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