mcs/mcs/attribute.cs

   1 //
   2 // attribute.cs: Attribute Handler
   3 //
   4 // Author: Ravi Pratap (ravi@ximian.com)
   5 //         Marek Safar (marek.safar@seznam.cz)
   6 //
   7 // Licensed under the terms of the GNU GPL
   8 //
   9 // (C) 2001 Ximian, Inc (http://www.ximian.com)
  10 //
  11 //
  12
  13 using System;
  14 using System.Diagnostics;
  15 using System.Collections;
  16 using System.Collections.Specialized;
  17 using System.Reflection;
  18 using System.Reflection.Emit;
  19 using System.Runtime.InteropServices;
  20 using System.Runtime.CompilerServices;
  21 using System.Security;
  22 using System.Security.Permissions;
  23 using System.Text;
  24 using System.IO;
  25
  26 namespace Mono.CSharp {
  27
  28         /// <summary>
  29         ///   Base class for objects that can have Attributes applied to them.
  30         /// </summary>
  31         public abstract class Attributable {
  32                 /// <summary>
  33                 ///   Attributes for this type
  34                 /// </summary>
  35                 Attributes attributes;
  36
  37                 public Attributable (Attributes attrs)
  38                 {
  39                         attributes = attrs;
  40                 }
  41
  42                 public Attributes OptAttributes
  43                 {
  44                         get {
  45                                 return attributes;
  46                         }
  47                         set {
  48                                 attributes = value;
  49                         }
  50                 }
  51
  52                 /// <summary>
  53                 /// Use member-specific procedure to apply attribute @a in @cb to the entity being built in @builder
  54                 /// </summary>
  55                 public abstract void ApplyAttributeBuilder (Attribute a, CustomAttributeBuilder cb);
  56
  57                 /// <summary>
  58                 /// Returns one AttributeTarget for this element.
  59                 /// </summary>
  60                 public abstract AttributeTargets AttributeTargets { get; }
  61
  62                 public abstract bool IsClsCompliaceRequired (DeclSpace ds);
  63
  64                 /// <summary>
  65                 /// Gets list of valid attribute targets for explicit target declaration.
  66                 /// The first array item is default target. Don't break this rule.
  67                 /// </summary>
  68                 public abstract string[] ValidAttributeTargets { get; }
  69         };
  70
  71         public class Attribute {
  72                 public readonly string ExplicitTarget;
  73                 public AttributeTargets Target;
  74
  75                 // TODO: remove this member
  76                 public readonly string    Name;
  77                 public readonly Expression LeftExpr;
  78                 public readonly string Identifier;
  79
  80                 public readonly ArrayList Arguments;
  81
  82                 public readonly Location Location;
  83
  84                 public Type Type;
  85
  86                 bool resolve_error;
  87
  88                 readonly bool nameEscaped;
  89
  90                 static AttributeUsageAttribute DefaultUsageAttribute = new AttributeUsageAttribute (AttributeTargets.All);
  91                 static Assembly orig_sec_assembly;
  92
  93                 // non-null if named args present after Resolve () is called
  94                 PropertyInfo [] prop_info_arr;
  95                 FieldInfo [] field_info_arr;
  96                 object [] field_values_arr;
  97                 object [] prop_values_arr;
  98                 object [] pos_values;
  99
 100                 static PtrHashtable usage_attr_cache = new PtrHashtable ();
 101
 102                 public Attribute (string target, Expression left_expr, string identifier, ArrayList args, Location loc, bool nameEscaped)
 103                 {
 104                         LeftExpr = left_expr;
 105                         Identifier = identifier;
 106                         Name = LeftExpr == null ? identifier : LeftExpr + "." + identifier;
 107                         Arguments = args;
 108                         Location = loc;
 109                         ExplicitTarget = target;
 110                         this.nameEscaped = nameEscaped;
 111                 }
 112
 113                 void Error_InvalidNamedArgument (string name)
 114                 {
 115                         Report.Error (617, Location, "`{0}' is not a valid named attribute argument. Named attribute arguments must be fields which are not readonly, static, const or read-write properties which are public and not static",
 116                               name);
 117                 }
 118
 119                 void Error_InvalidNamedAgrumentType (string name)
 120                 {
 121                         Report.Error (655, Location, "`{0}' is not a valid named attribute argument because it is not a valid attribute parameter type", name);
 122                 }
 123
 124                 static void Error_AttributeArgumentNotValid (string extra, Location loc)
 125                 {
 126                         Report.Error (182, loc,
 127                                       "An attribute argument must be a constant expression, typeof " +
 128                                       "expression or array creation expression" + extra);
 129                 }
 130
 131                 static void Error_AttributeArgumentNotValid (Location loc)
 132                 {
 133                         Error_AttributeArgumentNotValid ("", loc);
 134                 }
 135
 136
 137                 /// <summary>
 138                 /// This is rather hack. We report many emit attribute error with same error to be compatible with
 139                 /// csc. But because csc has to report them this way because error came from ilasm we needn't.
 140                 /// </summary>
 141                 public void Error_AttributeEmitError (string inner)
 142                 {
 143                         Report.Error (647, Location, "Error during emitting `{0}' attribute. The reason is `{1}'", TypeManager.CSharpName (Type), inner);
 144                 }
 145
 146                 public void Error_InvalidSecurityParent ()
 147                 {
 148                         Error_AttributeEmitError ("it is attached to invalid parent");
 149                 }
 150
 151                 protected virtual FullNamedExpression ResolveAsTypeTerminal (Expression expr, EmitContext ec, bool silent)
 152                 {
 153                         return expr.ResolveAsTypeTerminal (ec, silent);
 154                 }
 155
 156                 protected virtual FullNamedExpression ResolveAsTypeStep (Expression expr, EmitContext ec, bool silent)
 157                 {
 158                         return expr.ResolveAsTypeStep (ec, silent);
 159                 }
 160
 161                 Type ResolvePossibleAttributeType (EmitContext ec, string name, bool silent, ref bool is_attr)
 162                 {
 163                         FullNamedExpression fn;
 164                         if (LeftExpr == null) {
 165                                 fn = ResolveAsTypeTerminal (new SimpleName (name, Location), ec, silent);
 166                         } else {
 167                                 fn = ResolveAsTypeStep (LeftExpr, ec, silent);
 168                                 if (fn == null)
 169                                         return null;
 170                                 fn = new MemberAccess (fn, name, Location).ResolveAsTypeTerminal (ec, silent);
 171                         }
 172
 173                         TypeExpr te = fn as TypeExpr;
 174                         if (te == null)
 175                                 return null;
 176
 177                         Type t = te.Type;
 178                         if (t.IsSubclassOf (TypeManager.attribute_type)) {
 179                                 is_attr = true;
 180                         } else if (!silent) {
 181                                 Report.SymbolRelatedToPreviousError (t);
 182                                 Report.Error (616, Location, "`{0}': is not an attribute class", TypeManager.CSharpName (t));
 183                         }
 184                         return t;
 185                 }
 186
 187                 /// <summary>
 188                 ///   Tries to resolve the type of the attribute. Flags an error if it can't, and complain is true.
 189                 /// </summary>
 190                 void ResolveAttributeType (EmitContext ec)
 191                 {
 192                         bool t1_is_attr = false;
 193                         Type t1 = ResolvePossibleAttributeType (ec, Identifier, true, ref t1_is_attr);
 194
 195                         // FIXME: Shouldn't do this for quoted attributes: [@A]
 196                         bool t2_is_attr = false;
 197                         Type t2 = ResolvePossibleAttributeType (ec, Identifier + "Attribute", true, ref t2_is_attr);
 198
 199                         if (t1_is_attr && t2_is_attr && !nameEscaped) {
 200                                 Report.Error (1614, Location, "`{0}' is ambiguous between `{0}' and `{0}Attribute'. Use either `@{0}' or `{0}Attribute'", GetSignatureForError ());
 201                                 resolve_error = true;
 202                                 return;
 203                         }
 204
 205                         if (t1_is_attr) {
 206                                 Type = t1;
 207                                 return;
 208                         }
 209
 210                         if (t2_is_attr) {
 211                                 Type = t2;
 212                                 return;
 213                         }
 214
 215                         if (t1 == null && t2 == null)
 216                                 ResolvePossibleAttributeType (ec, Identifier, false, ref t1_is_attr);
 217                         if (t1 != null)
 218                                 ResolvePossibleAttributeType (ec, Identifier, false, ref t1_is_attr);
 219                         if (t2 != null)
 220                                 ResolvePossibleAttributeType (ec, Identifier + "Attribute", false, ref t2_is_attr);
 221
 222                         resolve_error = true;
 223                 }
 224
 225                 public virtual Type ResolveType (EmitContext ec)
 226                 {
 227                         if (Type == null && !resolve_error)
 228                                 ResolveAttributeType (ec);
 229                         return Type;
 230                 }
 231
 232                 public string GetSignatureForError ()
 233                 {
 234                         return LeftExpr == null ? Identifier : LeftExpr.GetSignatureForError () + "." + Identifier;
 235                 }
 236
 237                 //
 238                 // Given an expression, if the expression is a valid attribute-argument-expression
 239                 // returns an object that can be used to encode it, or null on failure.
 240                 //
 241                 public static bool GetAttributeArgumentExpression (Expression e, Location loc, Type arg_type, out object result)
 242                 {
 243                         Constant constant = e as Constant;
 244                         if (constant != null) {
 245                                 constant = constant.ToType (arg_type, loc);
 246                                 if (constant == null) {
 247                                         result = null;
 248                                         return false;
 249                                 }
 250                                 result = constant.GetTypedValue ();
 251                                 return true;
 252                         } else if (e is TypeOf) {
 253                                 result = ((TypeOf) e).TypeArg;
 254                                 return true;
 255                         } else if (e is ArrayCreation){
 256                                 result =  ((ArrayCreation) e).EncodeAsAttribute ();
 257                                 if (result != null)
 258                                         return true;
 259                         } else if (e is EmptyCast) {
 260                                 Expression child = ((EmptyCast)e).Child;
 261                                 return GetAttributeArgumentExpression (child, loc, child.Type, out result);
 262                         }
 263
 264                         result = null;
 265                         Error_AttributeArgumentNotValid (loc);
 266                         return false;
 267                 }
 268
 269                 bool IsValidArgumentType (Type t)
 270                 {
 271                         return TypeManager.IsPrimitiveType (t) ||
 272                                 (t.IsArray && TypeManager.IsPrimitiveType (t.GetElementType ())) ||
 273                                 TypeManager.IsEnumType (t) ||
 274                                 t == TypeManager.string_type ||
 275                                 t == TypeManager.object_type ||
 276                                 t == TypeManager.type_type;
 277                 }
 278
 279                 // Cache for parameter-less attributes
 280                 static PtrHashtable att_cache = new PtrHashtable ();
 281
 282                 public CustomAttributeBuilder Resolve (EmitContext ec)
 283                 {
 284                         if (resolve_error)
 285                                 return null;
 286
 287                         resolve_error = true;
 288
 289                         if (Type == null) {
 290                                 ResolveAttributeType (ec);
 291                                 if (Type == null)
 292                                         return null;
 293                         }
 294
 295                         if (Type.IsAbstract) {
 296                                 Report.Error (653, Location, "Cannot apply attribute class `{0}' because it is abstract", GetSignatureForError ());
 297                                 return null;
 298                         }
 299
 300                         if (Arguments == null) {
 301                                 object o = att_cache [Type];
 302                                 if (o != null) {
 303                                         resolve_error = false;
 304                                         return (CustomAttributeBuilder)o;
 305                                 }
 306                         }
 307
 308                         ConstructorInfo ctor = ResolveArguments (ec);
 309                         if (ctor == null)
 310                                 return null;
 311
 312                         CustomAttributeBuilder cb;
 313
 314                         try {
 315                                 if (prop_info_arr != null || field_info_arr != null) {
 316                                         cb = new CustomAttributeBuilder (
 317                                                 ctor, pos_values,
 318                                                 prop_info_arr, prop_values_arr,
 319                                                 field_info_arr, field_values_arr);
 320                                 } else {
 321                                         cb = new CustomAttributeBuilder (
 322                                                 ctor, pos_values);
 323
 324                                         if (pos_values.Length == 0)
 325                                                 att_cache.Add (Type, cb);
 326                                 }
 327                         }
 328                         catch (Exception) {
 329                                 Error_AttributeArgumentNotValid (Location);
 330                                 return null;
 331                         }
 332
 333                         resolve_error = false;
 334                         return cb;
 335                 }
 336
 337                 protected virtual ConstructorInfo ResolveArguments (EmitContext ec)
 338                 {
 339                         // Now we extract the positional and named arguments
 340
 341                         ArrayList pos_args = null;
 342                         ArrayList named_args = null;
 343                         int pos_arg_count = 0;
 344                         int named_arg_count = 0;
 345
 346                         if (Arguments != null) {
 347                                 pos_args = (ArrayList) Arguments [0];
 348                                 if (pos_args != null)
 349                                         pos_arg_count = pos_args.Count;
 350                                 if (Arguments.Count > 1) {
 351                                         named_args = (ArrayList) Arguments [1];
 352                                         named_arg_count = named_args.Count;
 353                                 }
 354                         }
 355
 356                         pos_values = new object [pos_arg_count];
 357
 358                         //
 359                         // First process positional arguments
 360                         //
 361
 362                         int i;
 363                         for (i = 0; i < pos_arg_count; i++) {
 364                                 Argument a = (Argument) pos_args [i];
 365                                 Expression e;
 366
 367                                 if (!a.Resolve (ec, Location))
 368                                         return null;
 369
 370                                 e = a.Expr;
 371
 372                                 object val;
 373                                 if (!GetAttributeArgumentExpression (e, Location, a.Type, out val))
 374                                         return null;
 375
 376                                 pos_values [i] = val;
 377
 378                                 if (i == 0 && Type == TypeManager.attribute_usage_type && (int)val == 0) {
 379                                         Report.Error (591, Location, "Invalid value for argument to 'System.AttributeUsage' attribute");
 380                                         return null;
 381                                 }
 382                         }
 383
 384                         //
 385                         // Now process named arguments
 386                         //
 387
 388                         ArrayList field_infos = null;
 389                         ArrayList prop_infos  = null;
 390                         ArrayList field_values = null;
 391                         ArrayList prop_values = null;
 392                         Hashtable seen_names = null;
 393
 394                         if (named_arg_count > 0) {
 395                                 field_infos = new ArrayList ();
 396                                 prop_infos  = new ArrayList ();
 397                                 field_values = new ArrayList ();
 398                                 prop_values = new ArrayList ();
 399
 400                                 seen_names = new Hashtable();
 401                         }
 402
 403                         for (i = 0; i < named_arg_count; i++) {
 404                                 DictionaryEntry de = (DictionaryEntry) named_args [i];
 405                                 string member_name = (string) de.Key;
 406                                 Argument a  = (Argument) de.Value;
 407                                 Expression e;
 408
 409                                 if (seen_names.Contains(member_name)) {
 410                                         Report.Error(643, Location, "'" + member_name + "' duplicate named attribute argument");
 411                                         return null;
 412                                 }
 413                                 seen_names.Add(member_name, 1);
 414
 415                                 if (!a.Resolve (ec, Location))
 416                                         return null;
 417
 418                                 Expression member = Expression.MemberLookup (
 419                                         ec, Type, member_name,
 420                                         MemberTypes.Field | MemberTypes.Property,
 421                                         BindingFlags.Public | BindingFlags.Instance,
 422                                         Location);
 423
 424                                 if (member == null) {
 425                                         member = Expression.MemberLookup (ec, Type, member_name,
 426                                                 MemberTypes.Field | MemberTypes.Property, BindingFlags.NonPublic | BindingFlags.Instance,
 427                                                 Location);
 428
 429                                         if (member != null) {
 430                                                 Expression.ErrorIsInaccesible (Location, member.GetSignatureForError ());
 431                                                 return null;
 432                                         }
 433                                 }
 434
 435                                 if (member == null){
 436                                         Report.Error (117, Location, "`{0}' does not contain a definition for `{1}'",
 437                                                       Type, member_name);
 438                                         return null;
 439                                 }
 440
 441                                 if (!(member is PropertyExpr || member is FieldExpr)) {
 442                                         Error_InvalidNamedArgument (member_name);
 443                                         return null;
 444                                 }
 445
 446                                 e = a.Expr;
 447                                 if (member is PropertyExpr) {
 448                                         PropertyExpr pe = (PropertyExpr) member;
 449                                         PropertyInfo pi = pe.PropertyInfo;
 450
 451                                         if (!pi.CanWrite || !pi.CanRead) {
 452                                                 Report.SymbolRelatedToPreviousError (pi);
 453                                                 Error_InvalidNamedArgument (member_name);
 454                                                 return null;
 455                                         }
 456
 457                                         if (!IsValidArgumentType (pi.PropertyType)) {
 458                                                 Report.SymbolRelatedToPreviousError (pi);
 459                                                 Error_InvalidNamedAgrumentType (member_name);
 460                                                 return null;
 461                                         }
 462
 463                                         object value;
 464                                         if (!GetAttributeArgumentExpression (e, Location, pi.PropertyType, out value))
 465                                                 return null;
 466
 467                                         prop_values.Add (value);
 468                                         prop_infos.Add (pi);
 469
 470                                 } else if (member is FieldExpr) {
 471                                         FieldExpr fe = (FieldExpr) member;
 472                                         FieldInfo fi = fe.FieldInfo;
 473
 474                                         if (fi.IsInitOnly) {
 475                                                 Error_InvalidNamedArgument (member_name);
 476                                                 return null;
 477                                         }
 478
 479                                         if (!IsValidArgumentType (fi.FieldType)) {
 480                                                 Report.SymbolRelatedToPreviousError (fi);
 481                                                 Error_InvalidNamedAgrumentType (member_name);
 482                                                 return null;
 483                                         }
 484
 485                                         object value;
 486                                         if (!GetAttributeArgumentExpression (e, Location, fi.FieldType, out value))
 487                                                 return null;
 488
 489                                         field_values.Add (value);
 490                                         field_infos.Add (fi);
 491                                 }
 492                         }
 493
 494                         Expression mg = Expression.MemberLookup (
 495                                 ec, Type, ".ctor", MemberTypes.Constructor,
 496                                 BindingFlags.Public | BindingFlags.Instance | BindingFlags.DeclaredOnly,
 497                                 Location);
 498
 499                         MethodBase constructor = Invocation.OverloadResolve (
 500                                 ec, (MethodGroupExpr) mg, pos_args, false, Location);
 501
 502                         if (constructor == null) {
 503                                 return null;
 504                         }
 505
 506
 507                         // Here we do the checks which should be done by corlib or by runtime.
 508                         // However Zoltan doesn't like it and every Mono compiler has to do it again.
 509
 510                         if (Type == TypeManager.guid_attr_type) {
 511                                 try {
 512                                         new Guid ((string)pos_values [0]);
 513                                 }
 514                                 catch (Exception e) {
 515                                         Error_AttributeEmitError (e.Message);
 516                                 }
 517                         }
 518 // TODO: reenable
 519 //                      if (Type == TypeManager.methodimpl_attr_type &&
 520 //                              pos_values.Length == 1 && ((Argument)pos_args [0]).Type == TypeManager.short_type &&
 521 //                              !System.Enum.IsDefined (TypeManager.method_impl_options, pos_values [0])) {
 522 //                                      Error_AttributeEmitError ("Incorrect argument value.");
 523 //                      }
 524
 525                         //
 526                         // Now we perform some checks on the positional args as they
 527                         // cannot be null for a constructor which expects a parameter
 528                         // of type object
 529                         //
 530
 531                         ParameterData pd = TypeManager.GetParameterData (constructor);
 532
 533                         int last_real_param = pd.Count;
 534                         if (pd.HasParams) {
 535                                 // When the params is not filled we need to put one
 536                                 if (last_real_param > pos_arg_count) {
 537                                         object [] new_pos_values = new object [pos_arg_count + 1];
 538                                         pos_values.CopyTo (new_pos_values, 0);
 539                                         new_pos_values [pos_arg_count] = new object [] {} ;
 540                                         pos_values = new_pos_values;
 541                                 }
 542                                 last_real_param--;
 543                         }
 544
 545                         for (int j = 0; j < pos_arg_count; ++j) {
 546                                 Argument a = (Argument) pos_args [j];
 547
 548                                 if (a.Expr is NullLiteral && pd.ParameterType (j) == TypeManager.object_type) {
 549                                         Error_AttributeArgumentNotValid (Location);
 550                                         return null;
 551                                 }
 552
 553                                 object value = pos_values [j];
 554                                 if (value != null && a.Type != value.GetType () && TypeManager.IsPrimitiveType (a.Type)) {
 555                                         bool fail;
 556                                         pos_values [j] = TypeManager.ChangeType (value, a.Type, out fail);
 557                                         if (fail) {
 558                                                 // TODO: Can failed ?
 559                                                 throw new NotImplementedException ();
 560                                         }
 561                                 }
 562
 563                                 if (j < last_real_param)
 564                                         continue;
 565
 566                                 if (j == last_real_param) {
 567                                         object [] array = new object [pos_arg_count - last_real_param];
 568                                         array [0] = pos_values [j];
 569                                         pos_values [j] = array;
 570                                         continue;
 571                                 }
 572
 573                                 object [] params_array = (object []) pos_values [last_real_param];
 574                                 params_array [j - last_real_param] = pos_values [j];
 575                         }
 576
 577                         // Adjust the size of the pos_values if it had params
 578                         if (last_real_param != pos_arg_count) {
 579                                 object [] new_pos_values = new object [last_real_param + 1];
 580                                 Array.Copy (pos_values, new_pos_values, last_real_param + 1);
 581                                 pos_values = new_pos_values;
 582                         }
 583
 584                         if (named_arg_count > 0) {
 585                                 prop_info_arr = new PropertyInfo [prop_infos.Count];
 586                                 field_info_arr = new FieldInfo [field_infos.Count];
 587                                 field_values_arr = new object [field_values.Count];
 588                                 prop_values_arr = new object [prop_values.Count];
 589
 590                                 field_infos.CopyTo  (field_info_arr, 0);
 591                                 field_values.CopyTo (field_values_arr, 0);
 592
 593                                 prop_values.CopyTo  (prop_values_arr, 0);
 594                                 prop_infos.CopyTo   (prop_info_arr, 0);
 595                         }
 596
 597                         return (ConstructorInfo) constructor;
 598                 }
 599
 600                 /// <summary>
 601                 ///   Get a string containing a list of valid targets for the attribute 'attr'
 602                 /// </summary>
 603                 public string GetValidTargets ()
 604                 {
 605                         StringBuilder sb = new StringBuilder ();
 606                         AttributeTargets targets = GetAttributeUsage (null).ValidOn;
 607
 608                         if ((targets & AttributeTargets.Assembly) != 0)
 609                                 sb.Append ("assembly, ");
 610
 611                         if ((targets & AttributeTargets.Module) != 0)
 612                                 sb.Append ("module, ");
 613
 614                         if ((targets & AttributeTargets.Class) != 0)
 615                                 sb.Append ("class, ");
 616
 617                         if ((targets & AttributeTargets.Struct) != 0)
 618                                 sb.Append ("struct, ");
 619
 620                         if ((targets & AttributeTargets.Enum) != 0)
 621                                 sb.Append ("enum, ");
 622
 623                         if ((targets & AttributeTargets.Constructor) != 0)
 624                                 sb.Append ("constructor, ");
 625
 626                         if ((targets & AttributeTargets.Method) != 0)
 627                                 sb.Append ("method, ");
 628
 629                         if ((targets & AttributeTargets.Property) != 0)
 630                                 sb.Append ("property, indexer, ");
 631
 632                         if ((targets & AttributeTargets.Field) != 0)
 633                                 sb.Append ("field, ");
 634
 635                         if ((targets & AttributeTargets.Event) != 0)
 636                                 sb.Append ("event, ");
 637
 638                         if ((targets & AttributeTargets.Interface) != 0)
 639                                 sb.Append ("interface, ");
 640
 641                         if ((targets & AttributeTargets.Parameter) != 0)
 642                                 sb.Append ("parameter, ");
 643
 644                         if ((targets & AttributeTargets.Delegate) != 0)
 645                                 sb.Append ("delegate, ");
 646
 647                         if ((targets & AttributeTargets.ReturnValue) != 0)
 648                                 sb.Append ("return, ");
 649
 650 #if NET_2_0
 651                         if ((targets & AttributeTargets.GenericParameter) != 0)
 652                                 sb.Append ("type parameter, ");
 653 #endif
 654                         return sb.Remove (sb.Length - 2, 2).ToString ();
 655                 }
 656
 657                 /// <summary>
 658                 /// Returns AttributeUsage attribute for this type
 659                 /// </summary>
 660                 AttributeUsageAttribute GetAttributeUsage (EmitContext ec)
 661                 {
 662                         AttributeUsageAttribute ua = usage_attr_cache [Type] as AttributeUsageAttribute;
 663                         if (ua != null)
 664                                 return ua;
 665
 666                         Class attr_class = TypeManager.LookupClass (Type);
 667
 668                         if (attr_class == null) {
 669                                 object[] usage_attr = Type.GetCustomAttributes (TypeManager.attribute_usage_type, true);
 670                                 ua = (AttributeUsageAttribute)usage_attr [0];
 671                                 usage_attr_cache.Add (Type, ua);
 672                                 return ua;
 673                         }
 674
 675                         Attribute a = attr_class.OptAttributes == null
 676                                 ? null
 677                                 : attr_class.OptAttributes.Search (TypeManager.attribute_usage_type, attr_class.EmitContext);
 678
 679                         ua = a == null
 680                                 ? DefaultUsageAttribute
 681                                 : a.GetAttributeUsageAttribute (attr_class.EmitContext);
 682
 683                         usage_attr_cache.Add (Type, ua);
 684                         return ua;
 685                 }
 686
 687                 AttributeUsageAttribute GetAttributeUsageAttribute (EmitContext ec)
 688                 {
 689                         if (pos_values == null)
 690                                 // TODO: It is not neccessary to call whole Resolve (ApplyAttribute does it now) we need only ctor args.
 691                                 // But because a lot of attribute class code must be rewritten will be better to wait...
 692                                 Resolve (ec);
 693
 694                         if (resolve_error)
 695                                 return DefaultUsageAttribute;
 696
 697                         AttributeUsageAttribute usage_attribute = new AttributeUsageAttribute ((AttributeTargets)pos_values [0]);
 698
 699                         object field = GetPropertyValue ("AllowMultiple");
 700                         if (field != null)
 701                                 usage_attribute.AllowMultiple = (bool)field;
 702
 703                         field = GetPropertyValue ("Inherited");
 704                         if (field != null)
 705                                 usage_attribute.Inherited = (bool)field;
 706
 707                         return usage_attribute;
 708                 }
 709
 710                 /// <summary>
 711                 /// Returns custom name of indexer
 712                 /// </summary>
 713                 public string GetIndexerAttributeValue (EmitContext ec)
 714                 {
 715                         if (pos_values == null)
 716                                 // TODO: It is not neccessary to call whole Resolve (ApplyAttribute does it now) we need only ctor args.
 717                                 // But because a lot of attribute class code must be rewritten will be better to wait...
 718                                 Resolve (ec);
 719
 720                         if (resolve_error)
 721                                 return null;
 722
 723                         return pos_values [0] as string;
 724                 }
 725
 726                 /// <summary>
 727                 /// Returns condition of ConditionalAttribute
 728                 /// </summary>
 729                 public string GetConditionalAttributeValue (EmitContext ec)
 730                 {
 731                         if (pos_values == null)
 732                                 // TODO: It is not neccessary to call whole Resolve (ApplyAttribute does it now) we need only ctor args.
 733                                 // But because a lot of attribute class code must be rewritten will be better to wait...
 734                                 Resolve (ec);
 735
 736                         if (resolve_error)
 737                                 return null;
 738
 739                         return (string)pos_values [0];
 740                 }
 741
 742                 /// <summary>
 743                 /// Creates the instance of ObsoleteAttribute from this attribute instance
 744                 /// </summary>
 745                 public ObsoleteAttribute GetObsoleteAttribute (EmitContext ec)
 746                 {
 747                         if (pos_values == null)
 748                                 // TODO: It is not neccessary to call whole Resolve (ApplyAttribute does it now) we need only ctor args.
 749                                 // But because a lot of attribute class code must be rewritten will be better to wait...
 750                                 Resolve (ec);
 751
 752                         if (resolve_error)
 753                                 return null;
 754
 755                         if (pos_values == null || pos_values.Length == 0)
 756                                 return new ObsoleteAttribute ();
 757
 758                         if (pos_values.Length == 1)
 759                                 return new ObsoleteAttribute ((string)pos_values [0]);
 760
 761                         return new ObsoleteAttribute ((string)pos_values [0], (bool)pos_values [1]);
 762                 }
 763
 764                 /// <summary>
 765                 /// Returns value of CLSCompliantAttribute contructor parameter but because the method can be called
 766                 /// before ApplyAttribute. We need to resolve the arguments.
 767                 /// This situation occurs when class deps is differs from Emit order.
 768                 /// </summary>
 769                 public bool GetClsCompliantAttributeValue (EmitContext ec)
 770                 {
 771                         if (pos_values == null)
 772                                 // TODO: It is not neccessary to call whole Resolve (ApplyAttribute does it now) we need only ctor args.
 773                                 // But because a lot of attribute class code must be rewritten will be better to wait...
 774                                 Resolve (ec);
 775
 776                         if (resolve_error)
 777                                 return false;
 778
 779                         return (bool)pos_values [0];
 780                 }
 781
 782                 /// <summary>
 783                 /// Tests permitted SecurityAction for assembly or other types
 784                 /// </summary>
 785                 public bool CheckSecurityActionValidity (bool for_assembly)
 786                 {
 787                         SecurityAction action  = GetSecurityActionValue ();
 788
 789                         if ((action == SecurityAction.RequestMinimum || action == SecurityAction.RequestOptional || action == SecurityAction.RequestRefuse) && for_assembly)
 790                                 return true;
 791
 792                         if (!for_assembly) {
 793                                 if (action < SecurityAction.Demand || action > SecurityAction.InheritanceDemand) {
 794                                         Error_AttributeEmitError ("SecurityAction is out of range");
 795                                         return false;
 796                                 }
 797
 798                                 if ((action != SecurityAction.RequestMinimum && action != SecurityAction.RequestOptional && action != SecurityAction.RequestRefuse) && !for_assembly)
 799                                         return true;
 800                         }
 801
 802                         Error_AttributeEmitError (String.Concat ("SecurityAction '", action, "' is not valid for this declaration"));
 803                         return false;
 804                 }
 805
 806                 System.Security.Permissions.SecurityAction GetSecurityActionValue ()
 807                 {
 808                         return (SecurityAction)pos_values [0];
 809                 }
 810
 811                 /// <summary>
 812                 /// Creates instance of SecurityAttribute class and add result of CreatePermission method to permission table.
 813                 /// </summary>
 814                 /// <returns></returns>
 815                 public void ExtractSecurityPermissionSet (ListDictionary permissions)
 816                 {
 817                         Type orig_assembly_type = null;
 818
 819                         if (TypeManager.LookupDeclSpace (Type) != null) {
 820                                 if (!RootContext.StdLib) {
 821                                         orig_assembly_type = Type.GetType (Type.FullName);
 822                                 } else {
 823                                         string orig_version_path = Environment.GetEnvironmentVariable ("__SECURITY_BOOTSTRAP_DB");
 824                                         if (orig_version_path == null) {
 825                                                 Error_AttributeEmitError ("security custom attributes can not be referenced from defining assembly");
 826                                                 return;
 827                                         }
 828
 829                                         if (orig_sec_assembly == null) {
 830                                                 string file = Path.Combine (orig_version_path, Driver.OutputFile);
 831                                                 orig_sec_assembly = Assembly.LoadFile (file);
 832                                         }
 833
 834                                         orig_assembly_type = orig_sec_assembly.GetType (Type.FullName, true);
 835                                         if (orig_assembly_type == null) {
 836                                                 Report.Warning (-112, 1, Location, "Self-referenced security attribute `{0}' was not found in previous version of assembly");
 837                                                 return;
 838                                         }
 839                                 }
 840                         }
 841
 842                         SecurityAttribute sa;
 843                         // For all non-selfreferencing security attributes we can avoid all hacks
 844                         if (orig_assembly_type == null) {
 845                                 sa = (SecurityAttribute) Activator.CreateInstance (Type, pos_values);
 846
 847                                 if (prop_info_arr != null) {
 848                                         for (int i = 0; i < prop_info_arr.Length; ++i) {
 849                                                 PropertyInfo pi = prop_info_arr [i];
 850                                                 pi.SetValue (sa, prop_values_arr [i], null);
 851                                         }
 852                                 }
 853                         } else {
 854                                 // HACK: All security attributes have same ctor syntax
 855                                 sa = (SecurityAttribute) Activator.CreateInstance (orig_assembly_type, new object[] { GetSecurityActionValue () } );
 856
 857                                 // All types are from newly created assembly but for invocation with old one we need to convert them
 858                                 if (prop_info_arr != null) {
 859                                         for (int i = 0; i < prop_info_arr.Length; ++i) {
 860                                                 PropertyInfo emited_pi = prop_info_arr [i];
 861                                                 PropertyInfo pi = orig_assembly_type.GetProperty (emited_pi.Name, emited_pi.PropertyType);
 862
 863                                                 object old_instance = pi.PropertyType.IsEnum ?
 864                                                         System.Enum.ToObject (pi.PropertyType, prop_values_arr [i]) :
 865                                                         prop_values_arr [i];
 866
 867                                                 pi.SetValue (sa, old_instance, null);
 868                                         }
 869                                 }
 870                         }
 871
 872                         IPermission perm;
 873                         perm = sa.CreatePermission ();
 874                         SecurityAction action = GetSecurityActionValue ();
 875
 876                         // IS is correct because for corlib we are using an instance from old corlib
 877                         if (!(perm is System.Security.CodeAccessPermission)) {
 878                                 switch (action) {
 879                                         case SecurityAction.Demand:
 880                                                 action = (SecurityAction)13;
 881                                                 break;
 882                                         case SecurityAction.LinkDemand:
 883                                                 action = (SecurityAction)14;
 884                                                 break;
 885                                         case SecurityAction.InheritanceDemand:
 886                                                 action = (SecurityAction)15;
 887                                                 break;
 888                                 }
 889                         }
 890
 891                         PermissionSet ps = (PermissionSet)permissions [action];
 892                         if (ps == null) {
 893                                 if (sa is PermissionSetAttribute)
 894                                         ps = new PermissionSet (sa.Unrestricted ? PermissionState.Unrestricted : PermissionState.None);
 895                                 else
 896                                         ps = new PermissionSet (PermissionState.None);
 897
 898                                 permissions.Add (action, ps);
 899                         } else if (!ps.IsUnrestricted () && (sa is PermissionSetAttribute) && sa.Unrestricted) {
 900                                 ps = ps.Union (new PermissionSet (PermissionState.Unrestricted));
 901                                 permissions [action] = ps;
 902                         }
 903                         ps.AddPermission (perm);
 904                 }
 905
 906                 object GetValue (object value)
 907                 {
 908                         if (value is EnumConstant)
 909                                 return ((EnumConstant) value).GetValue ();
 910                         else
 911                                 return value;
 912                 }
 913
 914                 object GetPropertyValue (string name)
 915                 {
 916                         if (prop_info_arr == null)
 917                                 return null;
 918
 919                         for (int i = 0; i < prop_info_arr.Length; ++i) {
 920                                 if (prop_info_arr [i].Name == name)
 921                                         return prop_values_arr [i];
 922                         }
 923
 924                         return null;
 925                 }
 926
 927                 object GetFieldValue (string name)
 928                 {
 929                         int i;
 930                         if (field_info_arr == null)
 931                                 return null;
 932                         i = 0;
 933                         foreach (FieldInfo fi in field_info_arr) {
 934                                 if (fi.Name == name)
 935                                         return GetValue (field_values_arr [i]);
 936                                 i++;
 937                         }
 938                         return null;
 939                 }
 940
 941                 public UnmanagedMarshal GetMarshal (Attributable attr)
 942                 {
 943                         UnmanagedType UnmanagedType;
 944                         if (!RootContext.StdLib || pos_values [0].GetType () != typeof (UnmanagedType))
 945                                 UnmanagedType = (UnmanagedType)System.Enum.ToObject (typeof (UnmanagedType), pos_values [0]);
 946                         else
 947                                 UnmanagedType = (UnmanagedType) pos_values [0];
 948
 949                         object value = GetFieldValue ("SizeParamIndex");
 950                         if (value != null && UnmanagedType != UnmanagedType.LPArray) {
 951                                 Error_AttributeEmitError ("SizeParamIndex field is not valid for the specified unmanaged type");
 952                                 return null;
 953                         }
 954
 955                         object o = GetFieldValue ("ArraySubType");
 956                         UnmanagedType array_sub_type = o == null ? UnmanagedType.I4 : (UnmanagedType) o;
 957
 958                         switch (UnmanagedType) {
 959                         case UnmanagedType.CustomMarshaler: {
 960                                 MethodInfo define_custom = typeof (UnmanagedMarshal).GetMethod ("DefineCustom",
 961                                                                        BindingFlags.Static | BindingFlags.Public);
 962                                 if (define_custom == null) {
 963                                         Report.RuntimeMissingSupport (Location, "set marshal info");
 964                                         return null;
 965                                 }
 966
 967                                 object [] args = new object [4];
 968                                 args [0] = GetFieldValue ("MarshalTypeRef");
 969                                 args [1] = GetFieldValue ("MarshalCookie");
 970                                 args [2] = GetFieldValue ("MarshalType");
 971                                 args [3] = Guid.Empty;
 972                                 return (UnmanagedMarshal) define_custom.Invoke (null, args);
 973                         }
 974                         case UnmanagedType.LPArray: {
 975                                 object size_const = GetFieldValue ("SizeConst");
 976                                 object size_param_index = GetFieldValue ("SizeParamIndex");
 977
 978                                 if ((size_const != null) || (size_param_index != null)) {
 979                                         MethodInfo define_array = typeof (UnmanagedMarshal).GetMethod ("DefineLPArrayInternal", BindingFlags.Static | BindingFlags.Public | BindingFlags.NonPublic);
 980                                         if (define_array == null) {
 981                                                 Report.RuntimeMissingSupport (Location, "set marshal info");
 982                                                 return null;
 983                                         }
 984
 985                                         object [] args = new object [3];
 986                                         args [0] = array_sub_type;
 987                                         args [1] = size_const == null ? -1 : size_const;
 988                                         args [2] = size_param_index == null ? -1 : size_param_index;
 989                                         return (UnmanagedMarshal) define_array.Invoke (null, args);
 990                                 }
 991                                 else
 992                                         return UnmanagedMarshal.DefineLPArray (array_sub_type);
 993                         }
 994                         case UnmanagedType.SafeArray:
 995                                 return UnmanagedMarshal.DefineSafeArray (array_sub_type);
 996
 997                         case UnmanagedType.ByValArray:
 998                                 FieldMember fm = attr as FieldMember;
 999                                 if (fm == null) {
1000                                         Error_AttributeEmitError ("Specified unmanaged type is only valid on fields");
1001                                         return null;
1002                                 }
1003                                 return UnmanagedMarshal.DefineByValArray ((int) GetFieldValue ("SizeConst"));
1004
1005                         case UnmanagedType.ByValTStr:
1006                                 return UnmanagedMarshal.DefineByValTStr ((int) GetFieldValue ("SizeConst"));
1007
1008                         default:
1009                                 return UnmanagedMarshal.DefineUnmanagedMarshal (UnmanagedType);
1010                         }
1011                 }
1012
1013                 public CharSet GetCharSetValue ()
1014                 {
1015                         return (CharSet)System.Enum.Parse (typeof (CharSet), pos_values [0].ToString ());
1016                 }
1017
1018                 public MethodImplOptions GetMethodImplOptions ()
1019                 {
1020                         if (pos_values [0].GetType () != typeof (MethodImplOptions))
1021                                 return (MethodImplOptions)System.Enum.ToObject (typeof (MethodImplOptions), pos_values [0]);
1022                         return (MethodImplOptions)pos_values [0];
1023                 }
1024
1025                 public LayoutKind GetLayoutKindValue ()
1026                 {
1027                         if (!RootContext.StdLib || pos_values [0].GetType () != typeof (LayoutKind))
1028                                 return (LayoutKind)System.Enum.ToObject (typeof (LayoutKind), pos_values [0]);
1029
1030                         return (LayoutKind)pos_values [0];
1031                 }
1032
1033                 /// <summary>
1034                 /// Emit attribute for Attributable symbol
1035                 /// </summary>
1036                 public void Emit (EmitContext ec, Attributable ias, ListDictionary emitted_attr)
1037                 {
1038                         CustomAttributeBuilder cb = Resolve (ec);
1039                         if (cb == null)
1040                                 return;
1041
1042                         AttributeUsageAttribute usage_attr = GetAttributeUsage (ec);
1043                         if ((usage_attr.ValidOn & Target) == 0) {
1044                                 Report.Error (592, Location, "Attribute `{0}' is not valid on this declaration type. It is valid on `{1}' declarations only",
1045                                         GetSignatureForError (), GetValidTargets ());
1046                                 return;
1047                         }
1048
1049                         try {
1050                                 ias.ApplyAttributeBuilder (this, cb);
1051                         }
1052                         catch (Exception e) {
1053                                 Error_AttributeEmitError (e.Message);
1054                                 return;
1055                         }
1056
1057                         if (!usage_attr.AllowMultiple) {
1058                                 ArrayList emitted_targets = (ArrayList)emitted_attr [Type];
1059                                 if (emitted_targets == null) {
1060                                         emitted_targets = new ArrayList ();
1061                                         emitted_attr.Add (Type, emitted_targets);
1062                                 } else if (emitted_targets.Contains (Target)) {
1063                                         Report.Error (579, Location, "Duplicate `{0}' attribute", GetSignatureForError ());
1064                                         return;
1065                                 }
1066                                 emitted_targets.Add (Target);
1067                         }
1068
1069                         if (!RootContext.VerifyClsCompliance)
1070                                 return;
1071
1072                         // Here we are testing attribute arguments for array usage (error 3016)
1073                         if (ias.IsClsCompliaceRequired (ec.DeclSpace)) {
1074                                 if (Arguments == null)
1075                                         return;
1076
1077                                 ArrayList pos_args = (ArrayList) Arguments [0];
1078                                 if (pos_args != null) {
1079                                         foreach (Argument arg in pos_args) {
1080                                                 // Type is undefined (was error 246)
1081                                                 if (arg.Type == null)
1082                                                         return;
1083
1084                                                 if (arg.Type.IsArray) {
1085                                                         Report.Error (3016, Location, "Arrays as attribute arguments are not CLS-compliant");
1086                                                         return;
1087                                                 }
1088                                         }
1089                                 }
1090
1091                                 if (Arguments.Count < 2)
1092                                         return;
1093
1094                                 ArrayList named_args = (ArrayList) Arguments [1];
1095                                 foreach (DictionaryEntry de in named_args) {
1096                                         Argument arg  = (Argument) de.Value;
1097
1098                                         // Type is undefined (was error 246)
1099                                         if (arg.Type == null)
1100                                                 return;
1101
1102                                         if (arg.Type.IsArray) {
1103                                                 Report.Error (3016, Location, "Arrays as attribute arguments are not CLS-compliant");
1104                                                 return;
1105                                         }
1106                                 }
1107                         }
1108                 }
1109
1110                 public MethodBuilder DefinePInvokeMethod (EmitContext ec, TypeBuilder builder, string name,
1111                                                           MethodAttributes flags, Type ret_type, Type [] param_types)
1112                 {
1113                         if (pos_values == null)
1114                                 // TODO: It is not neccessary to call whole Resolve (ApplyAttribute does it now) we need only ctor args.
1115                                 // But because a lot of attribute class code must be rewritten will be better to wait...
1116                                 Resolve (ec);
1117
1118                         if (resolve_error)
1119                                 return null;
1120
1121                         string dll_name = (string)pos_values [0];
1122
1123                         // Default settings
1124                         CallingConvention cc = CallingConvention.Winapi;
1125                         CharSet charset = CodeGen.Module.DefaultCharSet;
1126                         bool preserve_sig = true;
1127                         string entry_point = name;
1128                         bool best_fit_mapping = false;
1129                         bool throw_on_unmappable = false;
1130                         bool exact_spelling = false;
1131                         bool set_last_error = false;
1132
1133                         bool best_fit_mapping_set = false;
1134                         bool throw_on_unmappable_set = false;
1135                         bool exact_spelling_set = false;
1136                         bool set_last_error_set = false;
1137
1138                         MethodInfo set_best_fit = null;
1139                         MethodInfo set_throw_on = null;
1140                         MethodInfo set_exact_spelling = null;
1141                         MethodInfo set_set_last_error = null;
1142
1143                         if (field_info_arr != null) {
1144
1145                                 for (int i = 0; i < field_info_arr.Length; i++) {
1146                                         switch (field_info_arr [i].Name) {
1147                                                 case "BestFitMapping":
1148                                                         best_fit_mapping = (bool) field_values_arr [i];
1149                                                         best_fit_mapping_set = true;
1150                                                         break;
1151                                                 case "CallingConvention":
1152                                                         cc = (CallingConvention) field_values_arr [i];
1153                                                         break;
1154                                                 case "CharSet":
1155                                                         charset = (CharSet) field_values_arr [i];
1156                                                         break;
1157                                                 case "EntryPoint":
1158                                                         entry_point = (string) field_values_arr [i];
1159                                                         break;
1160                                                 case "ExactSpelling":
1161                                                         exact_spelling = (bool) field_values_arr [i];
1162                                                         exact_spelling_set = true;
1163                                                         break;
1164                                                 case "PreserveSig":
1165                                                         preserve_sig = (bool) field_values_arr [i];
1166                                                         break;
1167                                                 case "SetLastError":
1168                                                         set_last_error = (bool) field_values_arr [i];
1169                                                         set_last_error_set = true;
1170                                                         break;
1171                                                 case "ThrowOnUnmappableChar":
1172                                                         throw_on_unmappable = (bool) field_values_arr [i];
1173                                                         throw_on_unmappable_set = true;
1174                                                         break;
1175                                                 default:
1176                                                         throw new InternalErrorException (field_info_arr [i].ToString ());
1177                                         }
1178                                 }
1179                         }
1180
1181                         if (throw_on_unmappable_set || best_fit_mapping_set || exact_spelling_set || set_last_error_set) {
1182                                 set_best_fit = typeof (MethodBuilder).GetMethod ("set_BestFitMapping", BindingFlags.Instance | BindingFlags.Public | BindingFlags.NonPublic);
1183                                 set_throw_on = typeof (MethodBuilder).GetMethod ("set_ThrowOnUnmappableChar", BindingFlags.Instance | BindingFlags.Public | BindingFlags.NonPublic);
1184                                 set_exact_spelling = typeof (MethodBuilder).GetMethod ("set_ExactSpelling", BindingFlags.Instance | BindingFlags.Public | BindingFlags.NonPublic);
1185                                 set_set_last_error = typeof (MethodBuilder).GetMethod ("set_SetLastError", BindingFlags.Instance | BindingFlags.Public | BindingFlags.NonPublic);
1186
1187                                 if ((set_best_fit == null) || (set_throw_on == null) || (set_exact_spelling == null) || (set_set_last_error == null)) {
1188                                         Report.Error (-1, Location,
1189                                                                   "The ThrowOnUnmappableChar, BestFitMapping, SetLastError, and ExactSpelling attributes can only be emitted when running on the mono runtime.");
1190                                         return null;
1191                                 }
1192                         }
1193
1194                         try {
1195                                 MethodBuilder mb = builder.DefinePInvokeMethod (
1196                                         name, dll_name, entry_point, flags | MethodAttributes.HideBySig | MethodAttributes.PinvokeImpl,
1197                                         CallingConventions.Standard, ret_type, param_types, cc, charset);
1198
1199                                 if (preserve_sig)
1200                                         mb.SetImplementationFlags (MethodImplAttributes.PreserveSig);
1201
1202                                 if (throw_on_unmappable_set)
1203                                         set_throw_on.Invoke (mb, 0, null, new object [] { throw_on_unmappable }, null);
1204                                 if (best_fit_mapping_set)
1205                                         set_best_fit.Invoke (mb, 0, null, new object [] { best_fit_mapping }, null);
1206                                 if (exact_spelling_set)
1207                                         set_exact_spelling.Invoke  (mb, 0, null, new object [] { exact_spelling }, null);
1208                                 if (set_last_error_set)
1209                                         set_set_last_error.Invoke  (mb, 0, null, new object [] { set_last_error }, null);
1210
1211                                 return mb;
1212                         }
1213                         catch (ArgumentException e) {
1214                                 Error_AttributeEmitError (e.Message);
1215                                 return null;
1216                         }
1217                 }
1218
1219                 private Expression GetValue ()
1220                 {
1221                         if ((Arguments == null) || (Arguments.Count < 1))
1222                                 return null;
1223                         ArrayList al = (ArrayList) Arguments [0];
1224                         if ((al == null) || (al.Count < 1))
1225                                 return null;
1226                         Argument arg = (Argument) al [0];
1227                         if ((arg == null) || (arg.Expr == null))
1228                                 return null;
1229                         return arg.Expr;
1230                 }
1231
1232                 public string GetString ()
1233                 {
1234                         Expression e = GetValue ();
1235                         if (e is StringLiteral)
1236                                 return (e as StringLiteral).Value;
1237                         return null;
1238                 }
1239
1240                 public bool GetBoolean ()
1241                 {
1242                         Expression e = GetValue ();
1243                         if (e is BoolLiteral)
1244                                 return (e as BoolLiteral).Value;
1245                         return false;
1246                 }
1247         }
1248
1249
1250         /// <summary>
1251         /// For global attributes (assembly, module) we need special handling.
1252         /// Attributes can be located in the several files
1253         /// </summary>
1254         public class GlobalAttribute: Attribute
1255         {
1256                 public readonly NamespaceEntry ns;
1257
1258                 public GlobalAttribute (TypeContainer container, string target,
1259                                         Expression left_expr, string identifier, ArrayList args, Location loc, bool nameEscaped):
1260                         base (target, left_expr, identifier, args, loc, nameEscaped)
1261                 {
1262                         ns = container.NamespaceEntry;
1263                 }
1264
1265                 void Enter ()
1266                 {
1267                         // RootContext.Tree.Types has a single NamespaceEntry which gets overwritten
1268                         // each time a new file is parsed.  However, we need to use the NamespaceEntry
1269                         // in effect where the attribute was used.  Since code elsewhere cannot assume
1270                         // that the NamespaceEntry is right, just overwrite it.
1271                         //
1272                         // Precondition: RootContext.Tree.Types == null
1273
1274                         if (RootContext.Tree.Types.NamespaceEntry != null)
1275                                 throw new InternalErrorException (Location + " non-null NamespaceEntry");
1276
1277                         RootContext.Tree.Types.NamespaceEntry = ns;
1278                 }
1279
1280                 void Leave ()
1281                 {
1282                         RootContext.Tree.Types.NamespaceEntry = null;
1283                 }
1284
1285                 protected override FullNamedExpression ResolveAsTypeStep (Expression expr, EmitContext ec, bool silent)
1286                 {
1287                         try {
1288                                 Enter ();
1289                                 return base.ResolveAsTypeStep (expr, ec, silent);
1290                         }
1291                         finally {
1292                                 Leave ();
1293                         }
1294                 }
1295
1296
1297                 protected override FullNamedExpression ResolveAsTypeTerminal (Expression expr, EmitContext ec, bool silent)
1298                 {
1299                         try {
1300                                 Enter ();
1301                                 return base.ResolveAsTypeTerminal (expr, ec, silent);
1302                         }
1303                         finally {
1304                                 Leave ();
1305                         }
1306                 }
1307
1308                 protected override ConstructorInfo ResolveArguments (EmitContext ec)
1309                 {
1310                         try {
1311                                 Enter ();
1312                                 return base.ResolveArguments (ec);
1313                         }
1314                         finally {
1315                                 Leave ();
1316                         }
1317                 }
1318         }
1319
1320         public class Attributes {
1321                 public ArrayList Attrs;
1322
1323                 public Attributes (Attribute a)
1324                 {
1325                         Attrs = new ArrayList ();
1326                         Attrs.Add (a);
1327                 }
1328
1329                 public Attributes (ArrayList attrs)
1330                 {
1331                         Attrs = attrs;
1332                 }
1333
1334                 public void AddAttributes (ArrayList attrs)
1335                 {
1336                         Attrs.AddRange (attrs);
1337                 }
1338
1339                 /// <summary>
1340                 /// Checks whether attribute target is valid for the current element
1341                 /// </summary>
1342                 public bool CheckTargets (Attributable member)
1343                 {
1344                         string[] valid_targets = member.ValidAttributeTargets;
1345                         foreach (Attribute a in Attrs) {
1346                                 if (a.ExplicitTarget == null || a.ExplicitTarget == valid_targets [0]) {
1347                                         a.Target = member.AttributeTargets;
1348                                         continue;
1349                                 }
1350
1351                                 // TODO: we can skip the first item
1352                                 if (((IList) valid_targets).Contains (a.ExplicitTarget)) {
1353                                         switch (a.ExplicitTarget) {
1354                                                 case "return": a.Target = AttributeTargets.ReturnValue; continue;
1355                                                 case "param": a.Target = AttributeTargets.Parameter; continue;
1356                                                 case "field": a.Target = AttributeTargets.Field; continue;
1357                                                 case "method": a.Target = AttributeTargets.Method; continue;
1358                                                 case "property": a.Target = AttributeTargets.Property; continue;
1359                                         }
1360                                         throw new InternalErrorException ("Unknown explicit target: " + a.ExplicitTarget);
1361                                 }
1362
1363                                 StringBuilder sb = new StringBuilder ();
1364                                 foreach (string s in valid_targets) {
1365                                         sb.Append (s);
1366                                         sb.Append (", ");
1367                                 }
1368                                 sb.Remove (sb.Length - 2, 2);
1369                                 Report.Error (657, a.Location, "`{0}' is not a valid attribute location for this declaration. Valid attribute locations for this declaration are `{1}'", a.ExplicitTarget, sb.ToString ());
1370                                 return false;
1371                         }
1372                         return true;
1373                 }
1374
1375                 public Attribute Search (Type t, EmitContext ec)
1376                 {
1377                         foreach (Attribute a in Attrs) {
1378                                 if (a.ResolveType (ec) == t)
1379                                         return a;
1380                         }
1381                         return null;
1382                 }
1383
1384                 /// <summary>
1385                 /// Returns all attributes of type 't'. Use it when attribute is AllowMultiple = true
1386                 /// </summary>
1387                 public Attribute[] SearchMulti (Type t, EmitContext ec)
1388                 {
1389                         ArrayList ar = null;
1390
1391                         foreach (Attribute a in Attrs) {
1392                                 if (a.ResolveType (ec) == t) {
1393                                         if (ar == null)
1394                                                 ar = new ArrayList ();
1395                                         ar.Add (a);
1396                                 }
1397                         }
1398
1399                         return ar == null ? null : ar.ToArray (typeof (Attribute)) as Attribute[];
1400                 }
1401
1402                 public void Emit (EmitContext ec, Attributable ias)
1403                 {
1404                         CheckTargets (ias);
1405
1406                         ListDictionary ld = new ListDictionary ();
1407
1408                         foreach (Attribute a in Attrs)
1409                                 a.Emit (ec, ias, ld);
1410                 }
1411
1412                 public bool Contains (Type t, EmitContext ec)
1413                 {
1414                         return Search (t, ec) != null;
1415                 }
1416         }
1417
1418         /// <summary>
1419         /// Helper class for attribute verification routine.
1420         /// </summary>
1421         sealed class AttributeTester
1422         {
1423                 static PtrHashtable analyzed_types = new PtrHashtable ();
1424                 static PtrHashtable analyzed_types_obsolete = new PtrHashtable ();
1425                 static PtrHashtable analyzed_member_obsolete = new PtrHashtable ();
1426                 static PtrHashtable analyzed_method_excluded = new PtrHashtable ();
1427
1428 #if NET_2_0
1429                 static PtrHashtable fixed_buffer_cache = new PtrHashtable ();
1430 #endif
1431
1432                 static object TRUE = new object ();
1433                 static object FALSE = new object ();
1434
1435                 private AttributeTester ()
1436                 {
1437                 }
1438
1439                 public enum Result {
1440                         Ok,
1441                         RefOutArrayError,
1442                         ArrayArrayError
1443                 }
1444
1445                 /// <summary>
1446                 /// Returns true if parameters of two compared methods are CLS-Compliant.
1447                 /// It tests differing only in ref or out, or in array rank.
1448                 /// </summary>
1449                 public static Result AreOverloadedMethodParamsClsCompliant (Type[] types_a, Type[] types_b)
1450                 {
1451                         if (types_a == null || types_b == null)
1452                                 return Result.Ok;
1453
1454                         if (types_a.Length != types_b.Length)
1455                                 return Result.Ok;
1456
1457                         Result result = Result.Ok;
1458                         for (int i = 0; i < types_b.Length; ++i) {
1459                                 Type aType = types_a [i];
1460                                 Type bType = types_b [i];
1461
1462                                 if (aType.IsArray && bType.IsArray) {
1463                                         Type a_el_type = aType.GetElementType ();
1464                                         Type b_el_type = bType.GetElementType ();
1465                                         if (aType.GetArrayRank () != bType.GetArrayRank () && a_el_type == b_el_type) {
1466                                                 result = Result.RefOutArrayError;
1467                                                 continue;
1468                                         }
1469
1470                                         if (a_el_type.IsArray || b_el_type.IsArray) {
1471                                                 result = Result.ArrayArrayError;
1472                                                 continue;
1473                                         }
1474                                 }
1475
1476                                 Type aBaseType = aType;
1477                                 bool is_either_ref_or_out = false;
1478
1479                                 if (aType.IsByRef || aType.IsPointer) {
1480                                         aBaseType = aType.GetElementType ();
1481                                         is_either_ref_or_out = true;
1482                                 }
1483
1484                                 Type bBaseType = bType;
1485                                 if (bType.IsByRef || bType.IsPointer)
1486                                 {
1487                                         bBaseType = bType.GetElementType ();
1488                                         is_either_ref_or_out = !is_either_ref_or_out;
1489                                 }
1490
1491                                 if (aBaseType != bBaseType)
1492                                         return Result.Ok;
1493
1494                                 if (is_either_ref_or_out)
1495                                         result = Result.RefOutArrayError;
1496                         }
1497                         return result;
1498                 }
1499
1500                 /// <summary>
1501                 /// Goes through all parameters and test if they are CLS-Compliant.
1502                 /// </summary>
1503                 public static bool AreParametersCompliant (Parameter[] fixedParameters, Location loc)
1504                 {
1505                         if (fixedParameters == null)
1506                                 return true;
1507
1508                         foreach (Parameter arg in fixedParameters) {
1509                                 if (!AttributeTester.IsClsCompliant (arg.ParameterType)) {
1510                                         Report.Error (3001, loc, "Argument type `{0}' is not CLS-compliant", arg.GetSignatureForError ());
1511                                         return false;
1512                                 }
1513                         }
1514                         return true;
1515                 }
1516
1517
1518                 /// <summary>
1519                 /// This method tests the CLS compliance of external types. It doesn't test type visibility.
1520                 /// </summary>
1521                 public static bool IsClsCompliant (Type type)
1522                 {
1523                         if (type == null)
1524                                 return true;
1525
1526                         object type_compliance = analyzed_types[type];
1527                         if (type_compliance != null)
1528                                 return type_compliance == TRUE;
1529
1530                         if (type.IsPointer) {
1531                                 analyzed_types.Add (type, null);
1532                                 return false;
1533                         }
1534
1535                         bool result;
1536                         if (type.IsArray || type.IsByRef)       {
1537                                 result = IsClsCompliant (TypeManager.GetElementType (type));
1538                         } else {
1539                                 result = AnalyzeTypeCompliance (type);
1540                         }
1541                         analyzed_types.Add (type, result ? TRUE : FALSE);
1542                         return result;
1543                 }
1544
1545                 /// <summary>
1546                 /// Returns IFixedBuffer implementation if field is fixed buffer else null.
1547                 /// </summary>
1548                 public static IFixedBuffer GetFixedBuffer (FieldInfo fi)
1549                 {
1550                         FieldBase fb = TypeManager.GetField (fi);
1551                         if (fb != null) {
1552                                 return fb as IFixedBuffer;
1553                         }
1554
1555 #if NET_2_0
1556                         object o = fixed_buffer_cache [fi];
1557                         if (o == null) {
1558                                 if (System.Attribute.GetCustomAttribute (fi, TypeManager.fixed_buffer_attr_type) == null) {
1559                                         fixed_buffer_cache.Add (fi, FALSE);
1560                                         return null;
1561                                 }
1562
1563                                 IFixedBuffer iff = new FixedFieldExternal (fi);
1564                                 fixed_buffer_cache.Add (fi, iff);
1565                                 return iff;
1566                         }
1567
1568                         if (o == FALSE)
1569                                 return null;
1570
1571                         return (IFixedBuffer)o;
1572 #else
1573                         return null;
1574 #endif
1575                 }
1576
1577                 public static void VerifyModulesClsCompliance ()
1578                 {
1579                         Module[] modules = TypeManager.Modules;
1580                         if (modules == null)
1581                                 return;
1582
1583                         // The first module is generated assembly
1584                         for (int i = 1; i < modules.Length; ++i) {
1585                                 Module module = modules [i];
1586                                 if (!IsClsCompliant (module)) {
1587                                         Report.Error (3013, "Added modules must be marked with the CLSCompliant attribute to match the assembly", module.Name);
1588                                         return;
1589                                 }
1590                         }
1591                 }
1592
1593                 public static Type GetImportedIgnoreCaseClsType (string name)
1594                 {
1595                         foreach (Assembly a in TypeManager.GetAssemblies ()) {
1596                                 Type t = a.GetType (name, false, true);
1597                                 if (t == null)
1598                                         continue;
1599
1600                                 if (IsClsCompliant (t))
1601                                         return t;
1602                         }
1603                         return null;
1604                 }
1605
1606                 static bool IsClsCompliant (ICustomAttributeProvider attribute_provider)
1607                 {
1608                         object[] CompliantAttribute = attribute_provider.GetCustomAttributes (TypeManager.cls_compliant_attribute_type, false);
1609                         if (CompliantAttribute.Length == 0)
1610                                 return false;
1611
1612                         return ((CLSCompliantAttribute)CompliantAttribute[0]).IsCompliant;
1613                 }
1614
1615                 static bool AnalyzeTypeCompliance (Type type)
1616                 {
1617                         DeclSpace ds = TypeManager.LookupDeclSpace (type);
1618                         if (ds != null) {
1619                                 return ds.IsClsCompliaceRequired (ds.Parent);
1620                         }
1621
1622                         object[] CompliantAttribute = type.GetCustomAttributes (TypeManager.cls_compliant_attribute_type, false);
1623                         if (CompliantAttribute.Length == 0)
1624                                 return IsClsCompliant (type.Assembly);
1625
1626                         return ((CLSCompliantAttribute)CompliantAttribute[0]).IsCompliant;
1627                 }
1628
1629                 /// <summary>
1630                 /// Returns instance of ObsoleteAttribute when type is obsolete
1631                 /// </summary>
1632                 public static ObsoleteAttribute GetObsoleteAttribute (Type type)
1633                 {
1634                         object type_obsolete = analyzed_types_obsolete [type];
1635                         if (type_obsolete == FALSE)
1636                                 return null;
1637
1638                         if (type_obsolete != null)
1639                                 return (ObsoleteAttribute)type_obsolete;
1640
1641                         ObsoleteAttribute result = null;
1642                         if (type.IsByRef || type.IsArray || type.IsPointer) {
1643                                 result = GetObsoleteAttribute (TypeManager.GetElementType (type));
1644                         } else {
1645                                 DeclSpace type_ds = TypeManager.LookupDeclSpace (type);
1646
1647                                 // Type is external, we can get attribute directly
1648                                 if (type_ds == null) {
1649                                         object[] attribute = type.GetCustomAttributes (TypeManager.obsolete_attribute_type, false);
1650                                         if (attribute.Length == 1)
1651                                                 result = (ObsoleteAttribute)attribute [0];
1652                                 } else {
1653                                         result = type_ds.GetObsoleteAttribute (type_ds);
1654                                 }
1655                         }
1656
1657                         analyzed_types_obsolete.Add (type, result == null ? FALSE : result);
1658                         return result;
1659                 }
1660
1661                 /// <summary>
1662                 /// Returns instance of ObsoleteAttribute when method is obsolete
1663                 /// </summary>
1664                 public static ObsoleteAttribute GetMethodObsoleteAttribute (MethodBase mb)
1665                 {
1666                         IMethodData mc = TypeManager.GetMethod (mb);
1667                         if (mc != null)
1668                                 return mc.GetObsoleteAttribute ();
1669
1670                         // compiler generated methods are not registered by AddMethod
1671                         if (mb.DeclaringType is TypeBuilder)
1672                                 return null;
1673
1674                         if (mb.IsSpecialName) {
1675                                 PropertyInfo pi = PropertyExpr.AccessorTable [mb] as PropertyInfo;
1676                                 if (pi != null) {
1677                                         // FIXME: This is buggy as properties from this assembly are included as well
1678                                         return null;
1679                                         //return GetMemberObsoleteAttribute (pi);
1680                                 }
1681                         }
1682
1683                         return GetMemberObsoleteAttribute (mb);
1684                 }
1685
1686                 /// <summary>
1687                 /// Returns instance of ObsoleteAttribute when member is obsolete
1688                 /// </summary>
1689                 public static ObsoleteAttribute GetMemberObsoleteAttribute (MemberInfo mi)
1690                 {
1691                         object type_obsolete = analyzed_member_obsolete [mi];
1692                         if (type_obsolete == FALSE)
1693                                 return null;
1694
1695                         if (type_obsolete != null)
1696                                 return (ObsoleteAttribute)type_obsolete;
1697
1698                         ObsoleteAttribute oa = System.Attribute.GetCustomAttribute (mi, TypeManager.obsolete_attribute_type, false) as ObsoleteAttribute;
1699                         analyzed_member_obsolete.Add (mi, oa == null ? FALSE : oa);
1700                         return oa;
1701                 }
1702
1703                 /// <summary>
1704                 /// Common method for Obsolete error/warning reporting.
1705                 /// </summary>
1706                 public static void Report_ObsoleteMessage (ObsoleteAttribute oa, string member, Location loc)
1707                 {
1708                         if (oa.IsError) {
1709                                 Report.Error (619, loc, "`{0}' is obsolete: `{1}'", member, oa.Message);
1710                                 return;
1711                         }
1712
1713                         if (oa.Message == null) {
1714                                 Report.Warning (612, loc, "`{0}' is obsolete", member);
1715                                 return;
1716                         }
1717                         if (RootContext.WarningLevel >= 2)
1718                                 Report.Warning (618, loc, "`{0}' is obsolete: `{1}'", member, oa.Message);
1719                 }
1720
1721                 public static bool IsConditionalMethodExcluded (MethodBase mb)
1722                 {
1723                         object excluded = analyzed_method_excluded [mb];
1724                         if (excluded != null)
1725                                 return excluded == TRUE ? true : false;
1726
1727                         ConditionalAttribute[] attrs = mb.GetCustomAttributes (TypeManager.conditional_attribute_type, true) as ConditionalAttribute[];
1728                         if (attrs.Length == 0) {
1729                                 analyzed_method_excluded.Add (mb, FALSE);
1730                                 return false;
1731                         }
1732
1733                         foreach (ConditionalAttribute a in attrs) {
1734                                 if (RootContext.AllDefines.Contains (a.ConditionString)) {
1735                                         analyzed_method_excluded.Add (mb, FALSE);
1736                                         return false;
1737                                 }
1738                         }
1739                         analyzed_method_excluded.Add (mb, TRUE);
1740                         return true;
1741                 }
1742
1743                 /// <summary>
1744                 /// Analyzes class whether it has attribute which has ConditionalAttribute
1745                 /// and its condition is not defined.
1746                 /// </summary>
1747                 public static bool IsAttributeExcluded (Type type)
1748                 {
1749                         if (!type.IsClass)
1750                                 return false;
1751
1752                         Class class_decl = TypeManager.LookupDeclSpace (type) as Class;
1753
1754                         // TODO: add caching
1755                         // TODO: merge all Type bases attribute caching to one cache to save memory
1756                         if (class_decl == null) {
1757                                 object[] attributes = type.GetCustomAttributes (TypeManager.conditional_attribute_type, false);
1758                                 foreach (ConditionalAttribute ca in attributes) {
1759                                         if (RootContext.AllDefines.Contains (ca.ConditionString))
1760                                                 return false;
1761                                 }
1762                                 return attributes.Length > 0;
1763                         }
1764
1765                         return class_decl.IsExcluded ();
1766                 }
1767         }
1768 }