mcs/field.cs

   1 //
   2 // field.cs: All field handlers
   3 //
   4 // Authors: Miguel de Icaza (miguel@gnu.org)
   5 //          Martin Baulig (martin@ximian.com)
   6 //          Marek Safar (marek.safar@seznam.cz)
   7 //
   8 // Dual licensed under the terms of the MIT X11 or GNU GPL
   9 //
  10 // Copyright 2001, 2002, 2003 Ximian, Inc (http://www.ximian.com)
  11 // Copyright 2004-2008 Novell, Inc
  12 //
  13
  14 using System;
  15 using System.Collections.Generic;
  16 using System.Reflection;
  17 using System.Reflection.Emit;
  18 using System.Runtime.InteropServices;
  19
  20 namespace Mono.CSharp
  21 {
  22         //
  23         // Abstract class for all fields
  24         //
  25         abstract public class FieldBase : MemberBase
  26         {
  27                 public FieldBuilder FieldBuilder;
  28                 protected FieldSpec spec;
  29                 public Status status;
  30                 protected Expression initializer;
  31
  32                 [Flags]
  33                 public enum Status : byte {
  34                         HAS_OFFSET = 4          // Used by FieldMember.
  35                 }
  36
  37                 static readonly string[] attribute_targets = new string [] { "field" };
  38
  39                 protected FieldBase (DeclSpace parent, FullNamedExpression type, Modifiers mod,
  40                                      Modifiers allowed_mod, MemberName name, Attributes attrs)
  41                         : base (parent, null, type, mod, allowed_mod | Modifiers.ABSTRACT, Modifiers.PRIVATE,
  42                                 name, attrs)
  43                 {
  44                         if ((mod & Modifiers.ABSTRACT) != 0)
  45                                 Report.Error (681, Location, "The modifier 'abstract' is not valid on fields. Try using a property instead");
  46                 }
  47
  48                 public override AttributeTargets AttributeTargets {
  49                         get {
  50                                 return AttributeTargets.Field;
  51                         }
  52                 }
  53
  54                 public override void ApplyAttributeBuilder (Attribute a, MethodSpec ctor, byte[] cdata, PredefinedAttributes pa)
  55                 {
  56                         if (a.Type == pa.FieldOffset) {
  57                                 status |= Status.HAS_OFFSET;
  58
  59                                 if (!Parent.PartialContainer.HasExplicitLayout) {
  60                                         Report.Error (636, Location, "The FieldOffset attribute can only be placed on members of types marked with the StructLayout(LayoutKind.Explicit)");
  61                                         return;
  62                                 }
  63
  64                                 if ((ModFlags & Modifiers.STATIC) != 0 || this is Const) {
  65                                         Report.Error (637, Location, "The FieldOffset attribute is not allowed on static or const fields");
  66                                         return;
  67                                 }
  68                         }
  69
  70                         if (a.Type == pa.FixedBuffer) {
  71                                 Report.Error (1716, Location, "Do not use 'System.Runtime.CompilerServices.FixedBuffer' attribute. Use the 'fixed' field modifier instead");
  72                                 return;
  73                         }
  74
  75 #if false
  76                         if (a.Type == pa.MarshalAs) {
  77                                 UnmanagedMarshal marshal = a.GetMarshal (this);
  78                                 if (marshal != null) {
  79                                         FieldBuilder.SetMarshal (marshal);
  80                                 }
  81                                 return;
  82                         }
  83 #endif
  84                         if ((a.HasSecurityAttribute)) {
  85                                 a.Error_InvalidSecurityParent ();
  86                                 return;
  87                         }
  88
  89                         if (a.Type == pa.Dynamic) {
  90                                 a.Error_MisusedDynamicAttribute ();
  91                                 return;
  92                         }
  93
  94                         FieldBuilder.SetCustomAttribute ((ConstructorInfo) ctor.GetMetaInfo (), cdata);
  95                 }
  96
  97                 protected override bool CheckBase ()
  98                 {
  99                         if (!base.CheckBase ())
 100                                 return false;
 101
 102                         MemberSpec candidate;
 103                         var conflict_symbol = MemberCache.FindBaseMember (this, out candidate);
 104                         if (conflict_symbol == null)
 105                                 conflict_symbol = candidate;
 106
 107                         if (conflict_symbol == null) {
 108                                 if ((ModFlags & Modifiers.NEW) != 0) {
 109                                         Report.Warning (109, 4, Location, "The member `{0}' does not hide an inherited member. The new keyword is not required",
 110                                                 GetSignatureForError ());
 111                                 }
 112                         } else {
 113                                 if ((ModFlags & (Modifiers.NEW | Modifiers.OVERRIDE | Modifiers.BACKING_FIELD)) == 0) {
 114                                         Report.SymbolRelatedToPreviousError (conflict_symbol);
 115                                         Report.Warning (108, 2, Location, "`{0}' hides inherited member `{1}'. Use the new keyword if hiding was intended",
 116                                                 GetSignatureForError (), conflict_symbol.GetSignatureForError ());
 117                                 }
 118
 119                                 if (conflict_symbol.IsAbstract) {
 120                                         Report.SymbolRelatedToPreviousError (conflict_symbol);
 121                                         Report.Error (533, Location, "`{0}' hides inherited abstract member `{1}'",
 122                                                 GetSignatureForError (), conflict_symbol.GetSignatureForError ());
 123                                 }
 124                         }
 125
 126                         return true;
 127                 }
 128
 129                 public virtual Constant ConvertInitializer (ResolveContext rc, Constant expr)
 130                 {
 131                         return expr.ConvertImplicitly (rc, MemberType);
 132                 }
 133
 134                 protected override void DoMemberTypeDependentChecks ()
 135                 {
 136                         base.DoMemberTypeDependentChecks ();
 137
 138                         if (MemberType.IsGenericParameter)
 139                                 return;
 140
 141                         if (MemberType.IsStatic)
 142                                 Error_VariableOfStaticClass (Location, GetSignatureForError (), MemberType, Report);
 143
 144                         CheckBase ();
 145                         IsTypePermitted ();
 146                 }
 147
 148                 //
 149                 //   Represents header string for documentation comment.
 150                 //
 151                 public override string DocCommentHeader {
 152                         get { return "F:"; }
 153                 }
 154
 155                 public override void Emit ()
 156                 {
 157                         if (member_type == InternalType.Dynamic) {
 158                                 PredefinedAttributes.Get.Dynamic.EmitAttribute (FieldBuilder);
 159                         } else {
 160                                 var trans_flags = TypeManager.HasDynamicTypeUsed (member_type);
 161                                 if (trans_flags != null) {
 162                                         var pa = PredefinedAttributes.Get.DynamicTransform;
 163                                         if (pa.Constructor != null || pa.ResolveConstructor (Location, ArrayContainer.MakeType (TypeManager.bool_type, 1))) {
 164                                                 FieldBuilder.SetCustomAttribute (new CustomAttributeBuilder (pa.Constructor, new object[] { trans_flags }));
 165                                         }
 166                                 }
 167                         }
 168
 169                         if ((ModFlags & Modifiers.COMPILER_GENERATED) != 0 && !Parent.IsCompilerGenerated)
 170                                 PredefinedAttributes.Get.CompilerGenerated.EmitAttribute (FieldBuilder);
 171
 172                         if (OptAttributes != null) {
 173                                 OptAttributes.Emit ();
 174                         }
 175
 176                         if (((status & Status.HAS_OFFSET) == 0) && (ModFlags & (Modifiers.STATIC | Modifiers.BACKING_FIELD)) == 0 && Parent.PartialContainer.HasExplicitLayout) {
 177                                 Report.Error (625, Location, "`{0}': Instance field types marked with StructLayout(LayoutKind.Explicit) must have a FieldOffset attribute", GetSignatureForError ());
 178                         }
 179
 180                         base.Emit ();
 181                 }
 182
 183                 public static void Error_VariableOfStaticClass (Location loc, string variable_name, TypeSpec static_class, Report Report)
 184                 {
 185                         Report.SymbolRelatedToPreviousError (static_class);
 186                         Report.Error (723, loc, "`{0}': cannot declare variables of static types",
 187                                 variable_name);
 188                 }
 189
 190                 public Expression Initializer {
 191                         get {
 192                                 return initializer;
 193                         }
 194                         set {
 195                                 if (value != null) {
 196                                         this.initializer = value;
 197                                 }
 198                         }
 199                 }
 200
 201                 public FieldSpec Spec {
 202                         get { return spec; }
 203                 }
 204
 205                 public override string[] ValidAttributeTargets
 206                 {
 207                         get {
 208                                 return attribute_targets;
 209                         }
 210                 }
 211
 212                 protected override bool VerifyClsCompliance ()
 213                 {
 214                         if (!base.VerifyClsCompliance ())
 215                                 return false;
 216
 217                         if (!MemberType.IsCLSCompliant () || this is FixedField) {
 218                                 Report.Warning (3003, 1, Location, "Type of `{0}' is not CLS-compliant",
 219                                         GetSignatureForError ());
 220                         }
 221                         return true;
 222                 }
 223         }
 224
 225         //
 226         // Field specification
 227         //
 228         public class FieldSpec : MemberSpec, IInterfaceMemberSpec
 229         {
 230                 FieldInfo metaInfo;
 231                 TypeSpec memberType;
 232
 233                 public FieldSpec (TypeSpec declaringType, IMemberDefinition definition, TypeSpec memberType, FieldInfo info, Modifiers modifiers)
 234                         : base (MemberKind.Field, declaringType, definition, modifiers)
 235                 {
 236                         this.metaInfo = info;
 237                         this.memberType = memberType;
 238                 }
 239
 240 #region Properties
 241
 242                 public bool IsReadOnly {
 243                         get {
 244                                 return (Modifiers & Modifiers.READONLY) != 0;
 245                         }
 246                 }
 247
 248                 public TypeSpec MemberType {
 249                         get {
 250                                 return memberType;
 251                         }
 252                 }
 253
 254 #endregion
 255
 256                 public FieldInfo GetMetaInfo ()
 257                 {
 258                         if ((state & StateFlags.PendingMetaInflate) != 0) {
 259                                 var decl_meta = DeclaringType.GetMetaInfo ();
 260                                 if (DeclaringType.IsTypeBuilder) {
 261                                         metaInfo = TypeBuilder.GetField (decl_meta, metaInfo);
 262                                 } else {
 263                                         var orig_token = metaInfo.MetadataToken;
 264                                         metaInfo = decl_meta.GetField (Name, BindingFlags.Public | BindingFlags.NonPublic | BindingFlags.Instance | BindingFlags.Static);
 265                                         if (metaInfo.MetadataToken != orig_token)
 266                                                 throw new NotImplementedException ("Resolved to wrong meta token");
 267
 268                                         // What a stupid API, does not work because field handle is imported
 269                                         // metaInfo = FieldInfo.GetFieldFromHandle (metaInfo.FieldHandle, DeclaringType.MetaInfo.TypeHandle);
 270                                 }
 271
 272                                 state &= ~StateFlags.PendingMetaInflate;
 273                         }
 274
 275                         return metaInfo;
 276                 }
 277
 278                 public override MemberSpec InflateMember (TypeParameterInflator inflator)
 279                 {
 280                         var fs = (FieldSpec) base.InflateMember (inflator);
 281                         fs.memberType = inflator.Inflate (memberType);
 282                         return fs;
 283                 }
 284
 285                 public FieldSpec Mutate (TypeParameterMutator mutator)
 286                 {
 287                         var decl = DeclaringType;
 288                         if (DeclaringType.IsGenericOrParentIsGeneric)
 289                                 decl = mutator.Mutate (decl);
 290
 291                         if (decl == DeclaringType)
 292                                 return this;
 293
 294                         var fs = (FieldSpec) MemberwiseClone ();
 295                         fs.declaringType = decl;
 296                         fs.state |= StateFlags.PendingMetaInflate;
 297
 298                         // Gets back FieldInfo in case of metaInfo was inflated
 299                         fs.metaInfo = MemberCache.GetMember (DeclaringType.GetDefinition (), this).metaInfo;
 300                         return fs;
 301                 }
 302         }
 303
 304         /// <summary>
 305         /// Fixed buffer implementation
 306         /// </summary>
 307         public class FixedField : FieldBase
 308         {
 309                 public const string FixedElementName = "FixedElementField";
 310                 static int GlobalCounter = 0;
 311                 static object[] ctor_args = new object[] { (short)LayoutKind.Sequential };
 312                 static FieldInfo[] fi;
 313
 314                 TypeBuilder fixed_buffer_type;
 315
 316                 const Modifiers AllowedModifiers =
 317                         Modifiers.NEW |
 318                         Modifiers.PUBLIC |
 319                         Modifiers.PROTECTED |
 320                         Modifiers.INTERNAL |
 321                         Modifiers.PRIVATE |
 322                         Modifiers.UNSAFE;
 323
 324                 public FixedField (DeclSpace parent, FullNamedExpression type, Modifiers mod, string name,
 325                         Expression size_expr, Attributes attrs, Location loc):
 326                         base (parent, type, mod, AllowedModifiers, new MemberName (name, loc), attrs)
 327                 {
 328                         initializer = new ConstInitializer (this, size_expr);
 329                 }
 330
 331                 public override Constant ConvertInitializer (ResolveContext rc, Constant expr)
 332                 {
 333                         return expr.ImplicitConversionRequired (rc, TypeManager.int32_type, Location);
 334                 }
 335
 336                 public override bool Define ()
 337                 {
 338                         if (!base.Define ())
 339                                 return false;
 340
 341                         if (!TypeManager.IsPrimitiveType (MemberType)) {
 342                                 Report.Error (1663, Location,
 343                                         "`{0}': Fixed size buffers type must be one of the following: bool, byte, short, int, long, char, sbyte, ushort, uint, ulong, float or double",
 344                                         GetSignatureForError ());
 345                         }
 346
 347                         // Create nested fixed buffer container
 348                         string name = String.Format ("<{0}>__FixedBuffer{1}", Name, GlobalCounter++);
 349                         fixed_buffer_type = Parent.TypeBuilder.DefineNestedType (name, Parent.Module.DefaultCharSetType |
 350                                 TypeAttributes.NestedPublic | TypeAttributes.Sealed | TypeAttributes.BeforeFieldInit, TypeManager.value_type.GetMetaInfo ());
 351
 352                         fixed_buffer_type.DefineField (FixedElementName, MemberType.GetMetaInfo (), FieldAttributes.Public);
 353                         RootContext.RegisterCompilerGeneratedType (fixed_buffer_type);
 354
 355                         FieldBuilder = Parent.TypeBuilder.DefineField (Name, fixed_buffer_type, ModifiersExtensions.FieldAttr (ModFlags));
 356                         var element_spec = new FieldSpec (null, this, MemberType, FieldBuilder, ModFlags);
 357                         spec = new FixedFieldSpec (Parent.Definition, this, FieldBuilder, element_spec, ModFlags);
 358
 359                         Parent.MemberCache.AddMember (spec);
 360                         return true;
 361                 }
 362
 363                 protected override void DoMemberTypeIndependentChecks ()
 364                 {
 365                         base.DoMemberTypeIndependentChecks ();
 366
 367                         if (!IsUnsafe)
 368                                 Expression.UnsafeError (Report, Location);
 369
 370                         if (Parent.PartialContainer.Kind != MemberKind.Struct) {
 371                                 Report.Error (1642, Location, "`{0}': Fixed size buffer fields may only be members of structs",
 372                                         GetSignatureForError ());
 373                         }
 374                 }
 375
 376                 public override void Emit()
 377                 {
 378                         ResolveContext rc = new ResolveContext (this);
 379                         IntConstant buffer_size_const = initializer.Resolve (rc) as IntConstant;
 380                         if (buffer_size_const == null)
 381                                 return;
 382
 383                         int buffer_size = buffer_size_const.Value;
 384
 385                         if (buffer_size <= 0) {
 386                                 Report.Error (1665, Location, "`{0}': Fixed size buffers must have a length greater than zero", GetSignatureForError ());
 387                                 return;
 388                         }
 389
 390                         int type_size = Expression.GetTypeSize (MemberType);
 391
 392                         if (buffer_size > int.MaxValue / type_size) {
 393                                 Report.Error (1664, Location, "Fixed size buffer `{0}' of length `{1}' and type `{2}' exceeded 2^31 limit",
 394                                         GetSignatureForError (), buffer_size.ToString (), TypeManager.CSharpName (MemberType));
 395                                 return;
 396                         }
 397
 398                         buffer_size *= type_size;
 399                         EmitFieldSize (buffer_size);
 400
 401                         PredefinedAttributes.Get.UnsafeValueType.EmitAttribute (fixed_buffer_type);
 402
 403                         base.Emit ();
 404                 }
 405
 406                 void EmitFieldSize (int buffer_size)
 407                 {
 408                         CustomAttributeBuilder cab;
 409                         PredefinedAttribute pa;
 410
 411                         pa = PredefinedAttributes.Get.StructLayout;
 412                         if (pa.Constructor == null &&
 413                                 !pa.ResolveConstructor (Location, TypeManager.short_type))
 414                                         return;
 415
 416                         // TODO: It's not cleared
 417                         if (fi == null) {
 418                                 var field = (FieldSpec) MemberCache.FindMember (pa.Type, MemberFilter.Field ("Size", null), BindingRestriction.DeclaredOnly);
 419                                 fi = new FieldInfo[] { field.GetMetaInfo () };
 420                         }
 421
 422                         object[] fi_val = new object[] { buffer_size };
 423                         cab = new CustomAttributeBuilder (pa.Constructor,
 424                                 ctor_args, fi, fi_val);
 425                         fixed_buffer_type.SetCustomAttribute (cab);
 426
 427                         //
 428                         // Don't emit FixedBufferAttribute attribute for private types
 429                         //
 430                         if ((ModFlags & Modifiers.PRIVATE) != 0)
 431                                 return;
 432
 433                         pa = PredefinedAttributes.Get.FixedBuffer;
 434                         if (pa.Constructor == null &&
 435                                 !pa.ResolveConstructor (Location, TypeManager.type_type, TypeManager.int32_type))
 436                                 return;
 437
 438                         cab = new CustomAttributeBuilder (pa.Constructor, new object[] { MemberType.GetMetaInfo (), buffer_size });
 439                         FieldBuilder.SetCustomAttribute (cab);
 440                 }
 441
 442                 public void SetCharSet (TypeAttributes ta)
 443                 {
 444                         TypeAttributes cta = fixed_buffer_type.Attributes;
 445                         if ((cta & TypeAttributes.UnicodeClass) != (ta & TypeAttributes.UnicodeClass))
 446                                 SetTypeBuilderCharSet ((cta & ~TypeAttributes.AutoClass) | TypeAttributes.UnicodeClass);
 447                         else if ((cta & TypeAttributes.AutoClass) != (ta & TypeAttributes.AutoClass))
 448                                 SetTypeBuilderCharSet ((cta & ~TypeAttributes.UnicodeClass) | TypeAttributes.AutoClass);
 449                         else if (cta == 0 && ta != 0)
 450                                 SetTypeBuilderCharSet (cta & ~(TypeAttributes.UnicodeClass | TypeAttributes.AutoClass));
 451                 }
 452
 453                 void SetTypeBuilderCharSet (TypeAttributes ta)
 454                 {
 455                         MethodInfo mi = typeof (TypeBuilder).GetMethod ("SetCharSet", BindingFlags.Instance | BindingFlags.NonPublic);
 456                         if (mi == null) {
 457                                 Report.RuntimeMissingSupport (Location, "TypeBuilder::SetCharSet");
 458                         } else {
 459                                 mi.Invoke (fixed_buffer_type, new object [] { ta });
 460                         }
 461                 }
 462         }
 463
 464         class FixedFieldSpec : FieldSpec
 465         {
 466                 readonly FieldSpec element;
 467
 468                 public FixedFieldSpec (TypeSpec declaringType, IMemberDefinition definition, FieldInfo info, FieldSpec element, Modifiers modifiers)
 469                         : base (declaringType, definition, element.MemberType, info, modifiers)
 470                 {
 471                         this.element = element;
 472
 473                         // It's never CLS-Compliant
 474                         state &= ~StateFlags.CLSCompliant_Undetected;
 475                 }
 476
 477                 public FieldSpec Element {
 478                         get {
 479                                 return element;
 480                         }
 481                 }
 482
 483                 public TypeSpec ElementType {
 484                         get {
 485                                 return MemberType;
 486                         }
 487                 }
 488         }
 489
 490         //
 491         // The Field class is used to represents class/struct fields during parsing.
 492         //
 493         public class Field : FieldBase {
 494                 // <summary>
 495                 //   Modifiers allowed in a class declaration
 496                 // </summary>
 497                 const Modifiers AllowedModifiers =
 498                         Modifiers.NEW |
 499                         Modifiers.PUBLIC |
 500                         Modifiers.PROTECTED |
 501                         Modifiers.INTERNAL |
 502                         Modifiers.PRIVATE |
 503                         Modifiers.STATIC |
 504                         Modifiers.VOLATILE |
 505                         Modifiers.UNSAFE |
 506                         Modifiers.READONLY;
 507
 508                 public Field (DeclSpace parent, FullNamedExpression type, Modifiers mod, MemberName name,
 509                               Attributes attrs)
 510                         : base (parent, type, mod, AllowedModifiers, name, attrs)
 511                 {
 512                 }
 513
 514                 bool CanBeVolatile ()
 515                 {
 516                         if (TypeManager.IsReferenceType (MemberType))
 517                                 return true;
 518
 519                         if (MemberType == TypeManager.bool_type || MemberType == TypeManager.char_type ||
 520                                 MemberType == TypeManager.sbyte_type || MemberType == TypeManager.byte_type ||
 521                                 MemberType == TypeManager.short_type || MemberType == TypeManager.ushort_type ||
 522                                 MemberType == TypeManager.int32_type || MemberType == TypeManager.uint32_type ||
 523                                 MemberType == TypeManager.float_type ||
 524                                 MemberType == TypeManager.intptr_type || MemberType == TypeManager.uintptr_type)
 525                                 return true;
 526
 527                         if (MemberType.IsEnum)
 528                                 return true;
 529
 530                         return false;
 531                 }
 532
 533                 public override bool Define ()
 534                 {
 535                         if (!base.Define ())
 536                                 return false;
 537
 538                         try {
 539                                 Type[] required_modifier = null;
 540                                 if ((ModFlags & Modifiers.VOLATILE) != 0) {
 541                                         if (TypeManager.isvolatile_type == null)
 542                                                 TypeManager.isvolatile_type = TypeManager.CoreLookupType (Compiler,
 543                                                         "System.Runtime.CompilerServices", "IsVolatile", MemberKind.Class, true);
 544
 545                                         if (TypeManager.isvolatile_type != null)
 546                                                 required_modifier = new Type[] { TypeManager.isvolatile_type.GetMetaInfo () };
 547                                 }
 548
 549                                 FieldBuilder = Parent.TypeBuilder.DefineField (
 550                                         Name, member_type.GetMetaInfo (), required_modifier, null, ModifiersExtensions.FieldAttr (ModFlags));
 551
 552                                 spec = new FieldSpec (Parent.Definition, this, MemberType, FieldBuilder, ModFlags);
 553
 554                                 // Don't cache inaccessible fields
 555                                 if ((ModFlags & Modifiers.BACKING_FIELD) == 0) {
 556                                         Parent.MemberCache.AddMember (spec);
 557                                 }
 558                         }
 559                         catch (ArgumentException) {
 560                                 Report.RuntimeMissingSupport (Location, "`void' or `void*' field type");
 561                                 return false;
 562                         }
 563
 564                         if (initializer != null) {
 565                                 ((TypeContainer) Parent).RegisterFieldForInitialization (this,
 566                                         new FieldInitializer (this, initializer, this));
 567                         }
 568
 569                         return true;
 570                 }
 571
 572                 protected override void DoMemberTypeDependentChecks ()
 573                 {
 574                         if ((ModFlags & Modifiers.BACKING_FIELD) != 0)
 575                                 return;
 576
 577                         base.DoMemberTypeDependentChecks ();
 578
 579                         if ((ModFlags & Modifiers.VOLATILE) != 0) {
 580                                 if (!CanBeVolatile ()) {
 581                                         Report.Error (677, Location, "`{0}': A volatile field cannot be of the type `{1}'",
 582                                                 GetSignatureForError (), TypeManager.CSharpName (MemberType));
 583                                 }
 584
 585                                 if ((ModFlags & Modifiers.READONLY) != 0) {
 586                                         Report.Error (678, Location, "`{0}': A field cannot be both volatile and readonly",
 587                                                 GetSignatureForError ());
 588                                 }
 589                         }
 590                 }
 591
 592                 protected override bool VerifyClsCompliance ()
 593                 {
 594                         if (!base.VerifyClsCompliance ())
 595                                 return false;
 596
 597                         if ((ModFlags & Modifiers.VOLATILE) != 0) {
 598                                 Report.Warning (3026, 1, Location, "CLS-compliant field `{0}' cannot be volatile", GetSignatureForError ());
 599                         }
 600
 601                         return true;
 602                 }
 603         }
 604 }