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 (entry.DeclaringType != member.DeclaringType) {
 377                                                         if (!TypeSpecComparer.Override.IsEqual (entry_param, member_param))
 378                                                                 continue;
 379                                                 } else {
 380                                                         if (!TypeSpecComparer.Equals (entry_param.Types, member_param.Types))
 381                                                                 continue;
 382                                                 }
 383                                         }
 384                                 }
 385
 386                                 if (member.DeclaringType.ImplementsInterface (entry.DeclaringType, false)) {
 387                                         if (existing.Count == 1) {
 388                                                 existing = new MemberSpec[] { member };
 389                                                 return true;
 390                                         }
 391
 392                                         existing.RemoveAt (i--);
 393                                         continue;
 394                                 }
 395
 396                                 if ((entry.DeclaringType == member.DeclaringType && entry.IsAccessor == member.IsAccessor))
 397                                         return false;
 398
 399                                 if (entry.DeclaringType.ImplementsInterface (member.DeclaringType, false) && AParametersCollection.HasSameParameterDefaults (entry_param, member_param))
 400                                         return false;
 401                         }
 402
 403                         if (existing.Count == 1) {
 404                                 existing = new List<MemberSpec> { existing[0], member };
 405                                 return true;
 406                         }
 407
 408                         existing.Add (member);
 409                         return false;
 410                 }
 411
 412                 public static MemberSpec FindMember (TypeSpec container, MemberFilter filter, BindingRestriction restrictions)
 413                 {
 414                         if (filter.Kind == MemberKind.Method && container.Kind == MemberKind.TypeParameter && filter.Parameters == null)
 415                                 throw new NotSupportedException ("type parameters methods cannot be lookup up due to two stage setup");
 416
 417                         IList<MemberSpec> applicable;
 418                         var top_container = container;
 419
 420                         do {
 421                                 if (container.MemberCache.member_hash.TryGetValue (filter.Name, out applicable)) {
 422                                         // Start from the end because interface members are in reverse order
 423                                         for (int i = applicable.Count - 1; i >= 0; i--) {
 424                                                 var entry = applicable [i];
 425
 426                                                 if ((restrictions & BindingRestriction.InstanceOnly) != 0 && entry.IsStatic)
 427                                                         continue;
 428
 429                                                 if ((restrictions & BindingRestriction.NoAccessors) != 0 && entry.IsAccessor)
 430                                                         continue;
 431
 432                                                 if ((restrictions & BindingRestriction.OverrideOnly) != 0 && (entry.Modifiers & Modifiers.OVERRIDE) == 0)
 433                                                         continue;
 434
 435                                                 if (!filter.Equals (entry))
 436                                                         continue;
 437
 438                                                 if ((restrictions & BindingRestriction.DeclaredOnly) != 0 && container.IsInterface && entry.DeclaringType != container)
 439                                                         continue;
 440
 441                                                 return entry;
 442                                         }
 443                                 }
 444
 445                                 if ((restrictions & BindingRestriction.DeclaredOnly) != 0)
 446                                         break;
 447
 448                                 container = container.BaseType;
 449                         } while (container != null);
 450
 451                         var tps = top_container as TypeParameterSpec;
 452                         if (tps != null && tps.InterfaceCache != null) {
 453                                 if (tps.InterfaceCache.member_hash.TryGetValue (filter.Name, out applicable)) {
 454                                         for (int i = applicable.Count - 1; i >= 0; i--) {
 455                                                 var entry = applicable [i];
 456
 457                                                 if ((restrictions & BindingRestriction.NoAccessors) != 0 && entry.IsAccessor)
 458                                                         continue;
 459
 460                                                 if ((restrictions & BindingRestriction.OverrideOnly) != 0 && (entry.Modifiers & Modifiers.OVERRIDE) == 0)
 461                                                         continue;
 462
 463                                                 if (!filter.Equals (entry))
 464                                                         continue;
 465
 466                                                 return entry;
 467                                         }
 468                                 }
 469                         }
 470
 471                         return null;
 472                 }
 473
 474                 //
 475                 // A special method to work with member lookup only. It returns a list of all members named @name
 476                 // starting from @container. It's very performance sensitive
 477                 //
 478                 // declaredOnlyClass cannot be used interfaces. Manual filtering is required because names are
 479                 // compacted
 480                 //
 481                 public static IList<MemberSpec> FindMembers (TypeSpec container, string name, bool declaredOnlyClass)
 482                 {
 483                         do {
 484                                 IList<MemberSpec> applicable;
 485
 486                                 if (container.MemberCache.member_hash.TryGetValue (name, out applicable) || declaredOnlyClass)
 487                                         return applicable;
 488
 489                                 container = container.BaseType;
 490                         } while (container != null);
 491
 492                         return null;
 493                 }
 494
 495                 public static IList<MemberSpec> FindInterfaceMembers (TypeParameterSpec typeParameter, string name)
 496                 {
 497                         if (typeParameter.InterfaceCache != null) {
 498                                 IList<MemberSpec> applicable;
 499                                 typeParameter.InterfaceCache.member_hash.TryGetValue (name, out applicable);
 500                                 return applicable;
 501                         }
 502
 503                         return null;
 504                 }
 505
 506                 //
 507                 // Finds the nested type in container
 508                 //
 509                 public static TypeSpec FindNestedType (TypeSpec container, string name, int arity, bool declaredOnlyClass)
 510                 {
 511                         IList<MemberSpec> applicable;
 512                         TypeSpec best_match = null;
 513                         do {
 514 #if !FULL_AOT_RUNTIME
 515                                 // TODO: Don't know how to handle this yet
 516                                 // When resolving base type of nested type, parent type must have
 517                                 // base type resolved to scan full hierarchy correctly
 518                                 // Similarly MemberCacheTypes will inflate BaseType and Interfaces
 519                                 // based on type definition
 520                                 var tc = container.MemberDefinition as TypeContainer;
 521                                 if (tc != null)
 522                                         tc.DefineContainer ();
 523 #endif
 524
 525                                 if (container.MemberCacheTypes.member_hash.TryGetValue (name, out applicable)) {
 526                                         for (int i = applicable.Count - 1; i >= 0; i--) {
 527                                                 var entry = applicable[i];
 528                                                 if ((entry.Kind & MemberKind.NestedMask) == 0)
 529                                                         continue;
 530
 531                                                 var ts = (TypeSpec) entry;
 532                                                 if (arity == ts.Arity)
 533                                                         return ts;
 534
 535                                                 if (arity < 0) {
 536                                                         if (best_match == null) {
 537                                                                 best_match = ts;
 538                                                         } else if (System.Math.Abs (ts.Arity + arity) < System.Math.Abs (best_match.Arity + arity)) {
 539                                                                 best_match = ts;
 540                                                         }
 541                                                 }
 542                                         }
 543                                 }
 544
 545                                 container = container.BaseType;
 546                         } while (container != null && !declaredOnlyClass);
 547
 548                         return best_match;
 549                 }
 550
 551                 //
 552                 // Looks for extension methods with defined name and extension type
 553                 //
 554                 public List<MethodSpec> FindExtensionMethods (IMemberContext invocationContext, string name, int arity)
 555                 {
 556                         IList<MemberSpec> entries;
 557                         if (!member_hash.TryGetValue (name, out entries))
 558                                 return null;
 559
 560                         List<MethodSpec> candidates = null;
 561                         foreach (var entry in entries) {
 562                                 if (entry.Kind != MemberKind.Method || (arity > 0 && entry.Arity != arity))
 563                                         continue;
 564
 565                                 var ms = (MethodSpec) entry;
 566                                 if (!ms.IsExtensionMethod)
 567                                         continue;
 568
 569                                 if (!ms.IsAccessible (invocationContext))
 570                                         continue;
 571
 572                                 //
 573                                 // Extension methods cannot be nested hence checking parent is enough
 574                                 //
 575                                 if ((ms.DeclaringType.Modifiers & Modifiers.INTERNAL) != 0 && !ms.DeclaringType.MemberDefinition.IsInternalAsPublic (invocationContext.Module.DeclaringAssembly))
 576                                         continue;
 577
 578                                 if (candidates == null)
 579                                         candidates = new List<MethodSpec> ();
 580                                 candidates.Add (ms);
 581                         }
 582
 583                         return candidates;
 584                 }
 585
 586                 //
 587                 // Returns base members of @member member if no exact match is found @bestCandidate returns
 588                 // the best match
 589                 //
 590                 public static MemberSpec FindBaseMember (MemberCore member, out MemberSpec bestCandidate, ref bool overrides)
 591                 {
 592                         bestCandidate = null;
 593                         var container = member.Parent.PartialContainer.Definition;
 594                         if (!container.IsInterface) {
 595                                 container = container.BaseType;
 596
 597                                 // It can happen for a user definition of System.Object
 598                                 if (container == null)
 599                                         return null;
 600                         }
 601
 602                         string name = GetLookupName (member);
 603                         var member_param = member is IParametersMember ? ((IParametersMember) member).Parameters : null;
 604
 605                         var mkind = GetMemberCoreKind (member);
 606                         bool member_with_accessors = mkind == MemberKind.Indexer || mkind == MemberKind.Property;
 607
 608                         IList<MemberSpec> applicable;
 609                         MemberSpec ambig_candidate = null;
 610
 611                         do {
 612                                 if (container.MemberCache.member_hash.TryGetValue (name, out applicable)) {
 613                                         for (int i = 0; i < applicable.Count; ++i) {
 614                                                 var entry = applicable [i];
 615
 616                                                 if ((entry.Modifiers & Modifiers.PUBLIC) == 0 && !entry.IsAccessible (member))
 617                                                         continue;
 618
 619                                                 //
 620                                                 // Isn't the member of same kind ?
 621                                                 //
 622                                                 if ((entry.Kind & ~MemberKind.Destructor & mkind & MemberKind.MaskType) == 0) {
 623                                                         // Destructors are ignored as they cannot be overridden by user
 624                                                         if ((entry.Kind & MemberKind.Destructor) != 0)
 625                                                                 continue;
 626
 627                                                         // A method with different arity does not hide base member
 628                                                         if (mkind != MemberKind.Method && member.MemberName.Arity != entry.Arity)
 629                                                                 continue;
 630
 631                                                         bestCandidate = entry;
 632                                                         return null;
 633                                                 }
 634
 635                                                 //
 636                                                 // Same kind of different arity is valid
 637                                                 //
 638                                                 if (member.MemberName.Arity != entry.Arity) {
 639                                                         continue;
 640                                                 }
 641
 642                                                 if ((entry.Kind & mkind & (MemberKind.Method | MemberKind.Indexer)) != 0) {
 643                                                         if (entry.IsAccessor != member is AbstractPropertyEventMethod)
 644                                                                 continue;
 645
 646                                                         var pm = entry as IParametersMember;
 647                                                         if (!TypeSpecComparer.Override.IsEqual (pm.Parameters, member_param))
 648                                                                 continue;
 649                                                 }
 650
 651                                                 //
 652                                                 // Skip override for member with accessors. It may not fully implement the base member
 653                                                 // but keep flag we found an implementation in case the base member is abstract
 654                                                 //
 655                                                 if (member_with_accessors && ((entry.Modifiers & (Modifiers.OVERRIDE | Modifiers.SEALED)) == Modifiers.OVERRIDE)) {
 656                                                         //
 657                                                         // Set candidate to override implementation to flag we found an implementation
 658                                                         //
 659                                                         overrides = true;
 660                                                         continue;
 661                                                 }
 662
 663                                                 //
 664                                                 // For members with parameters we can encounter an ambiguous candidates (they match exactly)
 665                                                 // because generic type parameters could be inflated into same types
 666                                                 //
 667                                                 if (ambig_candidate == null && (entry.Kind & mkind & (MemberKind.Method | MemberKind.Indexer)) != 0) {
 668                                                         bestCandidate = null;
 669                                                         ambig_candidate = entry;
 670                                                         continue;
 671                                                 }
 672
 673                                                 bestCandidate = ambig_candidate;
 674                                                 return entry;
 675                                         }
 676                                 }
 677
 678                                 if (container.IsInterface || ambig_candidate != null)
 679                                         break;
 680
 681                                 container = container.BaseType;
 682                         } while (container != null);
 683
 684                         return ambig_candidate;
 685                 }
 686
 687                 public static List<TypeSpec> GetDeclaredNestedTypes (TypeSpec container)
 688                 {
 689                         List<TypeSpec> found = null;
 690                         foreach (var entry in container.MemberCache.member_hash) {
 691                                 foreach (var member in entry.Value) {
 692                                         if ((member.Kind & MemberKind.NestedMask) == 0)
 693                                                 continue;
 694
 695                                         if (found == null)
 696                                                 found = new List<TypeSpec> ();
 697
 698                                         found.Add ((TypeSpec)member);
 699                                 }
 700                         }
 701
 702                         return found;
 703                 }
 704
 705                 //
 706                 // Returns inflated version of MemberSpec, it works similarly to
 707                 // SRE TypeBuilder.GetMethod
 708                 //
 709                 public static T GetMember<T> (TypeSpec container, T spec) where T : MemberSpec
 710                 {
 711                         IList<MemberSpec> applicable;
 712                         if (container.MemberCache.member_hash.TryGetValue (GetLookupName (spec), out applicable)) {
 713                                 for (int i = applicable.Count - 1; i >= 0; i--) {
 714                                         var entry = applicable[i];
 715                                         if (entry.MemberDefinition == spec.MemberDefinition)
 716                                                 return (T) entry;
 717                                 }
 718                         }
 719
 720                         throw new InternalErrorException ("Missing member `{0}' on inflated type `{1}'",
 721                                 spec.GetSignatureForError (), container.GetSignatureForError ());
 722                 }
 723
 724                 static MemberKind GetMemberCoreKind (MemberCore member)
 725                 {
 726                         if (member is FieldBase)
 727                                 return MemberKind.Field;
 728                         if (member is Indexer)
 729                                 return MemberKind.Indexer;
 730                         if (member is Class)
 731                                 return MemberKind.Class;
 732                         if (member is Struct)
 733                                 return MemberKind.Struct;
 734                         if (member is Destructor)
 735                                 return MemberKind.Destructor;
 736                         if (member is Method)
 737                                 return MemberKind.Method;
 738                         if (member is Property)
 739                                 return MemberKind.Property;
 740                         if (member is EventField)
 741                                 return MemberKind.Event;
 742                         if (member is Interface)
 743                                 return MemberKind.Interface;
 744                         if (member is EventProperty)
 745                                 return MemberKind.Event;
 746                         if (member is Delegate)
 747                                 return MemberKind.Delegate;
 748                         if (member is Enum)
 749                                 return MemberKind.Enum;
 750
 751                         throw new NotImplementedException (member.GetType ().ToString ());
 752                 }
 753
 754                 public static List<FieldSpec> GetAllFieldsForDefiniteAssignment (TypeSpec container, IMemberContext context)
 755                 {
 756                         List<FieldSpec> fields = null;
 757                         bool imported = container.MemberDefinition.IsImported;
 758                         foreach (var entry in container.MemberCache.member_hash) {
 759                                 foreach (var name_entry in entry.Value) {
 760                                         if (name_entry.Kind != MemberKind.Field)
 761                                                 continue;
 762
 763                                         if ((name_entry.Modifiers & Modifiers.STATIC) != 0)
 764                                                 continue;
 765
 766                                         //
 767                                         // Fixed size buffers are not subject to definite assignment checking
 768                                         //
 769                                         if (name_entry is FixedFieldSpec || name_entry is ConstSpec)
 770                                                 continue;
 771
 772                                         var fs = (FieldSpec) name_entry;
 773                                         if (imported && ShouldIgnoreFieldForDefiniteAssignment (fs, context))
 774                                                 continue;
 775
 776                                         //if ((fs.Modifiers & (Modifiers.BACKING_FIELD) != 0)
 777                                         //      continue;
 778
 779                                         if (fields == null)
 780                                                 fields = new List<FieldSpec> ();
 781
 782                                         fields.Add (fs);
 783                                         break;
 784                                 }
 785                         }
 786
 787                         return fields ?? new List<FieldSpec> (0);
 788                 }
 789
 790                 static bool ShouldIgnoreFieldForDefiniteAssignment (FieldSpec fs, IMemberContext context)
 791                 {
 792                         //
 793                         // LAMESPEC: This mimics csc quirk where definitive assignment is not done
 794                         // for all kinds of imported non-public struct fields
 795                         //
 796                         var mod = fs.Modifiers;
 797                         if ((mod & Modifiers.PRIVATE) == 0 && ((mod & Modifiers.INTERNAL) != 0 && fs.DeclaringType.MemberDefinition.IsInternalAsPublic (context.Module.DeclaringAssembly)))
 798                                 return false;
 799
 800                         //
 801                         // Ignore reference type fields except when type is an array or type parameter
 802                         //
 803                         var type = fs.MemberType;
 804                         switch (type.Kind) {
 805                         case MemberKind.ArrayType:
 806                         case MemberKind.TypeParameter:
 807                                 return false;
 808                         default:
 809                                 return TypeSpec.IsReferenceType (type);
 810                         }
 811                 }
 812
 813                 public static IList<MemberSpec> GetCompletitionMembers (IMemberContext ctx, TypeSpec container, string name)
 814                 {
 815                         var matches = new List<MemberSpec> ();
 816                         foreach (var entry in container.MemberCache.member_hash) {
 817                                 foreach (var name_entry in entry.Value) {
 818                                         if (name_entry.IsAccessor)
 819                                                 continue;
 820
 821                                         if ((name_entry.Kind & (MemberKind.Constructor | MemberKind.Destructor | MemberKind.Operator)) != 0)
 822                                                 continue;
 823
 824                                         if (!name_entry.IsAccessible (ctx))
 825                                                 continue;
 826
 827                                         if (name == null || name_entry.Name.StartsWith (name)) {
 828                                                 matches.Add (name_entry);
 829                                         }
 830                                 }
 831                         }
 832
 833                         return matches;
 834                 }
 835
 836                 //
 837                 // Returns members of @iface only, base members are ignored
 838                 //
 839                 public static List<MethodSpec> GetInterfaceMethods (TypeSpec iface)
 840                 {
 841                         //
 842                         // MemberCache flatten interfaces, therefore in cases like this one
 843                         //
 844                         // interface IA : IB {}
 845                         // interface IB { void Foo () }
 846                         //
 847                         // we would return Foo inside IA which is not expected in this case
 848                         //
 849                         var methods = new List<MethodSpec> ();
 850                         foreach (var entry in iface.MemberCache.member_hash.Values) {
 851                                 foreach (var name_entry in entry) {
 852                                         if (iface == name_entry.DeclaringType) {
 853                                                 if (name_entry.Kind == MemberKind.Method) {
 854                                                         methods.Add ((MethodSpec) name_entry);
 855                                                 }
 856                                         }
 857                                 }
 858                         }
 859
 860                         return methods;
 861                 }
 862
 863                 //
 864                 // Returns all not implememted abstract members inside abstract type
 865                 // NOTE: Returned list is shared and must not be modified
 866                 //
 867                 public static IList<MethodSpec> GetNotImplementedAbstractMethods (TypeSpec type)
 868                 {
 869                         if (type.MemberCache.missing_abstract != null)
 870                                 return type.MemberCache.missing_abstract;
 871
 872                         var abstract_methods = new List<MethodSpec> ();
 873                         List<TypeSpec> hierarchy = null;
 874
 875                         //
 876                         // Stage 1: top-to-bottom scan for abstract members
 877                         //
 878                         var abstract_type = type;
 879                         while (true) {
 880                                 foreach (var entry in abstract_type.MemberCache.member_hash) {
 881                                         foreach (var name_entry in entry.Value) {
 882                                                 if ((name_entry.Modifiers & Modifiers.ABSTRACT) == 0)
 883                                                         continue;
 884
 885                                                 var ms = name_entry as MethodSpec;
 886                                                 if (ms == null)
 887                                                         continue;
 888
 889                                                 abstract_methods.Add (ms);
 890                                         }
 891                                 }
 892
 893                                 var base_type = abstract_type.BaseType;
 894                                 if (!base_type.IsAbstract)
 895                                         break;
 896
 897                                 if (hierarchy == null)
 898                                         hierarchy = new List<TypeSpec> ();
 899
 900                                 hierarchy.Add (abstract_type);
 901                                 abstract_type = base_type;
 902                         }
 903
 904                         int not_implemented_count = abstract_methods.Count;
 905                         if (not_implemented_count == 0 || hierarchy == null) {
 906                                 type.MemberCache.missing_abstract = abstract_methods;
 907                                 return type.MemberCache.missing_abstract;
 908                         }
 909
 910                         //
 911                         // Stage 2: Remove already implemented methods
 912                         //
 913                         foreach (var type_up in hierarchy) {
 914                                 var members = type_up.MemberCache.member_hash;
 915                                 if (members.Count == 0)
 916                                         continue;
 917
 918                                 for (int i = 0; i < abstract_methods.Count; ++i) {
 919                                         var candidate = abstract_methods [i];
 920                                         if (candidate == null)
 921                                                 continue;
 922
 923                                         IList<MemberSpec> applicable;
 924                                         if (!members.TryGetValue (candidate.Name, out applicable))
 925                                                 continue;
 926
 927                                         var filter = new MemberFilter (candidate);
 928                                         foreach (var item in applicable) {
 929                                                 if ((item.Modifiers & (Modifiers.OVERRIDE | Modifiers.VIRTUAL)) == 0)
 930                                                         continue;
 931
 932                                                 //
 933                                                 // Abstract override does not override anything
 934                                                 //
 935                                                 if ((item.Modifiers & Modifiers.ABSTRACT) != 0)
 936                                                         continue;
 937
 938                                                 if (filter.Equals (item)) {
 939                                                         --not_implemented_count;
 940                                                         abstract_methods [i] = null;
 941                                                         break;
 942                                                 }
 943                                         }
 944                                 }
 945                         }
 946
 947                         if (not_implemented_count == abstract_methods.Count) {
 948                                 type.MemberCache.missing_abstract = abstract_methods;
 949                                 return type.MemberCache.missing_abstract;
 950                         }
 951
 952                         var not_implemented = new MethodSpec[not_implemented_count];
 953                         int counter = 0;
 954                         foreach (var m in abstract_methods) {
 955                                 if (m == null)
 956                                         continue;
 957
 958                                 not_implemented[counter++] = m;
 959                         }
 960
 961                         type.MemberCache.missing_abstract = not_implemented;
 962                         return type.MemberCache.missing_abstract;
 963                 }
 964
 965                 static string GetLookupName (MemberSpec ms)
 966                 {
 967                         if (ms.Kind == MemberKind.Indexer)
 968                                 return IndexerNameAlias;
 969
 970                         if (ms.Kind == MemberKind.Constructor) {
 971                                 if (ms.IsStatic)
 972                                         return Constructor.TypeConstructorName;
 973
 974                                 return Constructor.ConstructorName;
 975                         }
 976
 977                         return ms.Name;
 978                 }
 979
 980                 static string GetLookupName (MemberCore mc)
 981                 {
 982                         if (mc is Indexer)
 983                                 return IndexerNameAlias;
 984
 985                         if (mc is Constructor)
 986                                 return mc.IsStatic ? Constructor.TypeConstructorName : Constructor.ConstructorName;
 987
 988                         return mc.MemberName.Name;
 989                 }
 990
 991                 //
 992                 // Returns all operators declared on container and its base types (until declaredOnly is used)
 993                 //
 994                 public static IList<MemberSpec> GetUserOperator (TypeSpec container, Operator.OpType op, bool declaredOnly)
 995                 {
 996                         IList<MemberSpec> found = null;
 997                         bool shared_list = true;
 998                         IList<MemberSpec> applicable;
 999                         do {
1000                                 var mc = container.MemberCache;
1001
1002                                 if (((op == Operator.OpType.Implicit || op == Operator.OpType.Explicit) && (mc.state & StateFlags.HasConversionOperator) != 0) ||
1003                                          (mc.state & StateFlags.HasUserOperator) != 0) {
1004
1005                                         if (mc.member_hash.TryGetValue (Operator.GetMetadataName (op), out applicable)) {
1006                                                 int i;
1007                                                 for (i = 0; i < applicable.Count; ++i) {
1008                                                         if (applicable[i].Kind != MemberKind.Operator) {
1009                                                                 break;
1010                                                         }
1011                                                 }
1012
1013                                                 //
1014                                                 // Handles very rare case where a method with same name as operator (op_xxxx) exists
1015                                                 // and we have to resize the applicable list
1016                                                 //
1017                                                 if (i != applicable.Count) {
1018                                                         for (i = 0; i < applicable.Count; ++i) {
1019                                                                 if (applicable[i].Kind != MemberKind.Operator) {
1020                                                                         continue;
1021                                                                 }
1022
1023                                                                 if (found == null) {
1024                                                                         found = new List<MemberSpec> ();
1025                                                                         found.Add (applicable[i]);
1026                                                                 } else {
1027                                                                         List<MemberSpec> prev;
1028                                                                         if (shared_list) {
1029                                                                                 shared_list = false;
1030                                                                                 prev = new List<MemberSpec> (found.Count + 1);
1031                                                                                 prev.AddRange (found);
1032                                                                                 found = prev;
1033                                                                         } else {
1034                                                                                 prev = (List<MemberSpec>) found;
1035                                                                         }
1036
1037                                                                         prev.Add (applicable[i]);
1038                                                                 }
1039                                                         }
1040                                                 } else {
1041                                                         if (found == null) {
1042                                                                 found = applicable;
1043                                                                 shared_list = true;
1044                                                         } else {
1045                                                                 List<MemberSpec> merged;
1046                                                                 if (shared_list) {
1047                                                                         shared_list = false;
1048                                                                         merged = new List<MemberSpec> (found.Count + applicable.Count);
1049                                                                         merged.AddRange (found);
1050                                                                         found = merged;
1051                                                                 } else {
1052                                                                         merged = (List<MemberSpec>) found;
1053                                                                 }
1054
1055                                                                 merged.AddRange (applicable);
1056                                                         }
1057                                                 }
1058                                         }
1059                                 }
1060
1061                                 // BaseType call can be expensive
1062                                 if (declaredOnly)
1063                                         break;
1064
1065                                 container = container.BaseType;
1066                         } while (container != null);
1067
1068                         return found;
1069                 }
1070
1071                 //
1072                 // Inflates all member cache nested types
1073                 //
1074                 public void InflateTypes (MemberCache inflated_cache, TypeParameterInflator inflator)
1075                 {
1076                         foreach (var item in member_hash) {
1077                                 IList<MemberSpec> inflated_members = null;
1078                                 for (int i = 0; i < item.Value.Count; ++i ) {
1079                                         var member = item.Value[i];
1080
1081                                         // FIXME: When inflating members refering nested types before they are inflated
1082                                         if (member == null)
1083                                                 continue;
1084
1085                                         if ((member.Kind & MemberKind.NestedMask) != 0 &&
1086                                                 (member.Modifiers & Modifiers.COMPILER_GENERATED) == 0) {
1087                                                 if (inflated_members == null) {
1088                                                         inflated_members = new MemberSpec[item.Value.Count];
1089                                                         inflated_cache.member_hash.Add (item.Key, inflated_members);
1090                                                 }
1091
1092                                                 inflated_members [i] = member.InflateMember (inflator);
1093                                         }
1094                                 }
1095                         }
1096                 }
1097
1098                 //
1099                 // Inflates all open type members, requires InflateTypes to be called before
1100                 //
1101                 public void InflateMembers (MemberCache cacheToInflate, TypeSpec inflatedType, TypeParameterInflator inflator)
1102                 {
1103                         var inflated_member_hash = cacheToInflate.member_hash;
1104                         Dictionary<MemberSpec, MethodSpec> accessor_relation = null;
1105                         List<MemberSpec> accessor_members = null;
1106
1107                         // Copy member specific flags when all members were added
1108                         cacheToInflate.state = state;
1109
1110                         foreach (var item in member_hash) {
1111                                 var members = item.Value;
1112                                 IList<MemberSpec> inflated_members = null;
1113                                 for (int i = 0; i < members.Count; ++i ) {
1114                                         var member = members[i];
1115
1116                                         //
1117                                         // All nested types have been inflated earlier except for
1118                                         // compiler types which are created later and could miss InflateTypes
1119                                         //
1120                                         if ((member.Kind & MemberKind.NestedMask) != 0 &&
1121                                                 (member.Modifiers & Modifiers.COMPILER_GENERATED) == 0) {
1122                                                 if (inflated_members == null)
1123                                                         inflated_members = inflated_member_hash[item.Key];
1124
1125                                                 continue;
1126                                         }
1127
1128                                         //
1129                                         // Clone the container first
1130                                         //
1131                                         if (inflated_members == null) {
1132                                                 inflated_members = new MemberSpec [item.Value.Count];
1133                                                 inflated_member_hash.Add (item.Key, inflated_members);
1134                                         }
1135
1136                                         var local_inflator = inflator;
1137
1138                                         if (member.DeclaringType != inflatedType) {
1139                                                 //
1140                                                 // Don't inflate top-level non-generic interface members
1141                                                 // merged into generic interface
1142                                                 //
1143                                                 if (!member.DeclaringType.IsGeneric && !member.DeclaringType.IsNested) {
1144                                                         inflated_members [i] = member;
1145                                                         continue;
1146                                                 }
1147
1148                                                 //
1149                                                 // Needed when inflating flatten interfaces. It inflates
1150                                                 // container type only, type parameters are already done
1151                                                 //
1152                                                 // Handles cases like:
1153                                                 //
1154                                                 // interface I<T> {}
1155                                                 // interface I<U, V> : I<U> {}
1156                                                 //
1157                                                 // class C: I<int, bool> {}
1158                                                 //
1159                                                 var inflated_parent = inflator.Inflate (member.DeclaringType);
1160                                                 if (inflated_parent != inflator.TypeInstance)
1161                                                         local_inflator = new TypeParameterInflator (inflator, inflated_parent);
1162                                         }
1163
1164                                         //
1165                                         // Inflate every member, its parent is now different
1166                                         //
1167                                         var inflated = member.InflateMember (local_inflator);
1168                                         inflated_members [i] = inflated;
1169
1170                                         if (member is PropertySpec || member is EventSpec) {
1171                                                 if (accessor_members == null)
1172                                                         accessor_members = new List<MemberSpec> ();
1173
1174                                                 accessor_members.Add (inflated);
1175                                                 continue;
1176                                         }
1177
1178                                         if (member.IsAccessor) {
1179                                                 if (accessor_relation == null)
1180                                                         accessor_relation = new Dictionary<MemberSpec, MethodSpec> ();
1181                                                 accessor_relation.Add (member, (MethodSpec) inflated);
1182                                         }
1183                                 }
1184                         }
1185
1186                         if (accessor_members != null) {
1187                                 foreach (var member in accessor_members) {
1188                                         var prop = member as PropertySpec;
1189                                         if (prop != null) {
1190                                                 if (prop.Get != null)
1191                                                         prop.Get = accessor_relation[prop.Get];
1192                                                 if (prop.Set != null)
1193                                                         prop.Set = accessor_relation[prop.Set];
1194
1195                                                 continue;
1196                                         }
1197
1198                                         var ev = (EventSpec) member;
1199                                         ev.AccessorAdd = accessor_relation[ev.AccessorAdd];
1200                                         ev.AccessorRemove = accessor_relation[ev.AccessorRemove];
1201                                 }
1202                         }
1203                 }
1204
1205                 //
1206                 // Removes hidden base members of an interface. For compiled interfaces we cannot
1207                 // do name filtering during Add (as we do for import) because we need all base
1208                 // names to be valid during type definition.
1209                 // Add replaces hidden base member with current one which means any name collision
1210                 // (CS0108) of non-first name would be unnoticed because the name was replaced
1211                 // with the one from compiled type
1212                 //
1213                 public void RemoveHiddenMembers (TypeSpec container)
1214                 {
1215                         foreach (var entry in member_hash) {
1216                                 var values = entry.Value;
1217
1218                                 int container_members_start_at = 0;
1219                                 while (values[container_members_start_at].DeclaringType != container && ++container_members_start_at < entry.Value.Count);
1220
1221                                 if (container_members_start_at == 0 || container_members_start_at == values.Count)
1222                                         continue;
1223
1224                                 for (int i = 0; i < container_members_start_at; ++i) {
1225                                         var member = values[i];
1226
1227                                         if (!container.ImplementsInterface (member.DeclaringType, false))
1228                                                 continue;
1229
1230                                         var member_param = member is IParametersMember ? ((IParametersMember) member).Parameters : ParametersCompiled.EmptyReadOnlyParameters;
1231
1232                                         for (int ii = container_members_start_at; ii < values.Count; ++ii) {
1233                                                 var container_entry = values[ii];
1234
1235                                                 if (container_entry.Arity != member.Arity)
1236                                                         continue;
1237
1238                                                 if (container_entry is IParametersMember) {
1239                                                         if (!TypeSpecComparer.Override.IsEqual (((IParametersMember) container_entry).Parameters, member_param))
1240                                                                 continue;
1241                                                 }
1242
1243                                                 values.RemoveAt (i);
1244                                                 --container_members_start_at;
1245                                                 --ii;
1246                                                 --i;
1247                                         }
1248                                 }
1249                         }
1250                 }
1251
1252                 //
1253                 // Checks all appropriate container members for CLS compliance
1254                 //
1255                 public void VerifyClsCompliance (TypeSpec container, Report report)
1256                 {
1257                         if (locase_members != null)
1258                                 return;
1259
1260                         if (container.BaseType == null) {
1261                                 locase_members = new Dictionary<string, MemberSpec[]> (member_hash.Count); // StringComparer.OrdinalIgnoreCase);
1262                         } else {
1263                                 var btype = container.BaseType.GetDefinition ();
1264                                 btype.MemberCache.VerifyClsCompliance (btype, report);
1265                                 locase_members = new Dictionary<string, MemberSpec[]> (btype.MemberCache.locase_members); //, StringComparer.OrdinalIgnoreCase);
1266                         }
1267
1268                         var is_imported_type = container.MemberDefinition.IsImported;
1269                         foreach (var entry in container.MemberCache.member_hash) {
1270                                 for (int i = 0; i < entry.Value.Count; ++i ) {
1271                                         var name_entry = entry.Value[i];
1272                                         if ((name_entry.Modifiers & (Modifiers.PUBLIC | Modifiers.PROTECTED)) == 0)
1273                                                 continue;
1274
1275                                         if ((name_entry.Modifiers & (Modifiers.OVERRIDE | Modifiers.COMPILER_GENERATED)) != 0)
1276                                                 continue;
1277
1278                                         if ((name_entry.Kind & MemberKind.MaskType) == 0)
1279                                                 continue;
1280
1281                                         if (name_entry.MemberDefinition.CLSAttributeValue == false)
1282                                             continue;
1283
1284                                         IParametersMember p_a = null;
1285                                         if (!is_imported_type) {
1286                                                 p_a = name_entry as IParametersMember;
1287                                                 if (p_a != null && !name_entry.IsAccessor) {
1288                                                         var p_a_pd = p_a.Parameters;
1289                                                         //
1290                                                         // Check differing overloads in @container
1291                                                         //
1292                                                         for (int ii = i + 1; ii < entry.Value.Count; ++ii) {
1293                                                                 var checked_entry = entry.Value[ii];
1294                                                                 IParametersMember p_b = checked_entry as IParametersMember;
1295                                                                 if (p_b == null)
1296                                                                         continue;
1297
1298                                                                 if (p_a_pd.Count != p_b.Parameters.Count)
1299                                                                         continue;
1300
1301                                                                 if (checked_entry.IsAccessor)
1302                                                                         continue;
1303
1304                                                                 var res = ParametersCompiled.IsSameClsSignature (p_a.Parameters, p_b.Parameters);
1305                                                                 if (res != 0) {
1306                                                                         ReportOverloadedMethodClsDifference (name_entry, checked_entry, res, report);
1307                                                                 }
1308                                                         }
1309                                                 }
1310                                         }
1311
1312                                         if (i > 0 || name_entry.Kind == MemberKind.Constructor || name_entry.Kind == MemberKind.Indexer)
1313                                                 continue;
1314
1315                                         var name_entry_locase = name_entry.Name.ToLowerInvariant ();
1316
1317                                         MemberSpec[] found;
1318                                         if (!locase_members.TryGetValue (name_entry_locase, out found)) {
1319                                                 found = new MemberSpec[] { name_entry };
1320                                                 locase_members.Add (name_entry_locase, found);
1321                                         } else {
1322                                                 bool same_names_only = true;
1323                                                 foreach (var f in found) {
1324                                                         if (f.Name == name_entry.Name) {
1325                                                                 if (p_a != null) {
1326                                                                         IParametersMember p_b = f as IParametersMember;
1327                                                                         if (p_b == null)
1328                                                                                 continue;
1329
1330                                                                         if (p_a.Parameters.Count != p_b.Parameters.Count)
1331                                                                                 continue;
1332
1333                                                                         if (f.IsAccessor)
1334                                                                                 continue;
1335
1336                                                                         var res = ParametersCompiled.IsSameClsSignature (p_a.Parameters, p_b.Parameters);
1337                                                                         if (res != 0) {
1338                                                                                 ReportOverloadedMethodClsDifference (f, name_entry, res, report);
1339                                                                         }
1340                                                                 }
1341
1342                                                                 continue;
1343                                                         }
1344
1345                                                         same_names_only = false;
1346                                                         if (!is_imported_type) {
1347                                                                 var last = GetLaterDefinedMember (f, name_entry);
1348                                                                 if (last == f.MemberDefinition) {
1349                                                                         report.SymbolRelatedToPreviousError (name_entry);
1350                                                                 } else {
1351                                                                         report.SymbolRelatedToPreviousError (f);
1352                                                                 }
1353
1354                                                                 report.Warning (3005, 1, last.Location,
1355                                                                         "Identifier `{0}' differing only in case is not CLS-compliant", last.GetSignatureForError ());
1356                                                         }
1357                                                 }
1358
1359                                                 if (!same_names_only) {
1360                                                         Array.Resize (ref found, found.Length + 1);
1361                                                         found[found.Length - 1] = name_entry;
1362                                                         locase_members[name_entry_locase] = found;
1363                                                 }
1364                                         }
1365                                 }
1366                         }
1367                 }
1368
1369                 //
1370                 // Local report helper to issue correctly ordered members stored in hashtable
1371                 //
1372                 static MemberCore GetLaterDefinedMember (MemberSpec a, MemberSpec b)
1373                 {
1374                         var mc_a = a.MemberDefinition as MemberCore;
1375                         var mc_b = b.MemberDefinition as MemberCore;
1376                         if (mc_a == null)
1377                                 return mc_b;
1378
1379                         if (mc_b == null)
1380                                 return mc_a;
1381
1382                         if (a.DeclaringType.MemberDefinition != b.DeclaringType.MemberDefinition)
1383                                 return mc_b;
1384
1385                         if (mc_a.Location.File != mc_b.Location.File)
1386                                 return mc_b;
1387
1388                         return mc_b.Location.Row > mc_a.Location.Row ? mc_b : mc_a;
1389                 }
1390
1391                 static void ReportOverloadedMethodClsDifference (MemberSpec a, MemberSpec b, int res, Report report)
1392                 {
1393                         var last = GetLaterDefinedMember (a, b);
1394                         if (last == a.MemberDefinition) {
1395                                 report.SymbolRelatedToPreviousError (b);
1396                         } else {
1397                                 report.SymbolRelatedToPreviousError (a);
1398                         }
1399
1400                         if ((res & 1) != 0) {
1401                                 report.Warning (3006, 1, last.Location,
1402                                                 "Overloaded method `{0}' differing only in ref or out, or in array rank, is not CLS-compliant",
1403                                                 last.GetSignatureForError ());
1404                         }
1405
1406                         if ((res & 2) != 0) {
1407                                 report.Warning (3007, 1, last.Location,
1408                                         "Overloaded method `{0}' differing only by unnamed array types is not CLS-compliant",
1409                                         last.GetSignatureForError ());
1410                         }
1411                 }
1412
1413                 public bool CheckExistingMembersOverloads (MemberCore member, AParametersCollection parameters)
1414                 {
1415                         var name = GetLookupName (member);
1416                         var imb = member as InterfaceMemberBase;
1417                         if (imb != null && imb.IsExplicitImpl) {
1418                                 name = imb.GetFullName (name);
1419                         }
1420
1421                         return CheckExistingMembersOverloads (member, name, parameters);
1422                 }
1423
1424                 public bool CheckExistingMembersOverloads (MemberCore member, string name, AParametersCollection parameters)
1425                 {
1426                         IList<MemberSpec> entries;
1427                         if (!member_hash.TryGetValue (name, out entries))
1428                                 return false;
1429
1430                         var Report = member.Compiler.Report;
1431
1432                         int method_param_count = parameters.Count;
1433                         for (int i = entries.Count - 1; i >= 0; --i) {
1434                                 var ce = entries[i];
1435                                 var pm = ce as IParametersMember;
1436                                 var pd = pm == null ? ParametersCompiled.EmptyReadOnlyParameters : pm.Parameters;
1437                                 if (pd.Count != method_param_count)
1438                                         continue;
1439
1440                                 if (ce.Arity != member.MemberName.Arity)
1441                                         continue;
1442
1443                                 // Ignore merged interface members
1444                                 if (member.Parent.PartialContainer != ce.DeclaringType.MemberDefinition)
1445                                         continue;
1446
1447                                 var p_types = pd.Types;
1448                                 if (method_param_count > 0) {
1449                                         int ii = method_param_count - 1;
1450                                         TypeSpec type_a, type_b;
1451                                         do {
1452                                                 type_a = parameters.Types [ii];
1453                                                 type_b = p_types [ii];
1454
1455                                                 var a_byref = (pd.FixedParameters[ii].ModFlags & Parameter.Modifier.RefOutMask) != 0;
1456                                                 var b_byref = (parameters.FixedParameters[ii].ModFlags & Parameter.Modifier.RefOutMask) != 0;
1457
1458                                                 if (a_byref != b_byref)
1459                                                         break;
1460
1461                                         } while (TypeSpecComparer.Override.IsEqual (type_a, type_b) && ii-- != 0);
1462
1463                                         if (ii >= 0)
1464                                                 continue;
1465
1466                                         //
1467                                         // Operators can differ in return type only
1468                                         //
1469                                         if (member is Operator && ce.Kind == MemberKind.Operator && ((MethodSpec) ce).ReturnType != ((Operator) member).ReturnType)
1470                                                 continue;
1471
1472                                         //
1473                                         // Report difference in parameter modifiers only
1474                                         //
1475                                         if (pd != null && member is MethodCore) {
1476                                                 ii = method_param_count;
1477                                                 while (ii-- != 0 &&
1478                                                         (parameters.FixedParameters[ii].ModFlags & Parameter.Modifier.ModifierMask) ==
1479                                                         (pd.FixedParameters[ii].ModFlags & Parameter.Modifier.ModifierMask) &&
1480                                                         parameters.ExtensionMethodType == pd.ExtensionMethodType) ;
1481
1482                                                 if (ii >= 0) {
1483                                                         var mc = ce as MethodSpec;
1484                                                         member.Compiler.Report.SymbolRelatedToPreviousError (ce);
1485                                                         if ((member.ModFlags & Modifiers.PARTIAL) != 0 && (mc.Modifiers & Modifiers.PARTIAL) != 0) {
1486                                                                 if (parameters.HasParams || pd.HasParams) {
1487                                                                         Report.Error (758, member.Location,
1488                                                                                 "A partial method declaration and partial method implementation cannot differ on use of `params' modifier");
1489                                                                 } else {
1490                                                                         Report.Error (755, member.Location,
1491                                                                                 "A partial method declaration and partial method implementation must be both an extension method or neither");
1492                                                                 }
1493                                                         } else if (member is Constructor) {
1494                                                                 Report.Error (851, member.Location,
1495                                                                         "Overloaded contructor `{0}' cannot differ on use of parameter modifiers only",
1496                                                                         member.GetSignatureForError ());
1497                                                         } else {
1498                                                                 Report.Error (663, member.Location,
1499                                                                         "Overloaded method `{0}' cannot differ on use of parameter modifiers only",
1500                                                                         member.GetSignatureForError ());
1501                                                         }
1502                                                         return false;
1503                                                 }
1504
1505                                                 var pm_member = (MethodCore)member;
1506                                                 if (!NamedTupleSpec.CheckOverrideName (pm, pm_member) || !NamedTupleSpec.CheckOverrideName (pm.MemberType, pm_member.MemberType)) {
1507                                                         Report.Error (8142, member.Location,
1508                                                                 "A partial method declaration and partial method implementation must both use the same tuple element names");
1509                                                 }
1510                                         }
1511                                 }
1512
1513                                 if ((ce.Kind & MemberKind.Method) != 0) {
1514                                         Method method_a = member as Method;
1515                                         Method method_b = ce.MemberDefinition as Method;
1516                                         if (method_a != null && method_b != null && (method_a.ModFlags & method_b.ModFlags & Modifiers.PARTIAL) != 0) {
1517                                                 const Modifiers partial_modifiers = Modifiers.STATIC | Modifiers.UNSAFE;
1518                                                 if (method_a.IsPartialDefinition == method_b.IsPartialImplementation) {
1519                                                         if ((method_a.ModFlags & partial_modifiers) == (method_b.ModFlags & partial_modifiers) ||
1520                                                                 method_a.Parent.IsUnsafe && method_b.Parent.IsUnsafe) {
1521                                                                 if (method_a.IsPartialImplementation) {
1522                                                                         method_a.SetPartialDefinition (method_b);
1523                                                                         if (entries.Count == 1)
1524                                                                                 member_hash.Remove (name);
1525                                                                         else
1526                                                                                 entries.RemoveAt (i);
1527                                                                 } else {
1528                                                                         method_b.SetPartialDefinition (method_a);
1529                                                                         method_a.caching_flags |= MemberCore.Flags.PartialDefinitionExists;
1530                                                                 }
1531                                                                 continue;
1532                                                         }
1533
1534                                                         if (method_a.IsStatic != method_b.IsStatic) {
1535                                                                 Report.SymbolRelatedToPreviousError (ce);
1536                                                                 Report.Error (763, member.Location,
1537                                                                         "A partial method declaration and partial method implementation must be both `static' or neither");
1538                                                         }
1539
1540                                                         if ((method_a.ModFlags & Modifiers.UNSAFE) != (method_b.ModFlags & Modifiers.UNSAFE)) {
1541                                                                 Report.SymbolRelatedToPreviousError (ce);
1542                                                                 Report.Error (764, member.Location,
1543                                                                         "A partial method declaration and partial method implementation must be both `unsafe' or neither");
1544                                                         }
1545
1546                                                         return false;
1547                                                 }
1548
1549                                                 Report.SymbolRelatedToPreviousError (ce);
1550                                                 if (method_a.IsPartialDefinition) {
1551                                                         Report.Error (756, member.Location, "A partial method `{0}' declaration is already defined",
1552                                                                 member.GetSignatureForError ());
1553                                                 }
1554
1555                                                 Report.Error (757, member.Location, "A partial method `{0}' implementation is already defined",
1556                                                         member.GetSignatureForError ());
1557                                                 return false;
1558                                         }
1559
1560                                         Report.SymbolRelatedToPreviousError (ce);
1561
1562                                         bool is_reserved_a = member is AbstractPropertyEventMethod || member is Operator;
1563                                         bool is_reserved_b = ((MethodSpec) ce).IsReservedMethod;
1564
1565                                         if (is_reserved_a || is_reserved_b) {
1566                                                 Report.Error (82, member.Location, "A member `{0}' is already reserved",
1567                                                         is_reserved_a ?
1568                                                         ce.GetSignatureForError () :
1569                                                         member.GetSignatureForError ());
1570                                                 return false;
1571                                         }
1572                                 } else {
1573                                         Report.SymbolRelatedToPreviousError (ce);
1574                                 }
1575
1576                                 if (member is Operator && ce.Kind == MemberKind.Operator) {
1577                                         Report.Error (557, member.Location, "Duplicate user-defined conversion in type `{0}'",
1578                                                 member.Parent.GetSignatureForError ());
1579                                         return false;
1580                                 }
1581
1582                                 Report.Error (111, member.Location,
1583                                         "A member `{0}' is already defined. Rename this member or use different parameter types",
1584                                         member.GetSignatureForError ());
1585                                 return false;
1586                         }
1587
1588                         return true;
1589                 }
1590         }
1591 }