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                         }
  48                 }
  49
  50                 /// <summary>
  51                 /// Use member-specific procedure to apply attribute @a in @cb to the entity being built in @builder
  52                 /// </summary>
  53                 public abstract void ApplyAttributeBuilder (Attribute a, CustomAttributeBuilder cb);
  54
  55                 /// <summary>
  56                 /// Returns combination of enabled AttributeTargets
  57                 /// </summary>
  58                 public abstract AttributeTargets AttributeTargets { get; }
  59
  60                 public abstract bool IsClsCompliaceRequired (DeclSpace ds);
  61
  62                 /// <summary>
  63                 /// Gets list of valid attribute targets for explicit target declaration
  64                 /// </summary>
  65                 protected abstract string[] ValidAttributeTargets { get; }
  66         };
  67
  68         public class Attribute {
  69                 public readonly string Target;
  70                 public readonly string    Name;
  71                 public readonly ArrayList Arguments;
  72
  73                 public readonly Location Location;
  74
  75                 public Type Type;
  76
  77                 // Is non-null if type is AttributeUsageAttribute
  78                 AttributeUsageAttribute usage_attribute;
  79
  80                 public AttributeUsageAttribute UsageAttribute {
  81                         get {
  82                                 return usage_attribute;
  83                         }
  84                 }
  85
  86                 MethodImplOptions ImplOptions;
  87                 UnmanagedType     UnmanagedType;
  88                 CustomAttributeBuilder cb;
  89
  90                 // non-null if named args present after Resolve () is called
  91                 PropertyInfo [] prop_info_arr;
  92                 FieldInfo [] field_info_arr;
  93                 object [] field_values_arr;
  94                 object [] prop_values_arr;
  95                 object [] pos_values;
  96
  97                 static PtrHashtable usage_attr_cache = new PtrHashtable ();
  98
  99                 public Attribute (string target, string name, ArrayList args, Location loc)
 100                 {
 101                         Name = name;
 102                         Arguments = args;
 103                         Location = loc;
 104                         Target = target;
 105                 }
 106
 107                 void Error_InvalidNamedArgument (string name)
 108                 {
 109                         Report.Error (617, Location, "'" + name + "' is not a valid named attribute " +
 110                                       "argument. Named attribute arguments must be fields which are not " +
 111                                       "readonly, static or const, or properties with a set accessor which "+
 112                                       "are not static.");
 113                 }
 114
 115                 static void Error_AttributeArgumentNotValid (Location loc)
 116                 {
 117                         Report.Error (182, loc,
 118                                       "An attribute argument must be a constant expression, typeof " +
 119                                       "expression or array creation expression");
 120                 }
 121
 122                 void Error_AttributeConstructorMismatch ()
 123                 {
 124                         Report.Error (-6, Location,
 125                                       "Could not find a constructor for this argument list.");
 126                 }
 127
 128                 /// <summary>
 129                 ///   Tries to resolve the type of the attribute. Flags an error if it can't, and complain is true.
 130                 /// </summary>
 131                 protected virtual Type CheckAttributeType (DeclSpace ds, bool complain)
 132                 {
 133                         Type t1 = RootContext.LookupType (ds, Name, true, Location);
 134
 135                         // FIXME: Shouldn't do this for quoted attributes: [@A]
 136                         Type t2 = RootContext.LookupType (ds, Name + "Attribute", true, Location);
 137
 138                         String err0616 = null;
 139
 140                         if (t1 != null && ! t1.IsSubclassOf (TypeManager.attribute_type)) {
 141                                 t1 = null;
 142                                 err0616 = "'" + Name + "': is not an attribute class";
 143                         }
 144                         if (t2 != null && ! t2.IsSubclassOf (TypeManager.attribute_type)) {
 145                                 t2 = null;
 146                                 err0616 = (err0616 != null)
 147                                         ? "Neither '" + Name + "' nor '" + Name + "Attribute' is an attribute class"
 148                                         : "'" + Name + "Attribute': is not an attribute class";
 149                         }
 150
 151                         if (t1 != null && t2 != null) {
 152                                 Report.Error(1614, Location, "'" + Name + "': is ambiguous; "
 153                                              + " use either '@" + Name + "' or '" + Name + "Attribute'");
 154                                 return null;
 155                         }
 156                         if (t1 != null)
 157                                 return t1;
 158                         if (t2 != null)
 159                                 return t2;
 160
 161                         if (err0616 != null) {
 162                                 Report.Error (616, Location, err0616);
 163                                 return null;
 164                         }
 165
 166                         if (complain)
 167                                 Report.Error (246, Location,
 168                                               "Could not find attribute '" + Name
 169                                               + "' (are you missing a using directive or an assembly reference ?)");
 170                         return null;
 171                 }
 172
 173                 public Type ResolveType (DeclSpace ds, bool complain)
 174                 {
 175                         if (Type == null)
 176                                 Type = CheckAttributeType (ds, complain);
 177                         return Type;
 178                 }
 179
 180                 /// <summary>
 181                 ///   Validates the guid string
 182                 /// </summary>
 183                 bool ValidateGuid (string guid)
 184                 {
 185                         try {
 186                                 new Guid (guid);
 187                                 return true;
 188                         } catch {
 189                                 Report.Error (647, Location, "Format of GUID is invalid: " + guid);
 190                                 return false;
 191                         }
 192                 }
 193
 194                 //
 195                 // Given an expression, if the expression is a valid attribute-argument-expression
 196                 // returns an object that can be used to encode it, or null on failure.
 197                 //
 198                 public static bool GetAttributeArgumentExpression (Expression e, Location loc, out object result)
 199                 {
 200                         if (e is Constant) {
 201                                 result = ((Constant) e).GetValue ();
 202                                 return true;
 203                         } else if (e is TypeOf) {
 204                                 result = ((TypeOf) e).TypeArg;
 205                                 return true;
 206                         } else if (e is ArrayCreation){
 207                                 result =  ((ArrayCreation) e).EncodeAsAttribute ();
 208                                 if (result != null)
 209                                         return true;
 210                         } else if (e is EmptyCast) {
 211                                 result = e;
 212                                 if (((EmptyCast) e).Child is Constant) {
 213                                         result = ((Constant) ((EmptyCast)e).Child).GetValue();
 214                                 }
 215                                 return true;
 216                         }
 217
 218                         result = null;
 219                         Error_AttributeArgumentNotValid (loc);
 220                         return false;
 221                 }
 222
 223                 public CustomAttributeBuilder Resolve (EmitContext ec)
 224                 {
 225                         Type oldType = Type;
 226
 227                         // Sanity check.
 228                         Type = CheckAttributeType (ec.DeclSpace, true);
 229                         if (oldType == null && Type == null)
 230                                 return null;
 231                         if (oldType != null && oldType != Type) {
 232                                 Report.Error (-6, Location,
 233                                               "Attribute {0} resolved to different types at different times: {1} vs. {2}",
 234                                               Name, oldType, Type);
 235                                 return null;
 236                         }
 237
 238                         bool MethodImplAttr = false;
 239                         bool MarshalAsAttr = false;
 240                         bool GuidAttr = false;
 241                         bool usage_attr = false;
 242
 243                         bool DoCompares = true;
 244
 245                         //
 246                         // If we are a certain special attribute, we
 247                         // set the information accordingly
 248                         //
 249
 250                         if (Type == TypeManager.attribute_usage_type)
 251                                 usage_attr = true;
 252                         else if (Type == TypeManager.methodimpl_attr_type)
 253                                 MethodImplAttr = true;
 254                         else if (Type == TypeManager.marshal_as_attr_type)
 255                                 MarshalAsAttr = true;
 256                         else if (Type == TypeManager.guid_attr_type)
 257                                 GuidAttr = true;
 258                         else
 259                                 DoCompares = false;
 260
 261                         // Now we extract the positional and named arguments
 262
 263                         ArrayList pos_args = new ArrayList ();
 264                         ArrayList named_args = new ArrayList ();
 265                         int pos_arg_count = 0;
 266
 267                         if (Arguments != null) {
 268                                 pos_args = (ArrayList) Arguments [0];
 269                                 if (pos_args != null)
 270                                         pos_arg_count = pos_args.Count;
 271                                 if (Arguments.Count > 1)
 272                                         named_args = (ArrayList) Arguments [1];
 273                         }
 274
 275                         pos_values = new object [pos_arg_count];
 276
 277                         //
 278                         // First process positional arguments
 279                         //
 280
 281                         int i;
 282                         for (i = 0; i < pos_arg_count; i++) {
 283                                 Argument a = (Argument) pos_args [i];
 284                                 Expression e;
 285
 286                                 if (!a.Resolve (ec, Location))
 287                                         return null;
 288
 289                                 e = a.Expr;
 290
 291                                 object val;
 292                                 if (!GetAttributeArgumentExpression (e, Location, out val))
 293                                         return null;
 294
 295                                 pos_values [i] = val;
 296                                 if (DoCompares){
 297                                         if (usage_attr)
 298                                                 usage_attribute = new AttributeUsageAttribute ((AttributeTargets) pos_values [0]);
 299                                         else if (MethodImplAttr)
 300                                                 this.ImplOptions = (MethodImplOptions) pos_values [0];
 301                                         else if (GuidAttr){
 302                                                 //
 303                                                 // we will later check the validity of the type
 304                                                 //
 305                                                 if (pos_values [0] is string){
 306                                                         if (!ValidateGuid ((string) pos_values [0]))
 307                                                                 return null;
 308                                                 }
 309
 310                                         } else if (MarshalAsAttr)
 311                                                 this.UnmanagedType =
 312                                                 (System.Runtime.InteropServices.UnmanagedType) pos_values [0];
 313                                 }
 314                         }
 315
 316                         //
 317                         // Now process named arguments
 318                         //
 319
 320                         ArrayList field_infos = null;
 321                         ArrayList prop_infos  = null;
 322                         ArrayList field_values = null;
 323                         ArrayList prop_values = null;
 324
 325                         if (named_args.Count > 0) {
 326                                 field_infos = new ArrayList ();
 327                                 prop_infos  = new ArrayList ();
 328                                 field_values = new ArrayList ();
 329                                 prop_values = new ArrayList ();
 330                         }
 331
 332                         Hashtable seen_names = new Hashtable();
 333
 334                         for (i = 0; i < named_args.Count; i++) {
 335                                 DictionaryEntry de = (DictionaryEntry) named_args [i];
 336                                 string member_name = (string) de.Key;
 337                                 Argument a  = (Argument) de.Value;
 338                                 Expression e;
 339
 340                                 if (seen_names.Contains(member_name)) {
 341                                         Report.Error(643, Location, "'" + member_name + "' duplicate named attribute argument");
 342                                         return null;
 343                                 }
 344                                 seen_names.Add(member_name, 1);
 345
 346                                 if (!a.Resolve (ec, Location))
 347                                         return null;
 348
 349                                 Expression member = Expression.MemberLookup (
 350                                         ec, Type, member_name,
 351                                         MemberTypes.Field | MemberTypes.Property,
 352                                         BindingFlags.Public | BindingFlags.Instance,
 353                                         Location);
 354
 355                                 if (member == null || !(member is PropertyExpr || member is FieldExpr)) {
 356                                         Error_InvalidNamedArgument (member_name);
 357                                         return null;
 358                                 }
 359
 360                                 e = a.Expr;
 361                                 if (member is PropertyExpr) {
 362                                         PropertyExpr pe = (PropertyExpr) member;
 363                                         PropertyInfo pi = pe.PropertyInfo;
 364
 365                                         if (!pi.CanWrite) {
 366                                                 Error_InvalidNamedArgument (member_name);
 367                                                 return null;
 368                                         }
 369
 370                                         if (e is Constant) {
 371                                                 Constant c;
 372
 373                                                 if (e.Type != pi.PropertyType){
 374                                                         c = Const.ChangeType (Location, (Constant) e, pi.PropertyType);
 375                                                         if (c == null)
 376                                                                 return null;
 377                                                 } else
 378                                                         c = (Constant) e;
 379
 380                                                 object o = c.GetValue ();
 381                                                 prop_values.Add (o);
 382
 383                                                 if (usage_attribute != null) {
 384                                                         if (member_name == "AllowMultiple")
 385                                                                 usage_attribute.AllowMultiple = (bool) o;
 386                                                         if (member_name == "Inherited")
 387                                                                 usage_attribute.Inherited = (bool) o;
 388                                                 }
 389
 390                                         } else if (e is TypeOf) {
 391                                                 prop_values.Add (((TypeOf) e).TypeArg);
 392                                         } else if (e is ArrayCreation) {
 393                                                 prop_values.Add (((ArrayCreation) e).EncodeAsAttribute());
 394                                         } else {
 395                                                 Error_AttributeArgumentNotValid (Location);
 396                                                 return null;
 397                                         }
 398
 399                                         prop_infos.Add (pi);
 400
 401                                 } else if (member is FieldExpr) {
 402                                         FieldExpr fe = (FieldExpr) member;
 403                                         FieldInfo fi = fe.FieldInfo;
 404
 405                                         if (fi.IsInitOnly) {
 406                                                 Error_InvalidNamedArgument (member_name);
 407                                                 return null;
 408                                         }
 409
 410                                         //
 411                                         // Handle charset here, and set the TypeAttributes
 412
 413                                         if (e is Constant){
 414                                                 Constant c = (Constant) e;;
 415
 416                                                 if (c.Type != fi.FieldType){
 417                                                         c = Const.ChangeType (Location, (Constant) e, fi.FieldType);
 418                                                         if (c == null)
 419                                                                 return null;
 420                                                 }
 421
 422                                                 object value = c.GetValue ();
 423                                                 field_values.Add (value);
 424                                         } else if (e is TypeOf) {
 425                                                 field_values.Add (((TypeOf) e).TypeArg);
 426                                         } else {
 427                                                 Error_AttributeArgumentNotValid (Location);
 428                                                 return null;
 429                                         }
 430
 431                                         field_infos.Add (fi);
 432                                 }
 433                         }
 434
 435                         Expression mg = Expression.MemberLookup (
 436                                 ec, Type, ".ctor", MemberTypes.Constructor,
 437                                 BindingFlags.Public | BindingFlags.Instance | BindingFlags.DeclaredOnly,
 438                                 Location);
 439
 440                         if (mg == null) {
 441                                 Error_AttributeConstructorMismatch ();
 442                                 return null;
 443                         }
 444
 445                         MethodBase constructor = Invocation.OverloadResolve (
 446                                 ec, (MethodGroupExpr) mg, pos_args, Location);
 447
 448                         if (constructor == null) {
 449                                 Error_AttributeConstructorMismatch ();
 450                                 return null;
 451                         }
 452
 453                         //
 454                         // Now we perform some checks on the positional args as they
 455                         // cannot be null for a constructor which expects a parameter
 456                         // of type object
 457                         //
 458
 459                         ParameterData pd = Invocation.GetParameterData (constructor);
 460
 461                         int group_in_params_array = Int32.MaxValue;
 462                         int pc = pd.Count;
 463                         if (pc > 0 && pd.ParameterModifier (pc-1) == Parameter.Modifier.PARAMS)
 464                                 group_in_params_array = pc-1;
 465
 466                         for (int j = 0; j < pos_arg_count; ++j) {
 467                                 Argument a = (Argument) pos_args [j];
 468
 469                                 if (a.Expr is NullLiteral && pd.ParameterType (j) == TypeManager.object_type) {
 470                                         Error_AttributeArgumentNotValid (Location);
 471                                         return null;
 472                                 }
 473
 474                                 if (j < group_in_params_array)
 475                                         continue;
 476
 477                                 if (j == group_in_params_array){
 478                                         object v = pos_values [j];
 479                                         int count = pos_arg_count - j;
 480
 481                                         object [] array = new object [count];
 482                                         pos_values [j] = array;
 483                                         array [0] = v;
 484                                 } else {
 485                                         object [] array = (object []) pos_values [group_in_params_array];
 486
 487                                         array [j - group_in_params_array] = pos_values [j];
 488                                 }
 489                         }
 490
 491                         //
 492                         // Adjust the size of the pos_values if it had params
 493                         //
 494                         if (group_in_params_array != Int32.MaxValue){
 495                                 int argc = group_in_params_array+1;
 496                                 object [] new_pos_values = new object [argc];
 497
 498                                 for (int p = 0; p < argc; p++)
 499                                         new_pos_values [p] = pos_values [p];
 500                                 pos_values = new_pos_values;
 501                         }
 502
 503                         try {
 504                                 if (named_args.Count > 0) {
 505                                         prop_info_arr = new PropertyInfo [prop_infos.Count];
 506                                         field_info_arr = new FieldInfo [field_infos.Count];
 507                                         field_values_arr = new object [field_values.Count];
 508                                         prop_values_arr = new object [prop_values.Count];
 509
 510                                         field_infos.CopyTo  (field_info_arr, 0);
 511                                         field_values.CopyTo (field_values_arr, 0);
 512
 513                                         prop_values.CopyTo  (prop_values_arr, 0);
 514                                         prop_infos.CopyTo   (prop_info_arr, 0);
 515
 516                                         cb = new CustomAttributeBuilder (
 517                                                 (ConstructorInfo) constructor, pos_values,
 518                                                 prop_info_arr, prop_values_arr,
 519                                                 field_info_arr, field_values_arr);
 520                                 }
 521                                 else
 522                                         cb = new CustomAttributeBuilder (
 523                                                 (ConstructorInfo) constructor, pos_values);
 524                         } catch (NullReferenceException) {
 525                                 //
 526                                 // Don't know what to do here
 527                                 //
 528                                 Report.Warning (
 529                                         -101, Location, "NullReferenceException while trying to create attribute." +
 530                                         "Something's wrong!");
 531                         } catch (Exception e) {
 532                                 //
 533                                 // Sample:
 534                                 // using System.ComponentModel;
 535                                 // [DefaultValue (CollectionChangeAction.Add)]
 536                                 // class X { static void Main () {} }
 537                                 //
 538                                 Report.Warning (
 539                                         -23, Location,
 540                                         "The compiler can not encode this attribute in .NET due to\n" +
 541                                         "\ta bug in the .NET runtime.  Try the Mono runtime.\nThe error was: " + e.Message);
 542                         }
 543
 544                         return cb;
 545                 }
 546
 547                 /// <summary>
 548                 ///   Get a string containing a list of valid targets for the attribute 'attr'
 549                 /// </summary>
 550                 static string GetValidTargets (Attribute attr)
 551                 {
 552                         StringBuilder sb = new StringBuilder ();
 553                         AttributeTargets targets = attr.GetAttributeUsage ().ValidOn;
 554
 555                         if ((targets & AttributeTargets.Assembly) != 0)
 556                                 sb.Append ("'assembly' ");
 557
 558                         if ((targets & AttributeTargets.Class) != 0)
 559                                 sb.Append ("'class' ");
 560
 561                         if ((targets & AttributeTargets.Constructor) != 0)
 562                                 sb.Append ("'constructor' ");
 563
 564                         if ((targets & AttributeTargets.Delegate) != 0)
 565                                 sb.Append ("'delegate' ");
 566
 567                         if ((targets & AttributeTargets.Enum) != 0)
 568                                 sb.Append ("'enum' ");
 569
 570                         if ((targets & AttributeTargets.Event) != 0)
 571                                 sb.Append ("'event' ");
 572
 573                         if ((targets & AttributeTargets.Field) != 0)
 574                                 sb.Append ("'field' ");
 575
 576                         if ((targets & AttributeTargets.Interface) != 0)
 577                                 sb.Append ("'interface' ");
 578
 579                         if ((targets & AttributeTargets.Method) != 0)
 580                                 sb.Append ("'method' ");
 581
 582                         if ((targets & AttributeTargets.Module) != 0)
 583                                 sb.Append ("'module' ");
 584
 585                         if ((targets & AttributeTargets.Parameter) != 0)
 586                                 sb.Append ("'parameter' ");
 587
 588                         if ((targets & AttributeTargets.Property) != 0)
 589                                 sb.Append ("'property' ");
 590
 591                         if ((targets & AttributeTargets.ReturnValue) != 0)
 592                                 sb.Append ("'return' ");
 593
 594                         if ((targets & AttributeTargets.Struct) != 0)
 595                                 sb.Append ("'struct' ");
 596
 597                         return sb.ToString ();
 598
 599                 }
 600
 601                 public static void Error_AttributeNotValidForElement (Attribute a, Location loc)
 602                 {
 603                         Report.Error (
 604                                 592, loc, "Attribute '" + a.Name +
 605                                 "' is not valid on this declaration type. " +
 606                                 "It is valid on " + GetValidTargets (a) + "declarations only.");
 607                 }
 608
 609
 610                 /// <summary>
 611                 /// Returns AttributeUsage attribute for this type
 612                 /// </summary>
 613                 public AttributeUsageAttribute GetAttributeUsage ()
 614                 {
 615                         AttributeUsageAttribute ua = usage_attr_cache [Type] as AttributeUsageAttribute;
 616                         if (ua != null)
 617                                 return ua;
 618
 619                         Class attr_class = TypeManager.LookupClass (Type);
 620
 621                         if (attr_class == null) {
 622                                 object[] usage_attr = Type.GetCustomAttributes (TypeManager.attribute_usage_type, true);
 623                                 ua = (AttributeUsageAttribute)usage_attr [0];
 624                                 usage_attr_cache.Add (Type, ua);
 625                                 return ua;
 626                         }
 627
 628                         return attr_class.AttributeUsage;
 629                 }
 630
 631
 632                 //
 633                 // This pulls the condition name out of a Conditional attribute
 634                 //
 635                 public string Conditional_GetConditionName ()
 636                 {
 637                         //
 638                         // So we have a Conditional, pull the data out.
 639                         //
 640                         if (Arguments == null || Arguments [0] == null){
 641                                 Error_AttributeConstructorMismatch ();
 642                                 return null;
 643                         }
 644
 645                         ArrayList pos_args = (ArrayList) Arguments [0];
 646                         if (pos_args.Count != 1){
 647                                 Error_AttributeConstructorMismatch ();
 648                                 return null;
 649                         }
 650
 651                         Argument arg = (Argument) pos_args [0];
 652                         if (!(arg.Expr is StringConstant)){
 653                                 Error_AttributeConstructorMismatch ();
 654                                 return null;
 655                         }
 656
 657                         return ((StringConstant) arg.Expr).Value;
 658                 }
 659
 660                 //
 661                 // This pulls the obsolete message and error flag out of an Obsolete attribute
 662                 //
 663                 public string Obsolete_GetObsoleteMessage (out bool is_error)
 664                 {
 665                         is_error = false;
 666                         //
 667                         // So we have an Obsolete, pull the data out.
 668                         //
 669                         if (Arguments == null || Arguments [0] == null)
 670                                 return "";
 671
 672                         ArrayList pos_args = (ArrayList) Arguments [0];
 673                         if (pos_args.Count == 0)
 674                                 return "";
 675                         else if (pos_args.Count > 2){
 676                                 Error_AttributeConstructorMismatch ();
 677                                 return null;
 678                         }
 679
 680                         Argument arg = (Argument) pos_args [0];
 681                         if (!(arg.Expr is StringConstant)){
 682                                 Error_AttributeConstructorMismatch ();
 683                                 return null;
 684                         }
 685
 686                         if (pos_args.Count == 2){
 687                                 Argument arg2 = (Argument) pos_args [1];
 688                                 if (!(arg2.Expr is BoolConstant)){
 689                                         Error_AttributeConstructorMismatch ();
 690                                         return null;
 691                                 }
 692                                 is_error = ((BoolConstant) arg2.Expr).Value;
 693                         }
 694
 695                         return ((StringConstant) arg.Expr).Value;
 696                 }
 697
 698                 public string IndexerName_GetIndexerName (EmitContext ec)
 699                 {
 700                         if (Arguments == null || Arguments [0] == null){
 701                                 Error_AttributeConstructorMismatch ();
 702                                 return null;
 703                         }
 704                         ArrayList pos_args = (ArrayList) Arguments [0];
 705                         if (pos_args.Count != 1) {
 706                                 Error_AttributeConstructorMismatch ();
 707                                 return null;
 708                         }
 709
 710                         Argument arg = (Argument) pos_args [0];
 711                         if (!arg.Resolve (ec, Location))
 712                                 return null;
 713
 714                         StringConstant sc = arg.Expr as StringConstant;
 715                         if (sc == null){
 716                                 Error_AttributeConstructorMismatch ();
 717                                 return null;
 718                         }
 719
 720                         return sc.Value;
 721                 }
 722
 723                 /// <summary>
 724                 /// Returns value of CLSCompliantAttribute contructor parameter but because the method can be called
 725                 /// before ApplyAttribute. We need to resolve the arguments.
 726                 /// This situation occurs when class deps is differs from Emit order.
 727                 /// </summary>
 728                 public bool GetClsCompliantAttributeValue (DeclSpace ds)
 729                 {
 730                         if (pos_values == null) {
 731                                 EmitContext ec = new EmitContext (ds, ds, Location, null, null, 0, false);
 732
 733                                 // TODO: It is not neccessary to call whole Resolve (ApplyAttribute does it now) we need only ctor args.
 734                                 // But because a lot of attribute class code must be rewritten will be better to wait...
 735                                 Resolve (ec);
 736                         }
 737
 738                         // Some error occurred
 739                         if (pos_values [0] == null)
 740                                 return false;
 741
 742                         return (bool)pos_values [0];
 743                 }
 744
 745                 public object GetPositionalValue (int i)
 746                 {
 747                         return (pos_values == null) ? null : pos_values[i];
 748                 }
 749
 750                 object GetFieldValue (string name)
 751                 {
 752                         int i;
 753                         if (field_info_arr == null)
 754                                 return null;
 755                         i = 0;
 756                         foreach (FieldInfo fi in field_info_arr) {
 757                                 if (fi.Name == name)
 758                                         return field_values_arr [i];
 759                                 i++;
 760                         }
 761                         return null;
 762                 }
 763
 764                 public UnmanagedMarshal GetMarshal ()
 765                 {
 766                         object o = GetFieldValue ("ArraySubType");
 767                         UnmanagedType array_sub_type = o == null ? UnmanagedType.I4 : (UnmanagedType) o;
 768
 769                         switch (UnmanagedType) {
 770                         case UnmanagedType.CustomMarshaler:
 771                                 MethodInfo define_custom = typeof (UnmanagedMarshal).GetMethod ("DefineCustom",
 772                                                                        BindingFlags.Static | BindingFlags.Public);
 773                                 if (define_custom == null)
 774                                         return null;
 775
 776                                 object [] args = new object [4];
 777                                 args [0] = GetFieldValue ("MarshalTypeRef");
 778                                 args [1] = GetFieldValue ("MarshalCookie");
 779                                 args [2] = GetFieldValue ("MarshalType");
 780                                 args [3] = Guid.Empty;
 781                                 return (UnmanagedMarshal) define_custom.Invoke (null, args);
 782
 783                         case UnmanagedType.LPArray:
 784                                 return UnmanagedMarshal.DefineLPArray (array_sub_type);
 785
 786                         case UnmanagedType.SafeArray:
 787                                 return UnmanagedMarshal.DefineSafeArray (array_sub_type);
 788
 789                         case UnmanagedType.ByValArray:
 790                                 return UnmanagedMarshal.DefineByValArray ((int) GetFieldValue ("SizeConst"));
 791
 792                         case UnmanagedType.ByValTStr:
 793                                 return UnmanagedMarshal.DefineByValTStr ((int) GetFieldValue ("SizeConst"));
 794
 795                         default:
 796                                 return UnmanagedMarshal.DefineUnmanagedMarshal (UnmanagedType);
 797                         }
 798                 }
 799
 800                 public bool IsInternalCall
 801                 {
 802                         get { return ImplOptions == MethodImplOptions.InternalCall; }
 803                 }
 804
 805                 protected virtual bool CanIgnoreInvalidAttribute (Attributable ias)
 806                 {
 807                         return false;
 808                 }
 809
 810                 /// <summary>
 811                 /// Emit attribute for Attributable symbol
 812                 /// </summary>
 813                 public void Emit (EmitContext ec, Attributable ias, ListDictionary emitted_attr)
 814                 {
 815                         CustomAttributeBuilder cb = Resolve (ec);
 816                         if (cb == null)
 817                                 return;
 818
 819                         AttributeUsageAttribute usage_attr = GetAttributeUsage ();
 820                         if ((usage_attr.ValidOn & ias.AttributeTargets) == 0) {
 821                                 // The parser applies toplevel attributes both to the assembly and
 822                                 // to a top-level class, if any.  So, be silent about them.
 823                                 if (! CanIgnoreInvalidAttribute (ias))
 824                                         Error_AttributeNotValidForElement (this, Location);
 825                                 return;
 826                         }
 827
 828                         ias.ApplyAttributeBuilder (this, cb);
 829
 830                         string emitted = emitted_attr [Type] as string;
 831                         if (Target != null && emitted == Target && !usage_attr.AllowMultiple) {
 832                                 Report.Error (579, Location, "Duplicate '" + Name + "' attribute");
 833                         }
 834
 835                         emitted_attr [Type] = Target;
 836
 837                         // Here we are testing attribute arguments for array usage (error 3016)
 838                         if (ias.IsClsCompliaceRequired (ec.DeclSpace)) {
 839                                 if (Arguments == null)
 840                                         return;
 841
 842                                 ArrayList pos_args = (ArrayList) Arguments [0];
 843                                 if (pos_args != null) {
 844                                         foreach (Argument arg in pos_args) {
 845                                                 // Type is undefined (was error 246)
 846                                                 if (arg.Type == null)
 847                                                         return;
 848
 849                                                 if (arg.Type.IsArray) {
 850                                                         Report.Error_T (3016, Location);
 851                                                         return;
 852                                                 }
 853                                         }
 854                                 }
 855
 856                                 if (Arguments.Count < 2)
 857                                         return;
 858
 859                                 ArrayList named_args = (ArrayList) Arguments [1];
 860                                 foreach (DictionaryEntry de in named_args) {
 861                                         Argument arg  = (Argument) de.Value;
 862
 863                                         // Type is undefined (was error 246)
 864                                         if (arg.Type == null)
 865                                                 return;
 866
 867                                         if (arg.Type.IsArray) {
 868                                                 Report.Error_T (3016, Location);
 869                                                 return;
 870                                         }
 871                                 }
 872                         }
 873                 }
 874
 875                 public object GetValue (EmitContext ec, Constant c, Type target)
 876                 {
 877                         if (Convert.ImplicitConversionExists (ec, c, target))
 878                                 return c.GetValue ();
 879
 880                         Convert.Error_CannotImplicitConversion (Location, c.Type, target);
 881                         return null;
 882                 }
 883
 884                 public MethodBuilder DefinePInvokeMethod (EmitContext ec, TypeBuilder builder, string name,
 885                                                           MethodAttributes flags, Type ret_type, Type [] param_types)
 886                 {
 887                         //
 888                         // We extract from the attribute the information we need
 889                         //
 890
 891                         if (Arguments == null) {
 892                                 Console.WriteLine ("Internal error : this is not supposed to happen !");
 893                                 return null;
 894                         }
 895
 896                         ResolveType (ec.DeclSpace, true);
 897                         if (Type == null)
 898                                 return null;
 899
 900                         ArrayList named_args = new ArrayList ();
 901
 902                         ArrayList pos_args = (ArrayList) Arguments [0];
 903                         if (Arguments.Count > 1)
 904                                 named_args = (ArrayList) Arguments [1];
 905
 906
 907                         string dll_name = null;
 908
 909                         Argument tmp = (Argument) pos_args [0];
 910
 911                         if (!tmp.Resolve (ec, Location))
 912                                 return null;
 913
 914                         if (tmp.Expr is Constant)
 915                                 dll_name = (string) ((Constant) tmp.Expr).GetValue ();
 916                         else {
 917                                 Error_AttributeArgumentNotValid (Location);
 918                                 return null;
 919                         }
 920
 921                         // Now we process the named arguments
 922                         CallingConvention cc = CallingConvention.Winapi;
 923                         CharSet charset = CharSet.Ansi;
 924                         bool preserve_sig = true;
 925 #if FIXME
 926                         bool exact_spelling = false;
 927 #endif
 928                         bool set_last_err = false;
 929                         string entry_point = null;
 930
 931                         for (int i = 0; i < named_args.Count; i++) {
 932
 933                                 DictionaryEntry de = (DictionaryEntry) named_args [i];
 934
 935                                 string member_name = (string) de.Key;
 936                                 Argument a  = (Argument) de.Value;
 937
 938                                 if (!a.Resolve (ec, Location))
 939                                         return null;
 940
 941                                 Expression member = Expression.MemberLookup (
 942                                         ec, Type, member_name,
 943                                         MemberTypes.Field | MemberTypes.Property,
 944                                         BindingFlags.Public | BindingFlags.Instance,
 945                                         Location);
 946
 947                                 if (member == null || !(member is FieldExpr)) {
 948                                         Error_InvalidNamedArgument (member_name);
 949                                         return null;
 950                                 }
 951
 952                                 if (member is FieldExpr) {
 953                                         FieldExpr fe = (FieldExpr) member;
 954                                         FieldInfo fi = fe.FieldInfo;
 955
 956                                         if (fi.IsInitOnly) {
 957                                                 Error_InvalidNamedArgument (member_name);
 958                                                 return null;
 959                                         }
 960
 961                                         if (a.Expr is Constant) {
 962                                                 Constant c = (Constant) a.Expr;
 963
 964                                                 try {
 965                                                         if (member_name == "CallingConvention"){
 966                                                                 object val = GetValue (ec, c, typeof (CallingConvention));
 967                                                                 if (val == null)
 968                                                                         return null;
 969                                                                 cc = (CallingConvention) val;
 970                                                         } else if (member_name == "CharSet"){
 971                                                                 charset = (CharSet) c.GetValue ();
 972                                                         } else if (member_name == "EntryPoint")
 973                                                                 entry_point = (string) c.GetValue ();
 974                                                         else if (member_name == "SetLastError")
 975                                                                 set_last_err = (bool) c.GetValue ();
 976 #if FIXME
 977                                                         else if (member_name == "ExactSpelling")
 978                                                                 exact_spelling = (bool) c.GetValue ();
 979 #endif
 980                                                         else if (member_name == "PreserveSig")
 981                                                                 preserve_sig = (bool) c.GetValue ();
 982                                                 } catch (InvalidCastException){
 983                                                         Error_InvalidNamedArgument (member_name);
 984                                                         Error_AttributeArgumentNotValid (Location);
 985                                                 }
 986                                         } else {
 987                                                 Error_AttributeArgumentNotValid (Location);
 988                                                 return null;
 989                                         }
 990
 991                                 }
 992                         }
 993
 994                         if (entry_point == null)
 995                                 entry_point = name;
 996                         if (set_last_err)
 997                                 charset = (CharSet)((int)charset | 0x40);
 998
 999                         MethodBuilder mb = builder.DefinePInvokeMethod (
1000                                 name, dll_name, entry_point, flags | MethodAttributes.HideBySig,
1001                                 CallingConventions.Standard,
1002                                 ret_type,
1003                                 param_types,
1004                                 cc,
1005                                 charset);
1006
1007                         if (preserve_sig)
1008                                 mb.SetImplementationFlags (MethodImplAttributes.PreserveSig);
1009
1010                         return mb;
1011                 }
1012
1013                 private Expression GetValue ()
1014                 {
1015                         if ((Arguments == null) || (Arguments.Count < 1))
1016                                 return null;
1017                         ArrayList al = (ArrayList) Arguments [0];
1018                         if ((al == null) || (al.Count < 1))
1019                                 return null;
1020                         Argument arg = (Argument) al [0];
1021                         if ((arg == null) || (arg.Expr == null))
1022                                 return null;
1023                         return arg.Expr;
1024                 }
1025
1026                 public string GetString ()
1027                 {
1028                         Expression e = GetValue ();
1029                         if (e is StringLiteral)
1030                                 return (e as StringLiteral).Value;
1031                         return null;
1032                 }
1033
1034                 public bool GetBoolean ()
1035                 {
1036                         Expression e = GetValue ();
1037                         if (e is BoolLiteral)
1038                                 return (e as BoolLiteral).Value;
1039                         return false;
1040                 }
1041         }
1042
1043
1044         /// <summary>
1045         /// For global attributes (assembly, module) we need special handling.
1046         /// Attributes can be located in the several files
1047         /// </summary>
1048         public class GlobalAttribute: Attribute
1049         {
1050                 public readonly NamespaceEntry ns;
1051
1052                 public GlobalAttribute (TypeContainer container, string target, string name, ArrayList args, Location loc):
1053                         base (target, name, args, loc)
1054                 {
1055                         ns = container.NamespaceEntry;
1056                 }
1057
1058                 protected override Type CheckAttributeType (DeclSpace ds, bool complain)
1059                 {
1060                         NamespaceEntry old = ds.NamespaceEntry;
1061                         if (old == null || old.NS == null || old.NS == Namespace.Root)
1062                                 ds.NamespaceEntry = ns;
1063                         return base.CheckAttributeType (ds, complain);
1064                 }
1065
1066                 protected override bool CanIgnoreInvalidAttribute (Attributable ias)
1067                 {
1068                         // Ignore error if this attribute is shared between the Assembly
1069                         // and a top-level class.  The parser couldn't figure out which entity
1070                         // this attribute belongs to.  If this attribute is erroneous, it should
1071                         // be caught when it is processed by the top-level class.
1072
1073                         return (Target == null && ias is CommonAssemblyModulClass);
1074                 }
1075         }
1076
1077         public class Attributes {
1078                 public ArrayList Attrs;
1079
1080                 public Attributes (Attribute a)
1081                 {
1082                         Attrs = new ArrayList ();
1083                         Attrs.Add (a);
1084                 }
1085
1086                 public Attributes (ArrayList attrs)
1087                 {
1088                         Attrs = attrs;
1089                 }
1090
1091                 public void AddAttributes (ArrayList attrs)
1092                 {
1093                         Attrs.AddRange (attrs);
1094                 }
1095
1096                 /// <summary>
1097                 /// Checks whether attribute target is valid for the current element
1098                 /// </summary>
1099                 public void CheckTargets (string[] possible_targets)
1100                 {
1101                         foreach (Attribute a in Attrs) {
1102                                 if (a.Target == null)
1103                                         continue;
1104
1105                                 if (((IList) possible_targets).Contains (a.Target))
1106                                         continue;
1107
1108                                 StringBuilder sb = new StringBuilder ();
1109                                 foreach (string s in possible_targets) {
1110                                         sb.Append (s);
1111                                         sb.Append (", ");
1112                                 }
1113                                 sb.Remove (sb.Length - 2, 2);
1114                                 Report.Error_T (657, a.Location, a.Target, sb.ToString ());
1115                         }
1116                 }
1117
1118                 private Attribute Search (Type t, DeclSpace ds, bool complain)
1119                 {
1120                         foreach (Attribute a in Attrs) {
1121                                 if (a.ResolveType (ds, complain) == t)
1122                                         return a;
1123                         }
1124                         return null;
1125                 }
1126
1127                 public Attribute Search (Type t, DeclSpace ds)
1128                 {
1129                         return Search (t, ds, true);
1130                 }
1131
1132                 public void Emit (EmitContext ec, Attributable ias)
1133                 {
1134                         ListDictionary ld = new ListDictionary ();
1135
1136                         foreach (Attribute a in Attrs)
1137                                 a.Emit (ec, ias, ld);
1138                 }
1139
1140                 public bool Contains (Type t, DeclSpace ds)
1141                 {
1142                         return Search (t, ds) != null;
1143                 }
1144
1145                 public Attribute GetClsCompliantAttribute (DeclSpace ds)
1146                 {
1147                         return Search (TypeManager.cls_compliant_attribute_type, ds, false);
1148                 }
1149
1150                 /// <summary>
1151                 /// Pulls the IndexerName attribute from an Indexer if it exists.
1152                 /// </summary>
1153                 public string ScanForIndexerName (EmitContext ec)
1154                 {
1155                         Attribute a = Search (TypeManager.indexer_name_type, ec.DeclSpace);
1156                         if (a == null)
1157                                 return null;
1158
1159                         // Remove the attribute from the list
1160                         //TODO: It is very close to hack and it can crash here
1161                         Attrs.Remove (a);
1162
1163                         return a.IndexerName_GetIndexerName (ec);
1164                 }
1165
1166         }
1167
1168         /// <summary>
1169         /// Helper class for attribute verification routine.
1170         /// </summary>
1171         sealed class AttributeTester
1172         {
1173                 static PtrHashtable analyzed_types = new PtrHashtable ();
1174
1175                 private AttributeTester ()
1176                 {
1177                 }
1178
1179                 /// <summary>
1180                 /// Returns true if parameters of two compared methods are CLS-Compliant.
1181                 /// It tests differing only in ref or out, or in array rank.
1182                 /// </summary>
1183                 public static bool AreOverloadedMethodParamsClsCompliant (Type[] types_a, Type[] types_b)
1184                 {
1185                         if (types_a == null || types_b == null)
1186                                 return true;
1187
1188                         if (types_a.Length != types_b.Length)
1189                                 return true;
1190
1191                         for (int i = 0; i < types_b.Length; ++i) {
1192                                 Type aType = types_a [i];
1193                                 Type bType = types_b [i];
1194
1195                                 if (aType.IsArray && bType.IsArray && aType.GetArrayRank () != bType.GetArrayRank () && aType.GetElementType () == bType.GetElementType ()) {
1196                                         return false;
1197                                 }
1198
1199                                 Type aBaseType = aType;
1200                                 bool is_either_ref_or_out = false;
1201
1202                                 if (aType.IsByRef || aType.IsPointer) {
1203                                         aBaseType = aType.GetElementType ();
1204                                         is_either_ref_or_out = true;
1205                                 }
1206
1207                                 Type bBaseType = bType;
1208                                 if (bType.IsByRef || bType.IsPointer)
1209                                 {
1210                                         bBaseType = bType.GetElementType ();
1211                                         is_either_ref_or_out = !is_either_ref_or_out;
1212                                 }
1213
1214                                 if (aBaseType != bBaseType)
1215                                         continue;
1216
1217                                 if (is_either_ref_or_out)
1218                                         return false;
1219                         }
1220                         return true;
1221                 }
1222
1223                 /// <summary>
1224                 /// Goes through all parameters and test if they are CLS-Compliant.
1225                 /// </summary>
1226                 public static bool AreParametersCompliant (Parameter[] fixedParameters, Location loc)
1227                 {
1228                         if (fixedParameters == null)
1229                                 return true;
1230
1231                         foreach (Parameter arg in fixedParameters) {
1232                                 if (!AttributeTester.IsClsCompliant (arg.ParameterType)) {
1233                                         Report.Error_T (3001, loc, arg.GetSignatureForError ());
1234                                         return false;
1235                                 }
1236                         }
1237                         return true;
1238                 }
1239
1240
1241                 /// <summary>
1242                 /// This method tests the CLS compliance of external types. It doesn't test type visibility.
1243                 /// </summary>
1244                 public static bool IsClsCompliant (Type type)
1245                 {
1246                         if (type == null)
1247                                 return true;
1248
1249                         object type_compliance = analyzed_types[type];
1250                         if (type_compliance != null)
1251                                 return type_compliance == TRUE;
1252
1253                         if (type.IsPointer) {
1254                                 analyzed_types.Add (type, null);
1255                                 return false;
1256                         }
1257
1258                         bool result;
1259                         if (type.IsArray || type.IsByRef)       {
1260                                 result = IsClsCompliant (TypeManager.GetElementType (type));
1261                         } else {
1262                                 result = AnalyzeTypeCompliance (type);
1263                         }
1264                         analyzed_types.Add (type, result ? TRUE : FALSE);
1265                         return result;
1266                 }
1267
1268                 static object TRUE = new object ();
1269                 static object FALSE = new object ();
1270
1271                 /// <summary>
1272                 /// Non-hierarchical CLS Compliance analyzer
1273                 /// </summary>
1274                 public static bool IsComplianceRequired (MemberInfo mi, DeclSpace ds)
1275                 {
1276                         DeclSpace temp_ds = TypeManager.LookupDeclSpace (mi.DeclaringType);
1277
1278                         // Type is external, we can get attribute directly
1279                         if (temp_ds == null) {
1280                                 object[] cls_attribute = mi.GetCustomAttributes (TypeManager.cls_compliant_attribute_type, false);
1281                                 return (cls_attribute.Length == 1 && ((CLSCompliantAttribute)cls_attribute[0]).IsCompliant);
1282                         }
1283
1284                         string tmp_name;
1285                         // Interface doesn't store full name
1286                         if (temp_ds is Interface)
1287                                 tmp_name = mi.Name;
1288                         else
1289                                 tmp_name = String.Concat (temp_ds.Name, ".", mi.Name);
1290
1291                         MemberCore mc = temp_ds.GetDefinition (tmp_name) as MemberCore;
1292                         return mc.IsClsCompliaceRequired (ds);
1293                 }
1294
1295                 public static void VerifyModulesClsCompliance ()
1296                 {
1297                         Module[] modules = TypeManager.Modules;
1298                         if (modules == null)
1299                                 return;
1300
1301                         // The first module is generated assembly
1302                         for (int i = 1; i < modules.Length; ++i) {
1303                                 Module module = modules [i];
1304                                 if (!IsClsCompliant (module)) {
1305                                         Report.Error_T (3013, module.Name);
1306                                         return;
1307                                 }
1308                         }
1309                 }
1310
1311                 static bool IsClsCompliant (ICustomAttributeProvider attribute_provider)
1312                 {
1313                         object[] CompliantAttribute = attribute_provider.GetCustomAttributes (TypeManager.cls_compliant_attribute_type, false);
1314                         if (CompliantAttribute.Length == 0)
1315                                 return false;
1316
1317                         return ((CLSCompliantAttribute)CompliantAttribute[0]).IsCompliant;
1318                 }
1319
1320                 static bool AnalyzeTypeCompliance (Type type)
1321                 {
1322                         DeclSpace ds = TypeManager.LookupDeclSpace (type);
1323                         if (ds != null) {
1324                                 return ds.IsClsCompliaceRequired (ds.Parent);
1325                         }
1326
1327                         object[] CompliantAttribute = type.GetCustomAttributes (TypeManager.cls_compliant_attribute_type, false);
1328                         if (CompliantAttribute.Length == 0)
1329                                 return IsClsCompliant (type.Assembly);
1330
1331                         return ((CLSCompliantAttribute)CompliantAttribute[0]).IsCompliant;
1332                 }
1333         }
1334 }