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                 // Does not work recursively because of generic interfaces
 244                 //
 245                 public void AddInterface (TypeSpec iface)
 246                 {
 247                         var cache = iface.MemberCache;
 248
 249                         IList<MemberSpec> list;
 250                         foreach (var entry in cache.member_hash) {
 251                                 if (!member_hash.TryGetValue (entry.Key, out list)) {
 252                                         if (entry.Value.Count == 1) {
 253                                                 list = entry.Value;
 254                                         } else {
 255                                                 list = new List<MemberSpec> (entry.Value);
 256                                         }
 257
 258                                         member_hash.Add (entry.Key, list);
 259                                         continue;
 260                                 }
 261
 262                                 foreach (var ce in entry.Value) {
 263                                         //
 264                                         // When two or more different base interfaces implemenent common
 265                                         // interface
 266                                         //
 267                                         // I : IA, IFoo
 268                                         // IA : IFoo
 269                                         //
 270                                         if (list.Contains (ce))
 271                                                 continue;
 272
 273                                         if (AddInterfaceMember (ce, ref list))
 274                                                 member_hash[entry.Key] = list;
 275                                 }
 276                         }
 277                 }
 278
 279                 public void AddMember (InterfaceMemberBase imb, string exlicitName, MemberSpec ms)
 280                 {
 281                         // Explicit names cannot be looked-up but can be used for
 282                         // collision checking (no name mangling needed)
 283                         if (imb.IsExplicitImpl)
 284                                 AddMember (exlicitName, ms, false);
 285                         else
 286                                 AddMember (ms);
 287                 }
 288
 289                 //
 290                 // Add non-explicit member to member cache
 291                 //
 292                 public void AddMember (MemberSpec ms)
 293                 {
 294                         AddMember (GetLookupName (ms), ms, false);
 295                 }
 296
 297                 void AddMember (string name, MemberSpec member, bool removeHiddenMembers)
 298                 {
 299                         if (member.Kind == MemberKind.Operator) {
 300                                 var dt = member.DeclaringType;
 301
 302
 303                                 //
 304                                 // Some core types have user operators but they cannot be used like normal
 305                                 // user operators as they are predefined and therefore having different
 306                                 // rules (e.g. binary operators) by not setting the flag we hide them for
 307                                 // user conversions
 308                                 //
 309                                 if (!BuiltinTypeSpec.IsPrimitiveType (dt) || dt.BuiltinType == BuiltinTypeSpec.Type.Char) {
 310                                         switch (dt.BuiltinType) {
 311                                         case BuiltinTypeSpec.Type.String:
 312                                         case BuiltinTypeSpec.Type.Delegate:
 313                                         case BuiltinTypeSpec.Type.MulticastDelegate:
 314                                                 break;
 315                                         default:
 316                                                 if (name == Operator.GetMetadataName (Operator.OpType.Implicit) || name == Operator.GetMetadataName (Operator.OpType.Explicit)) {
 317                                                         state |= StateFlags.HasConversionOperator;
 318                                                 } else {
 319                                                         state |= StateFlags.HasUserOperator;
 320                                                 }
 321
 322                                                 break;
 323                                         }
 324                                 }
 325                         }
 326
 327                         IList<MemberSpec> list;
 328                         if (!member_hash.TryGetValue (name, out list)) {
 329                                 member_hash.Add (name, new MemberSpec[] { member });
 330                                 return;
 331                         }
 332
 333                         if (removeHiddenMembers && member.DeclaringType.IsInterface) {
 334                                 if (AddInterfaceMember (member, ref list))
 335                                         member_hash[name] = list;
 336                         } else {
 337                                 if (list.Count == 1) {
 338                                         list = new List<MemberSpec> { list[0] };
 339                                         member_hash[name] = list;
 340                                 }
 341
 342                                 list.Add (member);
 343                         }
 344                 }
 345
 346                 public void AddMemberImported (MemberSpec ms)
 347                 {
 348                         AddMember (GetLookupName (ms), ms, true);
 349                 }
 350
 351                 //
 352                 // Ignores any base interface member which can be hidden
 353                 // by this interface
 354                 //
 355                 static bool AddInterfaceMember (MemberSpec member, ref IList<MemberSpec> existing)
 356                 {
 357                         var member_param = member is IParametersMember ? ((IParametersMember) member).Parameters : null;
 358
 359                         //
 360                         // interface IA : IB { int Prop { set; } }
 361                         // interface IB { bool Prop { get; } }
 362                         //
 363                         // IB.Prop is never accessible from IA interface
 364                         //
 365                         for (int i = 0; i < existing.Count; ++i) {
 366                                 var entry = existing[i];
 367
 368                                 if (entry.Arity != member.Arity)
 369                                         continue;
 370
 371                                 AParametersCollection entry_param = null;
 372                                 if (member_param != null) {
 373                                         var entry_pm = entry as IParametersMember;
 374                                         if (entry_pm != null) {
 375                                                 entry_param = entry_pm.Parameters;
 376                                                 if (!TypeSpecComparer.Override.IsEqual (entry_param, member_param))
 377                                                         continue;
 378                                         }
 379                                 }
 380
 381                                 if (member.DeclaringType.ImplementsInterface (entry.DeclaringType, false)) {
 382                                         if (existing.Count == 1) {
 383                                                 existing = new MemberSpec[] { member };
 384                                                 return true;
 385                                         }
 386
 387                                         existing.RemoveAt (i--);
 388                                         continue;
 389                                 }
 390
 391                                 if ((entry.DeclaringType == member.DeclaringType && entry.IsAccessor == member.IsAccessor))
 392                                         return false;
 393
 394                                 if (entry.DeclaringType.ImplementsInterface (member.DeclaringType, false) && AParametersCollection.HasSameParameterDefaults (entry_param, member_param))
 395                                         return false;
 396                         }
 397
 398                         if (existing.Count == 1) {
 399                                 existing = new List<MemberSpec> { existing[0], member };
 400                                 return true;
 401                         }
 402
 403                         existing.Add (member);
 404                         return false;
 405                 }
 406
 407                 public static MemberSpec FindMember (TypeSpec container, MemberFilter filter, BindingRestriction restrictions)
 408                 {
 409                         do {
 410                                 IList<MemberSpec> applicable;
 411                                 if (container.MemberCache.member_hash.TryGetValue (filter.Name, out applicable)) {
 412                                         // Start from the end because interface members are in reverse order
 413                                         for (int i = applicable.Count - 1; i >= 0; i--) {
 414                                                 var entry = applicable [i];
 415
 416                                                 if ((restrictions & BindingRestriction.InstanceOnly) != 0 && entry.IsStatic)
 417                                                         continue;
 418
 419                                                 if ((restrictions & BindingRestriction.NoAccessors) != 0 && entry.IsAccessor)
 420                                                         continue;
 421
 422                                                 if ((restrictions & BindingRestriction.OverrideOnly) != 0 && (entry.Modifiers & Modifiers.OVERRIDE) == 0)
 423                                                         continue;
 424
 425                                                 if (!filter.Equals (entry))
 426                                                         continue;
 427
 428                                                 if ((restrictions & BindingRestriction.DeclaredOnly) != 0 && container.IsInterface && entry.DeclaringType != container)
 429                                                         continue;
 430
 431                                                 return entry;
 432                                         }
 433                                 }
 434
 435                                 if ((restrictions & BindingRestriction.DeclaredOnly) != 0)
 436                                         break;
 437
 438                                 container = container.BaseType;
 439                         } while (container != null);
 440
 441                         return null;
 442                 }
 443
 444                 //
 445                 // A special method to work with member lookup only. It returns a list of all members named @name
 446                 // starting from @container. It's very performance sensitive
 447                 //
 448                 // declaredOnlyClass cannot be used interfaces. Manual filtering is required because names are
 449                 // compacted
 450                 //
 451                 public static IList<MemberSpec> FindMembers (TypeSpec container, string name, bool declaredOnlyClass)
 452                 {
 453                         IList<MemberSpec> applicable;
 454
 455                         do {
 456                                 if (container.MemberCache.member_hash.TryGetValue (name, out applicable) || declaredOnlyClass)
 457                                         return applicable;
 458
 459                                 container = container.BaseType;
 460                         } while (container != null);
 461
 462                         return null;
 463                 }
 464
 465                 //
 466                 // Finds the nested type in container
 467                 //
 468                 public static TypeSpec FindNestedType (TypeSpec container, string name, int arity)
 469                 {
 470                         IList<MemberSpec> applicable;
 471                         TypeSpec best_match = null;
 472                         do {
 473 #if !FULL_AOT_RUNTIME
 474                                 // TODO: Don't know how to handle this yet
 475                                 // When resolving base type of nested type, parent type must have
 476                                 // base type resolved to scan full hierarchy correctly
 477                                 // Similarly MemberCacheTypes will inflate BaseType and Interfaces
 478                                 // based on type definition
 479                                 var tc = container.MemberDefinition as TypeContainer;
 480                                 if (tc != null)
 481                                         tc.DefineContainer ();
 482 #endif
 483
 484                                 if (container.MemberCacheTypes.member_hash.TryGetValue (name, out applicable)) {
 485                                         for (int i = applicable.Count - 1; i >= 0; i--) {
 486                                                 var entry = applicable[i];
 487                                                 if ((entry.Kind & MemberKind.NestedMask) == 0)
 488                                                         continue;
 489
 490                                                 var ts = (TypeSpec) entry;
 491                                                 if (arity == ts.Arity)
 492                                                         return ts;
 493
 494                                                 if (arity < 0) {
 495                                                         if (best_match == null) {
 496                                                                 best_match = ts;
 497                                                         } else if (System.Math.Abs (ts.Arity + arity) < System.Math.Abs (ts.Arity + arity)) {
 498                                                                 best_match = ts;
 499                                                         }
 500                                                 }
 501                                         }
 502                                 }
 503
 504                                 container = container.BaseType;
 505                         } while (container != null);
 506
 507                         return best_match;
 508                 }
 509
 510                 //
 511                 // Looks for extension methods with defined name and extension type
 512                 //
 513                 public List<MethodSpec> FindExtensionMethods (IMemberContext invocationContext, string name, int arity)
 514                 {
 515                         IList<MemberSpec> entries;
 516                         if (!member_hash.TryGetValue (name, out entries))
 517                                 return null;
 518
 519                         List<MethodSpec> candidates = null;
 520                         foreach (var entry in entries) {
 521                                 if (entry.Kind != MemberKind.Method || (arity > 0 && entry.Arity != arity))
 522                                         continue;
 523
 524                                 var ms = (MethodSpec) entry;
 525                                 if (!ms.IsExtensionMethod)
 526                                         continue;
 527
 528                                 if (!ms.IsAccessible (invocationContext))
 529                                         continue;
 530
 531                                 //
 532                                 // Extension methods cannot be nested hence checking parent is enough
 533                                 //
 534                                 if ((ms.DeclaringType.Modifiers & Modifiers.INTERNAL) != 0 && !ms.DeclaringType.MemberDefinition.IsInternalAsPublic (invocationContext.Module.DeclaringAssembly))
 535                                         continue;
 536
 537                                 if (candidates == null)
 538                                         candidates = new List<MethodSpec> ();
 539                                 candidates.Add (ms);
 540                         }
 541
 542                         return candidates;
 543                 }
 544
 545                 //
 546                 // Returns base members of @member member if no exact match is found @bestCandidate returns
 547                 // the best match
 548                 //
 549                 public static MemberSpec FindBaseMember (MemberCore member, out MemberSpec bestCandidate, ref bool overrides)
 550                 {
 551                         bestCandidate = null;
 552                         var container = member.Parent.PartialContainer.Definition;
 553                         if (!container.IsInterface) {
 554                                 container = container.BaseType;
 555
 556                                 // It can happen for a user definition of System.Object
 557                                 if (container == null)
 558                                         return null;
 559                         }
 560
 561                         string name = GetLookupName (member);
 562                         var member_param = member is IParametersMember ? ((IParametersMember) member).Parameters : null;
 563
 564                         var mkind = GetMemberCoreKind (member);
 565                         bool member_with_accessors = mkind == MemberKind.Indexer || mkind == MemberKind.Property;
 566
 567                         IList<MemberSpec> applicable;
 568                         MemberSpec ambig_candidate = null;
 569
 570                         do {
 571                                 if (container.MemberCache.member_hash.TryGetValue (name, out applicable)) {
 572                                         for (int i = 0; i < applicable.Count; ++i) {
 573                                                 var entry = applicable [i];
 574
 575                                                 if ((entry.Modifiers & Modifiers.PUBLIC) == 0 && !entry.IsAccessible (member))
 576                                                         continue;
 577
 578                                                 //
 579                                                 // Isn't the member of same kind ?
 580                                                 //
 581                                                 if ((entry.Kind & ~MemberKind.Destructor & mkind & MemberKind.MaskType) == 0) {
 582                                                         // Destructors are ignored as they cannot be overridden by user
 583                                                         if ((entry.Kind & MemberKind.Destructor) != 0)
 584                                                                 continue;
 585
 586                                                         // A method with different arity does not hide base member
 587                                                         if (mkind != MemberKind.Method && member.MemberName.Arity != entry.Arity)
 588                                                                 continue;
 589
 590                                                         bestCandidate = entry;
 591                                                         return null;
 592                                                 }
 593
 594                                                 //
 595                                                 // Same kind of different arity is valid
 596                                                 //
 597                                                 if (member.MemberName.Arity != entry.Arity) {
 598                                                         continue;
 599                                                 }
 600
 601                                                 if ((entry.Kind & mkind & (MemberKind.Method | MemberKind.Indexer)) != 0) {
 602                                                         if (entry.IsAccessor != member is AbstractPropertyEventMethod)
 603                                                                 continue;
 604
 605                                                         var pm = entry as IParametersMember;
 606                                                         if (!TypeSpecComparer.Override.IsEqual (pm.Parameters, member_param))
 607                                                                 continue;
 608                                                 }
 609
 610                                                 //
 611                                                 // Skip override for member with accessors. It may not fully implement the base member
 612                                                 // but keep flag we found an implementation in case the base member is abstract
 613                                                 //
 614                                                 if (member_with_accessors && ((entry.Modifiers & (Modifiers.OVERRIDE | Modifiers.SEALED)) == Modifiers.OVERRIDE)) {
 615                                                         //
 616                                                         // Set candidate to override implementation to flag we found an implementation
 617                                                         //
 618                                                         overrides = true;
 619                                                         continue;
 620                                                 }
 621
 622                                                 //
 623                                                 // For members with parameters we can encounter an ambiguous candidates (they match exactly)
 624                                                 // because generic type parameters could be inflated into same types
 625                                                 //
 626                                                 if (ambig_candidate == null && (entry.Kind & mkind & (MemberKind.Method | MemberKind.Indexer)) != 0) {
 627                                                         bestCandidate = null;
 628                                                         ambig_candidate = entry;
 629                                                         continue;
 630                                                 }
 631
 632                                                 bestCandidate = ambig_candidate;
 633                                                 return entry;
 634                                         }
 635                                 }
 636
 637                                 if (container.IsInterface || ambig_candidate != null)
 638                                         break;
 639
 640                                 container = container.BaseType;
 641                         } while (container != null);
 642
 643                         return ambig_candidate;
 644                 }
 645
 646                 public static List<TypeSpec> GetDeclaredNestedTypes (TypeSpec container)
 647                 {
 648                         List<TypeSpec> found = null;
 649                         foreach (var entry in container.MemberCache.member_hash) {
 650                                 foreach (var member in entry.Value) {
 651                                         if ((member.Kind & MemberKind.NestedMask) == 0)
 652                                                 continue;
 653
 654                                         if (found == null)
 655                                                 found = new List<TypeSpec> ();
 656
 657                                         found.Add ((TypeSpec)member);
 658                                 }
 659                         }
 660
 661                         return found;
 662                 }
 663
 664                 //
 665                 // Returns inflated version of MemberSpec, it works similarly to
 666                 // SRE TypeBuilder.GetMethod
 667                 //
 668                 public static T GetMember<T> (TypeSpec container, T spec) where T : MemberSpec
 669                 {
 670                         IList<MemberSpec> applicable;
 671                         if (container.MemberCache.member_hash.TryGetValue (GetLookupName (spec), out applicable)) {
 672                                 for (int i = applicable.Count - 1; i >= 0; i--) {
 673                                         var entry = applicable[i];
 674                                         if (entry.MemberDefinition == spec.MemberDefinition)
 675                                                 return (T) entry;
 676                                 }
 677                         }
 678
 679                         throw new InternalErrorException ("Missing member `{0}' on inflated type `{1}'",
 680                                 spec.GetSignatureForError (), container.GetSignatureForError ());
 681                 }
 682
 683                 static MemberKind GetMemberCoreKind (MemberCore member)
 684                 {
 685                         if (member is FieldBase)
 686                                 return MemberKind.Field;
 687                         if (member is Indexer)
 688                                 return MemberKind.Indexer;
 689                         if (member is Class)
 690                                 return MemberKind.Class;
 691                         if (member is Struct)
 692                                 return MemberKind.Struct;
 693                         if (member is Destructor)
 694                                 return MemberKind.Destructor;
 695                         if (member is Method)
 696                                 return MemberKind.Method;
 697                         if (member is Property)
 698                                 return MemberKind.Property;
 699                         if (member is EventField)
 700                                 return MemberKind.Event;
 701                         if (member is Interface)
 702                                 return MemberKind.Interface;
 703                         if (member is EventProperty)
 704                                 return MemberKind.Event;
 705                         if (member is Delegate)
 706                                 return MemberKind.Delegate;
 707                         if (member is Enum)
 708                                 return MemberKind.Enum;
 709
 710                         throw new NotImplementedException (member.GetType ().ToString ());
 711                 }
 712
 713                 public static List<FieldSpec> GetAllFieldsForDefiniteAssignment (TypeSpec container, IMemberContext context)
 714                 {
 715                         List<FieldSpec> fields = null;
 716                         bool imported = container.MemberDefinition.IsImported;
 717                         foreach (var entry in container.MemberCache.member_hash) {
 718                                 foreach (var name_entry in entry.Value) {
 719                                         if (name_entry.Kind != MemberKind.Field)
 720                                                 continue;
 721
 722                                         if ((name_entry.Modifiers & Modifiers.STATIC) != 0)
 723                                                 continue;
 724
 725                                         //
 726                                         // Fixed size buffers are not subject to definite assignment checking
 727                                         //
 728                                         if (name_entry is FixedFieldSpec || name_entry is ConstSpec)
 729                                                 continue;
 730
 731                                         var fs = (FieldSpec) name_entry;
 732                                         if (imported && ShouldIgnoreFieldForDefiniteAssignment (fs, context))
 733                                                 continue;
 734
 735                                         //if ((fs.Modifiers & (Modifiers.BACKING_FIELD) != 0)
 736                                         //      continue;
 737
 738                                         if (fields == null)
 739                                                 fields = new List<FieldSpec> ();
 740
 741                                         fields.Add (fs);
 742                                         break;
 743                                 }
 744                         }
 745
 746                         return fields ?? new List<FieldSpec> (0);
 747                 }
 748
 749                 static bool ShouldIgnoreFieldForDefiniteAssignment (FieldSpec fs, IMemberContext context)
 750                 {
 751                         //
 752                         // LAMESPEC: This mimics csc quirk where definitive assignment is not done
 753                         // for all kinds of imported non-public struct fields
 754                         //
 755                         var mod = fs.Modifiers;
 756                         if ((mod & Modifiers.PRIVATE) == 0 && ((mod & Modifiers.INTERNAL) != 0 && fs.DeclaringType.MemberDefinition.IsInternalAsPublic (context.Module.DeclaringAssembly)))
 757                                 return false;
 758
 759                         //
 760                         // Ignore reference type fields except when type is an array or type parameter
 761                         //
 762                         var type = fs.MemberType;
 763                         switch (type.Kind) {
 764                         case MemberKind.ArrayType:
 765                         case MemberKind.TypeParameter:
 766                                 return false;
 767                         default:
 768                                 return TypeSpec.IsReferenceType (type);
 769                         }
 770                 }
 771
 772                 public static IList<MemberSpec> GetCompletitionMembers (IMemberContext ctx, TypeSpec container, string name)
 773                 {
 774                         var matches = new List<MemberSpec> ();
 775                         foreach (var entry in container.MemberCache.member_hash) {
 776                                 foreach (var name_entry in entry.Value) {
 777                                         if (name_entry.IsAccessor)
 778                                                 continue;
 779
 780                                         if ((name_entry.Kind & (MemberKind.Constructor | MemberKind.Destructor | MemberKind.Operator)) != 0)
 781                                                 continue;
 782
 783                                         if (!name_entry.IsAccessible (ctx))
 784                                                 continue;
 785
 786                                         if (name == null || name_entry.Name.StartsWith (name)) {
 787                                                 matches.Add (name_entry);
 788                                         }
 789                                 }
 790                         }
 791
 792                         return matches;
 793                 }
 794
 795                 //
 796                 // Returns members of @iface only, base members are ignored
 797                 //
 798                 public static List<MethodSpec> GetInterfaceMethods (TypeSpec iface)
 799                 {
 800                         //
 801                         // MemberCache flatten interfaces, therefore in cases like this one
 802                         //
 803                         // interface IA : IB {}
 804                         // interface IB { void Foo () }
 805                         //
 806                         // we would return Foo inside IA which is not expected in this case
 807                         //
 808                         var methods = new List<MethodSpec> ();
 809                         foreach (var entry in iface.MemberCache.member_hash.Values) {
 810                                 foreach (var name_entry in entry) {
 811                                         if (iface == name_entry.DeclaringType) {
 812                                                 if (name_entry.Kind == MemberKind.Method) {
 813                                                         methods.Add ((MethodSpec) name_entry);
 814                                                 }
 815                                         }
 816                                 }
 817                         }
 818
 819                         return methods;
 820                 }
 821
 822                 //
 823                 // Returns all not implememted abstract members inside abstract type
 824                 // NOTE: Returned list is shared and must not be modified
 825                 //
 826                 public static IList<MethodSpec> GetNotImplementedAbstractMethods (TypeSpec type)
 827                 {
 828                         if (type.MemberCache.missing_abstract != null)
 829                                 return type.MemberCache.missing_abstract;
 830
 831                         var abstract_methods = new List<MethodSpec> ();
 832                         List<TypeSpec> hierarchy = null;
 833
 834                         //
 835                         // Stage 1: top-to-bottom scan for abstract members
 836                         //
 837                         var abstract_type = type;
 838                         while (true) {
 839                                 foreach (var entry in abstract_type.MemberCache.member_hash) {
 840                                         foreach (var name_entry in entry.Value) {
 841                                                 if ((name_entry.Modifiers & Modifiers.ABSTRACT) == 0)
 842                                                         continue;
 843
 844                                                 var ms = name_entry as MethodSpec;
 845                                                 if (ms == null)
 846                                                         continue;
 847
 848                                                 abstract_methods.Add (ms);
 849                                         }
 850                                 }
 851
 852                                 var base_type = abstract_type.BaseType;
 853                                 if (!base_type.IsAbstract)
 854                                         break;
 855
 856                                 if (hierarchy == null)
 857                                         hierarchy = new List<TypeSpec> ();
 858
 859                                 hierarchy.Add (abstract_type);
 860                                 abstract_type = base_type;
 861                         }
 862
 863                         int not_implemented_count = abstract_methods.Count;
 864                         if (not_implemented_count == 0 || hierarchy == null) {
 865                                 type.MemberCache.missing_abstract = abstract_methods;
 866                                 return type.MemberCache.missing_abstract;
 867                         }
 868
 869                         //
 870                         // Stage 2: Remove already implemented methods
 871                         //
 872                         foreach (var type_up in hierarchy) {
 873                                 var members = type_up.MemberCache.member_hash;
 874                                 if (members.Count == 0)
 875                                         continue;
 876
 877                                 for (int i = 0; i < abstract_methods.Count; ++i) {
 878                                         var candidate = abstract_methods [i];
 879                                         if (candidate == null)
 880                                                 continue;
 881
 882                                         IList<MemberSpec> applicable;
 883                                         if (!members.TryGetValue (candidate.Name, out applicable))
 884                                                 continue;
 885
 886                                         var filter = new MemberFilter (candidate);
 887                                         foreach (var item in applicable) {
 888                                                 if ((item.Modifiers & (Modifiers.OVERRIDE | Modifiers.VIRTUAL)) == 0)
 889                                                         continue;
 890
 891                                                 //
 892                                                 // Abstract override does not override anything
 893                                                 //
 894                                                 if ((item.Modifiers & Modifiers.ABSTRACT) != 0)
 895                                                         continue;
 896
 897                                                 if (filter.Equals (item)) {
 898                                                         --not_implemented_count;
 899                                                         abstract_methods [i] = null;
 900                                                         break;
 901                                                 }
 902                                         }
 903                                 }
 904                         }
 905
 906                         if (not_implemented_count == abstract_methods.Count) {
 907                                 type.MemberCache.missing_abstract = abstract_methods;
 908                                 return type.MemberCache.missing_abstract;
 909                         }
 910
 911                         var not_implemented = new MethodSpec[not_implemented_count];
 912                         int counter = 0;
 913                         foreach (var m in abstract_methods) {
 914                                 if (m == null)
 915                                         continue;
 916
 917                                 not_implemented[counter++] = m;
 918                         }
 919
 920                         type.MemberCache.missing_abstract = not_implemented;
 921                         return type.MemberCache.missing_abstract;
 922                 }
 923
 924                 static string GetLookupName (MemberSpec ms)
 925                 {
 926                         if (ms.Kind == MemberKind.Indexer)
 927                                 return IndexerNameAlias;
 928
 929                         if (ms.Kind == MemberKind.Constructor) {
 930                                 if (ms.IsStatic)
 931                                         return Constructor.TypeConstructorName;
 932
 933                                 return Constructor.ConstructorName;
 934                         }
 935
 936                         return ms.Name;
 937                 }
 938
 939                 static string GetLookupName (MemberCore mc)
 940                 {
 941                         if (mc is Indexer)
 942                                 return IndexerNameAlias;
 943
 944                         if (mc is Constructor)
 945                                 return mc.IsStatic ? Constructor.TypeConstructorName : Constructor.ConstructorName;
 946
 947                         return mc.MemberName.Name;
 948                 }
 949
 950                 //
 951                 // Returns all operators declared on container and its base types (until declaredOnly is used)
 952                 //
 953                 public static IList<MemberSpec> GetUserOperator (TypeSpec container, Operator.OpType op, bool declaredOnly)
 954                 {
 955                         IList<MemberSpec> found = null;
 956                         bool shared_list = true;
 957                         IList<MemberSpec> applicable;
 958                         do {
 959                                 var mc = container.MemberCache;
 960
 961                                 if (((op == Operator.OpType.Implicit || op == Operator.OpType.Explicit) && (mc.state & StateFlags.HasConversionOperator) != 0) ||
 962                                          (mc.state & StateFlags.HasUserOperator) != 0) {
 963
 964                                         if (mc.member_hash.TryGetValue (Operator.GetMetadataName (op), out applicable)) {
 965                                                 int i;
 966                                                 for (i = 0; i < applicable.Count; ++i) {
 967                                                         if (applicable[i].Kind != MemberKind.Operator) {
 968                                                                 break;
 969                                                         }
 970                                                 }
 971
 972                                                 //
 973                                                 // Handles very rare case where a method with same name as operator (op_xxxx) exists
 974                                                 // and we have to resize the applicable list
 975                                                 //
 976                                                 if (i != applicable.Count) {
 977                                                         for (i = 0; i < applicable.Count; ++i) {
 978                                                                 if (applicable[i].Kind != MemberKind.Operator) {
 979                                                                         continue;
 980                                                                 }
 981
 982                                                                 if (found == null) {
 983                                                                         found = new List<MemberSpec> ();
 984                                                                         found.Add (applicable[i]);
 985                                                                 } else {
 986                                                                         List<MemberSpec> prev;
 987                                                                         if (shared_list) {
 988                                                                                 shared_list = false;
 989                                                                                 prev = new List<MemberSpec> (found.Count + 1);
 990                                                                                 prev.AddRange (found);
 991                                                                         } else {
 992                                                                                 prev = (List<MemberSpec>) found;
 993                                                                         }
 994
 995                                                                         prev.Add (applicable[i]);
 996                                                                 }
 997                                                         }
 998                                                 } else {
 999                                                         if (found == null) {
1000                                                                 found = applicable;
1001                                                                 shared_list = true;
1002                                                         } else {
1003                                                                 List<MemberSpec> merged;
1004                                                                 if (shared_list) {
1005                                                                         shared_list = false;
1006                                                                         merged = new List<MemberSpec> (found.Count + applicable.Count);
1007                                                                         merged.AddRange (found);
1008                                                                         found = merged;
1009                                                                 } else {
1010                                                                         merged = (List<MemberSpec>) found;
1011                                                                 }
1012
1013                                                                 merged.AddRange (applicable);
1014                                                         }
1015                                                 }
1016                                         }
1017                                 }
1018
1019                                 // BaseType call can be expensive
1020                                 if (declaredOnly)
1021                                         break;
1022
1023                                 container = container.BaseType;
1024                         } while (container != null);
1025
1026                         return found;
1027                 }
1028
1029                 //
1030                 // Inflates all member cache nested types
1031                 //
1032                 public void InflateTypes (MemberCache inflated_cache, TypeParameterInflator inflator)
1033                 {
1034                         foreach (var item in member_hash) {
1035                                 IList<MemberSpec> inflated_members = null;
1036                                 for (int i = 0; i < item.Value.Count; ++i ) {
1037                                         var member = item.Value[i];
1038
1039                                         // FIXME: When inflating members refering nested types before they are inflated
1040                                         if (member == null)
1041                                                 continue;
1042
1043                                         if ((member.Kind & MemberKind.NestedMask) != 0 &&
1044                                                 (member.Modifiers & Modifiers.COMPILER_GENERATED) == 0) {
1045                                                 if (inflated_members == null) {
1046                                                         inflated_members = new MemberSpec[item.Value.Count];
1047                                                         inflated_cache.member_hash.Add (item.Key, inflated_members);
1048                                                 }
1049
1050                                                 inflated_members [i] = member.InflateMember (inflator);
1051                                         }
1052                                 }
1053                         }
1054                 }
1055
1056                 //
1057                 // Inflates all open type members, requires InflateTypes to be called before
1058                 //
1059                 public void InflateMembers (MemberCache cacheToInflate, TypeSpec inflatedType, TypeParameterInflator inflator)
1060                 {
1061                         var inflated_member_hash = cacheToInflate.member_hash;
1062                         Dictionary<MemberSpec, MethodSpec> accessor_relation = null;
1063                         List<MemberSpec> accessor_members = null;
1064
1065                         // Copy member specific flags when all members were added
1066                         cacheToInflate.state = state;
1067
1068                         foreach (var item in member_hash) {
1069                                 var members = item.Value;
1070                                 IList<MemberSpec> inflated_members = null;
1071                                 for (int i = 0; i < members.Count; ++i ) {
1072                                         var member = members[i];
1073
1074                                         //
1075                                         // All nested types have been inflated earlier except for
1076                                         // compiler types which are created later and could miss InflateTypes
1077                                         //
1078                                         if ((member.Kind & MemberKind.NestedMask) != 0 &&
1079                                                 (member.Modifiers & Modifiers.COMPILER_GENERATED) == 0) {
1080                                                 if (inflated_members == null)
1081                                                         inflated_members = inflated_member_hash[item.Key];
1082
1083                                                 continue;
1084                                         }
1085
1086                                         //
1087                                         // Clone the container first
1088                                         //
1089                                         if (inflated_members == null) {
1090                                                 inflated_members = new MemberSpec [item.Value.Count];
1091                                                 inflated_member_hash.Add (item.Key, inflated_members);
1092                                         }
1093
1094                                         var local_inflator = inflator;
1095
1096                                         if (member.DeclaringType != inflatedType) {
1097                                                 //
1098                                                 // Don't inflate top-level non-generic interface members
1099                                                 // merged into generic interface
1100                                                 //
1101                                                 if (!member.DeclaringType.IsGeneric && !member.DeclaringType.IsNested) {
1102                                                         inflated_members [i] = member;
1103                                                         continue;
1104                                                 }
1105
1106                                                 //
1107                                                 // Needed when inflating flatten interfaces. It inflates
1108                                                 // container type only, type parameters are already done
1109                                                 //
1110                                                 // Handles cases like:
1111                                                 //
1112                                                 // interface I<T> {}
1113                                                 // interface I<U, V> : I<U> {}
1114                                                 //
1115                                                 // class C: I<int, bool> {}
1116                                                 //
1117                                                 var inflated_parent = inflator.Inflate (member.DeclaringType);
1118                                                 if (inflated_parent != inflator.TypeInstance)
1119                                                         local_inflator = new TypeParameterInflator (inflator, inflated_parent);
1120                                         }
1121
1122                                         //
1123                                         // Inflate every member, its parent is now different
1124                                         //
1125                                         var inflated = member.InflateMember (local_inflator);
1126                                         inflated_members [i] = inflated;
1127
1128                                         if (member is PropertySpec || member is EventSpec) {
1129                                                 if (accessor_members == null)
1130                                                         accessor_members = new List<MemberSpec> ();
1131
1132                                                 accessor_members.Add (inflated);
1133                                                 continue;
1134                                         }
1135
1136                                         if (member.IsAccessor) {
1137                                                 if (accessor_relation == null)
1138                                                         accessor_relation = new Dictionary<MemberSpec, MethodSpec> ();
1139                                                 accessor_relation.Add (member, (MethodSpec) inflated);
1140                                         }
1141                                 }
1142                         }
1143
1144                         if (accessor_members != null) {
1145                                 foreach (var member in accessor_members) {
1146                                         var prop = member as PropertySpec;
1147                                         if (prop != null) {
1148                                                 if (prop.Get != null)
1149                                                         prop.Get = accessor_relation[prop.Get];
1150                                                 if (prop.Set != null)
1151                                                         prop.Set = accessor_relation[prop.Set];
1152
1153                                                 continue;
1154                                         }
1155
1156                                         var ev = (EventSpec) member;
1157                                         ev.AccessorAdd = accessor_relation[ev.AccessorAdd];
1158                                         ev.AccessorRemove = accessor_relation[ev.AccessorRemove];
1159                                 }
1160                         }
1161                 }
1162
1163                 //
1164                 // Removes hidden base members of an interface. For compiled interfaces we cannot
1165                 // do name filtering during Add (as we do for import) because we need all base
1166                 // names to be valid during type definition.
1167                 // Add replaces hidden base member with current one which means any name collision
1168                 // (CS0108) of non-first name would be unnoticed because the name was replaced
1169                 // with the one from compiled type
1170                 //
1171                 public void RemoveHiddenMembers (TypeSpec container)
1172                 {
1173                         foreach (var entry in member_hash) {
1174                                 var values = entry.Value;
1175
1176                                 int container_members_start_at = 0;
1177                                 while (values[container_members_start_at].DeclaringType != container && ++container_members_start_at < entry.Value.Count);
1178
1179                                 if (container_members_start_at == 0 || container_members_start_at == values.Count)
1180                                         continue;
1181
1182                                 for (int i = 0; i < container_members_start_at; ++i) {
1183                                         var member = values[i];
1184
1185                                         if (!container.ImplementsInterface (member.DeclaringType, false))
1186                                                 continue;
1187
1188                                         var member_param = member is IParametersMember ? ((IParametersMember) member).Parameters : ParametersCompiled.EmptyReadOnlyParameters;
1189
1190                                         for (int ii = container_members_start_at; ii < values.Count; ++ii) {
1191                                                 var container_entry = values[ii];
1192
1193                                                 if (container_entry.Arity != member.Arity)
1194                                                         continue;
1195
1196                                                 if (container_entry is IParametersMember) {
1197                                                         if (!TypeSpecComparer.Override.IsEqual (((IParametersMember) container_entry).Parameters, member_param))
1198                                                                 continue;
1199                                                 }
1200
1201                                                 values.RemoveAt (i);
1202                                                 --container_members_start_at;
1203                                                 --ii;
1204                                                 --i;
1205                                         }
1206                                 }
1207                         }
1208                 }
1209
1210                 //
1211                 // Checks all appropriate container members for CLS compliance
1212                 //
1213                 public void VerifyClsCompliance (TypeSpec container, Report report)
1214                 {
1215                         if (locase_members != null)
1216                                 return;
1217
1218                         if (container.BaseType == null) {
1219                                 locase_members = new Dictionary<string, MemberSpec[]> (member_hash.Count); // StringComparer.OrdinalIgnoreCase);
1220                         } else {
1221                                 var btype = container.BaseType.GetDefinition ();
1222                                 btype.MemberCache.VerifyClsCompliance (btype, report);
1223                                 locase_members = new Dictionary<string, MemberSpec[]> (btype.MemberCache.locase_members); //, StringComparer.OrdinalIgnoreCase);
1224                         }
1225
1226                         var is_imported_type = container.MemberDefinition.IsImported;
1227                         foreach (var entry in container.MemberCache.member_hash) {
1228                                 for (int i = 0; i < entry.Value.Count; ++i ) {
1229                                         var name_entry = entry.Value[i];
1230                                         if ((name_entry.Modifiers & (Modifiers.PUBLIC | Modifiers.PROTECTED)) == 0)
1231                                                 continue;
1232
1233                                         if ((name_entry.Modifiers & (Modifiers.OVERRIDE | Modifiers.COMPILER_GENERATED)) != 0)
1234                                                 continue;
1235
1236                                         if ((name_entry.Kind & MemberKind.MaskType) == 0)
1237                                                 continue;
1238
1239                                         if (name_entry.MemberDefinition.CLSAttributeValue == false)
1240                                             continue;
1241
1242                                         IParametersMember p_a = null;
1243                                         if (!is_imported_type) {
1244                                                 p_a = name_entry as IParametersMember;
1245                                                 if (p_a != null && !name_entry.IsAccessor) {
1246                                                         var p_a_pd = p_a.Parameters;
1247                                                         //
1248                                                         // Check differing overloads in @container
1249                                                         //
1250                                                         for (int ii = i + 1; ii < entry.Value.Count; ++ii) {
1251                                                                 var checked_entry = entry.Value[ii];
1252                                                                 IParametersMember p_b = checked_entry as IParametersMember;
1253                                                                 if (p_b == null)
1254                                                                         continue;
1255
1256                                                                 if (p_a_pd.Count != p_b.Parameters.Count)
1257                                                                         continue;
1258
1259                                                                 if (checked_entry.IsAccessor)
1260                                                                         continue;
1261
1262                                                                 var res = ParametersCompiled.IsSameClsSignature (p_a.Parameters, p_b.Parameters);
1263                                                                 if (res != 0) {
1264                                                                         ReportOverloadedMethodClsDifference (name_entry, checked_entry, res, report);
1265                                                                 }
1266                                                         }
1267                                                 }
1268                                         }
1269
1270                                         if (i > 0 || name_entry.Kind == MemberKind.Constructor || name_entry.Kind == MemberKind.Indexer)
1271                                                 continue;
1272
1273                                         var name_entry_locase = name_entry.Name.ToLowerInvariant ();
1274
1275                                         MemberSpec[] found;
1276                                         if (!locase_members.TryGetValue (name_entry_locase, out found)) {
1277                                                 found = new MemberSpec[] { name_entry };
1278                                                 locase_members.Add (name_entry_locase, found);
1279                                         } else {
1280                                                 bool same_names_only = true;
1281                                                 foreach (var f in found) {
1282                                                         if (f.Name == name_entry.Name) {
1283                                                                 if (p_a != null) {
1284                                                                         IParametersMember p_b = f as IParametersMember;
1285                                                                         if (p_b == null)
1286                                                                                 continue;
1287
1288                                                                         if (p_a.Parameters.Count != p_b.Parameters.Count)
1289                                                                                 continue;
1290
1291                                                                         if (f.IsAccessor)
1292                                                                                 continue;
1293
1294                                                                         var res = ParametersCompiled.IsSameClsSignature (p_a.Parameters, p_b.Parameters);
1295                                                                         if (res != 0) {
1296                                                                                 ReportOverloadedMethodClsDifference (f, name_entry, res, report);
1297                                                                         }
1298                                                                 }
1299
1300                                                                 continue;
1301                                                         }
1302
1303                                                         same_names_only = false;
1304                                                         if (!is_imported_type) {
1305                                                                 var last = GetLaterDefinedMember (f, name_entry);
1306                                                                 if (last == f.MemberDefinition) {
1307                                                                         report.SymbolRelatedToPreviousError (name_entry);
1308                                                                 } else {
1309                                                                         report.SymbolRelatedToPreviousError (f);
1310                                                                 }
1311
1312                                                                 report.Warning (3005, 1, last.Location,
1313                                                                         "Identifier `{0}' differing only in case is not CLS-compliant", last.GetSignatureForError ());
1314                                                         }
1315                                                 }
1316
1317                                                 if (!same_names_only) {
1318                                                         Array.Resize (ref found, found.Length + 1);
1319                                                         found[found.Length - 1] = name_entry;
1320                                                         locase_members[name_entry_locase] = found;
1321                                                 }
1322                                         }
1323                                 }
1324                         }
1325                 }
1326
1327                 //
1328                 // Local report helper to issue correctly ordered members stored in hashtable
1329                 //
1330                 static MemberCore GetLaterDefinedMember (MemberSpec a, MemberSpec b)
1331                 {
1332                         var mc_a = a.MemberDefinition as MemberCore;
1333                         var mc_b = b.MemberDefinition as MemberCore;
1334                         if (mc_a == null)
1335                                 return mc_b;
1336
1337                         if (mc_b == null)
1338                                 return mc_a;
1339
1340                         if (a.DeclaringType.MemberDefinition != b.DeclaringType.MemberDefinition)
1341                                 return mc_b;
1342
1343                         if (mc_a.Location.File != mc_b.Location.File)
1344                                 return mc_b;
1345
1346                         return mc_b.Location.Row > mc_a.Location.Row ? mc_b : mc_a;
1347                 }
1348
1349                 static void ReportOverloadedMethodClsDifference (MemberSpec a, MemberSpec b, int res, Report report)
1350                 {
1351                         var last = GetLaterDefinedMember (a, b);
1352                         if (last == a.MemberDefinition) {
1353                                 report.SymbolRelatedToPreviousError (b);
1354                         } else {
1355                                 report.SymbolRelatedToPreviousError (a);
1356                         }
1357
1358                         if ((res & 1) != 0) {
1359                                 report.Warning (3006, 1, last.Location,
1360                                                 "Overloaded method `{0}' differing only in ref or out, or in array rank, is not CLS-compliant",
1361                                                 last.GetSignatureForError ());
1362                         }
1363
1364                         if ((res & 2) != 0) {
1365                                 report.Warning (3007, 1, last.Location,
1366                                         "Overloaded method `{0}' differing only by unnamed array types is not CLS-compliant",
1367                                         last.GetSignatureForError ());
1368                         }
1369                 }
1370
1371                 public bool CheckExistingMembersOverloads (MemberCore member, AParametersCollection parameters)
1372                 {
1373                         var name = GetLookupName (member);
1374                         var imb = member as InterfaceMemberBase;
1375                         if (imb != null && imb.IsExplicitImpl) {
1376                                 name = imb.GetFullName (name);
1377                         }
1378
1379                         return CheckExistingMembersOverloads (member, name, parameters);
1380                 }
1381
1382                 public bool CheckExistingMembersOverloads (MemberCore member, string name, AParametersCollection parameters)
1383                 {
1384                         IList<MemberSpec> entries;
1385                         if (!member_hash.TryGetValue (name, out entries))
1386                                 return false;
1387
1388                         var Report = member.Compiler.Report;
1389
1390                         int method_param_count = parameters.Count;
1391                         for (int i = entries.Count - 1; i >= 0; --i) {
1392                                 var ce = entries[i];
1393                                 var pm = ce as IParametersMember;
1394                                 var pd = pm == null ? ParametersCompiled.EmptyReadOnlyParameters : pm.Parameters;
1395                                 if (pd.Count != method_param_count)
1396                                         continue;
1397
1398                                 if (ce.Arity != member.MemberName.Arity)
1399                                         continue;
1400
1401                                 // Ignore merged interface members
1402                                 if (member.Parent.PartialContainer != ce.DeclaringType.MemberDefinition)
1403                                         continue;
1404
1405                                 var p_types = pd.Types;
1406                                 if (method_param_count > 0) {
1407                                         int ii = method_param_count - 1;
1408                                         TypeSpec type_a, type_b;
1409                                         do {
1410                                                 type_a = parameters.Types [ii];
1411                                                 type_b = p_types [ii];
1412
1413                                                 var a_byref = (pd.FixedParameters[ii].ModFlags & Parameter.Modifier.RefOutMask) != 0;
1414                                                 var b_byref = (parameters.FixedParameters[ii].ModFlags & Parameter.Modifier.RefOutMask) != 0;
1415
1416                                                 if (a_byref != b_byref)
1417                                                         break;
1418
1419                                         } while (TypeSpecComparer.Override.IsEqual (type_a, type_b) && ii-- != 0);
1420
1421                                         if (ii >= 0)
1422                                                 continue;
1423
1424                                         //
1425                                         // Operators can differ in return type only
1426                                         //
1427                                         if (member is Operator && ce.Kind == MemberKind.Operator && ((MethodSpec) ce).ReturnType != ((Operator) member).ReturnType)
1428                                                 continue;
1429
1430                                         //
1431                                         // Report difference in parameter modifiers only
1432                                         //
1433                                         if (pd != null && member is MethodCore) {
1434                                                 ii = method_param_count;
1435                                                 while (ii-- != 0 &&
1436                                                         (parameters.FixedParameters[ii].ModFlags & Parameter.Modifier.ModifierMask) ==
1437                                                         (pd.FixedParameters[ii].ModFlags & Parameter.Modifier.ModifierMask) &&
1438                                                         parameters.ExtensionMethodType == pd.ExtensionMethodType) ;
1439
1440                                                 if (ii >= 0) {
1441                                                         var mc = ce as MethodSpec;
1442                                                         member.Compiler.Report.SymbolRelatedToPreviousError (ce);
1443                                                         if ((member.ModFlags & Modifiers.PARTIAL) != 0 && (mc.Modifiers & Modifiers.PARTIAL) != 0) {
1444                                                                 if (parameters.HasParams || pd.HasParams) {
1445                                                                         Report.Error (758, member.Location,
1446                                                                                 "A partial method declaration and partial method implementation cannot differ on use of `params' modifier");
1447                                                                 } else {
1448                                                                         Report.Error (755, member.Location,
1449                                                                                 "A partial method declaration and partial method implementation must be both an extension method or neither");
1450                                                                 }
1451                                                         } else if (member is Constructor) {
1452                                                                 Report.Error (851, member.Location,
1453                                                                         "Overloaded contructor `{0}' cannot differ on use of parameter modifiers only",
1454                                                                         member.GetSignatureForError ());
1455                                                         } else {
1456                                                                 Report.Error (663, member.Location,
1457                                                                         "Overloaded method `{0}' cannot differ on use of parameter modifiers only",
1458                                                                         member.GetSignatureForError ());
1459                                                         }
1460                                                         return false;
1461                                                 }
1462                                         }
1463                                 }
1464
1465                                 if ((ce.Kind & MemberKind.Method) != 0) {
1466                                         Method method_a = member as Method;
1467                                         Method method_b = ce.MemberDefinition as Method;
1468                                         if (method_a != null && method_b != null && (method_a.ModFlags & method_b.ModFlags & Modifiers.PARTIAL) != 0) {
1469                                                 const Modifiers partial_modifiers = Modifiers.STATIC | Modifiers.UNSAFE;
1470                                                 if (method_a.IsPartialDefinition == method_b.IsPartialImplementation) {
1471                                                         if ((method_a.ModFlags & partial_modifiers) == (method_b.ModFlags & partial_modifiers) ||
1472                                                                 method_a.Parent.IsUnsafe && method_b.Parent.IsUnsafe) {
1473                                                                 if (method_a.IsPartialImplementation) {
1474                                                                         method_a.SetPartialDefinition (method_b);
1475                                                                         if (entries.Count == 1)
1476                                                                                 member_hash.Remove (name);
1477                                                                         else
1478                                                                                 entries.RemoveAt (i);
1479                                                                 } else {
1480                                                                         method_b.SetPartialDefinition (method_a);
1481                                                                         method_a.caching_flags |= MemberCore.Flags.PartialDefinitionExists;
1482                                                                 }
1483                                                                 continue;
1484                                                         }
1485
1486                                                         if (method_a.IsStatic != method_b.IsStatic) {
1487                                                                 Report.SymbolRelatedToPreviousError (ce);
1488                                                                 Report.Error (763, member.Location,
1489                                                                         "A partial method declaration and partial method implementation must be both `static' or neither");
1490                                                         }
1491
1492                                                         if ((method_a.ModFlags & Modifiers.UNSAFE) != (method_b.ModFlags & Modifiers.UNSAFE)) {
1493                                                                 Report.SymbolRelatedToPreviousError (ce);
1494                                                                 Report.Error (764, member.Location,
1495                                                                         "A partial method declaration and partial method implementation must be both `unsafe' or neither");
1496                                                         }
1497
1498                                                         return false;
1499                                                 }
1500
1501                                                 Report.SymbolRelatedToPreviousError (ce);
1502                                                 if (method_a.IsPartialDefinition) {
1503                                                         Report.Error (756, member.Location, "A partial method `{0}' declaration is already defined",
1504                                                                 member.GetSignatureForError ());
1505                                                 }
1506
1507                                                 Report.Error (757, member.Location, "A partial method `{0}' implementation is already defined",
1508                                                         member.GetSignatureForError ());
1509                                                 return false;
1510                                         }
1511
1512                                         Report.SymbolRelatedToPreviousError (ce);
1513
1514                                         bool is_reserved_a = member is AbstractPropertyEventMethod || member is Operator;
1515                                         bool is_reserved_b = ((MethodSpec) ce).IsReservedMethod;
1516
1517                                         if (is_reserved_a || is_reserved_b) {
1518                                                 Report.Error (82, member.Location, "A member `{0}' is already reserved",
1519                                                         is_reserved_a ?
1520                                                         ce.GetSignatureForError () :
1521                                                         member.GetSignatureForError ());
1522                                                 return false;
1523                                         }
1524                                 } else {
1525                                         Report.SymbolRelatedToPreviousError (ce);
1526                                 }
1527
1528                                 if (member is Operator && ce.Kind == MemberKind.Operator) {
1529                                         Report.Error (557, member.Location, "Duplicate user-defined conversion in type `{0}'",
1530                                                 member.Parent.GetSignatureForError ());
1531                                         return false;
1532                                 }
1533
1534                                 Report.Error (111, member.Location,
1535                                         "A member `{0}' is already defined. Rename this member or use different parameter types",
1536                                         member.GetSignatureForError ());
1537                                 return false;
1538                         }
1539
1540                         return true;
1541                 }
1542         }
1543 }