mcs/mcs/membercache.cs

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