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                 ByRef           = 1 << 17,
  39
  40                 ArrayType = 1 << 19,
  41                 PointerType = 1 << 20,
  42                 InternalCompilerType = 1 << 21,
  43                 MissingType = 1 << 22,
  44                 Void = 1 << 23,
  45                 Namespace = 1 << 24,
  46
  47                 NestedMask = Class | Struct | Delegate | Enum | Interface,
  48                 GenericMask = Method | Class | Struct | Delegate | Interface,
  49                 MaskType = Constructor | Event | Field | Method | Property | Indexer | Operator | Destructor | NestedMask
  50         }
  51
  52         [Flags]
  53         public enum BindingRestriction
  54         {
  55                 None = 0,
  56
  57                 // Inspect only queried type members
  58                 DeclaredOnly = 1 << 1,
  59
  60                 // Exclude static
  61                 InstanceOnly = 1 << 2,
  62
  63                 NoAccessors = 1 << 3,
  64
  65                 // Member has to be override
  66                 OverrideOnly = 1 << 4
  67         }
  68
  69         public struct MemberFilter : IEquatable<MemberSpec>
  70         {
  71                 public readonly string Name;
  72                 public readonly MemberKind Kind;
  73                 public readonly AParametersCollection Parameters;
  74                 public readonly TypeSpec MemberType;
  75                 public readonly int Arity; // -1 to ignore the check
  76
  77                 public MemberFilter (MethodSpec m)
  78                 {
  79                         Name = m.Name;
  80                         Kind = MemberKind.Method;
  81                         Parameters = m.Parameters;
  82                         MemberType = m.ReturnType;
  83                         Arity = m.Arity;
  84                 }
  85
  86                 public MemberFilter (string name, int arity, MemberKind kind, AParametersCollection param, TypeSpec type)
  87                 {
  88                         Name = name;
  89                         Kind = kind;
  90                         Parameters = param;
  91                         MemberType = type;
  92                         this.Arity = arity;
  93                 }
  94
  95                 public static MemberFilter Constructor (AParametersCollection param)
  96                 {
  97                         return new MemberFilter (Mono.CSharp.Constructor.ConstructorName, 0, MemberKind.Constructor, param, null);
  98                 }
  99
 100                 public static MemberFilter Property (string name, TypeSpec type)
 101                 {
 102                         return new MemberFilter (name, 0, MemberKind.Property, null, type);
 103                 }
 104
 105                 public static MemberFilter Field (string name, TypeSpec type)
 106                 {
 107                         return new MemberFilter (name, 0, MemberKind.Field, null, type);
 108                 }
 109
 110                 public static MemberFilter Method (string name, int arity, AParametersCollection param, TypeSpec type)
 111                 {
 112                         return new MemberFilter (name, arity, MemberKind.Method, param, type);
 113                 }
 114
 115                 #region IEquatable<MemberSpec> Members
 116
 117                 public bool Equals (MemberSpec other)
 118                 {
 119                         // Is the member of the correct type ?
 120                         // TODO: Isn't this redundant ?
 121                         if ((other.Kind & Kind & MemberKind.MaskType) == 0)
 122                                 return false;
 123
 124                         // Check arity when not disabled
 125                         if (Arity >= 0 && Arity != other.Arity)
 126                                 return false;
 127
 128                         if (Parameters != null) {
 129                                 if (other is IParametersMember) {
 130                                         var other_param = ((IParametersMember) other).Parameters;
 131                                         if (!TypeSpecComparer.Override.IsEqual (Parameters, other_param))
 132                                                 return false;
 133                                 } else {
 134                                         return false;
 135                                 }
 136                         }
 137
 138                         if (MemberType != null) {
 139                                 if (other is IInterfaceMemberSpec) {
 140                                         var other_type = ((IInterfaceMemberSpec) other).MemberType;
 141                                         if (!TypeSpecComparer.Override.IsEqual (other_type, MemberType))
 142                                                 return false;
 143                                 } else {
 144                                         return false;
 145                                 }
 146                         }
 147
 148                         return true;
 149                 }
 150
 151                 #endregion
 152         }
 153
 154         //
 155         // The MemberCache is the main members container used by compiler. It contains
 156         // all members imported or defined during compilation using on demand filling
 157         // process. Inflated containers are also using MemberCache to make inflated
 158         // members look like normal definition.
 159         //
 160         // All of the methods are performance and memory sensitive as the MemberCache
 161         // is the underlying engine of all member based operations.
 162         //
 163         public class MemberCache
 164         {
 165                 [Flags]
 166                 enum StateFlags
 167                 {
 168                         HasConversionOperator = 1 << 1,
 169                         HasUserOperator = 1 << 2
 170                 }
 171
 172                 readonly Dictionary<string, IList<MemberSpec>> member_hash;
 173                 Dictionary<string, MemberSpec[]> locase_members;
 174                 IList<MethodSpec> missing_abstract;
 175                 StateFlags state;       // TODO: Move to TypeSpec or ITypeDefinition
 176
 177                 public static readonly string IndexerNameAlias = "<this>";
 178
 179                 public static readonly MemberCache Empty = new MemberCache (0);
 180
 181                 public MemberCache ()
 182                         : this (16)
 183                 {
 184                 }
 185
 186                 public MemberCache (int capacity)
 187                 {
 188                         member_hash = new Dictionary<string, IList<MemberSpec>> (capacity);
 189                 }
 190
 191                 public MemberCache (MemberCache cache)
 192                         : this (cache.member_hash.Count)
 193                 {
 194                         this.state = cache.state;
 195                 }
 196
 197                 //
 198                 // Creates a new MemberCache for the given `container'.
 199                 //
 200                 public MemberCache (TypeContainer container)
 201                         : this ()                               // TODO: Optimize the size
 202                 {
 203                 }
 204
 205                 //
 206                 // For cases where we need to union cache members
 207                 //
 208                 public void AddBaseType (TypeSpec baseType)
 209                 {
 210                         var cache = baseType.MemberCache;
 211
 212                         IList<MemberSpec> list;
 213                         foreach (var entry in cache.member_hash) {
 214                                 if (!member_hash.TryGetValue (entry.Key, out list)) {
 215                                         if (entry.Value.Count == 1) {
 216                                                 list = entry.Value;
 217                                         } else {
 218                                                 list = new List<MemberSpec> (entry.Value);
 219                                         }
 220
 221                                         member_hash.Add (entry.Key, list);
 222                                         continue;
 223                                 }
 224
 225                                 foreach (var ce in entry.Value) {
 226                                         if (list.Contains (ce))
 227                                                 continue;
 228
 229                                         if (list is MemberSpec[]) {
 230                                                 list = new List<MemberSpec> { list [0] };
 231                                                 member_hash[entry.Key] = list;
 232                                         }
 233
 234                                         list.Add (ce);
 235                                 }
 236                         }
 237                 }
 238
 239                 //
 240                 // Member-cache does not contain base members but it does
 241                 // contain all base interface members, so the Lookup code
 242                 // can use simple inheritance rules.
 243                 //
 244                 // Does not work recursively because of generic interfaces
 245                 //
 246                 public void AddInterface (TypeSpec iface)
 247                 {
 248                         var cache = iface.MemberCache;
 249
 250                         IList<MemberSpec> list;
 251                         foreach (var entry in cache.member_hash) {
 252                                 if (!member_hash.TryGetValue (entry.Key, out list)) {
 253                                         if (entry.Value.Count == 1) {
 254                                                 list = entry.Value;
 255                                         } else {
 256                                                 list = new List<MemberSpec> (entry.Value);
 257                                         }
 258
 259                                         member_hash.Add (entry.Key, list);
 260                                         continue;
 261                                 }
 262
 263                                 foreach (var ce in entry.Value) {
 264                                         //
 265                                         // When two or more different base interfaces implemenent common
 266                                         // interface
 267                                         //
 268                                         // I : IA, IFoo
 269                                         // IA : IFoo
 270                                         //
 271                                         if (list.Contains (ce))
 272                                                 continue;
 273
 274                                         if (AddInterfaceMember (ce, ref list))
 275                                                 member_hash[entry.Key] = list;
 276                                 }
 277                         }
 278                 }
 279
 280                 public void AddMember (InterfaceMemberBase imb, string exlicitName, MemberSpec ms)
 281                 {
 282                         // Explicit names cannot be looked-up but can be used for
 283                         // collision checking (no name mangling needed)
 284                         if (imb.IsExplicitImpl)
 285                                 AddMember (exlicitName, ms, false);
 286                         else
 287                                 AddMember (ms);
 288                 }
 289
 290                 //
 291                 // Add non-explicit member to member cache
 292                 //
 293                 public void AddMember (MemberSpec ms)
 294                 {
 295                         AddMember (GetLookupName (ms), ms, false);
 296                 }
 297
 298                 void AddMember (string name, MemberSpec member, bool removeHiddenMembers)
 299                 {
 300                         if (member.Kind == MemberKind.Operator) {
 301                                 var dt = member.DeclaringType;
 302
 303
 304                                 //
 305                                 // Some core types have user operators but they cannot be used like normal
 306                                 // user operators as they are predefined and therefore having different
 307                                 // rules (e.g. binary operators) by not setting the flag we hide them for
 308                                 // user conversions
 309                                 //
 310                                 if (!BuiltinTypeSpec.IsPrimitiveType (dt) || dt.BuiltinType == BuiltinTypeSpec.Type.Char) {
 311                                         switch (dt.BuiltinType) {
 312                                         case BuiltinTypeSpec.Type.String:
 313                                         case BuiltinTypeSpec.Type.Delegate:
 314                                         case BuiltinTypeSpec.Type.MulticastDelegate:
 315                                                 break;
 316                                         default:
 317                                                 if (name == Operator.GetMetadataName (Operator.OpType.Implicit) || name == Operator.GetMetadataName (Operator.OpType.Explicit)) {
 318                                                         state |= StateFlags.HasConversionOperator;
 319                                                 } else {
 320                                                         state |= StateFlags.HasUserOperator;
 321                                                 }
 322
 323                                                 break;
 324                                         }
 325                                 }
 326                         }
 327
 328                         IList<MemberSpec> list;
 329                         if (!member_hash.TryGetValue (name, out list)) {
 330                                 member_hash.Add (name, new MemberSpec[] { member });
 331                                 return;
 332                         }
 333
 334                         if (removeHiddenMembers && member.DeclaringType.IsInterface) {
 335                                 if (AddInterfaceMember (member, ref list))
 336                                         member_hash[name] = list;
 337                         } else {
 338                                 if (list.Count == 1) {
 339                                         list = new List<MemberSpec> { list[0] };
 340                                         member_hash[name] = list;
 341                                 }
 342
 343                                 list.Add (member);
 344                         }
 345                 }
 346
 347                 public void AddMemberImported (MemberSpec ms)
 348                 {
 349                         AddMember (GetLookupName (ms), ms, true);
 350                 }
 351
 352                 //
 353                 // Ignores any base interface member which can be hidden
 354                 // by this interface
 355                 //
 356                 static bool AddInterfaceMember (MemberSpec member, ref IList<MemberSpec> existing)
 357                 {
 358                         var member_param = member is IParametersMember ? ((IParametersMember) member).Parameters : null;
 359
 360                         //
 361                         // interface IA : IB { int Prop { set; } }
 362                         // interface IB { bool Prop { get; } }
 363                         //
 364                         // IB.Prop is never accessible from IA interface
 365                         //
 366                         for (int i = 0; i < existing.Count; ++i) {
 367                                 var entry = existing[i];
 368
 369                                 if (entry.Arity != member.Arity)
 370                                         continue;
 371
 372                                 AParametersCollection entry_param = null;
 373                                 if (member_param != null) {
 374                                         var entry_pm = entry as IParametersMember;
 375                                         if (entry_pm != null) {
 376                                                 entry_param = entry_pm.Parameters;
 377                                                 if (entry.DeclaringType != member.DeclaringType) {
 378                                                         if (!TypeSpecComparer.Override.IsEqual (entry_param, member_param))
 379                                                                 continue;
 380                                                 } else {
 381                                                         if (!TypeSpecComparer.Equals (entry_param.Types, member_param.Types))
 382                                                                 continue;
 383                                                 }
 384                                         }
 385                                 }
 386
 387                                 if (member.DeclaringType.ImplementsInterface (entry.DeclaringType, false)) {
 388                                         if (existing.Count == 1) {
 389                                                 existing = new MemberSpec[] { member };
 390                                                 return true;
 391                                         }
 392
 393                                         existing.RemoveAt (i--);
 394                                         continue;
 395                                 }
 396
 397                                 if ((entry.DeclaringType == member.DeclaringType && entry.IsAccessor == member.IsAccessor))
 398                                         return false;
 399
 400                                 if (entry.DeclaringType.ImplementsInterface (member.DeclaringType, false) && AParametersCollection.HasSameParameterDefaults (entry_param, member_param))
 401                                         return false;
 402                         }
 403
 404                         if (existing.Count == 1) {
 405                                 existing = new List<MemberSpec> { existing[0], member };
 406                                 return true;
 407                         }
 408
 409                         existing.Add (member);
 410                         return false;
 411                 }
 412
 413                 public static MemberSpec FindMember (TypeSpec container, MemberFilter filter, BindingRestriction restrictions)
 414                 {
 415                         if (filter.Kind == MemberKind.Method && container.Kind == MemberKind.TypeParameter && filter.Parameters == null)
 416                                 throw new NotSupportedException ("type parameters methods cannot be lookup up due to two stage setup");
 417
 418                         IList<MemberSpec> applicable;
 419                         var top_container = container;
 420
 421                         do {
 422                                 if (container.MemberCache.member_hash.TryGetValue (filter.Name, out applicable)) {
 423                                         // Start from the end because interface members are in reverse order
 424                                         for (int i = applicable.Count - 1; i >= 0; i--) {
 425                                                 var entry = applicable [i];
 426
 427                                                 if ((restrictions & BindingRestriction.InstanceOnly) != 0 && entry.IsStatic)
 428                                                         continue;
 429
 430                                                 if ((restrictions & BindingRestriction.NoAccessors) != 0 && entry.IsAccessor)
 431                                                         continue;
 432
 433                                                 if ((restrictions & BindingRestriction.OverrideOnly) != 0 && (entry.Modifiers & Modifiers.OVERRIDE) == 0)
 434                                                         continue;
 435
 436                                                 if (!filter.Equals (entry))
 437                                                         continue;
 438
 439                                                 if ((restrictions & BindingRestriction.DeclaredOnly) != 0 && container.IsInterface && entry.DeclaringType != container)
 440                                                         continue;
 441
 442                                                 return entry;
 443                                         }
 444                                 }
 445
 446                                 if ((restrictions & BindingRestriction.DeclaredOnly) != 0)
 447                                         break;
 448
 449                                 container = container.BaseType;
 450                         } while (container != null);
 451
 452                         var tps = top_container as TypeParameterSpec;
 453                         if (tps != null && tps.InterfaceCache != null) {
 454                                 if (tps.InterfaceCache.member_hash.TryGetValue (filter.Name, out applicable)) {
 455                                         for (int i = applicable.Count - 1; i >= 0; i--) {
 456                                                 var entry = applicable [i];
 457
 458                                                 if ((restrictions & BindingRestriction.NoAccessors) != 0 && entry.IsAccessor)
 459                                                         continue;
 460
 461                                                 if ((restrictions & BindingRestriction.OverrideOnly) != 0 && (entry.Modifiers & Modifiers.OVERRIDE) == 0)
 462                                                         continue;
 463
 464                                                 if (!filter.Equals (entry))
 465                                                         continue;
 466
 467                                                 return entry;
 468                                         }
 469                                 }
 470                         }
 471
 472                         return null;
 473                 }
 474
 475                 //
 476                 // A special method to work with member lookup only. It returns a list of all members named @name
 477                 // starting from @container. It's very performance sensitive
 478                 //
 479                 // declaredOnlyClass cannot be used interfaces. Manual filtering is required because names are
 480                 // compacted
 481                 //
 482                 public static IList<MemberSpec> FindMembers (TypeSpec container, string name, bool declaredOnlyClass)
 483                 {
 484                         do {
 485                                 IList<MemberSpec> applicable;
 486
 487                                 if (container.MemberCache.member_hash.TryGetValue (name, out applicable) || declaredOnlyClass)
 488                                         return applicable;
 489
 490                                 container = container.BaseType;
 491                         } while (container != null);
 492
 493                         return null;
 494                 }
 495
 496                 public static IList<MemberSpec> FindInterfaceMembers (TypeParameterSpec typeParameter, string name)
 497                 {
 498                         if (typeParameter.InterfaceCache != null) {
 499                                 IList<MemberSpec> applicable;
 500                                 typeParameter.InterfaceCache.member_hash.TryGetValue (name, out applicable);
 501                                 return applicable;
 502                         }
 503
 504                         return null;
 505                 }
 506
 507                 //
 508                 // Finds the nested type in container
 509                 //
 510                 public static TypeSpec FindNestedType (TypeSpec container, string name, int arity, bool declaredOnlyClass)
 511                 {
 512                         IList<MemberSpec> applicable;
 513                         TypeSpec best_match = null;
 514                         do {
 515 #if !FULL_AOT_RUNTIME
 516                                 // TODO: Don't know how to handle this yet
 517                                 // When resolving base type of nested type, parent type must have
 518                                 // base type resolved to scan full hierarchy correctly
 519                                 // Similarly MemberCacheTypes will inflate BaseType and Interfaces
 520                                 // based on type definition
 521                                 var tc = container.MemberDefinition as TypeContainer;
 522                                 if (tc != null)
 523                                         tc.DefineContainer ();
 524 #endif
 525
 526                                 if (container.MemberCacheTypes.member_hash.TryGetValue (name, out applicable)) {
 527                                         for (int i = applicable.Count - 1; i >= 0; i--) {
 528                                                 var entry = applicable[i];
 529                                                 if ((entry.Kind & MemberKind.NestedMask) == 0)
 530                                                         continue;
 531
 532                                                 var ts = (TypeSpec) entry;
 533                                                 if (arity == ts.Arity)
 534                                                         return ts;
 535
 536                                                 if (arity < 0) {
 537                                                         if (best_match == null) {
 538                                                                 best_match = ts;
 539                                                         } else if (System.Math.Abs (ts.Arity + arity) < System.Math.Abs (best_match.Arity + arity)) {
 540                                                                 best_match = ts;
 541                                                         }
 542                                                 }
 543                                         }
 544                                 }
 545
 546                                 container = container.BaseType;
 547                         } while (container != null && !declaredOnlyClass);
 548
 549                         return best_match;
 550                 }
 551
 552                 //
 553                 // Looks for extension methods with defined name and extension type
 554                 //
 555                 public List<MethodSpec> FindExtensionMethods (IMemberContext invocationContext, string name, int arity)
 556                 {
 557                         IList<MemberSpec> entries;
 558                         if (!member_hash.TryGetValue (name, out entries))
 559                                 return null;
 560
 561                         List<MethodSpec> candidates = null;
 562                         foreach (var entry in entries) {
 563                                 if (entry.Kind != MemberKind.Method || (arity > 0 && entry.Arity != arity))
 564                                         continue;
 565
 566                                 var ms = (MethodSpec) entry;
 567                                 if (!ms.IsExtensionMethod)
 568                                         continue;
 569
 570                                 if (!ms.IsAccessible (invocationContext))
 571                                         continue;
 572
 573                                 //
 574                                 // Extension methods cannot be nested hence checking parent is enough
 575                                 //
 576                                 if ((ms.DeclaringType.Modifiers & Modifiers.INTERNAL) != 0 && !ms.DeclaringType.MemberDefinition.IsInternalAsPublic (invocationContext.Module.DeclaringAssembly))
 577                                         continue;
 578
 579                                 if (candidates == null)
 580                                         candidates = new List<MethodSpec> ();
 581                                 candidates.Add (ms);
 582                         }
 583
 584                         return candidates;
 585                 }
 586
 587                 //
 588                 // Returns base members of @member member if no exact match is found @bestCandidate returns
 589                 // the best match
 590                 //
 591                 public static MemberSpec FindBaseMember (MemberCore member, out MemberSpec bestCandidate, ref bool overrides)
 592                 {
 593                         bestCandidate = null;
 594                         var container = member.Parent.PartialContainer.Definition;
 595                         if (!container.IsInterface) {
 596                                 container = container.BaseType;
 597
 598                                 // It can happen for a user definition of System.Object
 599                                 if (container == null)
 600                                         return null;
 601                         }
 602
 603                         string name = GetLookupName (member);
 604                         var member_param = member is IParametersMember ? ((IParametersMember) member).Parameters : null;
 605
 606                         var mkind = GetMemberCoreKind (member);
 607                         bool member_with_accessors = mkind == MemberKind.Indexer || mkind == MemberKind.Property;
 608
 609                         IList<MemberSpec> applicable;
 610                         MemberSpec ambig_candidate = null;
 611
 612                         do {
 613                                 if (container.MemberCache.member_hash.TryGetValue (name, out applicable)) {
 614                                         for (int i = 0; i < applicable.Count; ++i) {
 615                                                 var entry = applicable [i];
 616
 617                                                 if ((entry.Modifiers & Modifiers.PUBLIC) == 0 && !entry.IsAccessible (member))
 618                                                         continue;
 619
 620                                                 //
 621                                                 // Isn't the member of same kind ?
 622                                                 //
 623                                                 if ((entry.Kind & ~MemberKind.Destructor & mkind & MemberKind.MaskType) == 0) {
 624                                                         // Destructors are ignored as they cannot be overridden by user
 625                                                         if ((entry.Kind & MemberKind.Destructor) != 0)
 626                                                                 continue;
 627
 628                                                         // A method with different arity does not hide base member
 629                                                         if (mkind != MemberKind.Method && member.MemberName.Arity != entry.Arity)
 630                                                                 continue;
 631
 632                                                         bestCandidate = entry;
 633                                                         return null;
 634                                                 }
 635
 636                                                 //
 637                                                 // Same kind of different arity is valid
 638                                                 //
 639                                                 if (member.MemberName.Arity != entry.Arity) {
 640                                                         continue;
 641                                                 }
 642
 643                                                 if ((entry.Kind & mkind & (MemberKind.Method | MemberKind.Indexer)) != 0) {
 644                                                         if (entry.IsAccessor != member is AbstractPropertyEventMethod)
 645                                                                 continue;
 646
 647                                                         var pm = entry as IParametersMember;
 648                                                         if (!TypeSpecComparer.Override.IsEqual (pm.Parameters, member_param))
 649                                                                 continue;
 650                                                 }
 651
 652                                                 //
 653                                                 // Skip override for member with accessors. It may not fully implement the base member
 654                                                 // but keep flag we found an implementation in case the base member is abstract
 655                                                 //
 656                                                 if (member_with_accessors && ((entry.Modifiers & (Modifiers.OVERRIDE | Modifiers.SEALED)) == Modifiers.OVERRIDE)) {
 657                                                         //
 658                                                         // Set candidate to override implementation to flag we found an implementation
 659                                                         //
 660                                                         overrides = true;
 661                                                         continue;
 662                                                 }
 663
 664                                                 //
 665                                                 // For members with parameters we can encounter an ambiguous candidates (they match exactly)
 666                                                 // because generic type parameters could be inflated into same types
 667                                                 //
 668                                                 if (ambig_candidate == null && (entry.Kind & mkind & (MemberKind.Method | MemberKind.Indexer)) != 0) {
 669                                                         bestCandidate = null;
 670                                                         ambig_candidate = entry;
 671                                                         continue;
 672                                                 }
 673
 674                                                 bestCandidate = ambig_candidate;
 675                                                 return entry;
 676                                         }
 677                                 }
 678
 679                                 if (container.IsInterface || ambig_candidate != null)
 680                                         break;
 681
 682                                 container = container.BaseType;
 683                         } while (container != null);
 684
 685                         return ambig_candidate;
 686                 }
 687
 688                 public static List<TypeSpec> GetDeclaredNestedTypes (TypeSpec container)
 689                 {
 690                         List<TypeSpec> found = null;
 691                         foreach (var entry in container.MemberCache.member_hash) {
 692                                 foreach (var member in entry.Value) {
 693                                         if ((member.Kind & MemberKind.NestedMask) == 0)
 694                                                 continue;
 695
 696                                         if (found == null)
 697                                                 found = new List<TypeSpec> ();
 698
 699                                         found.Add ((TypeSpec)member);
 700                                 }
 701                         }
 702
 703                         return found;
 704                 }
 705
 706                 //
 707                 // Returns inflated version of MemberSpec, it works similarly to
 708                 // SRE TypeBuilder.GetMethod
 709                 //
 710                 public static T GetMember<T> (TypeSpec container, T spec) where T : MemberSpec
 711                 {
 712                         IList<MemberSpec> applicable;
 713                         if (container.MemberCache.member_hash.TryGetValue (GetLookupName (spec), out applicable)) {
 714                                 for (int i = applicable.Count - 1; i >= 0; i--) {
 715                                         var entry = applicable[i];
 716                                         if (entry.MemberDefinition == spec.MemberDefinition)
 717                                                 return (T) entry;
 718                                 }
 719                         }
 720
 721                         throw new InternalErrorException ("Missing member `{0}' on inflated type `{1}'",
 722                                 spec.GetSignatureForError (), container.GetSignatureForError ());
 723                 }
 724
 725                 static MemberKind GetMemberCoreKind (MemberCore member)
 726                 {
 727                         if (member is FieldBase)
 728                                 return MemberKind.Field;
 729                         if (member is Indexer)
 730                                 return MemberKind.Indexer;
 731                         if (member is Class)
 732                                 return MemberKind.Class;
 733                         if (member is Struct)
 734                                 return MemberKind.Struct;
 735                         if (member is Destructor)
 736                                 return MemberKind.Destructor;
 737                         if (member is Method)
 738                                 return MemberKind.Method;
 739                         if (member is Property)
 740                                 return MemberKind.Property;
 741                         if (member is EventField)
 742                                 return MemberKind.Event;
 743                         if (member is Interface)
 744                                 return MemberKind.Interface;
 745                         if (member is EventProperty)
 746                                 return MemberKind.Event;
 747                         if (member is Delegate)
 748                                 return MemberKind.Delegate;
 749                         if (member is Enum)
 750                                 return MemberKind.Enum;
 751
 752                         throw new NotImplementedException (member.GetType ().ToString ());
 753                 }
 754
 755                 public static List<FieldSpec> GetAllFieldsForDefiniteAssignment (TypeSpec container, IMemberContext context)
 756                 {
 757                         List<FieldSpec> fields = null;
 758                         bool imported = container.MemberDefinition.IsImported;
 759                         foreach (var entry in container.MemberCache.member_hash) {
 760                                 foreach (var name_entry in entry.Value) {
 761                                         if (name_entry.Kind != MemberKind.Field)
 762                                                 continue;
 763
 764                                         if ((name_entry.Modifiers & Modifiers.STATIC) != 0)
 765                                                 continue;
 766
 767                                         //
 768                                         // Fixed size buffers are not subject to definite assignment checking
 769                                         //
 770                                         if (name_entry is FixedFieldSpec || name_entry is ConstSpec)
 771                                                 continue;
 772
 773                                         var fs = (FieldSpec) name_entry;
 774                                         if (imported && ShouldIgnoreFieldForDefiniteAssignment (fs, context))
 775                                                 continue;
 776
 777                                         //if ((fs.Modifiers & (Modifiers.BACKING_FIELD) != 0)
 778                                         //      continue;
 779
 780                                         if (fields == null)
 781                                                 fields = new List<FieldSpec> ();
 782
 783                                         fields.Add (fs);
 784                                         break;
 785                                 }
 786                         }
 787
 788                         return fields ?? new List<FieldSpec> (0);
 789                 }
 790
 791                 static bool ShouldIgnoreFieldForDefiniteAssignment (FieldSpec fs, IMemberContext context)
 792                 {
 793                         //
 794                         // LAMESPEC: This mimics csc quirk where definitive assignment is not done
 795                         // for all kinds of imported non-public struct fields
 796                         //
 797                         var mod = fs.Modifiers;
 798                         if ((mod & Modifiers.PRIVATE) == 0 && ((mod & Modifiers.INTERNAL) != 0 && fs.DeclaringType.MemberDefinition.IsInternalAsPublic (context.Module.DeclaringAssembly)))
 799                                 return false;
 800
 801                         //
 802                         // Ignore reference type fields except when type is an array or type parameter
 803                         //
 804                         var type = fs.MemberType;
 805                         switch (type.Kind) {
 806                         case MemberKind.ArrayType:
 807                         case MemberKind.TypeParameter:
 808                                 return false;
 809                         default:
 810                                 return TypeSpec.IsReferenceType (type);
 811                         }
 812                 }
 813
 814                 public static IList<MemberSpec> GetCompletitionMembers (IMemberContext ctx, TypeSpec container, string name)
 815                 {
 816                         var matches = new List<MemberSpec> ();
 817                         foreach (var entry in container.MemberCache.member_hash) {
 818                                 foreach (var name_entry in entry.Value) {
 819                                         if (name_entry.IsAccessor)
 820                                                 continue;
 821
 822                                         if ((name_entry.Kind & (MemberKind.Constructor | MemberKind.Destructor | MemberKind.Operator)) != 0)
 823                                                 continue;
 824
 825                                         if (!name_entry.IsAccessible (ctx))
 826                                                 continue;
 827
 828                                         if (name == null || name_entry.Name.StartsWith (name)) {
 829                                                 matches.Add (name_entry);
 830                                         }
 831                                 }
 832                         }
 833
 834                         return matches;
 835                 }
 836
 837                 //
 838                 // Returns members of @iface only, base members are ignored
 839                 //
 840                 public static List<MethodSpec> GetInterfaceMethods (TypeSpec iface)
 841                 {
 842                         //
 843                         // MemberCache flatten interfaces, therefore in cases like this one
 844                         //
 845                         // interface IA : IB {}
 846                         // interface IB { void Foo () }
 847                         //
 848                         // we would return Foo inside IA which is not expected in this case
 849                         //
 850                         var methods = new List<MethodSpec> ();
 851                         foreach (var entry in iface.MemberCache.member_hash.Values) {
 852                                 foreach (var name_entry in entry) {
 853                                         if (iface == name_entry.DeclaringType) {
 854                                                 if (name_entry.Kind == MemberKind.Method) {
 855                                                         methods.Add ((MethodSpec) name_entry);
 856                                                 }
 857                                         }
 858                                 }
 859                         }
 860
 861                         return methods;
 862                 }
 863
 864                 //
 865                 // Returns all not implememted abstract members inside abstract type
 866                 // NOTE: Returned list is shared and must not be modified
 867                 //
 868                 public static IList<MethodSpec> GetNotImplementedAbstractMethods (TypeSpec type)
 869                 {
 870                         if (type.MemberCache.missing_abstract != null)
 871                                 return type.MemberCache.missing_abstract;
 872
 873                         var abstract_methods = new List<MethodSpec> ();
 874                         List<TypeSpec> hierarchy = null;
 875
 876                         //
 877                         // Stage 1: top-to-bottom scan for abstract members
 878                         //
 879                         var abstract_type = type;
 880                         while (true) {
 881                                 foreach (var entry in abstract_type.MemberCache.member_hash) {
 882                                         foreach (var name_entry in entry.Value) {
 883                                                 if ((name_entry.Modifiers & Modifiers.ABSTRACT) == 0)
 884                                                         continue;
 885
 886                                                 var ms = name_entry as MethodSpec;
 887                                                 if (ms == null)
 888                                                         continue;
 889
 890                                                 abstract_methods.Add (ms);
 891                                         }
 892                                 }
 893
 894                                 var base_type = abstract_type.BaseType;
 895                                 if (!base_type.IsAbstract)
 896                                         break;
 897
 898                                 if (hierarchy == null)
 899                                         hierarchy = new List<TypeSpec> ();
 900
 901                                 hierarchy.Add (abstract_type);
 902                                 abstract_type = base_type;
 903                         }
 904
 905                         int not_implemented_count = abstract_methods.Count;
 906                         if (not_implemented_count == 0 || hierarchy == null) {
 907                                 type.MemberCache.missing_abstract = abstract_methods;
 908                                 return type.MemberCache.missing_abstract;
 909                         }
 910
 911                         //
 912                         // Stage 2: Remove already implemented methods
 913                         //
 914                         foreach (var type_up in hierarchy) {
 915                                 var members = type_up.MemberCache.member_hash;
 916                                 if (members.Count == 0)
 917                                         continue;
 918
 919                                 for (int i = 0; i < abstract_methods.Count; ++i) {
 920                                         var candidate = abstract_methods [i];
 921                                         if (candidate == null)
 922                                                 continue;
 923
 924                                         IList<MemberSpec> applicable;
 925                                         if (!members.TryGetValue (candidate.Name, out applicable))
 926                                                 continue;
 927
 928                                         var filter = new MemberFilter (candidate);
 929                                         foreach (var item in applicable) {
 930                                                 if ((item.Modifiers & (Modifiers.OVERRIDE | Modifiers.VIRTUAL)) == 0)
 931                                                         continue;
 932
 933                                                 //
 934                                                 // Abstract override does not override anything
 935                                                 //
 936                                                 if ((item.Modifiers & Modifiers.ABSTRACT) != 0)
 937                                                         continue;
 938
 939                                                 if (filter.Equals (item)) {
 940                                                         --not_implemented_count;
 941                                                         abstract_methods [i] = null;
 942                                                         break;
 943                                                 }
 944                                         }
 945                                 }
 946                         }
 947
 948                         if (not_implemented_count == abstract_methods.Count) {
 949                                 type.MemberCache.missing_abstract = abstract_methods;
 950                                 return type.MemberCache.missing_abstract;
 951                         }
 952
 953                         var not_implemented = new MethodSpec[not_implemented_count];
 954                         int counter = 0;
 955                         foreach (var m in abstract_methods) {
 956                                 if (m == null)
 957                                         continue;
 958
 959                                 not_implemented[counter++] = m;
 960                         }
 961
 962                         type.MemberCache.missing_abstract = not_implemented;
 963                         return type.MemberCache.missing_abstract;
 964                 }
 965
 966                 static string GetLookupName (MemberSpec ms)
 967                 {
 968                         if (ms.Kind == MemberKind.Indexer)
 969                                 return IndexerNameAlias;
 970
 971                         if (ms.Kind == MemberKind.Constructor) {
 972                                 if (ms.IsStatic)
 973                                         return Constructor.TypeConstructorName;
 974
 975                                 return Constructor.ConstructorName;
 976                         }
 977
 978                         return ms.Name;
 979                 }
 980
 981                 static string GetLookupName (MemberCore mc)
 982                 {
 983                         if (mc is Indexer)
 984                                 return IndexerNameAlias;
 985
 986                         if (mc is Constructor)
 987                                 return mc.IsStatic ? Constructor.TypeConstructorName : Constructor.ConstructorName;
 988
 989                         return mc.MemberName.Name;
 990                 }
 991
 992                 //
 993                 // Returns all operators declared on container and its base types (until declaredOnly is used)
 994                 //
 995                 public static IList<MemberSpec> GetUserOperator (TypeSpec container, Operator.OpType op, bool declaredOnly)
 996                 {
 997                         IList<MemberSpec> found = null;
 998                         bool shared_list = true;
 999                         IList<MemberSpec> applicable;
1000                         do {
1001                                 var mc = container.MemberCache;
1002
1003                                 if (((op == Operator.OpType.Implicit || op == Operator.OpType.Explicit) && (mc.state & StateFlags.HasConversionOperator) != 0) ||
1004                                          (mc.state & StateFlags.HasUserOperator) != 0) {
1005
1006                                         if (mc.member_hash.TryGetValue (Operator.GetMetadataName (op), out applicable)) {
1007                                                 int i;
1008                                                 for (i = 0; i < applicable.Count; ++i) {
1009                                                         if (applicable[i].Kind != MemberKind.Operator) {
1010                                                                 break;
1011                                                         }
1012                                                 }
1013
1014                                                 //
1015                                                 // Handles very rare case where a method with same name as operator (op_xxxx) exists
1016                                                 // and we have to resize the applicable list
1017                                                 //
1018                                                 if (i != applicable.Count) {
1019                                                         for (i = 0; i < applicable.Count; ++i) {
1020                                                                 if (applicable[i].Kind != MemberKind.Operator) {
1021                                                                         continue;
1022                                                                 }
1023
1024                                                                 if (found == null) {
1025                                                                         found = new List<MemberSpec> ();
1026                                                                         found.Add (applicable[i]);
1027                                                                 } else {
1028                                                                         List<MemberSpec> prev;
1029                                                                         if (shared_list) {
1030                                                                                 shared_list = false;
1031                                                                                 prev = new List<MemberSpec> (found.Count + 1);
1032                                                                                 prev.AddRange (found);
1033                                                                                 found = prev;
1034                                                                         } else {
1035                                                                                 prev = (List<MemberSpec>) found;
1036                                                                         }
1037
1038                                                                         prev.Add (applicable[i]);
1039                                                                 }
1040                                                         }
1041                                                 } else {
1042                                                         if (found == null) {
1043                                                                 found = applicable;
1044                                                                 shared_list = true;
1045                                                         } else {
1046                                                                 List<MemberSpec> merged;
1047                                                                 if (shared_list) {
1048                                                                         shared_list = false;
1049                                                                         merged = new List<MemberSpec> (found.Count + applicable.Count);
1050                                                                         merged.AddRange (found);
1051                                                                         found = merged;
1052                                                                 } else {
1053                                                                         merged = (List<MemberSpec>) found;
1054                                                                 }
1055
1056                                                                 merged.AddRange (applicable);
1057                                                         }
1058                                                 }
1059                                         }
1060                                 }
1061
1062                                 // BaseType call can be expensive
1063                                 if (declaredOnly)
1064                                         break;
1065
1066                                 container = container.BaseType;
1067                         } while (container != null);
1068
1069                         return found;
1070                 }
1071
1072                 //
1073                 // Inflates all member cache nested types
1074                 //
1075                 public void InflateTypes (MemberCache inflated_cache, TypeParameterInflator inflator)
1076                 {
1077                         foreach (var item in member_hash) {
1078                                 IList<MemberSpec> inflated_members = null;
1079                                 for (int i = 0; i < item.Value.Count; ++i ) {
1080                                         var member = item.Value[i];
1081
1082                                         // FIXME: When inflating members refering nested types before they are inflated
1083                                         if (member == null)
1084                                                 continue;
1085
1086                                         if ((member.Kind & MemberKind.NestedMask) != 0 &&
1087                                                 (member.Modifiers & Modifiers.COMPILER_GENERATED) == 0) {
1088                                                 if (inflated_members == null) {
1089                                                         inflated_members = new MemberSpec[item.Value.Count];
1090                                                         inflated_cache.member_hash.Add (item.Key, inflated_members);
1091                                                 }
1092
1093                                                 inflated_members [i] = member.InflateMember (inflator);
1094                                         }
1095                                 }
1096                         }
1097                 }
1098
1099                 //
1100                 // Inflates all open type members, requires InflateTypes to be called before
1101                 //
1102                 public void InflateMembers (MemberCache cacheToInflate, TypeSpec inflatedType, TypeParameterInflator inflator)
1103                 {
1104                         var inflated_member_hash = cacheToInflate.member_hash;
1105                         Dictionary<MemberSpec, MethodSpec> accessor_relation = null;
1106                         List<MemberSpec> accessor_members = null;
1107
1108                         // Copy member specific flags when all members were added
1109                         cacheToInflate.state = state;
1110
1111                         foreach (var item in member_hash) {
1112                                 var members = item.Value;
1113                                 IList<MemberSpec> inflated_members = null;
1114                                 for (int i = 0; i < members.Count; ++i ) {
1115                                         var member = members[i];
1116
1117                                         //
1118                                         // All nested types have been inflated earlier except for
1119                                         // compiler types which are created later and could miss InflateTypes
1120                                         //
1121                                         if ((member.Kind & MemberKind.NestedMask) != 0 &&
1122                                                 (member.Modifiers & Modifiers.COMPILER_GENERATED) == 0) {
1123                                                 if (inflated_members == null)
1124                                                         inflated_members = inflated_member_hash[item.Key];
1125
1126                                                 continue;
1127                                         }
1128
1129                                         //
1130                                         // Clone the container first
1131                                         //
1132                                         if (inflated_members == null) {
1133                                                 inflated_members = new MemberSpec [item.Value.Count];
1134                                                 inflated_member_hash.Add (item.Key, inflated_members);
1135                                         }
1136
1137                                         var local_inflator = inflator;
1138
1139                                         if (member.DeclaringType != inflatedType) {
1140                                                 //
1141                                                 // Don't inflate top-level non-generic interface members
1142                                                 // merged into generic interface
1143                                                 //
1144                                                 if (!member.DeclaringType.IsGeneric && !member.DeclaringType.IsNested) {
1145                                                         inflated_members [i] = member;
1146                                                         continue;
1147                                                 }
1148
1149                                                 //
1150                                                 // Needed when inflating flatten interfaces. It inflates
1151                                                 // container type only, type parameters are already done
1152                                                 //
1153                                                 // Handles cases like:
1154                                                 //
1155                                                 // interface I<T> {}
1156                                                 // interface I<U, V> : I<U> {}
1157                                                 //
1158                                                 // class C: I<int, bool> {}
1159                                                 //
1160                                                 var inflated_parent = inflator.Inflate (member.DeclaringType);
1161                                                 if (inflated_parent != inflator.TypeInstance)
1162                                                         local_inflator = new TypeParameterInflator (inflator, inflated_parent);
1163                                         }
1164
1165                                         //
1166                                         // Inflate every member, its parent is now different
1167                                         //
1168                                         var inflated = member.InflateMember (local_inflator);
1169                                         inflated_members [i] = inflated;
1170
1171                                         if (member is PropertySpec || member is EventSpec) {
1172                                                 if (accessor_members == null)
1173                                                         accessor_members = new List<MemberSpec> ();
1174
1175                                                 accessor_members.Add (inflated);
1176                                                 continue;
1177                                         }
1178
1179                                         if (member.IsAccessor) {
1180                                                 if (accessor_relation == null)
1181                                                         accessor_relation = new Dictionary<MemberSpec, MethodSpec> ();
1182                                                 accessor_relation.Add (member, (MethodSpec) inflated);
1183                                         }
1184                                 }
1185                         }
1186
1187                         if (accessor_members != null) {
1188                                 foreach (var member in accessor_members) {
1189                                         var prop = member as PropertySpec;
1190                                         if (prop != null) {
1191                                                 if (prop.Get != null)
1192                                                         prop.Get = accessor_relation[prop.Get];
1193                                                 if (prop.Set != null)
1194                                                         prop.Set = accessor_relation[prop.Set];
1195
1196                                                 continue;
1197                                         }
1198
1199                                         var ev = (EventSpec) member;
1200                                         ev.AccessorAdd = accessor_relation[ev.AccessorAdd];
1201                                         ev.AccessorRemove = accessor_relation[ev.AccessorRemove];
1202                                 }
1203                         }
1204                 }
1205
1206                 //
1207                 // Removes hidden base members of an interface. For compiled interfaces we cannot
1208                 // do name filtering during Add (as we do for import) because we need all base
1209                 // names to be valid during type definition.
1210                 // Add replaces hidden base member with current one which means any name collision
1211                 // (CS0108) of non-first name would be unnoticed because the name was replaced
1212                 // with the one from compiled type
1213                 //
1214                 public void RemoveHiddenMembers (TypeSpec container)
1215                 {
1216                         foreach (var entry in member_hash) {
1217                                 var values = entry.Value;
1218
1219                                 int container_members_start_at = 0;
1220                                 while (values[container_members_start_at].DeclaringType != container && ++container_members_start_at < entry.Value.Count);
1221
1222                                 if (container_members_start_at == 0 || container_members_start_at == values.Count)
1223                                         continue;
1224
1225                                 for (int i = 0; i < container_members_start_at; ++i) {
1226                                         var member = values[i];
1227
1228                                         if (!container.ImplementsInterface (member.DeclaringType, false))
1229                                                 continue;
1230
1231                                         var member_param = member is IParametersMember ? ((IParametersMember) member).Parameters : ParametersCompiled.EmptyReadOnlyParameters;
1232
1233                                         for (int ii = container_members_start_at; ii < values.Count; ++ii) {
1234                                                 var container_entry = values[ii];
1235
1236                                                 if (container_entry.Arity != member.Arity)
1237                                                         continue;
1238
1239                                                 if (container_entry is IParametersMember) {
1240                                                         if (!TypeSpecComparer.Override.IsEqual (((IParametersMember) container_entry).Parameters, member_param))
1241                                                                 continue;
1242                                                 }
1243
1244                                                 values.RemoveAt (i);
1245                                                 --container_members_start_at;
1246                                                 --ii;
1247                                                 --i;
1248                                         }
1249                                 }
1250                         }
1251                 }
1252
1253                 //
1254                 // Checks all appropriate container members for CLS compliance
1255                 //
1256                 public void VerifyClsCompliance (TypeSpec container, Report report)
1257                 {
1258                         if (locase_members != null)
1259                                 return;
1260
1261                         if (container.BaseType == null) {
1262                                 locase_members = new Dictionary<string, MemberSpec[]> (member_hash.Count); // StringComparer.OrdinalIgnoreCase);
1263                         } else {
1264                                 var btype = container.BaseType.GetDefinition ();
1265                                 btype.MemberCache.VerifyClsCompliance (btype, report);
1266                                 locase_members = new Dictionary<string, MemberSpec[]> (btype.MemberCache.locase_members); //, StringComparer.OrdinalIgnoreCase);
1267                         }
1268
1269                         var is_imported_type = container.MemberDefinition.IsImported;
1270                         foreach (var entry in container.MemberCache.member_hash) {
1271                                 for (int i = 0; i < entry.Value.Count; ++i ) {
1272                                         var name_entry = entry.Value[i];
1273                                         if ((name_entry.Modifiers & (Modifiers.PUBLIC | Modifiers.PROTECTED)) == 0)
1274                                                 continue;
1275
1276                                         if ((name_entry.Modifiers & (Modifiers.OVERRIDE | Modifiers.COMPILER_GENERATED)) != 0)
1277                                                 continue;
1278
1279                                         if ((name_entry.Kind & MemberKind.MaskType) == 0)
1280                                                 continue;
1281
1282                                         if (name_entry.MemberDefinition.CLSAttributeValue == false)
1283                                             continue;
1284
1285                                         IParametersMember p_a = null;
1286                                         if (!is_imported_type) {
1287                                                 p_a = name_entry as IParametersMember;
1288                                                 if (p_a != null && !name_entry.IsAccessor) {
1289                                                         var p_a_pd = p_a.Parameters;
1290                                                         //
1291                                                         // Check differing overloads in @container
1292                                                         //
1293                                                         for (int ii = i + 1; ii < entry.Value.Count; ++ii) {
1294                                                                 var checked_entry = entry.Value[ii];
1295                                                                 IParametersMember p_b = checked_entry as IParametersMember;
1296                                                                 if (p_b == null)
1297                                                                         continue;
1298
1299                                                                 if (p_a_pd.Count != p_b.Parameters.Count)
1300                                                                         continue;
1301
1302                                                                 if (checked_entry.IsAccessor)
1303                                                                         continue;
1304
1305                                                                 var res = ParametersCompiled.IsSameClsSignature (p_a.Parameters, p_b.Parameters);
1306                                                                 if (res != 0) {
1307                                                                         ReportOverloadedMethodClsDifference (name_entry, checked_entry, res, report);
1308                                                                 }
1309                                                         }
1310                                                 }
1311                                         }
1312
1313                                         if (i > 0 || name_entry.Kind == MemberKind.Constructor || name_entry.Kind == MemberKind.Indexer)
1314                                                 continue;
1315
1316                                         var name_entry_locase = name_entry.Name.ToLowerInvariant ();
1317
1318                                         MemberSpec[] found;
1319                                         if (!locase_members.TryGetValue (name_entry_locase, out found)) {
1320                                                 found = new MemberSpec[] { name_entry };
1321                                                 locase_members.Add (name_entry_locase, found);
1322                                         } else {
1323                                                 bool same_names_only = true;
1324                                                 foreach (var f in found) {
1325                                                         if (f.Name == name_entry.Name) {
1326                                                                 if (p_a != null) {
1327                                                                         IParametersMember p_b = f as IParametersMember;
1328                                                                         if (p_b == null)
1329                                                                                 continue;
1330
1331                                                                         if (p_a.Parameters.Count != p_b.Parameters.Count)
1332                                                                                 continue;
1333
1334                                                                         if (f.IsAccessor)
1335                                                                                 continue;
1336
1337                                                                         var res = ParametersCompiled.IsSameClsSignature (p_a.Parameters, p_b.Parameters);
1338                                                                         if (res != 0) {
1339                                                                                 ReportOverloadedMethodClsDifference (f, name_entry, res, report);
1340                                                                         }
1341                                                                 }
1342
1343                                                                 continue;
1344                                                         }
1345
1346                                                         same_names_only = false;
1347                                                         if (!is_imported_type) {
1348                                                                 var last = GetLaterDefinedMember (f, name_entry);
1349                                                                 if (last == f.MemberDefinition) {
1350                                                                         report.SymbolRelatedToPreviousError (name_entry);
1351                                                                 } else {
1352                                                                         report.SymbolRelatedToPreviousError (f);
1353                                                                 }
1354
1355                                                                 report.Warning (3005, 1, last.Location,
1356                                                                         "Identifier `{0}' differing only in case is not CLS-compliant", last.GetSignatureForError ());
1357                                                         }
1358                                                 }
1359
1360                                                 if (!same_names_only) {
1361                                                         Array.Resize (ref found, found.Length + 1);
1362                                                         found[found.Length - 1] = name_entry;
1363                                                         locase_members[name_entry_locase] = found;
1364                                                 }
1365                                         }
1366                                 }
1367                         }
1368                 }
1369
1370                 //
1371                 // Local report helper to issue correctly ordered members stored in hashtable
1372                 //
1373                 static MemberCore GetLaterDefinedMember (MemberSpec a, MemberSpec b)
1374                 {
1375                         var mc_a = a.MemberDefinition as MemberCore;
1376                         var mc_b = b.MemberDefinition as MemberCore;
1377                         if (mc_a == null)
1378                                 return mc_b;
1379
1380                         if (mc_b == null)
1381                                 return mc_a;
1382
1383                         if (a.DeclaringType.MemberDefinition != b.DeclaringType.MemberDefinition)
1384                                 return mc_b;
1385
1386                         if (mc_a.Location.File != mc_b.Location.File)
1387                                 return mc_b;
1388
1389                         return mc_b.Location.Row > mc_a.Location.Row ? mc_b : mc_a;
1390                 }
1391
1392                 static void ReportOverloadedMethodClsDifference (MemberSpec a, MemberSpec b, int res, Report report)
1393                 {
1394                         var last = GetLaterDefinedMember (a, b);
1395                         if (last == a.MemberDefinition) {
1396                                 report.SymbolRelatedToPreviousError (b);
1397                         } else {
1398                                 report.SymbolRelatedToPreviousError (a);
1399                         }
1400
1401                         if ((res & 1) != 0) {
1402                                 report.Warning (3006, 1, last.Location,
1403                                                 "Overloaded method `{0}' differing only in ref or out, or in array rank, is not CLS-compliant",
1404                                                 last.GetSignatureForError ());
1405                         }
1406
1407                         if ((res & 2) != 0) {
1408                                 report.Warning (3007, 1, last.Location,
1409                                         "Overloaded method `{0}' differing only by unnamed array types is not CLS-compliant",
1410                                         last.GetSignatureForError ());
1411                         }
1412                 }
1413
1414                 public bool CheckExistingMembersOverloads (MemberCore member, AParametersCollection parameters)
1415                 {
1416                         var name = GetLookupName (member);
1417                         var imb = member as InterfaceMemberBase;
1418                         if (imb != null && imb.IsExplicitImpl) {
1419                                 name = imb.GetFullName (name);
1420                         }
1421
1422                         return CheckExistingMembersOverloads (member, name, parameters);
1423                 }
1424
1425                 public bool CheckExistingMembersOverloads (MemberCore member, string name, AParametersCollection parameters)
1426                 {
1427                         IList<MemberSpec> entries;
1428                         if (!member_hash.TryGetValue (name, out entries))
1429                                 return false;
1430
1431                         var Report = member.Compiler.Report;
1432
1433                         int method_param_count = parameters.Count;
1434                         for (int i = entries.Count - 1; i >= 0; --i) {
1435                                 var ce = entries[i];
1436                                 var pm = ce as IParametersMember;
1437                                 var pd = pm == null ? ParametersCompiled.EmptyReadOnlyParameters : pm.Parameters;
1438                                 if (pd.Count != method_param_count)
1439                                         continue;
1440
1441                                 if (ce.Arity != member.MemberName.Arity)
1442                                         continue;
1443
1444                                 // Ignore merged interface members
1445                                 if (member.Parent.PartialContainer != ce.DeclaringType.MemberDefinition)
1446                                         continue;
1447
1448                                 var p_types = pd.Types;
1449                                 if (method_param_count > 0) {
1450                                         int ii = method_param_count - 1;
1451                                         TypeSpec type_a, type_b;
1452                                         do {
1453                                                 type_a = parameters.Types [ii];
1454                                                 type_b = p_types [ii];
1455
1456                                                 var a_byref = (pd.FixedParameters[ii].ModFlags & Parameter.Modifier.RefOutMask) != 0;
1457                                                 var b_byref = (parameters.FixedParameters[ii].ModFlags & Parameter.Modifier.RefOutMask) != 0;
1458
1459                                                 if (a_byref != b_byref)
1460                                                         break;
1461
1462                                         } while (TypeSpecComparer.Override.IsEqual (type_a, type_b) && ii-- != 0);
1463
1464                                         if (ii >= 0)
1465                                                 continue;
1466
1467                                         //
1468                                         // Operators can differ in return type only
1469                                         //
1470                                         if (member is Operator && ce.Kind == MemberKind.Operator && ((MethodSpec) ce).ReturnType != ((Operator) member).ReturnType)
1471                                                 continue;
1472
1473                                         //
1474                                         // Report difference in parameter modifiers only
1475                                         //
1476                                         if (pd != null && member is MethodCore) {
1477                                                 ii = method_param_count;
1478                                                 while (ii-- != 0 &&
1479                                                         (parameters.FixedParameters[ii].ModFlags & Parameter.Modifier.ModifierMask) ==
1480                                                         (pd.FixedParameters[ii].ModFlags & Parameter.Modifier.ModifierMask) &&
1481                                                         parameters.ExtensionMethodType == pd.ExtensionMethodType) ;
1482
1483                                                 if (ii >= 0) {
1484                                                         var mc = ce as MethodSpec;
1485                                                         member.Compiler.Report.SymbolRelatedToPreviousError (ce);
1486                                                         if ((member.ModFlags & Modifiers.PARTIAL) != 0 && (mc.Modifiers & Modifiers.PARTIAL) != 0) {
1487                                                                 if (parameters.HasParams || pd.HasParams) {
1488                                                                         Report.Error (758, member.Location,
1489                                                                                 "A partial method declaration and partial method implementation cannot differ on use of `params' modifier");
1490                                                                 } else {
1491                                                                         Report.Error (755, member.Location,
1492                                                                                 "A partial method declaration and partial method implementation must be both an extension method or neither");
1493                                                                 }
1494                                                         } else if (member is Constructor) {
1495                                                                 Report.Error (851, member.Location,
1496                                                                         "Overloaded contructor `{0}' cannot differ on use of parameter modifiers only",
1497                                                                         member.GetSignatureForError ());
1498                                                         } else {
1499                                                                 Report.Error (663, member.Location,
1500                                                                         "Overloaded method `{0}' cannot differ on use of parameter modifiers only",
1501                                                                         member.GetSignatureForError ());
1502                                                         }
1503                                                         return false;
1504                                                 }
1505
1506                                                 var pm_member = (MethodCore)member;
1507                                                 if (!NamedTupleSpec.CheckOverrideName (pm, pm_member) || !NamedTupleSpec.CheckOverrideName (pm.MemberType, pm_member.MemberType)) {
1508                                                         Report.Error (8142, member.Location,
1509                                                                 "A partial method declaration and partial method implementation must both use the same tuple element names");
1510                                                 }
1511                                         }
1512                                 }
1513
1514                                 if ((ce.Kind & MemberKind.Method) != 0) {
1515                                         Method method_a = member as Method;
1516                                         Method method_b = ce.MemberDefinition as Method;
1517                                         if (method_a != null && method_b != null && (method_a.ModFlags & method_b.ModFlags & Modifiers.PARTIAL) != 0) {
1518                                                 const Modifiers partial_modifiers = Modifiers.STATIC | Modifiers.UNSAFE;
1519                                                 if (method_a.IsPartialDefinition == method_b.IsPartialImplementation) {
1520                                                         if ((method_a.ModFlags & partial_modifiers) == (method_b.ModFlags & partial_modifiers) ||
1521                                                                 method_a.Parent.IsUnsafe && method_b.Parent.IsUnsafe) {
1522                                                                 if (method_a.IsPartialImplementation) {
1523                                                                         method_a.SetPartialDefinition (method_b);
1524                                                                         if (entries.Count == 1)
1525                                                                                 member_hash.Remove (name);
1526                                                                         else
1527                                                                                 entries.RemoveAt (i);
1528                                                                 } else {
1529                                                                         method_b.SetPartialDefinition (method_a);
1530                                                                         method_a.caching_flags |= MemberCore.Flags.PartialDefinitionExists;
1531                                                                 }
1532                                                                 continue;
1533                                                         }
1534
1535                                                         if (method_a.IsStatic != method_b.IsStatic) {
1536                                                                 Report.SymbolRelatedToPreviousError (ce);
1537                                                                 Report.Error (763, member.Location,
1538                                                                         "A partial method declaration and partial method implementation must be both `static' or neither");
1539                                                         }
1540
1541                                                         if ((method_a.ModFlags & Modifiers.UNSAFE) != (method_b.ModFlags & Modifiers.UNSAFE)) {
1542                                                                 Report.SymbolRelatedToPreviousError (ce);
1543                                                                 Report.Error (764, member.Location,
1544                                                                         "A partial method declaration and partial method implementation must be both `unsafe' or neither");
1545                                                         }
1546
1547                                                         return false;
1548                                                 }
1549
1550                                                 Report.SymbolRelatedToPreviousError (ce);
1551                                                 if (method_a.IsPartialDefinition) {
1552                                                         Report.Error (756, member.Location, "A partial method `{0}' declaration is already defined",
1553                                                                 member.GetSignatureForError ());
1554                                                 }
1555
1556                                                 Report.Error (757, member.Location, "A partial method `{0}' implementation is already defined",
1557                                                         member.GetSignatureForError ());
1558                                                 return false;
1559                                         }
1560
1561                                         Report.SymbolRelatedToPreviousError (ce);
1562
1563                                         bool is_reserved_a = member is AbstractPropertyEventMethod || member is Operator;
1564                                         bool is_reserved_b = ((MethodSpec) ce).IsReservedMethod;
1565
1566                                         if (is_reserved_a || is_reserved_b) {
1567                                                 Report.Error (82, member.Location, "A member `{0}' is already reserved",
1568                                                         is_reserved_a ?
1569                                                         ce.GetSignatureForError () :
1570                                                         member.GetSignatureForError ());
1571                                                 return false;
1572                                         }
1573                                 } else {
1574                                         Report.SymbolRelatedToPreviousError (ce);
1575                                 }
1576
1577                                 if (member is Operator && ce.Kind == MemberKind.Operator) {
1578                                         Report.Error (557, member.Location, "Duplicate user-defined conversion in type `{0}'",
1579                                                 member.Parent.GetSignatureForError ());
1580                                         return false;
1581                                 }
1582
1583                                 Report.Error (111, member.Location,
1584                                         "A member `{0}' is already defined. Rename this member or use different parameter types",
1585                                         member.GetSignatureForError ());
1586                                 return false;
1587                         }
1588
1589                         return true;
1590                 }
1591         }
1592 }