
1319
1320                 /// <summary>
1321                 /// Returns instance of ObsoleteAttribute when method is obsolete
1322                 /// </summary>
1323                 public static ObsoleteAttribute GetMethodObsoleteAttribute (MethodBase mb)
1324                 {
1325                         IMethodData mc = TypeManager.GetMethod (mb);
1326                         if (mc != null)
1327                                 return mc.GetObsoleteAttribute ();
1328
1329                         // TODO: remove after Constructor will be ready for IMethodData
1330                         if (mb.DeclaringType is TypeBuilder)
1331                                 return null;
1332
1333                         return GetMemberObsoleteAttribute (mb);
1334                 }
1335
1336                 /// <summary>
1337                 /// Returns instance of ObsoleteAttribute when member is obsolete
1338                 /// </summary>
1339                 public static ObsoleteAttribute GetMemberObsoleteAttribute (MemberInfo mi)
1340                 {
1341                         object type_obsolete = analyzed_member_obsolete [mi];
1342                         if (type_obsolete == FALSE)
1343                                 return null;
1344
1345                         if (type_obsolete != null)
1346                                 return (ObsoleteAttribute)type_obsolete;
1347
1348                         ObsoleteAttribute oa = System.Attribute.GetCustomAttribute (mi, TypeManager.obsolete_attribute_type, false) as ObsoleteAttribute;
1349                         analyzed_member_obsolete.Add (mi, oa == null ? FALSE : oa);
1350                         return oa;
1351                 }
1352
1353                 /// <summary>
1354                 /// Common method for Obsolete error/warning reporting.
1355                 /// </summary>
1356                 public static void Report_ObsoleteMessage (ObsoleteAttribute oa, string member, Location loc)
1357                 {
1358                         if (oa.IsError) {
1359                                 Report.Error_T (619, loc, member, oa.Message);
1360                                 return;
1361                         }
1362
1363                         if (oa.Message == null) {
1364                                 Report.Warning_T (612, loc, member);
1365                                 return;
1366                         }
1367                         Report.Warning_T (618, loc, member, oa.Message);
1368                 }
1369         }
1370 }