mcs/mcs/membercache.cs

   1 //
   2 // membercache.cs: A container for all member lookups
   3 //
   4 // Author: Miguel de Icaza (miguel@gnu.org)
   5 //         Marek Safar (marek.safar@gmail.com)
   6 //
   7 // Dual licensed under the terms of the MIT X11 or GNU GPL
   8 //
   9 // Copyright 2001 Ximian, Inc (http://www.ximian.com)
  10 // Copyright 2004-2010 Novell, Inc
  11 // Copyright 2011 Xamarin Inc
  12 //
  13 //
  14
  15 using System;
  16 using System.Collections.Generic;
  17
  18 namespace Mono.CSharp {
  19
  20         [Flags]
  21         public enum MemberKind
  22         {
  23                 Constructor = 1,
  24                 Event = 1 << 1,
  25                 Field = 1 << 2,
  26                 Method = 1 << 3,
  27                 Property = 1 << 4,
  28                 Indexer = 1 << 5,
  29                 Operator = 1 << 6,
  30                 Destructor      = 1 << 7,
  31
  32                 Class           = 1 << 11,
  33                 Struct          = 1 << 12,
  34                 Delegate        = 1 << 13,
  35                 Enum            = 1 << 14,
  36                 Interface       = 1 << 15,
  37                 TypeParameter = 1 << 16,
  38
  39                 ArrayType = 1 << 19,
  40                 PointerType = 1 << 20,
  41                 InternalCompilerType = 1 << 21,
  42                 MissingType = 1 << 22,
  43                 Void = 1 << 23,
  44                 Namespace = 1 << 24,
  45
  46                 NestedMask = Class | Struct | Delegate | Enum | Interface,
  47                 GenericMask = Method | Class | Struct | Delegate | Interface,
  48                 MaskType = Constructor | Event | Field | Method | Property | Indexer | Operator | Destructor | NestedMask
  49         }
  50
  51         [Flags]
  52         public enum BindingRestriction
  53         {
  54                 None = 0,
  55
  56                 // Inspect only queried type members
  57                 DeclaredOnly = 1 << 1,
  58
  59                 // Exclude static
  60                 InstanceOnly = 1 << 2,
  61
  62                 NoAccessors = 1 << 3,
  63
  64                 // Member has to be override
  65                 OverrideOnly = 1 << 4
  66         }
  67
  68         public struct MemberFilter : IEquatable<MemberSpec>
  69         {
  70                 public readonly string Name;
  71                 public readonly MemberKind Kind;
  72                 public readonly AParametersCollection Parameters;
  73                 public readonly TypeSpec MemberType;
  74                 public readonly int Arity; // -1 to ignore the check
  75
  76                 public MemberFilter (MethodSpec m)
  77                 {
  78                         Name = m.Name;
  79                         Kind = MemberKind.Method;
  80                         Parameters = m.Parameters;
  81                         MemberType = m.ReturnType;
  82                         Arity = m.Arity;
  83                 }
  84
  85                 public MemberFilter (string name, int arity, MemberKind kind, AParametersCollection param, TypeSpec type)
  86                 {
  87                         Name = name;
  88                         Kind = kind;
  89                         Parameters = param;
  90                         MemberType = type;
  91                         this.Arity = arity;
  92                 }
  93
  94                 public static MemberFilter Constructor (AParametersCollection param)
  95                 {
  96                         return new MemberFilter (Mono.CSharp.Constructor.ConstructorName, 0, MemberKind.Constructor, param, null);
  97                 }
  98
  99                 public static MemberFilter Property (string name, TypeSpec type)
 100                 {
 101                         return new MemberFilter (name, 0, MemberKind.Property, null, type);
 102                 }
 103
 104                 public static MemberFilter Field (string name, TypeSpec type)
 105                 {
 106                         return new MemberFilter (name, 0, MemberKind.Field, null, type);
 107                 }
 108
 109                 public static MemberFilter Method (string name, int arity, AParametersCollection param, TypeSpec type)
 110                 {
 111                         return new MemberFilter (name, arity, MemberKind.Method, param, type);
 112                 }
 113
 114                 #region IEquatable<MemberSpec> Members
 115
 116                 public bool Equals (MemberSpec other)
 117                 {
 118                         // Is the member of the correct type ?
 119                         // TODO: Isn't this redundant ?
 120                         if ((other.Kind & Kind & MemberKind.MaskType) == 0)
 121                                 return false;
 122
 123                         // Check arity when not disabled
 124                         if (Arity >= 0 && Arity != other.Arity)
 125                                 return false;
 126
 127                         if (Parameters != null) {
 128                                 if (other is IParametersMember) {
 129                                         var other_param = ((IParametersMember) other).Parameters;
 130                                         if (!TypeSpecComparer.Override.IsEqual (Parameters, other_param))
 131                                                 return false;
 132                                 } else {
 133                                         return false;
 134                                 }
 135                         }
 136
 137                         if (MemberType != null) {
 138                                 if (other is IInterfaceMemberSpec) {
 139                                         var other_type = ((IInterfaceMemberSpec) other).MemberType;
 140                                         if (!TypeSpecComparer.Override.IsEqual (other_type, MemberType))
 141                                                 return false;
 142                                 } else {
 143                                         return false;
 144                                 }
 145                         }
 146
 147                         return true;
 148                 }
 149
 150                 #endregion
 151         }
 152
 153         //
 154         // The MemberCache is the main members container used by compiler. It contains
 155         // all members imported or defined during compilation using on demand filling
 156         // process. Inflated containers are also using MemberCache to make inflated
 157         // members look like normal definition.
 158         //
 159         // All of the methods are performance and memory sensitive as the MemberCache
 160         // is the underlying engine of all member based operations.
 161         //
 162         public class MemberCache
 163         {
 164                 [Flags]
 165                 enum StateFlags
 166                 {
 167                         HasConversionOperator = 1 << 1,
 168                         HasUserOperator = 1 << 2
 169                 }
 170
 171                 readonly Dictionary<string, IList<MemberSpec>> member_hash;
 172                 Dictionary<string, MemberSpec[]> locase_members;
 173                 IList<MethodSpec> missing_abstract;
 174                 StateFlags state;       // TODO: Move to TypeSpec or ITypeDefinition
 175
 176                 public static readonly string IndexerNameAlias = "<this>";
 177
 178                 public static readonly MemberCache Empty = new MemberCache (0);
 179
 180                 public MemberCache ()
 181                         : this (16)
 182                 {
 183                 }
 184
 185                 public MemberCache (int capacity)
 186                 {
 187                         member_hash = new Dictionary<string, IList<MemberSpec>> (capacity);
 188                 }
 189
 190                 public MemberCache (MemberCache cache)
 191                         : this (cache.member_hash.Count)
 192                 {
 193                         this.state = cache.state;
 194                 }
 195
 196                 //
 197                 // Creates a new MemberCache for the given `container'.
 198                 //
 199                 public MemberCache (TypeContainer container)
 200                         : this ()                               // TODO: Optimize the size
 201                 {
 202                 }
 203
 204                 //
 205                 // For cases where we need to union cache members
 206                 //
 207                 public void AddBaseType (TypeSpec baseType)
 208                 {
 209                         var cache = baseType.MemberCache;
 210
 211                         IList<MemberSpec> list;
 212                         foreach (var entry in cache.member_hash) {
 213                                 if (!member_hash.TryGetValue (entry.Key, out list)) {
 214                                         if (entry.Value.Count == 1) {
 215                                                 list = entry.Value;
 216                                         } else {
 217                                                 list = new List<MemberSpec> (entry.Value);
 218                                         }
 219
 220                                         member_hash.Add (entry.Key, list);
 221                                         continue;
 222                                 }
 223
 224                                 foreach (var ce in entry.Value) {
 225                                         if (list.Contains (ce))
 226                                                 continue;
 227
 228                                         if (list is MemberSpec[]) {
 229                                                 list = new List<MemberSpec> () { list [0] };
 230                                                 member_hash[entry.Key] = list;
 231                                         }
 232
 233                                         list.Add (ce);
 234                                 }
 235                         }
 236                 }
 237
 238                 //
 239                 // Member-cache does not contain base members but it does
 240                 // contain all base interface members, so the Lookup code
 241                 // can use simple inheritance rules.
 242                 //
 243                 public void AddInterface (TypeSpec iface)
 244                 {
 245                         var cache = iface.MemberCache;
 246
 247                         IList<MemberSpec> list;
 248                         foreach (var entry in cache.member_hash) {
 249                                 if (!member_hash.TryGetValue (entry.Key, out list)) {
 250                                         if (entry.Value.Count == 1) {
 251                                                 list = entry.Value;
 252                                         } else {
 253                                                 list = new List<MemberSpec> (entry.Value);
 254                                         }
 255
 256                                         member_hash.Add (entry.Key, list);
 257                                         continue;
 258                                 }
 259
 260                                 foreach (var ce in entry.Value) {
 261                                         if (list.Contains (ce))
 262                                                 continue;
 263
 264                                         if (AddInterfaceMember (ce, ref list))
 265                                                 member_hash[entry.Key] = list;
 266                                 }
 267                         }
 268
 269                         // Add also all base interfaces
 270                         if (iface.Interfaces != null) {
 271                                 foreach (var base_iface in iface.Interfaces)
 272                                         AddInterface (base_iface);
 273                         }
 274                 }
 275
 276                 public void AddMember (InterfaceMemberBase imb, string exlicitName, MemberSpec ms)
 277                 {
 278                         // Explicit names cannot be looked-up but can be used for
 279                         // collision checking (no name mangling needed)
 280                         if (imb.IsExplicitImpl)
 281                                 AddMember (exlicitName, ms, false);
 282                         else
 283                                 AddMember (ms);
 284                 }
 285
 286                 //
 287                 // Add non-explicit member to member cache
 288                 //
 289                 public void AddMember (MemberSpec ms)
 290                 {
 291                         AddMember (GetLookupName (ms), ms, false);
 292                 }
 293
 294                 void AddMember (string name, MemberSpec member, bool removeHiddenMembers)
 295                 {
 296                         if (member.Kind == MemberKind.Operator) {
 297                                 var dt = member.DeclaringType;
 298
 299                                 //
 300                                 // Some core types have user operators but they cannot be used like normal
 301                                 // user operators as they are predefined and therefore having different
 302                                 // rules (e.g. binary operators) by not setting the flag we hide them for
 303                                 // user conversions
 304                                 //
 305                                 if (!BuiltinTypeSpec.IsPrimitiveType (dt)) {
 306                                         switch (dt.BuiltinType) {
 307                                         case BuiltinTypeSpec.Type.String:
 308                                         case BuiltinTypeSpec.Type.Delegate:
 309                                         case BuiltinTypeSpec.Type.MulticastDelegate:
 310                                                 break;
 311                                         default:
 312                                                 if (name == Operator.GetMetadataName (Operator.OpType.Implicit) || name == Operator.GetMetadataName (Operator.OpType.Explicit)) {
 313                                                         state |= StateFlags.HasConversionOperator;
 314                                                 } else {
 315                                                         state |= StateFlags.HasUserOperator;
 316                                                 }
 317
 318                                                 break;
 319                                         }
 320                                 }
 321                         }
 322
 323                         IList<MemberSpec> list;
 324                         if (!member_hash.TryGetValue (name, out list)) {
 325                                 member_hash.Add (name, new MemberSpec[] { member });
 326                                 return;
 327                         }
 328
 329                         if (removeHiddenMembers && member.DeclaringType.IsInterface) {
 330                                 if (AddInterfaceMember (member, ref list))
 331                                         member_hash[name] = list;
 332                         } else {
 333                                 if (list.Count == 1) {
 334                                         list = new List<MemberSpec> () { list[0] };
 335                                         member_hash[name] = list;
 336                                 }
 337
 338                                 list.Add (member);
 339                         }
 340                 }
 341
 342                 public void AddMemberImported (MemberSpec ms)
 343                 {
 344                         AddMember (GetLookupName (ms), ms, true);
 345                 }
 346
 347                 //
 348                 // Ignores any base interface member which can be hidden
 349                 // by this interface
 350                 //
 351                 static bool AddInterfaceMember (MemberSpec member, ref IList<MemberSpec> existing)
 352                 {
 353                         var member_param = member is IParametersMember ? ((IParametersMember) member).Parameters : ParametersCompiled.EmptyReadOnlyParameters;
 354
 355                         //
 356                         // interface IA : IB { int Prop { set; } }
 357                         // interface IB { bool Prop { get; } }
 358                         //
 359                         // IB.Prop is never accessible from IA interface
 360                         //
 361                         for (int i = 0; i < existing.Count; ++i) {
 362                                 var entry = existing[i];
 363
 364                                 if (entry.Arity != member.Arity)
 365                                         continue;
 366
 367                                 if (entry is IParametersMember) {
 368                                         var entry_param = ((IParametersMember) entry).Parameters;
 369                                         if (!TypeSpecComparer.Override.IsEqual (entry_param, member_param))
 370                                                 continue;
 371                                 }
 372
 373                                 if (member.DeclaringType.ImplementsInterface (entry.DeclaringType, false)) {
 374                                         if (existing.Count == 1) {
 375                                                 existing = new MemberSpec[] { member };
 376                                                 return true;
 377                                         }
 378
 379                                         existing.RemoveAt (i--);
 380                                         continue;
 381                                 }
 382
 383                                 if ((entry.DeclaringType == member.DeclaringType && entry.IsAccessor == member.IsAccessor) ||
 384                                         entry.DeclaringType.ImplementsInterface (member.DeclaringType, false))
 385                                         return false;
 386                         }
 387
 388                         if (existing.Count == 1) {
 389                                 existing = new List<MemberSpec> () { existing[0], member };
 390                                 return true;
 391                         }
 392
 393                         existing.Add (member);
 394                         return false;
 395                 }
 396
 397                 public static MemberSpec FindMember (TypeSpec container, MemberFilter filter, BindingRestriction restrictions)
 398                 {
 399                         do {
 400                                 IList<MemberSpec> applicable;
 401                                 if (container.MemberCache.member_hash.TryGetValue (filter.Name, out applicable)) {
 402                                         // Start from the end because interface members are in reverse order
 403                                         for (int i = applicable.Count - 1; i >= 0; i--) {
 404                                                 var entry = applicable [i];
 405
 406                                                 if ((restrictions & BindingRestriction.InstanceOnly) != 0 && entry.IsStatic)
 407                                                         continue;
 408
 409                                                 if ((restrictions & BindingRestriction.NoAccessors) != 0 && entry.IsAccessor)
 410                                                         continue;
 411
 412                                                 if ((restrictions & BindingRestriction.OverrideOnly) != 0 && (entry.Modifiers & Modifiers.OVERRIDE) == 0)
 413                                                         continue;
 414
 415                                                 if (!filter.Equals (entry))
 416                                                         continue;
 417
 418                                                 if ((restrictions & BindingRestriction.DeclaredOnly) != 0 && container.IsInterface && entry.DeclaringType != container)
 419                                                         continue;
 420
 421                                                 return entry;
 422                                         }
 423                                 }
 424
 425                                 if ((restrictions & BindingRestriction.DeclaredOnly) != 0)
 426                                         break;
 427
 428                                 container = container.BaseType;
 429                         } while (container != null);
 430
 431                         return null;
 432                 }
 433
 434                 //
 435                 // A special method to work with member lookup only. It returns a list of all members named @name
 436                 // starting from @container. It's very performance sensitive
 437                 //
 438                 // declaredOnlyClass cannot be used interfaces. Manual filtering is required because names are
 439                 // compacted
 440                 //
 441                 public static IList<MemberSpec> FindMembers (TypeSpec container, string name, bool declaredOnlyClass)
 442                 {
 443                         IList<MemberSpec> applicable;
 444
 445                         do {
 446                                 if (container.MemberCache.member_hash.TryGetValue (name, out applicable) || declaredOnlyClass)
 447                                         return applicable;
 448
 449                                 container = container.BaseType;
 450                         } while (container != null);
 451
 452                         return null;
 453                 }
 454
 455                 //
 456                 // Finds the nested type in container
 457                 //
 458                 public static TypeSpec FindNestedType (TypeSpec container, string name, int arity)
 459                 {
 460                         IList<MemberSpec> applicable;
 461                         TypeSpec best_match = null;
 462                         do {
 463                                 // TODO: Don't know how to handle this yet
 464                                 // When resolving base type of nested type, parent type must have
 465                                 // base type resolved to scan full hierarchy correctly
 466                                 // Similarly MemberCacheTypes will inflate BaseType and Interfaces
 467                                 // based on type definition
 468                                 var tc = container.MemberDefinition as TypeContainer;
 469                                 if (tc != null)
 470                                         tc.DefineContainer ();
 471
 472                                 if (container.MemberCacheTypes.member_hash.TryGetValue (name, out applicable)) {
 473                                         for (int i = applicable.Count - 1; i >= 0; i--) {
 474                                                 var entry = applicable[i];
 475                                                 if ((entry.Kind & MemberKind.NestedMask) == 0)
 476                                                         continue;
 477
 478                                                 var ts = (TypeSpec) entry;
 479                                                 if (arity == ts.Arity)
 480                                                         return ts;
 481
 482                                                 if (arity < 0) {
 483                                                         if (best_match == null) {
 484                                                                 best_match = ts;
 485                                                         } else if (System.Math.Abs (ts.Arity + arity) < System.Math.Abs (ts.Arity + arity)) {
 486                                                                 best_match = ts;
 487                                                         }
 488                                                 }
 489                                         }
 490                                 }
 491
 492                                 container = container.BaseType;
 493                         } while (container != null);
 494
 495                         return best_match;
 496                 }
 497
 498                 //
 499                 // Looks for extension methods with defined name and extension type
 500                 //
 501                 public List<MethodSpec> FindExtensionMethods (IMemberContext invocationContext, TypeSpec extensionType, string name, int arity)
 502                 {
 503                         IList<MemberSpec> entries;
 504                         if (!member_hash.TryGetValue (name, out entries))
 505                                 return null;
 506
 507                         List<MethodSpec> candidates = null;
 508                         foreach (var entry in entries) {
 509                                 if (entry.Kind != MemberKind.Method || (arity > 0 && entry.Arity != arity))
 510                                         continue;
 511
 512                                 var ms = (MethodSpec) entry;
 513                                 if (!ms.IsExtensionMethod)
 514                                         continue;
 515
 516                                 if (!ms.IsAccessible (invocationContext))
 517                                         continue;
 518
 519                                 //
 520                                 // Extension methods cannot be nested hence checking parent is enough
 521                                 //
 522                                 if ((ms.DeclaringType.Modifiers & Modifiers.INTERNAL) != 0 && !ms.DeclaringType.MemberDefinition.IsInternalAsPublic (invocationContext.Module.DeclaringAssembly))
 523                                         continue;
 524
 525                                 if (candidates == null)
 526                                         candidates = new List<MethodSpec> ();
 527                                 candidates.Add (ms);
 528                         }
 529
 530                         return candidates;
 531                 }
 532
 533                 //
 534                 // Returns base members of @member member if no exact match is found @bestCandidate returns
 535                 // the best match
 536                 //
 537                 public static MemberSpec FindBaseMember (MemberCore member, out MemberSpec bestCandidate, ref bool overrides)
 538                 {
 539                         bestCandidate = null;
 540                         var container = member.Parent.PartialContainer.Definition;
 541                         if (!container.IsInterface) {
 542                                 container = container.BaseType;
 543
 544                                 // It can happen for a user definition of System.Object
 545                                 if (container == null)
 546                                         return null;
 547                         }
 548
 549                         string name = GetLookupName (member);
 550                         var member_param = member is IParametersMember ? ((IParametersMember) member).Parameters : null;
 551
 552                         var mkind = GetMemberCoreKind (member);
 553                         bool member_with_accessors = mkind == MemberKind.Indexer || mkind == MemberKind.Property;
 554
 555                         IList<MemberSpec> applicable;
 556                         MemberSpec ambig_candidate = null;
 557
 558                         do {
 559                                 if (container.MemberCache.member_hash.TryGetValue (name, out applicable)) {
 560                                         for (int i = 0; i < applicable.Count; ++i) {
 561                                                 var entry = applicable [i];
 562
 563                                                 if ((entry.Modifiers & Modifiers.PRIVATE) != 0)
 564                                                         continue;
 565
 566                                                 if ((entry.Modifiers & Modifiers.AccessibilityMask) == Modifiers.INTERNAL &&
 567                                                         !entry.DeclaringType.MemberDefinition.IsInternalAsPublic (member.Module.DeclaringAssembly))
 568                                                         continue;
 569
 570                                                 //
 571                                                 // Isn't the member of same kind ?
 572                                                 //
 573                                                 if ((entry.Kind & ~MemberKind.Destructor & mkind & MemberKind.MaskType) == 0) {
 574                                                         // Destructors are ignored as they cannot be overridden by user
 575                                                         if ((entry.Kind & MemberKind.Destructor) != 0)
 576                                                                 continue;
 577
 578                                                         // A method with different arity does not hide base member
 579                                                         if (mkind != MemberKind.Method && member.MemberName.Arity != entry.Arity)
 580                                                                 continue;
 581
 582                                                         bestCandidate = entry;
 583                                                         return null;
 584                                                 }
 585
 586                                                 //
 587                                                 // Same kind of different arity is valid
 588                                                 //
 589                                                 if (member.MemberName.Arity != entry.Arity) {
 590                                                         continue;
 591                                                 }
 592
 593                                                 if ((entry.Kind & mkind & (MemberKind.Method | MemberKind.Indexer)) != 0) {
 594                                                         if (entry.IsAccessor != member is AbstractPropertyEventMethod)
 595                                                                 continue;
 596
 597                                                         var pm = entry as IParametersMember;
 598                                                         if (!TypeSpecComparer.Override.IsEqual (pm.Parameters, member_param))
 599                                                                 continue;
 600                                                 }
 601
 602                                                 //
 603                                                 // Skip override for member with accessors. It may not fully implement the base member
 604                                                 // but keep flag we found an implementation in case the base member is abstract
 605                                                 //
 606                                                 if (member_with_accessors && ((entry.Modifiers & (Modifiers.OVERRIDE | Modifiers.SEALED)) == Modifiers.OVERRIDE)) {
 607                                                         //
 608                                                         // Set candidate to override implementation to flag we found an implementation
 609                                                         //
 610                                                         overrides = true;
 611                                                         continue;
 612                                                 }
 613
 614                                                 //
 615                                                 // For members with parameters we can encounter an ambiguous candidates (they match exactly)
 616                                                 // because generic type parameters could be inflated into same types
 617                                                 //
 618                                                 if (ambig_candidate == null && (entry.Kind & mkind & (MemberKind.Method | MemberKind.Indexer)) != 0) {
 619                                                         bestCandidate = null;
 620                                                         ambig_candidate = entry;
 621                                                         continue;
 622                                                 }
 623
 624                                                 bestCandidate = ambig_candidate;
 625                                                 return entry;
 626                                         }
 627                                 }
 628
 629                                 if (container.IsInterface || ambig_candidate != null)
 630                                         break;
 631
 632                                 container = container.BaseType;
 633                         } while (container != null);
 634
 635                         return ambig_candidate;
 636                 }
 637
 638                 //
 639                 // Returns inflated version of MemberSpec, it works similarly to
 640                 // SRE TypeBuilder.GetMethod
 641                 //
 642                 public static T GetMember<T> (TypeSpec container, T spec) where T : MemberSpec
 643                 {
 644                         IList<MemberSpec> applicable;
 645                         if (container.MemberCache.member_hash.TryGetValue (GetLookupName (spec), out applicable)) {
 646                                 for (int i = applicable.Count - 1; i >= 0; i--) {
 647                                         var entry = applicable[i];
 648                                         if (entry.MemberDefinition == spec.MemberDefinition)
 649                                                 return (T) entry;
 650                                 }
 651                         }
 652
 653                         throw new InternalErrorException ("Missing member `{0}' on inflated type `{1}'",
 654                                 spec.GetSignatureForError (), container.GetSignatureForError ());
 655                 }
 656
 657                 static MemberKind GetMemberCoreKind (MemberCore member)
 658                 {
 659                         if (member is FieldBase)
 660                                 return MemberKind.Field;
 661                         if (member is Indexer)
 662                                 return MemberKind.Indexer;
 663                         if (member is Class)
 664                                 return MemberKind.Class;
 665                         if (member is Struct)
 666                                 return MemberKind.Struct;
 667                         if (member is Destructor)
 668                                 return MemberKind.Destructor;
 669                         if (member is Method)
 670                                 return MemberKind.Method;
 671                         if (member is Property)
 672                                 return MemberKind.Property;
 673                         if (member is EventField)
 674                                 return MemberKind.Event;
 675                         if (member is Interface)
 676                                 return MemberKind.Interface;
 677                         if (member is EventProperty)
 678                                 return MemberKind.Event;
 679                         if (member is Delegate)
 680                                 return MemberKind.Delegate;
 681                         if (member is Enum)
 682                                 return MemberKind.Enum;
 683
 684                         throw new NotImplementedException (member.GetType ().ToString ());
 685                 }
 686
 687                 public static List<FieldSpec> GetAllFieldsForDefiniteAssignment (TypeSpec container)
 688                 {
 689                         List<FieldSpec> fields = null;
 690                         foreach (var entry in container.MemberCache.member_hash) {
 691                                 foreach (var name_entry in entry.Value) {
 692                                         if (name_entry.Kind != MemberKind.Field)
 693                                                 continue;
 694
 695                                         if ((name_entry.Modifiers & Modifiers.STATIC) != 0)
 696                                                 continue;
 697
 698                                         //
 699                                         // Fixed size buffers are not subject to definite assignment checking
 700                                         //
 701                                         if (name_entry is FixedFieldSpec || name_entry is ConstSpec)
 702                                                 continue;
 703
 704                                         var fs = (FieldSpec) name_entry;
 705
 706                                         //
 707                                         // LAMESPEC: Very bizzare hack, definitive assignment is not done
 708                                         // for imported non-public reference fields except array. No idea what the
 709                                         // actual csc rule is
 710                                         //
 711                                         if (!fs.IsPublic && container.MemberDefinition.IsImported && (!fs.MemberType.IsArray && TypeSpec.IsReferenceType (fs.MemberType)))
 712                                                 continue;
 713
 714                                         if (fields == null)
 715                                                 fields = new List<FieldSpec> ();
 716
 717                                         fields.Add (fs);
 718                                         break;
 719                                 }
 720                         }
 721
 722                         return fields ?? new List<FieldSpec> (0);
 723                 }
 724
 725                 public static IList<MemberSpec> GetCompletitionMembers (IMemberContext ctx, TypeSpec container, string name)
 726                 {
 727                         var matches = new List<MemberSpec> ();
 728                         foreach (var entry in container.MemberCache.member_hash) {
 729                                 foreach (var name_entry in entry.Value) {
 730                                         if (name_entry.IsAccessor)
 731                                                 continue;
 732
 733                                         if ((name_entry.Kind & (MemberKind.Constructor | MemberKind.Destructor | MemberKind.Operator)) != 0)
 734                                                 continue;
 735
 736                                         if (!name_entry.IsAccessible (ctx))
 737                                                 continue;
 738
 739                                         if (name == null || name_entry.Name.StartsWith (name)) {
 740                                                 matches.Add (name_entry);
 741                                         }
 742                                 }
 743                         }
 744
 745                         return matches;
 746                 }
 747
 748                 //
 749                 // Returns members of @iface only, base members are ignored
 750                 //
 751                 public static List<MethodSpec> GetInterfaceMethods (TypeSpec iface)
 752                 {
 753                         //
 754                         // MemberCache flatten interfaces, therefore in cases like this one
 755                         //
 756                         // interface IA : IB {}
 757                         // interface IB { void Foo () }
 758                         //
 759                         // we would return Foo inside IA which is not expected in this case
 760                         //
 761                         var methods = new List<MethodSpec> ();
 762                         foreach (var entry in iface.MemberCache.member_hash.Values) {
 763                                 foreach (var name_entry in entry) {
 764                                         if (iface == name_entry.DeclaringType) {
 765                                                 if (name_entry.Kind == MemberKind.Method) {
 766                                                         methods.Add ((MethodSpec) name_entry);
 767                                                 }
 768                                         }
 769                                 }
 770                         }
 771
 772                         return methods;
 773                 }
 774
 775                 //
 776                 // Returns all not implememted abstract members inside abstract type
 777                 // NOTE: Returned list is shared and must not be modified
 778                 //
 779                 public static IList<MethodSpec> GetNotImplementedAbstractMethods (TypeSpec type)
 780                 {
 781                         if (type.MemberCache.missing_abstract != null)
 782                                 return type.MemberCache.missing_abstract;
 783
 784                         var abstract_methods = new List<MethodSpec> ();
 785                         List<TypeSpec> hierarchy = null;
 786
 787                         //
 788                         // Stage 1: top-to-bottom scan for abstract members
 789                         //
 790                         var abstract_type = type;
 791                         while (true) {
 792                                 foreach (var entry in abstract_type.MemberCache.member_hash) {
 793                                         foreach (var name_entry in entry.Value) {
 794                                                 if ((name_entry.Modifiers & (Modifiers.ABSTRACT | Modifiers.OVERRIDE)) != Modifiers.ABSTRACT)
 795                                                         continue;
 796
 797                                                 if (name_entry.Kind != MemberKind.Method)
 798                                                         continue;
 799
 800                                                 abstract_methods.Add ((MethodSpec) name_entry);
 801                                         }
 802                                 }
 803
 804                                 var base_type = abstract_type.BaseType;
 805                                 if (!base_type.IsAbstract)
 806                                         break;
 807
 808                                 if (hierarchy == null)
 809                                         hierarchy = new List<TypeSpec> ();
 810
 811                                 hierarchy.Add (abstract_type);
 812                                 abstract_type = base_type;
 813                         }
 814
 815                         int not_implemented_count = abstract_methods.Count;
 816                         if (not_implemented_count == 0 || hierarchy == null) {
 817                                 type.MemberCache.missing_abstract = abstract_methods;
 818                                 return type.MemberCache.missing_abstract;
 819                         }
 820
 821                         //
 822                         // Stage 2: Remove already implemented methods
 823                         //
 824                         foreach (var type_up in hierarchy) {
 825                                 var members = type_up.MemberCache.member_hash;
 826                                 if (members.Count == 0)
 827                                         continue;
 828
 829                                 for (int i = 0; i < abstract_methods.Count; ++i) {
 830                                         var candidate = abstract_methods [i];
 831                                         if (candidate == null)
 832                                                 continue;
 833
 834                                         IList<MemberSpec> applicable;
 835                                         if (!members.TryGetValue (candidate.Name, out applicable))
 836                                                 continue;
 837
 838                                         var filter = new MemberFilter (candidate);
 839                                         foreach (var item in applicable) {
 840                                                 if ((item.Modifiers & (Modifiers.OVERRIDE | Modifiers.VIRTUAL)) == 0)
 841                                                         continue;
 842
 843                                                 //
 844                                                 // Abstract override does not override anything
 845                                                 //
 846                                                 if ((item.Modifiers & Modifiers.ABSTRACT) != 0)
 847                                                         continue;
 848
 849                                                 if (filter.Equals (item)) {
 850                                                         --not_implemented_count;
 851                                                         abstract_methods [i] = null;
 852                                                         break;
 853                                                 }
 854                                         }
 855                                 }
 856                         }
 857
 858                         if (not_implemented_count == abstract_methods.Count) {
 859                                 type.MemberCache.missing_abstract = abstract_methods;
 860                                 return type.MemberCache.missing_abstract;
 861                         }
 862
 863                         var not_implemented = new MethodSpec[not_implemented_count];
 864                         int counter = 0;
 865                         foreach (var m in abstract_methods) {
 866                                 if (m == null)
 867                                         continue;
 868
 869                                 not_implemented[counter++] = m;
 870                         }
 871
 872                         type.MemberCache.missing_abstract = not_implemented;
 873                         return type.MemberCache.missing_abstract;
 874                 }
 875
 876                 static string GetLookupName (MemberSpec ms)
 877                 {
 878                         if (ms.Kind == MemberKind.Indexer)
 879                                 return IndexerNameAlias;
 880
 881                         if (ms.Kind == MemberKind.Constructor) {
 882                                 if (ms.IsStatic)
 883                                         return Constructor.TypeConstructorName;
 884
 885                                 return Constructor.ConstructorName;
 886                         }
 887
 888                         return ms.Name;
 889                 }
 890
 891                 static string GetLookupName (MemberCore mc)
 892                 {
 893                         if (mc is Indexer)
 894                                 return IndexerNameAlias;
 895
 896                         if (mc is Constructor)
 897                                 return mc.IsStatic ? Constructor.TypeConstructorName : Constructor.ConstructorName;
 898
 899                         return mc.MemberName.Name;
 900                 }
 901
 902                 //
 903                 // Returns all operators declared on container and its base types (until declaredOnly is used)
 904                 //
 905                 public static IList<MemberSpec> GetUserOperator (TypeSpec container, Operator.OpType op, bool declaredOnly)
 906                 {
 907                         IList<MemberSpec> found = null;
 908
 909                         IList<MemberSpec> applicable;
 910                         do {
 911                                 var mc = container.MemberCache;
 912
 913                                 if (((op == Operator.OpType.Implicit || op == Operator.OpType.Explicit) && (mc.state & StateFlags.HasConversionOperator) != 0) ||
 914                                          (mc.state & StateFlags.HasUserOperator) != 0) {
 915
 916                                         if (mc.member_hash.TryGetValue (Operator.GetMetadataName (op), out applicable)) {
 917                                                 int i;
 918                                                 for (i = 0; i < applicable.Count; ++i) {
 919                                                         if (applicable[i].Kind != MemberKind.Operator) {
 920                                                                 break;
 921                                                         }
 922                                                 }
 923
 924                                                 //
 925                                                 // Handles very rare case where a method with same name as operator (op_xxxx) exists
 926                                                 // and we have to resize the applicable list
 927                                                 //
 928                                                 if (i != applicable.Count) {
 929                                                         for (i = 0; i < applicable.Count; ++i) {
 930                                                                 if (applicable[i].Kind != MemberKind.Operator) {
 931                                                                         continue;
 932                                                                 }
 933
 934                                                                 if (found == null) {
 935                                                                         found = new List<MemberSpec> ();
 936                                                                         found.Add (applicable[i]);
 937                                                                 } else {
 938                                                                         var prev = found as List<MemberSpec>;
 939                                                                         if (prev == null) {
 940                                                                                 prev = new List<MemberSpec> (found.Count + 1);
 941                                                                                 prev.AddRange (found);
 942                                                                         }
 943
 944                                                                         prev.Add (applicable[i]);
 945                                                                 }
 946                                                         }
 947                                                 } else {
 948                                                         if (found == null) {
 949                                                                 found = applicable;
 950                                                         } else {
 951                                                                 var merged = found as List<MemberSpec>;
 952                                                                 if (merged == null) {
 953                                                                         merged = new List<MemberSpec> (found.Count + applicable.Count);
 954                                                                         merged.AddRange (found);
 955                                                                         found = merged;
 956                                                                 }
 957
 958                                                                 merged.AddRange (applicable);
 959                                                         }
 960                                                 }
 961                                         }
 962                                 }
 963
 964                                 // BaseType call can be expensive
 965                                 if (declaredOnly)
 966                                         break;
 967
 968                                 container = container.BaseType;
 969                         } while (container != null);
 970
 971                         return found;
 972                 }
 973
 974                 //
 975                 // Inflates all member cache nested types
 976                 //
 977                 public void InflateTypes (MemberCache inflated_cache, TypeParameterInflator inflator)
 978                 {
 979                         foreach (var item in member_hash) {
 980                                 IList<MemberSpec> inflated_members = null;
 981                                 for (int i = 0; i < item.Value.Count; ++i ) {
 982                                         var member = item.Value[i];
 983
 984                                         // FIXME: When inflating members refering nested types before they are inflated
 985                                         if (member == null)
 986                                                 continue;
 987
 988                                         if ((member.Kind & MemberKind.NestedMask) != 0 &&
 989                                                 (member.Modifiers & Modifiers.COMPILER_GENERATED) == 0) {
 990                                                 if (inflated_members == null) {
 991                                                         inflated_members = new MemberSpec[item.Value.Count];
 992                                                         inflated_cache.member_hash.Add (item.Key, inflated_members);
 993                                                 }
 994
 995                                                 inflated_members [i] = member.InflateMember (inflator);
 996                                         }
 997                                 }
 998                         }
 999                 }
1000
1001                 //
1002                 // Inflates all open type members, requires InflateTypes to be called before
1003                 //
1004                 public void InflateMembers (MemberCache cacheToInflate, TypeSpec inflatedType, TypeParameterInflator inflator)
1005                 {
1006                         var inflated_member_hash = cacheToInflate.member_hash;
1007                         Dictionary<MemberSpec, MethodSpec> accessor_relation = null;
1008                         List<MemberSpec> accessor_members = null;
1009
1010                         // Copy member specific flags when all members were added
1011                         cacheToInflate.state = state;
1012
1013                         foreach (var item in member_hash) {
1014                                 var members = item.Value;
1015                                 IList<MemberSpec> inflated_members = null;
1016                                 for (int i = 0; i < members.Count; ++i ) {
1017                                         var member = members[i];
1018
1019                                         //
1020                                         // All nested types have been inflated earlier except for
1021                                         // compiler types which are created later and could miss InflateTypes
1022                                         //
1023                                         if ((member.Kind & MemberKind.NestedMask) != 0 &&
1024                                                 (member.Modifiers & Modifiers.COMPILER_GENERATED) == 0) {
1025                                                 if (inflated_members == null)
1026                                                         inflated_members = inflated_member_hash[item.Key];
1027
1028                                                 continue;
1029                                         }
1030
1031                                         //
1032                                         // Clone the container first
1033                                         //
1034                                         if (inflated_members == null) {
1035                                                 inflated_members = new MemberSpec [item.Value.Count];
1036                                                 inflated_member_hash.Add (item.Key, inflated_members);
1037                                         }
1038
1039                                         var local_inflator = inflator;
1040
1041                                         if (member.DeclaringType != inflatedType) {
1042                                                 //
1043                                                 // Don't inflate top-level non-generic interface members
1044                                                 // merged into generic interface
1045                                                 //
1046                                                 if (!member.DeclaringType.IsGeneric && !member.DeclaringType.IsNested) {
1047                                                         inflated_members [i] = member;
1048                                                         continue;
1049                                                 }
1050
1051                                                 //
1052                                                 // Needed when inflating flatten interfaces. It inflates
1053                                                 // container type only, type parameters are already done
1054                                                 //
1055                                                 // Handles cases like:
1056                                                 //
1057                                                 // interface I<T> {}
1058                                                 // interface I<U, V> : I<U> {}
1059                                                 //
1060                                                 // class C: I<int, bool> {}
1061                                                 //
1062                                                 var inflated_parent = inflator.Inflate (member.DeclaringType);
1063                                                 if (inflated_parent != inflator.TypeInstance)
1064                                                         local_inflator = new TypeParameterInflator (inflator, inflated_parent);
1065                                         }
1066
1067                                         //
1068                                         // Inflate every member, its parent is now different
1069                                         //
1070                                         var inflated = member.InflateMember (local_inflator);
1071                                         inflated_members [i] = inflated;
1072
1073                                         if (member is PropertySpec || member is EventSpec) {
1074                                                 if (accessor_members == null)
1075                                                         accessor_members = new List<MemberSpec> ();
1076
1077                                                 accessor_members.Add (inflated);
1078                                                 continue;
1079                                         }
1080
1081                                         if (member.IsAccessor) {
1082                                                 if (accessor_relation == null)
1083                                                         accessor_relation = new Dictionary<MemberSpec, MethodSpec> ();
1084                                                 accessor_relation.Add (member, (MethodSpec) inflated);
1085                                         }
1086                                 }
1087                         }
1088
1089                         if (accessor_members != null) {
1090                                 foreach (var member in accessor_members) {
1091                                         var prop = member as PropertySpec;
1092                                         if (prop != null) {
1093                                                 if (prop.Get != null)
1094                                                         prop.Get = accessor_relation[prop.Get];
1095                                                 if (prop.Set != null)
1096                                                         prop.Set = accessor_relation[prop.Set];
1097
1098                                                 continue;
1099                                         }
1100
1101                                         var ev = (EventSpec) member;
1102                                         ev.AccessorAdd = accessor_relation[ev.AccessorAdd];
1103                                         ev.AccessorRemove = accessor_relation[ev.AccessorRemove];
1104                                 }
1105                         }
1106                 }
1107
1108                 //
1109                 // Removes hidden base members of an interface. For compiled interfaces we cannot
1110                 // do name filtering during Add (as we do for import) because we need all base
1111                 // names to be valid during type definition.
1112                 // Add replaces hidden base member with current one which means any name collision
1113                 // (CS0108) of non-first name would be unnoticed because the name was replaced
1114                 // with the one from compiled type
1115                 //
1116                 public void RemoveHiddenMembers (TypeSpec container)
1117                 {
1118                         foreach (var entry in member_hash) {
1119                                 var values = entry.Value;
1120
1121                                 int container_members_start_at = 0;
1122                                 while (values[container_members_start_at].DeclaringType != container && ++container_members_start_at < entry.Value.Count);
1123
1124                                 if (container_members_start_at == 0 || container_members_start_at == values.Count)
1125                                         continue;
1126
1127                                 for (int i = 0; i < container_members_start_at; ++i) {
1128                                         var member = values[i];
1129
1130                                         if (!container.ImplementsInterface (member.DeclaringType, false))
1131                                                 continue;
1132
1133                                         var member_param = member is IParametersMember ? ((IParametersMember) member).Parameters : ParametersCompiled.EmptyReadOnlyParameters;
1134
1135                                         for (int ii = container_members_start_at; ii < values.Count; ++ii) {
1136                                                 var container_entry = values[ii];
1137
1138                                                 if (container_entry.Arity != member.Arity)
1139                                                         continue;
1140
1141                                                 if (container_entry is IParametersMember) {
1142                                                         if (!TypeSpecComparer.Override.IsEqual (((IParametersMember) container_entry).Parameters, member_param))
1143                                                                 continue;
1144                                                 }
1145
1146                                                 values.RemoveAt (i);
1147                                                 --container_members_start_at;
1148                                                 --ii;
1149                                                 --i;
1150                                         }
1151                                 }
1152                         }
1153                 }
1154
1155                 //
1156                 // Checks all appropriate container members for CLS compliance
1157                 //
1158                 public void VerifyClsCompliance (TypeSpec container, Report report)
1159                 {
1160                         if (locase_members != null)
1161                                 return;
1162
1163                         if (container.BaseType == null) {
1164                                 locase_members = new Dictionary<string, MemberSpec[]> (member_hash.Count); // StringComparer.OrdinalIgnoreCase);
1165                         } else {
1166                                 var btype = container.BaseType.GetDefinition ();
1167                                 btype.MemberCache.VerifyClsCompliance (btype, report);
1168                                 locase_members = new Dictionary<string, MemberSpec[]> (btype.MemberCache.locase_members); //, StringComparer.OrdinalIgnoreCase);
1169                         }
1170
1171                         var is_imported_type = container.MemberDefinition.IsImported;
1172                         foreach (var entry in container.MemberCache.member_hash) {
1173                                 for (int i = 0; i < entry.Value.Count; ++i ) {
1174                                         var name_entry = entry.Value[i];
1175                                         if ((name_entry.Modifiers & (Modifiers.PUBLIC | Modifiers.PROTECTED)) == 0)
1176                                                 continue;
1177
1178                                         if ((name_entry.Modifiers & (Modifiers.OVERRIDE | Modifiers.COMPILER_GENERATED)) != 0)
1179                                                 continue;
1180
1181                                         if ((name_entry.Kind & MemberKind.MaskType) == 0)
1182                                                 continue;
1183
1184                                         if (name_entry.MemberDefinition.CLSAttributeValue == false)
1185                                             continue;
1186
1187                                         IParametersMember p_a = null;
1188                                         if (!is_imported_type) {
1189                                                 p_a = name_entry as IParametersMember;
1190                                                 if (p_a != null && !name_entry.IsAccessor) {
1191                                                         var p_a_pd = p_a.Parameters;
1192                                                         //
1193                                                         // Check differing overloads in @container
1194                                                         //
1195                                                         for (int ii = i + 1; ii < entry.Value.Count; ++ii) {
1196                                                                 var checked_entry = entry.Value[ii];
1197                                                                 IParametersMember p_b = checked_entry as IParametersMember;
1198                                                                 if (p_b == null)
1199                                                                         continue;
1200
1201                                                                 if (p_a_pd.Count != p_b.Parameters.Count)
1202                                                                         continue;
1203
1204                                                                 if (checked_entry.IsAccessor)
1205                                                                         continue;
1206
1207                                                                 var res = ParametersCompiled.IsSameClsSignature (p_a.Parameters, p_b.Parameters);
1208                                                                 if (res != 0) {
1209                                                                         ReportOverloadedMethodClsDifference (name_entry, checked_entry, res, report);
1210                                                                 }
1211                                                         }
1212                                                 }
1213                                         }
1214
1215                                         if (i > 0 || name_entry.Kind == MemberKind.Constructor || name_entry.Kind == MemberKind.Indexer)
1216                                                 continue;
1217
1218                                         var name_entry_locase = name_entry.Name.ToLowerInvariant ();
1219
1220                                         MemberSpec[] found;
1221                                         if (!locase_members.TryGetValue (name_entry_locase, out found)) {
1222                                                 found = new MemberSpec[] { name_entry };
1223                                                 locase_members.Add (name_entry_locase, found);
1224                                         } else {
1225                                                 bool same_names_only = true;
1226                                                 foreach (var f in found) {
1227                                                         if (f.Name == name_entry.Name) {
1228                                                                 if (p_a != null) {
1229                                                                         IParametersMember p_b = f as IParametersMember;
1230                                                                         if (p_b == null)
1231                                                                                 continue;
1232
1233                                                                         if (p_a.Parameters.Count != p_b.Parameters.Count)
1234                                                                                 continue;
1235
1236                                                                         if (f.IsAccessor)
1237                                                                                 continue;
1238
1239                                                                         var res = ParametersCompiled.IsSameClsSignature (p_a.Parameters, p_b.Parameters);
1240                                                                         if (res != 0) {
1241                                                                                 ReportOverloadedMethodClsDifference (f, name_entry, res, report);
1242                                                                         }
1243                                                                 }
1244
1245                                                                 continue;
1246                                                         }
1247
1248                                                         same_names_only = false;
1249                                                         if (!is_imported_type) {
1250                                                                 var last = GetLaterDefinedMember (f, name_entry);
1251                                                                 if (last == f.MemberDefinition) {
1252                                                                         report.SymbolRelatedToPreviousError (name_entry);
1253                                                                 } else {
1254                                                                         report.SymbolRelatedToPreviousError (f);
1255                                                                 }
1256
1257                                                                 report.Warning (3005, 1, last.Location,
1258                                                                         "Identifier `{0}' differing only in case is not CLS-compliant", last.GetSignatureForError ());
1259                                                         }
1260                                                 }
1261
1262                                                 if (!same_names_only) {
1263                                                         Array.Resize (ref found, found.Length + 1);
1264                                                         found[found.Length - 1] = name_entry;
1265                                                         locase_members[name_entry_locase] = found;
1266                                                 }
1267                                         }
1268                                 }
1269                         }
1270                 }
1271
1272                 //
1273                 // Local report helper to issue correctly ordered members stored in hashtable
1274                 //
1275                 static MemberCore GetLaterDefinedMember (MemberSpec a, MemberSpec b)
1276                 {
1277                         var mc_a = a.MemberDefinition as MemberCore;
1278                         var mc_b = b.MemberDefinition as MemberCore;
1279                         if (mc_a == null)
1280                                 return mc_b;
1281
1282                         if (mc_b == null)
1283                                 return mc_a;
1284
1285                         if (a.DeclaringType.MemberDefinition != b.DeclaringType.MemberDefinition)
1286                                 return mc_b;
1287
1288                         if (mc_a.Location.File != mc_a.Location.File)
1289                                 return mc_b;
1290
1291                         return mc_b.Location.Row > mc_a.Location.Row ? mc_b : mc_a;
1292                 }
1293
1294                 static void ReportOverloadedMethodClsDifference (MemberSpec a, MemberSpec b, int res, Report report)
1295                 {
1296                         var last = GetLaterDefinedMember (a, b);
1297                         if (last == a.MemberDefinition) {
1298                                 report.SymbolRelatedToPreviousError (b);
1299                         } else {
1300                                 report.SymbolRelatedToPreviousError (a);
1301                         }
1302
1303                         if ((res & 1) != 0) {
1304                                 report.Warning (3006, 1, last.Location,
1305                                                 "Overloaded method `{0}' differing only in ref or out, or in array rank, is not CLS-compliant",
1306                                                 last.GetSignatureForError ());
1307                         }
1308
1309                         if ((res & 2) != 0) {
1310                                 report.Warning (3007, 1, last.Location,
1311                                         "Overloaded method `{0}' differing only by unnamed array types is not CLS-compliant",
1312                                         last.GetSignatureForError ());
1313                         }
1314                 }
1315
1316                 public bool CheckExistingMembersOverloads (MemberCore member, AParametersCollection parameters)
1317                 {
1318                         var name = GetLookupName (member);
1319                         var imb = member as InterfaceMemberBase;
1320                         if (imb != null && imb.IsExplicitImpl) {
1321                                 name = imb.GetFullName (name);
1322                         }
1323
1324                         return CheckExistingMembersOverloads (member, name, parameters);
1325                 }
1326
1327                 public bool CheckExistingMembersOverloads (MemberCore member, string name, AParametersCollection parameters)
1328                 {
1329                         IList<MemberSpec> entries;
1330                         if (!member_hash.TryGetValue (name, out entries))
1331                                 return false;
1332
1333                         var Report = member.Compiler.Report;
1334
1335                         int method_param_count = parameters.Count;
1336                         for (int i = entries.Count - 1; i >= 0; --i) {
1337                                 var ce = entries[i];
1338                                 var pm = ce as IParametersMember;
1339                                 var pd = pm == null ? ParametersCompiled.EmptyReadOnlyParameters : pm.Parameters;
1340                                 if (pd.Count != method_param_count)
1341                                         continue;
1342
1343                                 if (ce.Arity != member.MemberName.Arity)
1344                                         continue;
1345
1346                                 // Ignore merged interface members
1347                                 if (member.Parent.PartialContainer != ce.DeclaringType.MemberDefinition)
1348                                         continue;
1349
1350                                 var p_types = pd.Types;
1351                                 if (method_param_count > 0) {
1352                                         int ii = method_param_count - 1;
1353                                         TypeSpec type_a, type_b;
1354                                         do {
1355                                                 type_a = parameters.Types [ii];
1356                                                 type_b = p_types [ii];
1357
1358                                                 var a_byref = (pd.FixedParameters[ii].ModFlags & Parameter.Modifier.RefOutMask) != 0;
1359                                                 var b_byref = (parameters.FixedParameters[ii].ModFlags & Parameter.Modifier.RefOutMask) != 0;
1360
1361                                                 if (a_byref != b_byref)
1362                                                         break;
1363
1364                                         } while (TypeSpecComparer.Override.IsEqual (type_a, type_b) && ii-- != 0);
1365
1366                                         if (ii >= 0)
1367                                                 continue;
1368
1369                                         //
1370                                         // Operators can differ in return type only
1371                                         //
1372                                         if (member is Operator && ce.Kind == MemberKind.Operator && ((MethodSpec) ce).ReturnType != ((Operator) member).ReturnType)
1373                                                 continue;
1374
1375                                         //
1376                                         // Report difference in parameter modifiers only
1377                                         //
1378                                         if (pd != null && member is MethodCore) {
1379                                                 ii = method_param_count;
1380                                                 while (ii-- != 0 &&
1381                                                         (parameters.FixedParameters[ii].ModFlags & Parameter.Modifier.ModifierMask) ==
1382                                                         (pd.FixedParameters[ii].ModFlags & Parameter.Modifier.ModifierMask) &&
1383                                                         parameters.ExtensionMethodType == pd.ExtensionMethodType) ;
1384
1385                                                 if (ii >= 0) {
1386                                                         var mc = ce as MethodSpec;
1387                                                         member.Compiler.Report.SymbolRelatedToPreviousError (ce);
1388                                                         if ((member.ModFlags & Modifiers.PARTIAL) != 0 && (mc.Modifiers & Modifiers.PARTIAL) != 0) {
1389                                                                 if (parameters.HasParams || pd.HasParams) {
1390                                                                         Report.Error (758, member.Location,
1391                                                                                 "A partial method declaration and partial method implementation cannot differ on use of `params' modifier");
1392                                                                 } else {
1393                                                                         Report.Error (755, member.Location,
1394                                                                                 "A partial method declaration and partial method implementation must be both an extension method or neither");
1395                                                                 }
1396                                                         } else if (member is Constructor) {
1397                                                                 Report.Error (851, member.Location,
1398                                                                         "Overloaded contructor `{0}' cannot differ on use of parameter modifiers only",
1399                                                                         member.GetSignatureForError ());
1400                                                         } else {
1401                                                                 Report.Error (663, member.Location,
1402                                                                         "Overloaded method `{0}' cannot differ on use of parameter modifiers only",
1403                                                                         member.GetSignatureForError ());
1404                                                         }
1405                                                         return false;
1406                                                 }
1407                                         }
1408                                 }
1409
1410                                 if ((ce.Kind & MemberKind.Method) != 0) {
1411                                         Method method_a = member as Method;
1412                                         Method method_b = ce.MemberDefinition as Method;
1413                                         if (method_a != null && method_b != null && (method_a.ModFlags & method_b.ModFlags & Modifiers.PARTIAL) != 0) {
1414                                                 const Modifiers partial_modifiers = Modifiers.STATIC | Modifiers.UNSAFE;
1415                                                 if (method_a.IsPartialDefinition == method_b.IsPartialImplementation) {
1416                                                         if ((method_a.ModFlags & partial_modifiers) == (method_b.ModFlags & partial_modifiers) ||
1417                                                                 method_a.Parent.IsUnsafe && method_b.Parent.IsUnsafe) {
1418                                                                 if (method_a.IsPartialImplementation) {
1419                                                                         method_a.SetPartialDefinition (method_b);
1420                                                                         if (entries.Count == 1)
1421                                                                                 member_hash.Remove (name);
1422                                                                         else
1423                                                                                 entries.RemoveAt (i);
1424                                                                 } else {
1425                                                                         method_b.SetPartialDefinition (method_a);
1426                                                                         method_a.caching_flags |= MemberCore.Flags.PartialDefinitionExists;
1427                                                                 }
1428                                                                 continue;
1429                                                         }
1430
1431                                                         if (method_a.IsStatic != method_b.IsStatic) {
1432                                                                 Report.SymbolRelatedToPreviousError (ce);
1433                                                                 Report.Error (763, member.Location,
1434                                                                         "A partial method declaration and partial method implementation must be both `static' or neither");
1435                                                         }
1436
1437                                                         Report.SymbolRelatedToPreviousError (ce);
1438                                                         Report.Error (764, member.Location,
1439                                                                 "A partial method declaration and partial method implementation must be both `unsafe' or neither");
1440                                                         return false;
1441                                                 }
1442
1443                                                 Report.SymbolRelatedToPreviousError (ce);
1444                                                 if (method_a.IsPartialDefinition) {
1445                                                         Report.Error (756, member.Location, "A partial method `{0}' declaration is already defined",
1446                                                                 member.GetSignatureForError ());
1447                                                 }
1448
1449                                                 Report.Error (757, member.Location, "A partial method `{0}' implementation is already defined",
1450                                                         member.GetSignatureForError ());
1451                                                 return false;
1452                                         }
1453
1454                                         Report.SymbolRelatedToPreviousError (ce);
1455
1456                                         bool is_reserved_a = member is AbstractPropertyEventMethod || member is Operator;
1457                                         bool is_reserved_b = ((MethodSpec) ce).IsReservedMethod;
1458
1459                                         if (is_reserved_a || is_reserved_b) {
1460                                                 Report.Error (82, member.Location, "A member `{0}' is already reserved",
1461                                                         is_reserved_a ?
1462                                                         ce.GetSignatureForError () :
1463                                                         member.GetSignatureForError ());
1464                                                 return false;
1465                                         }
1466                                 } else {
1467                                         Report.SymbolRelatedToPreviousError (ce);
1468                                 }
1469
1470                                 if (member is Operator && ce.Kind == MemberKind.Operator) {
1471                                         Report.Error (557, member.Location, "Duplicate user-defined conversion in type `{0}'",
1472                                                 member.Parent.GetSignatureForError ());
1473                                         return false;
1474                                 }
1475
1476                                 Report.Error (111, member.Location,
1477                                         "A member `{0}' is already defined. Rename this member or use different parameter types",
1478                                         member.GetSignatureForError ());
1479                                 return false;
1480                         }
1481
1482                         return true;
1483                 }
1484         }
1485 }