Merge pull request #3962 from mkorkalo/fix_MonoBtlsContext_memory_leak
[mono.git] / mcs / mcs / membercache.cs
1 //
2 // membercache.cs: A container for all member lookups
3 //
4 // Author: Miguel de Icaza (miguel@gnu.org)
5 //         Marek Safar (marek.safar@gmail.com)
6 //
7 // Dual licensed under the terms of the MIT X11 or GNU GPL
8 //
9 // Copyright 2001 Ximian, Inc (http://www.ximian.com)
10 // Copyright 2004-2010 Novell, Inc
11 // Copyright 2011 Xamarin Inc
12 //
13 //
14
15 using System;
16 using System.Collections.Generic;
17
18 namespace Mono.CSharp {
19
20         [Flags]
21         public enum MemberKind
22         {
23                 Constructor = 1,
24                 Event = 1 << 1,
25                 Field = 1 << 2,
26                 Method = 1 << 3,
27                 Property = 1 << 4,
28                 Indexer = 1 << 5,
29                 Operator = 1 << 6,
30                 Destructor      = 1 << 7,
31
32                 Class           = 1 << 11,
33                 Struct          = 1 << 12,
34                 Delegate        = 1 << 13,
35                 Enum            = 1 << 14,
36                 Interface       = 1 << 15,
37                 TypeParameter = 1 << 16,
38
39                 ArrayType = 1 << 19,
40                 PointerType = 1 << 20,
41                 InternalCompilerType = 1 << 21,
42                 MissingType = 1 << 22,
43                 Void = 1 << 23,
44                 Namespace = 1 << 24,
45
46                 NestedMask = Class | Struct | Delegate | Enum | Interface,
47                 GenericMask = Method | Class | Struct | Delegate | Interface,
48                 MaskType = Constructor | Event | Field | Method | Property | Indexer | Operator | Destructor | NestedMask
49         }
50
51         [Flags]
52         public enum BindingRestriction
53         {
54                 None = 0,
55
56                 // Inspect only queried type members
57                 DeclaredOnly = 1 << 1,
58
59                 // Exclude static
60                 InstanceOnly = 1 << 2,
61
62                 NoAccessors = 1 << 3,
63
64                 // Member has to be override
65                 OverrideOnly = 1 << 4
66         }
67
68         public struct MemberFilter : IEquatable<MemberSpec>
69         {
70                 public readonly string Name;
71                 public readonly MemberKind Kind;
72                 public readonly AParametersCollection Parameters;
73                 public readonly TypeSpec MemberType;
74                 public readonly int Arity; // -1 to ignore the check
75
76                 public MemberFilter (MethodSpec m)
77                 {
78                         Name = m.Name;
79                         Kind = MemberKind.Method;
80                         Parameters = m.Parameters;
81                         MemberType = m.ReturnType;
82                         Arity = m.Arity;
83                 }
84
85                 public MemberFilter (string name, int arity, MemberKind kind, AParametersCollection param, TypeSpec type)
86                 {
87                         Name = name;
88                         Kind = kind;
89                         Parameters = param;
90                         MemberType = type;
91                         this.Arity = arity;
92                 }
93
94                 public static MemberFilter Constructor (AParametersCollection param)
95                 {
96                         return new MemberFilter (Mono.CSharp.Constructor.ConstructorName, 0, MemberKind.Constructor, param, null);
97                 }
98
99                 public static MemberFilter Property (string name, TypeSpec type)
100                 {
101                         return new MemberFilter (name, 0, MemberKind.Property, null, type);
102                 }
103
104                 public static MemberFilter Field (string name, TypeSpec type)
105                 {
106                         return new MemberFilter (name, 0, MemberKind.Field, null, type);
107                 }
108
109                 public static MemberFilter Method (string name, int arity, AParametersCollection param, TypeSpec type)
110                 {
111                         return new MemberFilter (name, arity, MemberKind.Method, param, type);
112                 }
113
114                 #region IEquatable<MemberSpec> Members
115
116                 public bool Equals (MemberSpec other)
117                 {
118                         // Is the member of the correct type ?
119                         // TODO: Isn't this redundant ?
120                         if ((other.Kind & Kind & MemberKind.MaskType) == 0)
121                                 return false;
122
123                         // Check arity when not disabled
124                         if (Arity >= 0 && Arity != other.Arity)
125                                 return false;
126
127                         if (Parameters != null) {
128                                 if (other is IParametersMember) {
129                                         var other_param = ((IParametersMember) other).Parameters;
130                                         if (!TypeSpecComparer.Override.IsEqual (Parameters, other_param))
131                                                 return false;
132                                 } else {
133                                         return false;
134                                 }
135                         }
136
137                         if (MemberType != null) {
138                                 if (other is IInterfaceMemberSpec) {
139                                         var other_type = ((IInterfaceMemberSpec) other).MemberType;
140                                         if (!TypeSpecComparer.Override.IsEqual (other_type, MemberType))
141                                                 return false;
142                                 } else {
143                                         return false;
144                                 }
145                         }
146
147                         return true;
148                 }
149
150                 #endregion
151         }
152
153         //
154         // The MemberCache is the main members container used by compiler. It contains
155         // all members imported or defined during compilation using on demand filling
156         // process. Inflated containers are also using MemberCache to make inflated
157         // members look like normal definition.
158         //
159         // All of the methods are performance and memory sensitive as the MemberCache
160         // is the underlying engine of all member based operations.
161         //
162         public class MemberCache
163         {
164                 [Flags]
165                 enum StateFlags
166                 {
167                         HasConversionOperator = 1 << 1,
168                         HasUserOperator = 1 << 2
169                 }
170
171                 readonly Dictionary<string, IList<MemberSpec>> member_hash;
172                 Dictionary<string, MemberSpec[]> locase_members;
173                 IList<MethodSpec> missing_abstract;
174                 StateFlags state;       // TODO: Move to TypeSpec or ITypeDefinition
175
176                 public static readonly string IndexerNameAlias = "<this>";
177
178                 public static readonly MemberCache Empty = new MemberCache (0);
179
180                 public MemberCache ()
181                         : this (16)
182                 {
183                 }
184
185                 public MemberCache (int capacity)
186                 {
187                         member_hash = new Dictionary<string, IList<MemberSpec>> (capacity);
188                 }
189
190                 public MemberCache (MemberCache cache)
191                         : this (cache.member_hash.Count)
192                 {
193                         this.state = cache.state;
194                 }
195
196                 //
197                 // Creates a new MemberCache for the given `container'.
198                 //
199                 public MemberCache (TypeContainer container)
200                         : this ()                               // TODO: Optimize the size
201                 {
202                 }
203
204                 //
205                 // For cases where we need to union cache members
206                 //
207                 public void AddBaseType (TypeSpec baseType)
208                 {
209                         var cache = baseType.MemberCache;
210
211                         IList<MemberSpec> list;
212                         foreach (var entry in cache.member_hash) {
213                                 if (!member_hash.TryGetValue (entry.Key, out list)) {
214                                         if (entry.Value.Count == 1) {
215                                                 list = entry.Value;
216                                         } else {
217                                                 list = new List<MemberSpec> (entry.Value);
218                                         }
219
220                                         member_hash.Add (entry.Key, list);
221                                         continue;
222                                 }
223
224                                 foreach (var ce in entry.Value) {
225                                         if (list.Contains (ce))
226                                                 continue;
227
228                                         if (list is MemberSpec[]) {
229                                                 list = new List<MemberSpec> { list [0] };
230                                                 member_hash[entry.Key] = list;
231                                         }
232
233                                         list.Add (ce);
234                                 }
235                         }
236                 }
237
238                 //
239                 // Member-cache does not contain base members but it does
240                 // contain all base interface members, so the Lookup code
241                 // can use simple inheritance rules.
242                 //
243                 // Does not work recursively because of generic interfaces
244                 //
245                 public void AddInterface (TypeSpec iface)
246                 {
247                         var cache = iface.MemberCache;
248
249                         IList<MemberSpec> list;
250                         foreach (var entry in cache.member_hash) {
251                                 if (!member_hash.TryGetValue (entry.Key, out list)) {
252                                         if (entry.Value.Count == 1) {
253                                                 list = entry.Value;
254                                         } else {
255                                                 list = new List<MemberSpec> (entry.Value);
256                                         }
257
258                                         member_hash.Add (entry.Key, list);
259                                         continue;
260                                 }
261
262                                 foreach (var ce in entry.Value) {
263                                         //
264                                         // When two or more different base interfaces implemenent common
265                                         // interface
266                                         //
267                                         // I : IA, IFoo
268                                         // IA : IFoo
269                                         //
270                                         if (list.Contains (ce))
271                                                 continue;
272
273                                         if (AddInterfaceMember (ce, ref list))
274                                                 member_hash[entry.Key] = list;
275                                 }
276                         }
277                 }
278
279                 public void AddMember (InterfaceMemberBase imb, string exlicitName, MemberSpec ms)
280                 {
281                         // Explicit names cannot be looked-up but can be used for
282                         // collision checking (no name mangling needed)
283                         if (imb.IsExplicitImpl)
284                                 AddMember (exlicitName, ms, false);
285                         else
286                                 AddMember (ms);
287                 }
288
289                 //
290                 // Add non-explicit member to member cache
291                 //
292                 public void AddMember (MemberSpec ms)
293                 {
294                         AddMember (GetLookupName (ms), ms, false);
295                 }
296
297                 void AddMember (string name, MemberSpec member, bool removeHiddenMembers)
298                 {
299                         if (member.Kind == MemberKind.Operator) {
300                                 var dt = member.DeclaringType;
301
302
303                                 //
304                                 // Some core types have user operators but they cannot be used like normal
305                                 // user operators as they are predefined and therefore having different
306                                 // rules (e.g. binary operators) by not setting the flag we hide them for
307                                 // user conversions
308                                 //
309                                 if (!BuiltinTypeSpec.IsPrimitiveType (dt) || dt.BuiltinType == BuiltinTypeSpec.Type.Char) {
310                                         switch (dt.BuiltinType) {
311                                         case BuiltinTypeSpec.Type.String:
312                                         case BuiltinTypeSpec.Type.Delegate:
313                                         case BuiltinTypeSpec.Type.MulticastDelegate:
314                                                 break;
315                                         default:
316                                                 if (name == Operator.GetMetadataName (Operator.OpType.Implicit) || name == Operator.GetMetadataName (Operator.OpType.Explicit)) {
317                                                         state |= StateFlags.HasConversionOperator;
318                                                 } else {
319                                                         state |= StateFlags.HasUserOperator;
320                                                 }
321
322                                                 break;
323                                         }
324                                 }
325                         }
326
327                         IList<MemberSpec> list;
328                         if (!member_hash.TryGetValue (name, out list)) {
329                                 member_hash.Add (name, new MemberSpec[] { member });
330                                 return;
331                         }
332
333                         if (removeHiddenMembers && member.DeclaringType.IsInterface) {
334                                 if (AddInterfaceMember (member, ref list))
335                                         member_hash[name] = list;
336                         } else {
337                                 if (list.Count == 1) {
338                                         list = new List<MemberSpec> { list[0] };
339                                         member_hash[name] = list;
340                                 }
341
342                                 list.Add (member);
343                         }
344                 }
345
346                 public void AddMemberImported (MemberSpec ms)
347                 {
348                         AddMember (GetLookupName (ms), ms, true);
349                 }
350
351                 //
352                 // Ignores any base interface member which can be hidden
353                 // by this interface
354                 //
355                 static bool AddInterfaceMember (MemberSpec member, ref IList<MemberSpec> existing)
356                 {
357                         var member_param = member is IParametersMember ? ((IParametersMember) member).Parameters : null;
358
359                         //
360                         // interface IA : IB { int Prop { set; } }
361                         // interface IB { bool Prop { get; } }
362                         //
363                         // IB.Prop is never accessible from IA interface
364                         //
365                         for (int i = 0; i < existing.Count; ++i) {
366                                 var entry = existing[i];
367
368                                 if (entry.Arity != member.Arity)
369                                         continue;
370
371                                 AParametersCollection entry_param = null;
372                                 if (member_param != null) {
373                                         var entry_pm = entry as IParametersMember;
374                                         if (entry_pm != null) {
375                                                 entry_param = entry_pm.Parameters;
376                                                 if (!TypeSpecComparer.Override.IsEqual (entry_param, member_param))
377                                                         continue;
378                                         }
379                                 }
380
381                                 if (member.DeclaringType.ImplementsInterface (entry.DeclaringType, false)) {
382                                         if (existing.Count == 1) {
383                                                 existing = new MemberSpec[] { member };
384                                                 return true;
385                                         }
386
387                                         existing.RemoveAt (i--);
388                                         continue;
389                                 }
390
391                                 if ((entry.DeclaringType == member.DeclaringType && entry.IsAccessor == member.IsAccessor))
392                                         return false;
393
394                                 if (entry.DeclaringType.ImplementsInterface (member.DeclaringType, false) && AParametersCollection.HasSameParameterDefaults (entry_param, member_param))
395                                         return false;
396                         }
397
398                         if (existing.Count == 1) {
399                                 existing = new List<MemberSpec> { existing[0], member };
400                                 return true;
401                         }
402
403                         existing.Add (member);
404                         return false;
405                 }
406
407                 public static MemberSpec FindMember (TypeSpec container, MemberFilter filter, BindingRestriction restrictions)
408                 {
409                         if (filter.Kind == MemberKind.Method && container.Kind == MemberKind.TypeParameter && filter.Parameters == null)
410                                 throw new NotSupportedException ("type parameters methods cannot be lookup up due to two stage setup");
411
412                         IList<MemberSpec> applicable;
413                         var top_container = container;
414
415                         do {
416                                 if (container.MemberCache.member_hash.TryGetValue (filter.Name, out applicable)) {
417                                         // Start from the end because interface members are in reverse order
418                                         for (int i = applicable.Count - 1; i >= 0; i--) {
419                                                 var entry = applicable [i];
420
421                                                 if ((restrictions & BindingRestriction.InstanceOnly) != 0 && entry.IsStatic)
422                                                         continue;
423
424                                                 if ((restrictions & BindingRestriction.NoAccessors) != 0 && entry.IsAccessor)
425                                                         continue;
426
427                                                 if ((restrictions & BindingRestriction.OverrideOnly) != 0 && (entry.Modifiers & Modifiers.OVERRIDE) == 0)
428                                                         continue;
429
430                                                 if (!filter.Equals (entry))
431                                                         continue;
432
433                                                 if ((restrictions & BindingRestriction.DeclaredOnly) != 0 && container.IsInterface && entry.DeclaringType != container)
434                                                         continue;
435
436                                                 return entry;
437                                         }
438                                 }
439
440                                 if ((restrictions & BindingRestriction.DeclaredOnly) != 0)
441                                         break;
442
443                                 container = container.BaseType;
444                         } while (container != null);
445
446                         var tps = top_container as TypeParameterSpec;
447                         if (tps != null && tps.InterfaceCache != null) {
448                                 if (tps.InterfaceCache.member_hash.TryGetValue (filter.Name, out applicable)) {
449                                         for (int i = applicable.Count - 1; i >= 0; i--) {
450                                                 var entry = applicable [i];
451
452                                                 if ((restrictions & BindingRestriction.NoAccessors) != 0 && entry.IsAccessor)
453                                                         continue;
454
455                                                 if ((restrictions & BindingRestriction.OverrideOnly) != 0 && (entry.Modifiers & Modifiers.OVERRIDE) == 0)
456                                                         continue;
457
458                                                 if (!filter.Equals (entry))
459                                                         continue;
460
461                                                 return entry;
462                                         }
463                                 }
464                         }
465
466                         return null;
467                 }
468
469                 //
470                 // A special method to work with member lookup only. It returns a list of all members named @name
471                 // starting from @container. It's very performance sensitive
472                 //
473                 // declaredOnlyClass cannot be used interfaces. Manual filtering is required because names are
474                 // compacted
475                 //
476                 public static IList<MemberSpec> FindMembers (TypeSpec container, string name, bool declaredOnlyClass)
477                 {
478                         do {
479                                 IList<MemberSpec> applicable;
480                                 
481                                 if (container.MemberCache.member_hash.TryGetValue (name, out applicable) || declaredOnlyClass)
482                                         return applicable;
483
484                                 container = container.BaseType;
485                         } while (container != null);
486
487                         return null;
488                 }
489
490                 public static IList<MemberSpec> FindInterfaceMembers (TypeParameterSpec typeParameter, string name)
491                 {
492                         if (typeParameter.InterfaceCache != null) {
493                                 IList<MemberSpec> applicable;
494                                 typeParameter.InterfaceCache.member_hash.TryGetValue (name, out applicable);
495                                 return applicable;
496                         }
497
498                         return null;
499                 }
500
501                 //
502                 // Finds the nested type in container
503                 //
504                 public static TypeSpec FindNestedType (TypeSpec container, string name, int arity, bool declaredOnlyClass)
505                 {
506                         IList<MemberSpec> applicable;
507                         TypeSpec best_match = null;
508                         do {
509 #if !FULL_AOT_RUNTIME
510                                 // TODO: Don't know how to handle this yet
511                                 // When resolving base type of nested type, parent type must have
512                                 // base type resolved to scan full hierarchy correctly
513                                 // Similarly MemberCacheTypes will inflate BaseType and Interfaces
514                                 // based on type definition
515                                 var tc = container.MemberDefinition as TypeContainer;
516                                 if (tc != null)
517                                         tc.DefineContainer ();
518 #endif
519
520                                 if (container.MemberCacheTypes.member_hash.TryGetValue (name, out applicable)) {
521                                         for (int i = applicable.Count - 1; i >= 0; i--) {
522                                                 var entry = applicable[i];
523                                                 if ((entry.Kind & MemberKind.NestedMask) == 0)
524                                                         continue;
525
526                                                 var ts = (TypeSpec) entry;
527                                                 if (arity == ts.Arity)
528                                                         return ts;
529
530                                                 if (arity < 0) {
531                                                         if (best_match == null) {
532                                                                 best_match = ts;
533                                                         } else if (System.Math.Abs (ts.Arity + arity) < System.Math.Abs (best_match.Arity + arity)) {
534                                                                 best_match = ts;
535                                                         }
536                                                 }
537                                         }
538                                 }
539
540                                 container = container.BaseType;
541                         } while (container != null && !declaredOnlyClass);
542
543                         return best_match;
544                 }
545
546                 //
547                 // Looks for extension methods with defined name and extension type
548                 //
549                 public List<MethodSpec> FindExtensionMethods (IMemberContext invocationContext, string name, int arity)
550                 {
551                         IList<MemberSpec> entries;
552                         if (!member_hash.TryGetValue (name, out entries))
553                                 return null;
554
555                         List<MethodSpec> candidates = null;
556                         foreach (var entry in entries) {
557                                 if (entry.Kind != MemberKind.Method || (arity > 0 && entry.Arity != arity))
558                                         continue;
559
560                                 var ms = (MethodSpec) entry;
561                                 if (!ms.IsExtensionMethod)
562                                         continue;
563
564                                 if (!ms.IsAccessible (invocationContext))
565                                         continue;
566
567                                 //
568                                 // Extension methods cannot be nested hence checking parent is enough
569                                 //
570                                 if ((ms.DeclaringType.Modifiers & Modifiers.INTERNAL) != 0 && !ms.DeclaringType.MemberDefinition.IsInternalAsPublic (invocationContext.Module.DeclaringAssembly))
571                                         continue;
572
573                                 if (candidates == null)
574                                         candidates = new List<MethodSpec> ();
575                                 candidates.Add (ms);
576                         }
577
578                         return candidates;
579                 }
580
581                 //
582                 // Returns base members of @member member if no exact match is found @bestCandidate returns
583                 // the best match
584                 //
585                 public static MemberSpec FindBaseMember (MemberCore member, out MemberSpec bestCandidate, ref bool overrides)
586                 {
587                         bestCandidate = null;
588                         var container = member.Parent.PartialContainer.Definition;
589                         if (!container.IsInterface) {
590                                 container = container.BaseType;
591
592                                 // It can happen for a user definition of System.Object
593                                 if (container == null)
594                                         return null;
595                         }
596
597                         string name = GetLookupName (member);
598                         var member_param = member is IParametersMember ? ((IParametersMember) member).Parameters : null;
599
600                         var mkind = GetMemberCoreKind (member);
601                         bool member_with_accessors = mkind == MemberKind.Indexer || mkind == MemberKind.Property;
602
603                         IList<MemberSpec> applicable;
604                         MemberSpec ambig_candidate = null;
605
606                         do {
607                                 if (container.MemberCache.member_hash.TryGetValue (name, out applicable)) {
608                                         for (int i = 0; i < applicable.Count; ++i) {
609                                                 var entry = applicable [i];
610
611                                                 if ((entry.Modifiers & Modifiers.PUBLIC) == 0 && !entry.IsAccessible (member))
612                                                         continue;
613
614                                                 //
615                                                 // Isn't the member of same kind ?
616                                                 //
617                                                 if ((entry.Kind & ~MemberKind.Destructor & mkind & MemberKind.MaskType) == 0) {
618                                                         // Destructors are ignored as they cannot be overridden by user
619                                                         if ((entry.Kind & MemberKind.Destructor) != 0)
620                                                                 continue;
621
622                                                         // A method with different arity does not hide base member
623                                                         if (mkind != MemberKind.Method && member.MemberName.Arity != entry.Arity)
624                                                                 continue;
625
626                                                         bestCandidate = entry;
627                                                         return null;
628                                                 }
629
630                                                 //
631                                                 // Same kind of different arity is valid
632                                                 //
633                                                 if (member.MemberName.Arity != entry.Arity) {
634                                                         continue;
635                                                 }
636
637                                                 if ((entry.Kind & mkind & (MemberKind.Method | MemberKind.Indexer)) != 0) {
638                                                         if (entry.IsAccessor != member is AbstractPropertyEventMethod)
639                                                                 continue;
640
641                                                         var pm = entry as IParametersMember;
642                                                         if (!TypeSpecComparer.Override.IsEqual (pm.Parameters, member_param))
643                                                                 continue;
644                                                 }
645
646                                                 //
647                                                 // Skip override for member with accessors. It may not fully implement the base member
648                                                 // but keep flag we found an implementation in case the base member is abstract
649                                                 //
650                                                 if (member_with_accessors && ((entry.Modifiers & (Modifiers.OVERRIDE | Modifiers.SEALED)) == Modifiers.OVERRIDE)) {
651                                                         //
652                                                         // Set candidate to override implementation to flag we found an implementation
653                                                         //
654                                                         overrides = true;
655                                                         continue;
656                                                 }
657
658                                                 //
659                                                 // For members with parameters we can encounter an ambiguous candidates (they match exactly)
660                                                 // because generic type parameters could be inflated into same types
661                                                 //
662                                                 if (ambig_candidate == null && (entry.Kind & mkind & (MemberKind.Method | MemberKind.Indexer)) != 0) {
663                                                         bestCandidate = null;
664                                                         ambig_candidate = entry;
665                                                         continue;
666                                                 }
667
668                                                 bestCandidate = ambig_candidate;
669                                                 return entry;
670                                         }
671                                 }
672
673                                 if (container.IsInterface || ambig_candidate != null)
674                                         break;
675
676                                 container = container.BaseType;
677                         } while (container != null);
678
679                         return ambig_candidate;
680                 }
681
682                 public static List<TypeSpec> GetDeclaredNestedTypes (TypeSpec container)
683                 {
684                         List<TypeSpec> found = null;
685                         foreach (var entry in container.MemberCache.member_hash) {
686                                 foreach (var member in entry.Value) {
687                                         if ((member.Kind & MemberKind.NestedMask) == 0)
688                                                 continue;
689
690                                         if (found == null)
691                                                 found = new List<TypeSpec> ();
692
693                                         found.Add ((TypeSpec)member);
694                                 }
695                         }
696
697                         return found;
698                 }
699
700                 //
701                 // Returns inflated version of MemberSpec, it works similarly to
702                 // SRE TypeBuilder.GetMethod
703                 //
704                 public static T GetMember<T> (TypeSpec container, T spec) where T : MemberSpec
705                 {
706                         IList<MemberSpec> applicable;
707                         if (container.MemberCache.member_hash.TryGetValue (GetLookupName (spec), out applicable)) {
708                                 for (int i = applicable.Count - 1; i >= 0; i--) {
709                                         var entry = applicable[i];
710                                         if (entry.MemberDefinition == spec.MemberDefinition)
711                                                 return (T) entry;
712                                 }
713                         }
714
715                         throw new InternalErrorException ("Missing member `{0}' on inflated type `{1}'",
716                                 spec.GetSignatureForError (), container.GetSignatureForError ());
717                 }
718
719                 static MemberKind GetMemberCoreKind (MemberCore member)
720                 {
721                         if (member is FieldBase)
722                                 return MemberKind.Field;
723                         if (member is Indexer)
724                                 return MemberKind.Indexer;
725                         if (member is Class)
726                                 return MemberKind.Class;
727                         if (member is Struct)
728                                 return MemberKind.Struct;
729                         if (member is Destructor)
730                                 return MemberKind.Destructor;
731                         if (member is Method)
732                                 return MemberKind.Method;
733                         if (member is Property)
734                                 return MemberKind.Property;
735                         if (member is EventField)
736                                 return MemberKind.Event;
737                         if (member is Interface)
738                                 return MemberKind.Interface;
739                         if (member is EventProperty)
740                                 return MemberKind.Event;
741                         if (member is Delegate)
742                                 return MemberKind.Delegate;
743                         if (member is Enum)
744                                 return MemberKind.Enum;
745
746                         throw new NotImplementedException (member.GetType ().ToString ());
747                 }
748
749                 public static List<FieldSpec> GetAllFieldsForDefiniteAssignment (TypeSpec container, IMemberContext context)
750                 {
751                         List<FieldSpec> fields = null;
752                         bool imported = container.MemberDefinition.IsImported;
753                         foreach (var entry in container.MemberCache.member_hash) {
754                                 foreach (var name_entry in entry.Value) {
755                                         if (name_entry.Kind != MemberKind.Field)
756                                                 continue;
757
758                                         if ((name_entry.Modifiers & Modifiers.STATIC) != 0)
759                                                 continue;
760
761                                         //
762                                         // Fixed size buffers are not subject to definite assignment checking
763                                         //
764                                         if (name_entry is FixedFieldSpec || name_entry is ConstSpec)
765                                                 continue;
766
767                                         var fs = (FieldSpec) name_entry;
768                                         if (imported && ShouldIgnoreFieldForDefiniteAssignment (fs, context))
769                                                 continue;
770
771                                         //if ((fs.Modifiers & (Modifiers.BACKING_FIELD) != 0)
772                                         //      continue;
773
774                                         if (fields == null)
775                                                 fields = new List<FieldSpec> ();
776
777                                         fields.Add (fs);
778                                         break;
779                                 }
780                         }
781
782                         return fields ?? new List<FieldSpec> (0);
783                 }
784
785                 static bool ShouldIgnoreFieldForDefiniteAssignment (FieldSpec fs, IMemberContext context)
786                 {
787                         //
788                         // LAMESPEC: This mimics csc quirk where definitive assignment is not done
789                         // for all kinds of imported non-public struct fields
790                         //
791                         var mod = fs.Modifiers;
792                         if ((mod & Modifiers.PRIVATE) == 0 && ((mod & Modifiers.INTERNAL) != 0 && fs.DeclaringType.MemberDefinition.IsInternalAsPublic (context.Module.DeclaringAssembly)))
793                                 return false;
794
795                         //
796                         // Ignore reference type fields except when type is an array or type parameter
797                         //
798                         var type = fs.MemberType;
799                         switch (type.Kind) {
800                         case MemberKind.ArrayType:
801                         case MemberKind.TypeParameter:
802                                 return false;
803                         default:
804                                 return TypeSpec.IsReferenceType (type);
805                         }
806                 }
807
808                 public static IList<MemberSpec> GetCompletitionMembers (IMemberContext ctx, TypeSpec container, string name)
809                 {
810                         var matches = new List<MemberSpec> ();
811                         foreach (var entry in container.MemberCache.member_hash) {
812                                 foreach (var name_entry in entry.Value) {
813                                         if (name_entry.IsAccessor)
814                                                 continue;
815
816                                         if ((name_entry.Kind & (MemberKind.Constructor | MemberKind.Destructor | MemberKind.Operator)) != 0)
817                                                 continue;
818
819                                         if (!name_entry.IsAccessible (ctx))
820                                                 continue;
821
822                                         if (name == null || name_entry.Name.StartsWith (name)) {
823                                                 matches.Add (name_entry);
824                                         }
825                                 }
826                         }
827
828                         return matches;
829                 }
830
831                 //
832                 // Returns members of @iface only, base members are ignored
833                 //
834                 public static List<MethodSpec> GetInterfaceMethods (TypeSpec iface)
835                 {
836                         //
837                         // MemberCache flatten interfaces, therefore in cases like this one
838                         // 
839                         // interface IA : IB {}
840                         // interface IB { void Foo () }
841                         //
842                         // we would return Foo inside IA which is not expected in this case
843                         //
844                         var methods = new List<MethodSpec> ();
845                         foreach (var entry in iface.MemberCache.member_hash.Values) {
846                                 foreach (var name_entry in entry) {
847                                         if (iface == name_entry.DeclaringType) {
848                                                 if (name_entry.Kind == MemberKind.Method) {
849                                                         methods.Add ((MethodSpec) name_entry);
850                                                 }
851                                         }
852                                 }
853                         }
854
855                         return methods;
856                 }
857
858                 //
859                 // Returns all not implememted abstract members inside abstract type
860                 // NOTE: Returned list is shared and must not be modified
861                 //
862                 public static IList<MethodSpec> GetNotImplementedAbstractMethods (TypeSpec type)
863                 {
864                         if (type.MemberCache.missing_abstract != null)
865                                 return type.MemberCache.missing_abstract;
866                                 
867                         var abstract_methods = new List<MethodSpec> ();
868                         List<TypeSpec> hierarchy = null;
869
870                         //
871                         // Stage 1: top-to-bottom scan for abstract members
872                         //
873                         var abstract_type = type;
874                         while (true) {
875                                 foreach (var entry in abstract_type.MemberCache.member_hash) {
876                                         foreach (var name_entry in entry.Value) {
877                                                 if ((name_entry.Modifiers & Modifiers.ABSTRACT) == 0)
878                                                         continue;
879
880                                                 var ms = name_entry as MethodSpec;
881                                                 if (ms == null)
882                                                         continue;
883
884                                                 abstract_methods.Add (ms);
885                                         }
886                                 }
887
888                                 var base_type = abstract_type.BaseType;
889                                 if (!base_type.IsAbstract)
890                                         break;
891
892                                 if (hierarchy == null)
893                                         hierarchy = new List<TypeSpec> ();
894
895                                 hierarchy.Add (abstract_type);
896                                 abstract_type = base_type;
897                         }
898
899                         int not_implemented_count = abstract_methods.Count;
900                         if (not_implemented_count == 0 || hierarchy == null) {
901                                 type.MemberCache.missing_abstract = abstract_methods;
902                                 return type.MemberCache.missing_abstract;
903                         }
904
905                         //
906                         // Stage 2: Remove already implemented methods
907                         //
908                         foreach (var type_up in hierarchy) {
909                                 var members = type_up.MemberCache.member_hash;
910                                 if (members.Count == 0)
911                                         continue;
912
913                                 for (int i = 0; i < abstract_methods.Count; ++i) {
914                                         var candidate = abstract_methods [i];
915                                         if (candidate == null)
916                                                 continue;
917
918                                         IList<MemberSpec> applicable;
919                                         if (!members.TryGetValue (candidate.Name, out applicable))
920                                                 continue;
921
922                                         var filter = new MemberFilter (candidate);
923                                         foreach (var item in applicable) {
924                                                 if ((item.Modifiers & (Modifiers.OVERRIDE | Modifiers.VIRTUAL)) == 0)
925                                                         continue;
926
927                                                 //
928                                                 // Abstract override does not override anything
929                                                 //
930                                                 if ((item.Modifiers & Modifiers.ABSTRACT) != 0)
931                                                         continue;
932
933                                                 if (filter.Equals (item)) {
934                                                         --not_implemented_count;
935                                                         abstract_methods [i] = null;
936                                                         break;
937                                                 }
938                                         }
939                                 }
940                         }
941
942                         if (not_implemented_count == abstract_methods.Count) {
943                                 type.MemberCache.missing_abstract = abstract_methods;
944                                 return type.MemberCache.missing_abstract;
945                         }
946
947                         var not_implemented = new MethodSpec[not_implemented_count];
948                         int counter = 0;
949                         foreach (var m in abstract_methods) {
950                                 if (m == null)
951                                         continue;
952
953                                 not_implemented[counter++] = m;
954                         }
955
956                         type.MemberCache.missing_abstract = not_implemented;
957                         return type.MemberCache.missing_abstract;
958                 }
959
960                 static string GetLookupName (MemberSpec ms)
961                 {
962                         if (ms.Kind == MemberKind.Indexer)
963                                 return IndexerNameAlias;
964
965                         if (ms.Kind == MemberKind.Constructor) {
966                                 if (ms.IsStatic)
967                                         return Constructor.TypeConstructorName;
968
969                                 return Constructor.ConstructorName;
970                         }
971
972                         return ms.Name;
973                 }
974
975                 static string GetLookupName (MemberCore mc)
976                 {
977                         if (mc is Indexer)
978                                 return IndexerNameAlias;
979
980                         if (mc is Constructor)
981                                 return mc.IsStatic ? Constructor.TypeConstructorName : Constructor.ConstructorName;
982
983                         return mc.MemberName.Name;
984                 }
985
986                 //
987                 // Returns all operators declared on container and its base types (until declaredOnly is used)
988                 //
989                 public static IList<MemberSpec> GetUserOperator (TypeSpec container, Operator.OpType op, bool declaredOnly)
990                 {
991                         IList<MemberSpec> found = null;
992                         bool shared_list = true;
993                         IList<MemberSpec> applicable;
994                         do {
995                                 var mc = container.MemberCache;
996
997                                 if (((op == Operator.OpType.Implicit || op == Operator.OpType.Explicit) && (mc.state & StateFlags.HasConversionOperator) != 0) ||
998                                          (mc.state & StateFlags.HasUserOperator) != 0) {
999
1000                                         if (mc.member_hash.TryGetValue (Operator.GetMetadataName (op), out applicable)) {
1001                                                 int i;
1002                                                 for (i = 0; i < applicable.Count; ++i) {
1003                                                         if (applicable[i].Kind != MemberKind.Operator) {
1004                                                                 break;
1005                                                         }
1006                                                 }
1007
1008                                                 //
1009                                                 // Handles very rare case where a method with same name as operator (op_xxxx) exists
1010                                                 // and we have to resize the applicable list
1011                                                 //
1012                                                 if (i != applicable.Count) {
1013                                                         for (i = 0; i < applicable.Count; ++i) {
1014                                                                 if (applicable[i].Kind != MemberKind.Operator) {
1015                                                                         continue;
1016                                                                 }
1017
1018                                                                 if (found == null) {
1019                                                                         found = new List<MemberSpec> ();
1020                                                                         found.Add (applicable[i]);
1021                                                                 } else {
1022                                                                         List<MemberSpec> prev;
1023                                                                         if (shared_list) {
1024                                                                                 shared_list = false;
1025                                                                                 prev = new List<MemberSpec> (found.Count + 1);
1026                                                                                 prev.AddRange (found);
1027                                                                                 found = prev;
1028                                                                         } else {
1029                                                                                 prev = (List<MemberSpec>) found;
1030                                                                         }
1031
1032                                                                         prev.Add (applicable[i]);
1033                                                                 }
1034                                                         }
1035                                                 } else {
1036                                                         if (found == null) {
1037                                                                 found = applicable;
1038                                                                 shared_list = true;
1039                                                         } else {
1040                                                                 List<MemberSpec> merged;
1041                                                                 if (shared_list) {
1042                                                                         shared_list = false;
1043                                                                         merged = new List<MemberSpec> (found.Count + applicable.Count);
1044                                                                         merged.AddRange (found);
1045                                                                         found = merged;
1046                                                                 } else {
1047                                                                         merged = (List<MemberSpec>) found;
1048                                                                 }
1049
1050                                                                 merged.AddRange (applicable);
1051                                                         }
1052                                                 }
1053                                         }
1054                                 }
1055
1056                                 // BaseType call can be expensive
1057                                 if (declaredOnly)
1058                                         break;
1059
1060                                 container = container.BaseType;
1061                         } while (container != null);
1062
1063                         return found;
1064                 }
1065
1066                 //
1067                 // Inflates all member cache nested types
1068                 //
1069                 public void InflateTypes (MemberCache inflated_cache, TypeParameterInflator inflator)
1070                 {
1071                         foreach (var item in member_hash) {
1072                                 IList<MemberSpec> inflated_members = null;
1073                                 for (int i = 0; i < item.Value.Count; ++i ) {
1074                                         var member = item.Value[i];
1075
1076                                         // FIXME: When inflating members refering nested types before they are inflated
1077                                         if (member == null)
1078                                                 continue;
1079
1080                                         if ((member.Kind & MemberKind.NestedMask) != 0 &&
1081                                                 (member.Modifiers & Modifiers.COMPILER_GENERATED) == 0) {
1082                                                 if (inflated_members == null) {
1083                                                         inflated_members = new MemberSpec[item.Value.Count];
1084                                                         inflated_cache.member_hash.Add (item.Key, inflated_members);
1085                                                 }
1086
1087                                                 inflated_members [i] = member.InflateMember (inflator);
1088                                         }
1089                                 }
1090                         }
1091                 }
1092
1093                 //
1094                 // Inflates all open type members, requires InflateTypes to be called before
1095                 //
1096                 public void InflateMembers (MemberCache cacheToInflate, TypeSpec inflatedType, TypeParameterInflator inflator)
1097                 {
1098                         var inflated_member_hash = cacheToInflate.member_hash;
1099                         Dictionary<MemberSpec, MethodSpec> accessor_relation = null;
1100                         List<MemberSpec> accessor_members = null;
1101
1102                         // Copy member specific flags when all members were added
1103                         cacheToInflate.state = state;
1104
1105                         foreach (var item in member_hash) {
1106                                 var members = item.Value;
1107                                 IList<MemberSpec> inflated_members = null;
1108                                 for (int i = 0; i < members.Count; ++i ) {
1109                                         var member = members[i];
1110
1111                                         //
1112                                         // All nested types have been inflated earlier except for
1113                                         // compiler types which are created later and could miss InflateTypes
1114                                         //
1115                                         if ((member.Kind & MemberKind.NestedMask) != 0 &&
1116                                                 (member.Modifiers & Modifiers.COMPILER_GENERATED) == 0) {
1117                                                 if (inflated_members == null)
1118                                                         inflated_members = inflated_member_hash[item.Key];
1119
1120                                                 continue;
1121                                         }
1122
1123                                         //
1124                                         // Clone the container first
1125                                         //
1126                                         if (inflated_members == null) {
1127                                                 inflated_members = new MemberSpec [item.Value.Count];
1128                                                 inflated_member_hash.Add (item.Key, inflated_members);
1129                                         }
1130
1131                                         var local_inflator = inflator;
1132
1133                                         if (member.DeclaringType != inflatedType) {
1134                                                 //
1135                                                 // Don't inflate top-level non-generic interface members
1136                                                 // merged into generic interface
1137                                                 //
1138                                                 if (!member.DeclaringType.IsGeneric && !member.DeclaringType.IsNested) {
1139                                                         inflated_members [i] = member;
1140                                                         continue;
1141                                                 }
1142
1143                                                 //
1144                                                 // Needed when inflating flatten interfaces. It inflates
1145                                                 // container type only, type parameters are already done
1146                                                 //
1147                                                 // Handles cases like:
1148                                                 //
1149                                                 // interface I<T> {}
1150                                                 // interface I<U, V> : I<U> {}
1151                                                 // 
1152                                                 // class C: I<int, bool> {}
1153                                                 //
1154                                                 var inflated_parent = inflator.Inflate (member.DeclaringType);
1155                                                 if (inflated_parent != inflator.TypeInstance)
1156                                                         local_inflator = new TypeParameterInflator (inflator, inflated_parent);
1157                                         }
1158
1159                                         //
1160                                         // Inflate every member, its parent is now different
1161                                         //
1162                                         var inflated = member.InflateMember (local_inflator);
1163                                         inflated_members [i] = inflated;
1164
1165                                         if (member is PropertySpec || member is EventSpec) {
1166                                                 if (accessor_members == null)
1167                                                         accessor_members = new List<MemberSpec> ();
1168
1169                                                 accessor_members.Add (inflated);
1170                                                 continue;
1171                                         }
1172
1173                                         if (member.IsAccessor) {
1174                                                 if (accessor_relation == null)
1175                                                         accessor_relation = new Dictionary<MemberSpec, MethodSpec> ();
1176                                                 accessor_relation.Add (member, (MethodSpec) inflated);
1177                                         }
1178                                 }
1179                         }
1180
1181                         if (accessor_members != null) {
1182                                 foreach (var member in accessor_members) {
1183                                         var prop = member as PropertySpec;
1184                                         if (prop != null) {
1185                                                 if (prop.Get != null)
1186                                                         prop.Get = accessor_relation[prop.Get];
1187                                                 if (prop.Set != null)
1188                                                         prop.Set = accessor_relation[prop.Set];
1189
1190                                                 continue;
1191                                         }
1192
1193                                         var ev = (EventSpec) member;
1194                                         ev.AccessorAdd = accessor_relation[ev.AccessorAdd];
1195                                         ev.AccessorRemove = accessor_relation[ev.AccessorRemove];
1196                                 }
1197                         }
1198                 }
1199
1200                 //
1201                 // Removes hidden base members of an interface. For compiled interfaces we cannot
1202                 // do name filtering during Add (as we do for import) because we need all base
1203                 // names to be valid during type definition.
1204                 // Add replaces hidden base member with current one which means any name collision
1205                 // (CS0108) of non-first name would be unnoticed because the name was replaced
1206                 // with the one from compiled type
1207                 //
1208                 public void RemoveHiddenMembers (TypeSpec container)
1209                 {
1210                         foreach (var entry in member_hash) {
1211                                 var values = entry.Value;
1212
1213                                 int container_members_start_at = 0;
1214                                 while (values[container_members_start_at].DeclaringType != container && ++container_members_start_at < entry.Value.Count);
1215
1216                                 if (container_members_start_at == 0 || container_members_start_at == values.Count)
1217                                         continue;
1218
1219                                 for (int i = 0; i < container_members_start_at; ++i) {
1220                                         var member = values[i];
1221
1222                                         if (!container.ImplementsInterface (member.DeclaringType, false))
1223                                                 continue;
1224
1225                                         var member_param = member is IParametersMember ? ((IParametersMember) member).Parameters : ParametersCompiled.EmptyReadOnlyParameters;
1226
1227                                         for (int ii = container_members_start_at; ii < values.Count; ++ii) {
1228                                                 var container_entry = values[ii];
1229
1230                                                 if (container_entry.Arity != member.Arity)
1231                                                         continue;
1232
1233                                                 if (container_entry is IParametersMember) {
1234                                                         if (!TypeSpecComparer.Override.IsEqual (((IParametersMember) container_entry).Parameters, member_param))
1235                                                                 continue;
1236                                                 }
1237
1238                                                 values.RemoveAt (i);
1239                                                 --container_members_start_at;
1240                                                 --ii;
1241                                                 --i;
1242                                         }
1243                                 }
1244                         }
1245                 }
1246
1247                 //
1248                 // Checks all appropriate container members for CLS compliance
1249                 //
1250                 public void VerifyClsCompliance (TypeSpec container, Report report)
1251                 {
1252                         if (locase_members != null)
1253                                 return;
1254
1255                         if (container.BaseType == null) {
1256                                 locase_members = new Dictionary<string, MemberSpec[]> (member_hash.Count); // StringComparer.OrdinalIgnoreCase);
1257                         } else {
1258                                 var btype = container.BaseType.GetDefinition ();
1259                                 btype.MemberCache.VerifyClsCompliance (btype, report);
1260                                 locase_members = new Dictionary<string, MemberSpec[]> (btype.MemberCache.locase_members); //, StringComparer.OrdinalIgnoreCase);
1261                         }
1262
1263                         var is_imported_type = container.MemberDefinition.IsImported;
1264                         foreach (var entry in container.MemberCache.member_hash) {
1265                                 for (int i = 0; i < entry.Value.Count; ++i ) {
1266                                         var name_entry = entry.Value[i];
1267                                         if ((name_entry.Modifiers & (Modifiers.PUBLIC | Modifiers.PROTECTED)) == 0)
1268                                                 continue;
1269
1270                                         if ((name_entry.Modifiers & (Modifiers.OVERRIDE | Modifiers.COMPILER_GENERATED)) != 0)
1271                                                 continue;
1272
1273                                         if ((name_entry.Kind & MemberKind.MaskType) == 0)
1274                                                 continue;
1275
1276                                         if (name_entry.MemberDefinition.CLSAttributeValue == false)
1277                                             continue;
1278
1279                                         IParametersMember p_a = null;
1280                                         if (!is_imported_type) {
1281                                                 p_a = name_entry as IParametersMember;
1282                                                 if (p_a != null && !name_entry.IsAccessor) {
1283                                                         var p_a_pd = p_a.Parameters;
1284                                                         //
1285                                                         // Check differing overloads in @container
1286                                                         //
1287                                                         for (int ii = i + 1; ii < entry.Value.Count; ++ii) {
1288                                                                 var checked_entry = entry.Value[ii];
1289                                                                 IParametersMember p_b = checked_entry as IParametersMember;
1290                                                                 if (p_b == null)
1291                                                                         continue;
1292
1293                                                                 if (p_a_pd.Count != p_b.Parameters.Count)
1294                                                                         continue;
1295
1296                                                                 if (checked_entry.IsAccessor)
1297                                                                         continue;
1298
1299                                                                 var res = ParametersCompiled.IsSameClsSignature (p_a.Parameters, p_b.Parameters);
1300                                                                 if (res != 0) {
1301                                                                         ReportOverloadedMethodClsDifference (name_entry, checked_entry, res, report);
1302                                                                 }
1303                                                         }
1304                                                 }
1305                                         }
1306
1307                                         if (i > 0 || name_entry.Kind == MemberKind.Constructor || name_entry.Kind == MemberKind.Indexer)
1308                                                 continue;
1309
1310                                         var name_entry_locase = name_entry.Name.ToLowerInvariant ();
1311
1312                                         MemberSpec[] found;
1313                                         if (!locase_members.TryGetValue (name_entry_locase, out found)) {
1314                                                 found = new MemberSpec[] { name_entry };
1315                                                 locase_members.Add (name_entry_locase, found);
1316                                         } else {
1317                                                 bool same_names_only = true;
1318                                                 foreach (var f in found) {
1319                                                         if (f.Name == name_entry.Name) {
1320                                                                 if (p_a != null) {
1321                                                                         IParametersMember p_b = f as IParametersMember;
1322                                                                         if (p_b == null)
1323                                                                                 continue;
1324
1325                                                                         if (p_a.Parameters.Count != p_b.Parameters.Count)
1326                                                                                 continue;
1327
1328                                                                         if (f.IsAccessor)
1329                                                                                 continue;
1330
1331                                                                         var res = ParametersCompiled.IsSameClsSignature (p_a.Parameters, p_b.Parameters);
1332                                                                         if (res != 0) {
1333                                                                                 ReportOverloadedMethodClsDifference (f, name_entry, res, report);
1334                                                                         }
1335                                                                 }
1336
1337                                                                 continue;
1338                                                         }
1339
1340                                                         same_names_only = false;
1341                                                         if (!is_imported_type) {
1342                                                                 var last = GetLaterDefinedMember (f, name_entry);
1343                                                                 if (last == f.MemberDefinition) {
1344                                                                         report.SymbolRelatedToPreviousError (name_entry);
1345                                                                 } else {
1346                                                                         report.SymbolRelatedToPreviousError (f);
1347                                                                 }
1348
1349                                                                 report.Warning (3005, 1, last.Location,
1350                                                                         "Identifier `{0}' differing only in case is not CLS-compliant", last.GetSignatureForError ());
1351                                                         }
1352                                                 }
1353
1354                                                 if (!same_names_only) {
1355                                                         Array.Resize (ref found, found.Length + 1);
1356                                                         found[found.Length - 1] = name_entry;
1357                                                         locase_members[name_entry_locase] = found;
1358                                                 }
1359                                         }
1360                                 }
1361                         }
1362                 }
1363
1364                 //
1365                 // Local report helper to issue correctly ordered members stored in hashtable
1366                 //
1367                 static MemberCore GetLaterDefinedMember (MemberSpec a, MemberSpec b)
1368                 {
1369                         var mc_a = a.MemberDefinition as MemberCore;
1370                         var mc_b = b.MemberDefinition as MemberCore;
1371                         if (mc_a == null)
1372                                 return mc_b;
1373
1374                         if (mc_b == null)
1375                                 return mc_a;
1376
1377                         if (a.DeclaringType.MemberDefinition != b.DeclaringType.MemberDefinition)
1378                                 return mc_b;
1379
1380                         if (mc_a.Location.File != mc_b.Location.File)
1381                                 return mc_b;
1382
1383                         return mc_b.Location.Row > mc_a.Location.Row ? mc_b : mc_a;
1384                 }
1385
1386                 static void ReportOverloadedMethodClsDifference (MemberSpec a, MemberSpec b, int res, Report report)
1387                 {
1388                         var last = GetLaterDefinedMember (a, b);
1389                         if (last == a.MemberDefinition) {
1390                                 report.SymbolRelatedToPreviousError (b);
1391                         } else {
1392                                 report.SymbolRelatedToPreviousError (a);
1393                         }
1394
1395                         if ((res & 1) != 0) {
1396                                 report.Warning (3006, 1, last.Location,
1397                                                 "Overloaded method `{0}' differing only in ref or out, or in array rank, is not CLS-compliant",
1398                                                 last.GetSignatureForError ());
1399                         }
1400
1401                         if ((res & 2) != 0) {
1402                                 report.Warning (3007, 1, last.Location,
1403                                         "Overloaded method `{0}' differing only by unnamed array types is not CLS-compliant",
1404                                         last.GetSignatureForError ());
1405                         }
1406                 }
1407
1408                 public bool CheckExistingMembersOverloads (MemberCore member, AParametersCollection parameters)
1409                 {
1410                         var name = GetLookupName (member);
1411                         var imb = member as InterfaceMemberBase;
1412                         if (imb != null && imb.IsExplicitImpl) {
1413                                 name = imb.GetFullName (name);
1414                         }
1415
1416                         return CheckExistingMembersOverloads (member, name, parameters);
1417                 }
1418
1419                 public bool CheckExistingMembersOverloads (MemberCore member, string name, AParametersCollection parameters)
1420                 {
1421                         IList<MemberSpec> entries;
1422                         if (!member_hash.TryGetValue (name, out entries))
1423                                 return false;
1424
1425                         var Report = member.Compiler.Report;
1426
1427                         int method_param_count = parameters.Count;
1428                         for (int i = entries.Count - 1; i >= 0; --i) {
1429                                 var ce = entries[i];
1430                                 var pm = ce as IParametersMember;
1431                                 var pd = pm == null ? ParametersCompiled.EmptyReadOnlyParameters : pm.Parameters;
1432                                 if (pd.Count != method_param_count)
1433                                         continue;
1434
1435                                 if (ce.Arity != member.MemberName.Arity)
1436                                         continue;
1437
1438                                 // Ignore merged interface members
1439                                 if (member.Parent.PartialContainer != ce.DeclaringType.MemberDefinition)
1440                                         continue;
1441
1442                                 var p_types = pd.Types;
1443                                 if (method_param_count > 0) {
1444                                         int ii = method_param_count - 1;
1445                                         TypeSpec type_a, type_b;
1446                                         do {
1447                                                 type_a = parameters.Types [ii];
1448                                                 type_b = p_types [ii];
1449
1450                                                 var a_byref = (pd.FixedParameters[ii].ModFlags & Parameter.Modifier.RefOutMask) != 0;
1451                                                 var b_byref = (parameters.FixedParameters[ii].ModFlags & Parameter.Modifier.RefOutMask) != 0;
1452
1453                                                 if (a_byref != b_byref)
1454                                                         break;
1455
1456                                         } while (TypeSpecComparer.Override.IsEqual (type_a, type_b) && ii-- != 0);
1457
1458                                         if (ii >= 0)
1459                                                 continue;
1460
1461                                         //
1462                                         // Operators can differ in return type only
1463                                         //
1464                                         if (member is Operator && ce.Kind == MemberKind.Operator && ((MethodSpec) ce).ReturnType != ((Operator) member).ReturnType)
1465                                                 continue;
1466
1467                                         //
1468                                         // Report difference in parameter modifiers only
1469                                         //
1470                                         if (pd != null && member is MethodCore) {
1471                                                 ii = method_param_count;
1472                                                 while (ii-- != 0 &&
1473                                                         (parameters.FixedParameters[ii].ModFlags & Parameter.Modifier.ModifierMask) ==
1474                                                         (pd.FixedParameters[ii].ModFlags & Parameter.Modifier.ModifierMask) &&
1475                                                         parameters.ExtensionMethodType == pd.ExtensionMethodType) ;
1476
1477                                                 if (ii >= 0) {
1478                                                         var mc = ce as MethodSpec;
1479                                                         member.Compiler.Report.SymbolRelatedToPreviousError (ce);
1480                                                         if ((member.ModFlags & Modifiers.PARTIAL) != 0 && (mc.Modifiers & Modifiers.PARTIAL) != 0) {
1481                                                                 if (parameters.HasParams || pd.HasParams) {
1482                                                                         Report.Error (758, member.Location,
1483                                                                                 "A partial method declaration and partial method implementation cannot differ on use of `params' modifier");
1484                                                                 } else {
1485                                                                         Report.Error (755, member.Location,
1486                                                                                 "A partial method declaration and partial method implementation must be both an extension method or neither");
1487                                                                 }
1488                                                         } else if (member is Constructor) {
1489                                                                 Report.Error (851, member.Location,
1490                                                                         "Overloaded contructor `{0}' cannot differ on use of parameter modifiers only",
1491                                                                         member.GetSignatureForError ());
1492                                                         } else {
1493                                                                 Report.Error (663, member.Location,
1494                                                                         "Overloaded method `{0}' cannot differ on use of parameter modifiers only",
1495                                                                         member.GetSignatureForError ());
1496                                                         }
1497                                                         return false;
1498                                                 }
1499                                         }
1500                                 }
1501
1502                                 if ((ce.Kind & MemberKind.Method) != 0) {
1503                                         Method method_a = member as Method;
1504                                         Method method_b = ce.MemberDefinition as Method;
1505                                         if (method_a != null && method_b != null && (method_a.ModFlags & method_b.ModFlags & Modifiers.PARTIAL) != 0) {
1506                                                 const Modifiers partial_modifiers = Modifiers.STATIC | Modifiers.UNSAFE;
1507                                                 if (method_a.IsPartialDefinition == method_b.IsPartialImplementation) {
1508                                                         if ((method_a.ModFlags & partial_modifiers) == (method_b.ModFlags & partial_modifiers) ||
1509                                                                 method_a.Parent.IsUnsafe && method_b.Parent.IsUnsafe) {
1510                                                                 if (method_a.IsPartialImplementation) {
1511                                                                         method_a.SetPartialDefinition (method_b);
1512                                                                         if (entries.Count == 1)
1513                                                                                 member_hash.Remove (name);
1514                                                                         else
1515                                                                                 entries.RemoveAt (i);
1516                                                                 } else {
1517                                                                         method_b.SetPartialDefinition (method_a);
1518                                                                         method_a.caching_flags |= MemberCore.Flags.PartialDefinitionExists;
1519                                                                 }
1520                                                                 continue;
1521                                                         }
1522
1523                                                         if (method_a.IsStatic != method_b.IsStatic) {
1524                                                                 Report.SymbolRelatedToPreviousError (ce);
1525                                                                 Report.Error (763, member.Location,
1526                                                                         "A partial method declaration and partial method implementation must be both `static' or neither");
1527                                                         }
1528
1529                                                         if ((method_a.ModFlags & Modifiers.UNSAFE) != (method_b.ModFlags & Modifiers.UNSAFE)) {
1530                                                                 Report.SymbolRelatedToPreviousError (ce);
1531                                                                 Report.Error (764, member.Location,
1532                                                                         "A partial method declaration and partial method implementation must be both `unsafe' or neither");
1533                                                         }
1534
1535                                                         return false;
1536                                                 }
1537
1538                                                 Report.SymbolRelatedToPreviousError (ce);
1539                                                 if (method_a.IsPartialDefinition) {
1540                                                         Report.Error (756, member.Location, "A partial method `{0}' declaration is already defined",
1541                                                                 member.GetSignatureForError ());
1542                                                 }
1543
1544                                                 Report.Error (757, member.Location, "A partial method `{0}' implementation is already defined",
1545                                                         member.GetSignatureForError ());
1546                                                 return false;
1547                                         }
1548
1549                                         Report.SymbolRelatedToPreviousError (ce);
1550
1551                                         bool is_reserved_a = member is AbstractPropertyEventMethod || member is Operator;
1552                                         bool is_reserved_b = ((MethodSpec) ce).IsReservedMethod;
1553
1554                                         if (is_reserved_a || is_reserved_b) {
1555                                                 Report.Error (82, member.Location, "A member `{0}' is already reserved",
1556                                                         is_reserved_a ?
1557                                                         ce.GetSignatureForError () :
1558                                                         member.GetSignatureForError ());
1559                                                 return false;
1560                                         }
1561                                 } else {
1562                                         Report.SymbolRelatedToPreviousError (ce);
1563                                 }
1564
1565                                 if (member is Operator && ce.Kind == MemberKind.Operator) {
1566                                         Report.Error (557, member.Location, "Duplicate user-defined conversion in type `{0}'",
1567                                                 member.Parent.GetSignatureForError ());
1568                                         return false;
1569                                 }
1570
1571                                 Report.Error (111, member.Location,
1572                                         "A member `{0}' is already defined. Rename this member or use different parameter types",
1573                                         member.GetSignatureForError ());
1574                                 return false;
1575                         }
1576
1577                         return true;
1578                 }
1579         }
1580 }