refresh after mcs update
[mono.git] / mcs / mcs / decl.cs
1 //
2 // decl.cs: Declaration base class for structs, classes, enums and interfaces.
3 //
4 // Author: Miguel de Icaza (miguel@gnu.org)
5 //         Marek Safar (marek.safar@seznam.cz)
6 //
7 // Licensed under the terms of the GNU GPL
8 //
9 // (C) 2001 Ximian, Inc (http://www.ximian.com)
10 // (C) 2004 Novell, Inc
11 //
12 // TODO: Move the method verification stuff from the class.cs and interface.cs here
13 //
14
15 using System;
16 using System.Collections;
17 using System.Globalization;
18 using System.Reflection.Emit;
19 using System.Reflection;
20
21 #if BOOTSTRAP_WITH_OLDLIB
22 using XmlElement = System.Object;
23 #else
24 using System.Xml;
25 #endif
26
27 namespace Mono.CSharp {
28
29         public class MemberName {
30                 public readonly string Name;
31                 public readonly MemberName Left;
32
33                 public static readonly MemberName Null = new MemberName ("");
34
35                 public MemberName (string name)
36                 {
37                         this.Name = name;
38                 }
39
40                 public MemberName (MemberName left, string name)
41                         : this (name)
42                 {
43                         this.Left = left;
44                 }
45
46                 public MemberName (MemberName left, MemberName right)
47                 {
48                         Name = right.Name;
49                         Left = (right.Left == null) ? left : new MemberName (left, right.Left);
50                 }
51
52                 static readonly char [] dot_array = { '.' };
53
54                 public static MemberName FromDotted (string name)
55                 {
56                         string [] elements = name.Split (dot_array);
57                         int count = elements.Length;
58                         int i = 0;
59                         MemberName n = new MemberName (elements [i++]);
60                         while (i < count)
61                                 n = new MemberName (n, elements [i++]);
62                         return n;
63                 }
64
65                 public string GetName ()
66                 {
67                         return GetName (false);
68                 }
69
70                 public string GetName (bool is_generic)
71                 {
72                         string name = is_generic ? Basename : Name;
73                         if (Left != null)
74                                 return Left.GetName (is_generic) + "." + name;
75                         else
76                                 return name;
77                 }
78
79                 ///
80                 /// This returns exclusively the name as seen on the source code
81                 /// it is not the fully qualifed type after resolution
82                 ///
83                 public string GetPartialName ()
84                 {
85                         if (Left != null)
86                                 return Left.GetPartialName () + "." + Name;
87                         else
88                                 return Name;
89                 }
90
91                 public string GetTypeName ()
92                 {
93                         if (Left != null)
94                                 return Left.GetTypeName () + "." + Name;
95                         else
96                                 return Name;
97                 }
98
99                 public Expression GetTypeExpression (Location loc)
100                 {
101                         if (Left != null) {
102                                 Expression lexpr = Left.GetTypeExpression (loc);
103
104                                 return new MemberAccess (lexpr, Name, loc);
105                         } else {
106                                 return new SimpleName (Name, loc);
107                         }
108                 }
109
110                 public MemberName Clone ()
111                 {
112                         if (Left != null)
113                                 return new MemberName (Left.Clone (), Name);
114                         else
115                                 return new MemberName (Name);
116                 }
117
118                 public string Basename {
119                         get {
120                                 return Name;
121                         }
122                 }
123
124                 public override string ToString ()
125                 {
126                         if (Left != null)
127                                 return Left + "." + Name;
128                         else
129                                 return Name;
130                 }
131
132                 public override bool Equals (object other)
133                 {
134                         return Equals (other as MemberName);
135                 }
136
137                 public bool Equals (MemberName other)
138                 {
139                         if (this == other)
140                                 return true;
141                         if (other == null || Name != other.Name)
142                                 return false;
143 #if NET_2_0
144                         if (TypeArguments == null)
145                                 return other.TypeArguments == null;
146
147                         if (other.TypeArguments == null || TypeArguments.Count != other.TypeArguments.Count)
148                                 return false;
149 #endif
150                         if (Left == null)
151                                 return other.Left == null;
152
153                         return Left.Equals (other.Left);
154                 }
155
156                 public override int GetHashCode ()
157                 {
158                         int hash = Name.GetHashCode ();
159                         for (MemberName n = Left; n != null; n = n.Left)
160                                 hash ^= n.Name.GetHashCode ();
161
162 #if NET_2_0
163                         if (TypeArguments != null)
164                                 hash ^= TypeArguments.Count << 5;
165 #endif
166
167                         return hash & 0x7FFFFFFF;
168                 }
169         }
170
171         /// <summary>
172         ///   Base representation for members.  This is used to keep track
173         ///   of Name, Location and Modifier flags, and handling Attributes.
174         /// </summary>
175         public abstract class MemberCore : Attributable {
176                 /// <summary>
177                 ///   Public name
178                 /// </summary>
179
180                 protected string cached_name;
181                 public string Name {
182                         get {
183                                 if (cached_name == null)
184                                         cached_name = MemberName.GetName (false);
185                                 return cached_name;
186                         }
187                 }
188
189                 // Is not readonly because of IndexerName attribute
190                 private MemberName member_name;
191                 public MemberName MemberName {
192                         get { return member_name; }
193                 }
194
195                 /// <summary>
196                 ///   Modifier flags that the user specified in the source code
197                 /// </summary>
198                 public int ModFlags;
199
200                 public /*readonly*/ TypeContainer Parent;
201
202                 /// <summary>
203                 ///   Location where this declaration happens
204                 /// </summary>
205                 public readonly Location Location;
206
207                 /// <summary>
208                 ///   XML documentation comment
209                 /// </summary>
210                 public string DocComment;
211
212                 /// <summary>
213                 ///   Represents header string for documentation comment 
214                 ///   for each member types.
215                 /// </summary>
216                 public abstract string DocCommentHeader { get; }
217
218                 [Flags]
219                 public enum Flags {
220                         Obsolete_Undetected = 1,                // Obsolete attribute has not been detected yet
221                         Obsolete = 1 << 1,                      // Type has obsolete attribute
222                         ClsCompliance_Undetected = 1 << 2,      // CLS Compliance has not been detected yet
223                         ClsCompliant = 1 << 3,                  // Type is CLS Compliant
224                         CloseTypeCreated = 1 << 4,              // Tracks whether we have Closed the type
225                         HasCompliantAttribute_Undetected = 1 << 5,      // Presence of CLSCompliantAttribute has not been detected
226                         HasClsCompliantAttribute = 1 << 6,                      // Type has CLSCompliantAttribute
227                         ClsCompliantAttributeTrue = 1 << 7,                     // Type has CLSCompliant (true)
228                         Excluded_Undetected = 1 << 8,           // Conditional attribute has not been detected yet
229                         Excluded = 1 << 9,                                      // Method is conditional
230                         TestMethodDuplication = 1 << 10,                // Test for duplication must be performed
231                         IsUsed = 1 << 11
232                 }
233
234                 /// <summary>
235                 ///   MemberCore flags at first detected then cached
236                 /// </summary>
237                 internal Flags caching_flags;
238
239                 public MemberCore (TypeContainer parent, MemberName name, Attributes attrs,
240                                    Location loc)
241                         : base (attrs)
242                 {
243                         if (parent is PartialContainer && !(this is PartialContainer))
244                                 throw new InternalErrorException ("A PartialContainer cannot be the direct parent of a member");
245
246                         Parent = parent;
247                         member_name = name;
248                         Location = loc;
249                         caching_flags = Flags.Obsolete_Undetected | Flags.ClsCompliance_Undetected | Flags.HasCompliantAttribute_Undetected | Flags.Excluded_Undetected;
250                 }
251
252                 protected virtual void SetMemberName (MemberName new_name)
253                 {
254                         member_name = new_name;
255                         cached_name = null;
256                 }
257
258                 /// <summary>
259                 /// Tests presence of ObsoleteAttribute and report proper error
260                 /// </summary>
261                 protected void CheckUsageOfObsoleteAttribute (Type type)
262                 {
263                         if (type == null)
264                                 return;
265
266                         ObsoleteAttribute obsolete_attr = AttributeTester.GetObsoleteAttribute (type);
267                         if (obsolete_attr == null)
268                                 return;
269
270                         AttributeTester.Report_ObsoleteMessage (obsolete_attr, type.FullName, Location);
271                 }
272
273                 public abstract bool Define ();
274
275                 // 
276                 // Returns full member name for error message
277                 //
278                 public virtual string GetSignatureForError ()
279                 {
280                         return Name;
281                 }
282
283                 /// <summary>
284                 /// Use this method when MethodBuilder is null
285                 /// </summary>
286                 public virtual string GetSignatureForError (TypeContainer tc)
287                 {
288                         return Name;
289                 }
290
291                 /// <summary>
292                 /// Base Emit method. This is also entry point for CLS-Compliant verification.
293                 /// </summary>
294                 public virtual void Emit ()
295                 {
296                         // Hack with Parent == null is for EnumMember
297                         if (Parent == null || (GetObsoleteAttribute (Parent) == null && Parent.GetObsoleteAttribute (Parent) == null))
298                                 VerifyObsoleteAttribute ();
299
300                         if (!RootContext.VerifyClsCompliance)
301                                 return;
302
303                         VerifyClsCompliance (Parent);
304                 }
305
306                 public bool InUnsafe {
307                         get {
308                                 return ((ModFlags & Modifiers.UNSAFE) != 0) || Parent.UnsafeContext;
309                         }
310                 }
311
312                 public virtual bool IsUsed {
313                         get {
314                                 return (caching_flags & Flags.IsUsed) != 0;
315                         }
316                 }
317
318                 public void SetMemberIsUsed ()
319                 {
320                         caching_flags |= Flags.IsUsed;
321                 }
322
323                 // 
324                 // Whehter is it ok to use an unsafe pointer in this type container
325                 //
326                 public bool UnsafeOK (DeclSpace parent)
327                 {
328                         //
329                         // First check if this MemberCore modifier flags has unsafe set
330                         //
331                         if ((ModFlags & Modifiers.UNSAFE) != 0)
332                                 return true;
333
334                         if (parent.UnsafeContext)
335                                 return true;
336
337                         Expression.UnsafeError (Location);
338                         return false;
339                 }
340
341                 /// <summary>
342                 /// Returns instance of ObsoleteAttribute for this MemberCore
343                 /// </summary>
344                 public ObsoleteAttribute GetObsoleteAttribute (DeclSpace ds)
345                 {
346                         // ((flags & (Flags.Obsolete_Undetected | Flags.Obsolete)) == 0) is slower, but why ?
347                         if ((caching_flags & Flags.Obsolete_Undetected) == 0 && (caching_flags & Flags.Obsolete) == 0) {
348                                 return null;
349                         }
350
351                         caching_flags &= ~Flags.Obsolete_Undetected;
352
353                         if (OptAttributes == null)
354                                 return null;
355
356                         Attribute obsolete_attr = OptAttributes.Search (
357                                 TypeManager.obsolete_attribute_type, ds.EmitContext);
358                         if (obsolete_attr == null)
359                                 return null;
360
361                         ObsoleteAttribute obsolete = obsolete_attr.GetObsoleteAttribute (ds.EmitContext);
362                         if (obsolete == null)
363                                 return null;
364
365                         caching_flags |= Flags.Obsolete;
366                         return obsolete;
367                 }
368
369                 /// <summary>
370                 /// Analyze whether CLS-Compliant verification must be execute for this MemberCore.
371                 /// </summary>
372                 public override bool IsClsCompliaceRequired (DeclSpace container)
373                 {
374                         if ((caching_flags & Flags.ClsCompliance_Undetected) == 0)
375                                 return (caching_flags & Flags.ClsCompliant) != 0;
376
377                         if (GetClsCompliantAttributeValue (container) && IsExposedFromAssembly (container)) {
378                                 caching_flags &= ~Flags.ClsCompliance_Undetected;
379                                 caching_flags |= Flags.ClsCompliant;
380                                 return true;
381                         }
382
383                         caching_flags &= ~Flags.ClsCompliance_Undetected;
384                         return false;
385                 }
386
387                 /// <summary>
388                 /// Returns true when MemberCore is exposed from assembly.
389                 /// </summary>
390                 public bool IsExposedFromAssembly (DeclSpace ds)
391                 {
392                         if ((ModFlags & (Modifiers.PUBLIC | Modifiers.PROTECTED)) == 0)
393                                 return false;
394                         
395                         DeclSpace parentContainer = ds;
396                         while (parentContainer != null && parentContainer.ModFlags != 0) {
397                                 if ((parentContainer.ModFlags & (Modifiers.PUBLIC | Modifiers.PROTECTED)) == 0)
398                                         return false;
399                                 parentContainer = parentContainer.Parent;
400                         }
401                         return true;
402                 }
403
404                 /// <summary>
405                 /// Resolve CLSCompliantAttribute value or gets cached value.
406                 /// </summary>
407                 bool GetClsCompliantAttributeValue (DeclSpace ds)
408                 {
409                         if (OptAttributes != null) {
410                                 Attribute cls_attribute = OptAttributes.Search (
411                                         TypeManager.cls_compliant_attribute_type, ds.EmitContext);
412                                 if (cls_attribute != null) {
413                                         caching_flags |= Flags.HasClsCompliantAttribute;
414                                         return cls_attribute.GetClsCompliantAttributeValue (ds.EmitContext);
415                                 }
416                         }
417                         return ds.GetClsCompliantAttributeValue ();
418                 }
419
420                 /// <summary>
421                 /// Returns true if MemberCore is explicitly marked with CLSCompliantAttribute
422                 /// </summary>
423                 protected bool HasClsCompliantAttribute {
424                         get {
425                                 return (caching_flags & Flags.HasClsCompliantAttribute) != 0;
426                         }
427                 }
428
429                 /// <summary>
430                 /// It helps to handle error 102 & 111 detection
431                 /// </summary>
432                 public virtual bool MarkForDuplicationCheck ()
433                 {
434                         return false;
435                 }
436
437                 /// <summary>
438                 /// The main virtual method for CLS-Compliant verifications.
439                 /// The method returns true if member is CLS-Compliant and false if member is not
440                 /// CLS-Compliant which means that CLS-Compliant tests are not necessary. A descendants override it
441                 /// and add their extra verifications.
442                 /// </summary>
443                 protected virtual bool VerifyClsCompliance (DeclSpace ds)
444                 {
445                         if (!IsClsCompliaceRequired (ds)) {
446                                 if (HasClsCompliantAttribute && RootContext.WarningLevel >= 2) {
447                                         if (!IsExposedFromAssembly (ds))
448                                                 Report.Warning (3019, Location, "CLS compliance checking will not be performed on '{0}' because it is private or internal", GetSignatureForError ());
449                                         if (!CodeGen.Assembly.IsClsCompliant)
450                                                 Report.Warning (3021, Location, "'{0}' does not need a CLSCompliant attribute because the assembly does not have a CLSCompliant attribute", GetSignatureForError ());
451                                 }
452                                 return false;
453                         }
454
455                         if (!CodeGen.Assembly.IsClsCompliant) {
456                                 if (HasClsCompliantAttribute) {
457                                         Report.Error (3014, Location, "'{0}' cannot be marked as CLS-compliant because the assembly does not have a CLSCompliant attribute", GetSignatureForError ());
458                                 }
459                                 return false;
460                         }
461
462                         int index = Name.LastIndexOf ('.');
463                         if (Name [index > 0 ? index + 1 : 0] == '_') {
464                                 Report.Error (3008, Location, "Identifier '{0}' is not CLS-compliant", GetSignatureForError () );
465                         }
466                         return true;
467                 }
468
469                 protected abstract void VerifyObsoleteAttribute ();
470
471                 //
472                 // Raised (and passed an XmlElement that contains the comment)
473                 // when GenerateDocComment is writing documentation expectedly.
474                 //
475                 internal virtual void OnGenerateDocComment (DeclSpace ds, XmlElement intermediateNode)
476                 {
477                 }
478
479                 //
480                 // Returns a string that represents the signature for this 
481                 // member which should be used in XML documentation.
482                 //
483                 public virtual string GetDocCommentName (DeclSpace ds)
484                 {
485                         if (ds == null || this is DeclSpace)
486                                 return DocCommentHeader + Name;
487                         else
488                                 return String.Concat (DocCommentHeader, ds.Name, ".", Name);
489                 }
490
491                 //
492                 // Generates xml doc comments (if any), and if required,
493                 // handle warning report.
494                 //
495                 internal virtual void GenerateDocComment (DeclSpace ds)
496                 {
497                         DocUtil.GenerateDocComment (this, ds);
498                 }
499         }
500
501         /// <summary>
502         ///   Base class for structs, classes, enumerations and interfaces.  
503         /// </summary>
504         /// <remarks>
505         ///   They all create new declaration spaces.  This
506         ///   provides the common foundation for managing those name
507         ///   spaces.
508         /// </remarks>
509         public abstract class DeclSpace : MemberCore, IAlias {
510                 /// <summary>
511                 ///   This points to the actual definition that is being
512                 ///   created with System.Reflection.Emit
513                 /// </summary>
514                 public TypeBuilder TypeBuilder;
515
516                 //
517                 // This is the namespace in which this typecontainer
518                 // was declared.  We use this to resolve names.
519                 //
520                 public NamespaceEntry NamespaceEntry;
521
522                 private Hashtable Cache = new Hashtable ();
523                 
524                 public string Basename;
525                 
526                 protected Hashtable defined_names;
527
528                 // The emit context for toplevel objects.
529                 protected EmitContext ec;
530                 
531                 public EmitContext EmitContext {
532                         get { return ec; }
533                 }
534
535                 static string[] attribute_targets = new string [] { "type" };
536
537                 public DeclSpace (NamespaceEntry ns, TypeContainer parent, MemberName name,
538                                   Attributes attrs, Location l)
539                         : base (parent, name, attrs, l)
540                 {
541                         NamespaceEntry = ns;
542                         Basename = name.Name;
543                         defined_names = new Hashtable ();
544                 }
545
546                 /// <summary>
547                 /// Adds the member to defined_names table. It tests for duplications and enclosing name conflicts
548                 /// </summary>
549                 protected bool AddToContainer (MemberCore symbol, string name)
550                 {
551                         if (name == Basename && !(this is Interface) && !(this is Enum)) {
552                                 Report.SymbolRelatedToPreviousError (this);
553                                 Report.Error (542,  symbol.Location, "'{0}': member names cannot be the same as their enclosing type", symbol.GetSignatureForError ());
554                                 return false;
555                         }
556
557                         MemberCore mc = (MemberCore) defined_names [name];
558
559                         if (mc == null) {
560                                 defined_names.Add (name, symbol);
561                                 return true;
562                         }
563
564                         if (symbol.MarkForDuplicationCheck () && mc.MarkForDuplicationCheck ())
565                                 return true;
566
567                         Report.SymbolRelatedToPreviousError (mc);
568                         Report.Error (102, symbol.Location, "The type '{0}' already contains a definition for '{1}'", GetSignatureForError (), name);
569                         return false;
570                 }
571
572                 public void RecordDecl ()
573                 {
574                         if ((NamespaceEntry != null) && (Parent == RootContext.Tree.Types))
575                                 NamespaceEntry.DefineName (MemberName.Basename, this);
576                 }
577
578                 /// <summary>
579                 ///   Returns the MemberCore associated with a given name in the declaration
580                 ///   space. It doesn't return method based symbols !!
581                 /// </summary>
582                 /// 
583                 public MemberCore GetDefinition (string name)
584                 {
585                         return (MemberCore)defined_names [name];
586                 }
587                 
588                 // 
589                 // root_types contains all the types.  All TopLevel types
590                 // hence have a parent that points to `root_types', that is
591                 // why there is a non-obvious test down here.
592                 //
593                 public bool IsTopLevel {
594                         get {
595                                 if (Parent != null){
596                                         if (Parent.Parent == null)
597                                                 return true;
598                                 }
599                                 return false;
600                         }
601                 }
602
603                 public virtual void CloseType ()
604                 {
605                         if ((caching_flags & Flags.CloseTypeCreated) == 0){
606                                 try {
607                                         TypeBuilder.CreateType ();
608                                 } catch {
609                                         //
610                                         // The try/catch is needed because
611                                         // nested enumerations fail to load when they
612                                         // are defined.
613                                         //
614                                         // Even if this is the right order (enumerations
615                                         // declared after types).
616                                         //
617                                         // Note that this still creates the type and
618                                         // it is possible to save it
619                                 }
620                                 caching_flags |= Flags.CloseTypeCreated;
621                         }
622                 }
623
624                 /// <remarks>
625                 ///  Should be overriten by the appropriate declaration space
626                 /// </remarks>
627                 public abstract TypeBuilder DefineType ();
628                 
629                 /// <summary>
630                 ///   Define all members, but don't apply any attributes or do anything which may
631                 ///   access not-yet-defined classes.  This method also creates the MemberCache.
632                 /// </summary>
633                 public abstract bool DefineMembers (TypeContainer parent);
634
635                 //
636                 // Whether this is an `unsafe context'
637                 //
638                 public bool UnsafeContext {
639                         get {
640                                 if ((ModFlags & Modifiers.UNSAFE) != 0)
641                                         return true;
642                                 if (Parent != null)
643                                         return Parent.UnsafeContext;
644                                 return false;
645                         }
646                 }
647
648                 EmitContext type_resolve_ec;
649                 protected EmitContext TypeResolveEmitContext {
650                         get {
651                                 if (type_resolve_ec == null) {
652                                         // FIXME: I think this should really be one of:
653                                         //
654                                         // a. type_resolve_ec = Parent.EmitContext;
655                                         // b. type_resolve_ec = new EmitContext (Parent, Parent, loc, null, null, ModFlags, false);
656                                         //
657                                         // However, if Parent == RootContext.Tree.Types, its NamespaceEntry will be null.
658                                         //
659                                         type_resolve_ec = new EmitContext (Parent, this, Location.Null, null, null, ModFlags, false);
660                                 }
661                                 return type_resolve_ec;
662                         }
663                 }
664
665                 // <summary>
666                 //    Resolves the expression `e' for a type, and will recursively define
667                 //    types.  This should only be used for resolving base types.
668                 // </summary>
669                 public TypeExpr ResolveBaseTypeExpr (Expression e, bool silent, Location loc)
670                 {
671                         TypeResolveEmitContext.loc = loc;
672                         TypeResolveEmitContext.ContainerType = TypeBuilder;
673
674                         return e.ResolveAsTypeTerminal (TypeResolveEmitContext, silent);
675                 }
676                 
677                 public bool CheckAccessLevel (Type check_type)
678                 {
679                         if (check_type == TypeBuilder)
680                                 return true;
681                         
682                         TypeAttributes check_attr = check_type.Attributes & TypeAttributes.VisibilityMask;
683
684                         //
685                         // Broken Microsoft runtime, return public for arrays, no matter what 
686                         // the accessibility is for their underlying class, and they return 
687                         // NonPublic visibility for pointers
688                         //
689                         if (check_type.IsArray || check_type.IsPointer)
690                                 return CheckAccessLevel (TypeManager.GetElementType (check_type));
691
692                         if (TypeBuilder == null)
693                                 // FIXME: TypeBuilder will be null when invoked by Class.GetNormalBases().
694                                 //        However, this is invoked again later -- so safe to return true.
695                                 //        May also be null when resolving top-level attributes.
696                                 return true;
697
698                         switch (check_attr){
699                         case TypeAttributes.Public:
700                                 return true;
701
702                         case TypeAttributes.NotPublic:
703                                 //
704                                 // This test should probably use the declaringtype.
705                                 //
706                                 return check_type.Assembly == TypeBuilder.Assembly;
707                                 
708                         case TypeAttributes.NestedPublic:
709                                 return true;
710
711                         case TypeAttributes.NestedPrivate:
712                                 return NestedAccessible (check_type);
713
714                         case TypeAttributes.NestedFamily:
715                                 return FamilyAccessible (check_type);
716
717                         case TypeAttributes.NestedFamANDAssem:
718                                 return (check_type.Assembly == TypeBuilder.Assembly) &&
719                                         FamilyAccessible (check_type);
720
721                         case TypeAttributes.NestedFamORAssem:
722                                 return (check_type.Assembly == TypeBuilder.Assembly) ||
723                                         FamilyAccessible (check_type);
724
725                         case TypeAttributes.NestedAssembly:
726                                 return check_type.Assembly == TypeBuilder.Assembly;
727                         }
728
729                         Console.WriteLine ("HERE: " + check_attr);
730                         return false;
731
732                 }
733
734                 protected bool NestedAccessible (Type check_type)
735                 {
736                         Type declaring = check_type.DeclaringType;
737                         return TypeBuilder == declaring ||
738                                 TypeManager.IsNestedChildOf (TypeBuilder, declaring);
739                 }
740
741                 protected bool FamilyAccessible (Type check_type)
742                 {
743                         Type declaring = check_type.DeclaringType;
744                         if (TypeBuilder == declaring ||
745                             TypeBuilder.IsSubclassOf (declaring))
746                                 return true;
747
748                         return NestedAccessible (check_type);
749                 }
750
751                 // Access level of a type.
752                 const int X = 1;
753                 enum AccessLevel { // Each column represents `is this scope larger or equal to Blah scope'
754                                             // Public    Assembly   Protected
755                         Protected           = (0 << 0) | (0 << 1) | (X << 2),
756                         Public              = (X << 0) | (X << 1) | (X << 2),
757                         Private             = (0 << 0) | (0 << 1) | (0 << 2),
758                         Internal            = (0 << 0) | (X << 1) | (0 << 2),
759                         ProtectedOrInternal = (0 << 0) | (X << 1) | (X << 2),
760                 }
761                 
762                 static AccessLevel GetAccessLevelFromModifiers (int flags)
763                 {
764                         if ((flags & Modifiers.INTERNAL) != 0) {
765                                 
766                                 if ((flags & Modifiers.PROTECTED) != 0)
767                                         return AccessLevel.ProtectedOrInternal;
768                                 else
769                                         return AccessLevel.Internal;
770                                 
771                         } else if ((flags & Modifiers.PROTECTED) != 0)
772                                 return AccessLevel.Protected;
773                         
774                         else if ((flags & Modifiers.PRIVATE) != 0)
775                                 return AccessLevel.Private;
776                         
777                         else
778                                 return AccessLevel.Public;
779                 }
780
781                 // What is the effective access level of this?
782                 // TODO: Cache this?
783                 AccessLevel EffectiveAccessLevel {
784                         get {
785                                 AccessLevel myAccess = GetAccessLevelFromModifiers (ModFlags);
786                                 if (!IsTopLevel && (Parent != null))
787                                         return myAccess & Parent.EffectiveAccessLevel;
788                                 else
789                                         return myAccess;
790                         }
791                 }
792
793                 // Return the access level for type `t'
794                 static AccessLevel TypeEffectiveAccessLevel (Type t)
795                 {
796                         if (t.IsPublic)
797                                 return AccessLevel.Public;              
798                         if (t.IsNestedPrivate)
799                                 return AccessLevel.Private;
800                         if (t.IsNotPublic)
801                                 return AccessLevel.Internal;
802                         
803                         // By now, it must be nested
804                         AccessLevel parentLevel = TypeEffectiveAccessLevel (t.DeclaringType);
805                         
806                         if (t.IsNestedPublic)
807                                 return parentLevel;
808                         if (t.IsNestedAssembly)
809                                 return parentLevel & AccessLevel.Internal;
810                         if (t.IsNestedFamily)
811                                 return parentLevel & AccessLevel.Protected;
812                         if (t.IsNestedFamORAssem)
813                                 return parentLevel & AccessLevel.ProtectedOrInternal;
814                         if (t.IsNestedFamANDAssem)
815                                 throw new NotImplementedException ("NestedFamANDAssem not implemented, cant make this kind of type from c# anyways");
816                         
817                         // nested private is taken care of
818                         
819                         throw new Exception ("I give up, what are you?");
820                 }
821
822                 //
823                 // This answers `is the type P, as accessible as a member M which has the
824                 // accessability @flags which is declared as a nested member of the type T, this declspace'
825                 //
826                 public bool AsAccessible (Type p, int flags)
827                 {
828                         //
829                         // 1) if M is private, its accessability is the same as this declspace.
830                         // we already know that P is accessible to T before this method, so we
831                         // may return true.
832                         //
833                         
834                         if ((flags & Modifiers.PRIVATE) != 0)
835                                 return true;
836                         
837                         while (p.IsArray || p.IsPointer || p.IsByRef)
838                                 p = TypeManager.GetElementType (p);
839                         
840                         AccessLevel pAccess = TypeEffectiveAccessLevel (p);
841                         AccessLevel mAccess = this.EffectiveAccessLevel &
842                                 GetAccessLevelFromModifiers (flags);
843                         
844                         // for every place from which we can access M, we must
845                         // be able to access P as well. So, we want
846                         // For every bit in M and P, M_i -> P_1 == true
847                         // or, ~ (M -> P) == 0 <-> ~ ( ~M | P) == 0
848                         
849                         return ~ (~ mAccess | pAccess) == 0;
850                 }
851
852                 public static void Error_AmbiguousTypeReference (Location loc, string name, string t1, string t2)
853                 {
854                         Report.Error (104, loc,
855                                       "`{0}' is an ambiguous reference ({1} or {2})",
856                                       name, t1, t2);
857                 }
858
859                 //
860                 // Return the nested type with name @name.  Ensures that the nested type
861                 // is defined if necessary.  Do _not_ use this when you have a MemberCache handy.
862                 //
863                 public virtual Type FindNestedType (string name)
864                 {
865                         return null;
866                 }
867
868                 private Type LookupNestedTypeInHierarchy (string name)
869                 {
870                         // if the member cache has been created, lets use it.
871                         // the member cache is MUCH faster.
872                         if (MemberCache != null)
873                                 return MemberCache.FindNestedType (name);
874
875                         // no member cache. Do it the hard way -- reflection
876                         Type t = null;
877                         for (Type current_type = TypeBuilder;
878                              current_type != null && current_type != TypeManager.object_type;
879                              current_type = current_type.BaseType) {
880                                 if (current_type is TypeBuilder) {
881                                         DeclSpace decl = this;
882                                         if (current_type != TypeBuilder)
883                                                 decl = TypeManager.LookupDeclSpace (current_type);
884                                         t = decl.FindNestedType (name);
885                                 } else {
886                                         t = TypeManager.GetNestedType (current_type, name);
887                                 }
888
889                                 if (t != null && CheckAccessLevel (t))
890                                         return t;
891                         }
892
893                         return null;
894                 }
895
896                 //
897                 // Public function used to locate types, this can only
898                 // be used after the ResolveTree function has been invoked.
899                 //
900                 // Set 'ignore_cs0104' to true if you want to ignore cs0104 errors.
901                 //
902                 // Returns: Type or null if they type can not be found.
903                 //
904                 public FullNamedExpression LookupType (string name, Location loc, bool ignore_cs0104)
905                 {
906                         if (this is PartialContainer)
907                                 throw new InternalErrorException ("Should not get here");
908
909                         if (Cache.Contains (name))
910                                 return (FullNamedExpression) Cache [name];
911
912                         FullNamedExpression e;
913                         Type t = LookupNestedTypeInHierarchy (name);
914                         if (t != null)
915                                 e = new TypeExpression (t, Location.Null);
916                         else if (Parent != null && Parent != RootContext.Tree.Types)
917                                 e = Parent.LookupType (name, loc, ignore_cs0104);
918                         else
919                                 e = NamespaceEntry.LookupNamespaceOrType (this, name, loc, ignore_cs0104);
920
921                         Cache [name] = e;
922                         return e;
923                 }
924
925                 /// <remarks>
926                 ///   This function is broken and not what you're looking for.  It should only
927                 ///   be used while the type is still being created since it doesn't use the cache
928                 ///   and relies on the filter doing the member name check.
929                 /// </remarks>
930                 public abstract MemberList FindMembers (MemberTypes mt, BindingFlags bf,
931                                                         MemberFilter filter, object criteria);
932
933                 /// <remarks>
934                 ///   If we have a MemberCache, return it.  This property may return null if the
935                 ///   class doesn't have a member cache or while it's still being created.
936                 /// </remarks>
937                 public abstract MemberCache MemberCache {
938                         get;
939                 }
940
941                 public override void ApplyAttributeBuilder (Attribute a, CustomAttributeBuilder cb)
942                 {
943                         if (a.Type == TypeManager.required_attr_type) {
944                                 Report.Error (1608, a.Location, "The RequiredAttribute attribute is not permitted on C# types");
945                                 return;
946                         }
947                         TypeBuilder.SetCustomAttribute (cb);
948                 }
949
950                 /// <summary>
951                 /// Goes through class hierarchy and get value of first CLSCompliantAttribute that found.
952                 /// If no is attribute exists then return assembly CLSCompliantAttribute.
953                 /// </summary>
954                 public bool GetClsCompliantAttributeValue ()
955                 {
956                         if ((caching_flags & Flags.HasCompliantAttribute_Undetected) == 0)
957                                 return (caching_flags & Flags.ClsCompliantAttributeTrue) != 0;
958
959                         caching_flags &= ~Flags.HasCompliantAttribute_Undetected;
960
961                         if (OptAttributes != null) {
962                                 Attribute cls_attribute = OptAttributes.Search (TypeManager.cls_compliant_attribute_type, ec);
963                                 if (cls_attribute != null) {
964                                         caching_flags |= Flags.HasClsCompliantAttribute;
965                                         if (cls_attribute.GetClsCompliantAttributeValue (ec)) {
966                                                 caching_flags |= Flags.ClsCompliantAttributeTrue;
967                                                 return true;
968                                         }
969                                         return false;
970                                 }
971                         }
972
973                         if (Parent == null) {
974                                 if (CodeGen.Assembly.IsClsCompliant) {
975                                         caching_flags |= Flags.ClsCompliantAttributeTrue;
976                                         return true;
977                                 }
978                                 return false;
979                         }
980
981                         if (Parent.GetClsCompliantAttributeValue ()) {
982                                 caching_flags |= Flags.ClsCompliantAttributeTrue;
983                                 return true;
984                         }
985                         return false;
986                 }
987
988                 public override string[] ValidAttributeTargets {
989                         get {
990                                 return attribute_targets;
991                         }
992                 }
993
994                 bool IAlias.IsType {
995                         get { return true; }
996                 }
997
998                 string IAlias.Name {
999                         get { return Name; }
1000                 }
1001
1002                 TypeExpr IAlias.ResolveAsType (EmitContext ec)
1003                 {
1004                         if (TypeBuilder == null)
1005                                 throw new InvalidOperationException ();
1006
1007                         return new TypeExpression (TypeBuilder, Location);
1008                 }
1009         }
1010
1011         /// <summary>
1012         ///   This is a readonly list of MemberInfo's.      
1013         /// </summary>
1014         public class MemberList : IList {
1015                 public readonly IList List;
1016                 int count;
1017
1018                 /// <summary>
1019                 ///   Create a new MemberList from the given IList.
1020                 /// </summary>
1021                 public MemberList (IList list)
1022                 {
1023                         if (list != null)
1024                                 this.List = list;
1025                         else
1026                                 this.List = new ArrayList ();
1027                         count = List.Count;
1028                 }
1029
1030                 /// <summary>
1031                 ///   Concatenate the ILists `first' and `second' to a new MemberList.
1032                 /// </summary>
1033                 public MemberList (IList first, IList second)
1034                 {
1035                         ArrayList list = new ArrayList ();
1036                         list.AddRange (first);
1037                         list.AddRange (second);
1038                         count = list.Count;
1039                         List = list;
1040                 }
1041
1042                 public static readonly MemberList Empty = new MemberList (new ArrayList ());
1043
1044                 /// <summary>
1045                 ///   Cast the MemberList into a MemberInfo[] array.
1046                 /// </summary>
1047                 /// <remarks>
1048                 ///   This is an expensive operation, only use it if it's really necessary.
1049                 /// </remarks>
1050                 public static explicit operator MemberInfo [] (MemberList list)
1051                 {
1052                         Timer.StartTimer (TimerType.MiscTimer);
1053                         MemberInfo [] result = new MemberInfo [list.Count];
1054                         list.CopyTo (result, 0);
1055                         Timer.StopTimer (TimerType.MiscTimer);
1056                         return result;
1057                 }
1058
1059                 // ICollection
1060
1061                 public int Count {
1062                         get {
1063                                 return count;
1064                         }
1065                 }
1066
1067                 public bool IsSynchronized {
1068                         get {
1069                                 return List.IsSynchronized;
1070                         }
1071                 }
1072
1073                 public object SyncRoot {
1074                         get {
1075                                 return List.SyncRoot;
1076                         }
1077                 }
1078
1079                 public void CopyTo (Array array, int index)
1080                 {
1081                         List.CopyTo (array, index);
1082                 }
1083
1084                 // IEnumerable
1085
1086                 public IEnumerator GetEnumerator ()
1087                 {
1088                         return List.GetEnumerator ();
1089                 }
1090
1091                 // IList
1092
1093                 public bool IsFixedSize {
1094                         get {
1095                                 return true;
1096                         }
1097                 }
1098
1099                 public bool IsReadOnly {
1100                         get {
1101                                 return true;
1102                         }
1103                 }
1104
1105                 object IList.this [int index] {
1106                         get {
1107                                 return List [index];
1108                         }
1109
1110                         set {
1111                                 throw new NotSupportedException ();
1112                         }
1113                 }
1114
1115                 // FIXME: try to find out whether we can avoid the cast in this indexer.
1116                 public MemberInfo this [int index] {
1117                         get {
1118                                 return (MemberInfo) List [index];
1119                         }
1120                 }
1121
1122                 public int Add (object value)
1123                 {
1124                         throw new NotSupportedException ();
1125                 }
1126
1127                 public void Clear ()
1128                 {
1129                         throw new NotSupportedException ();
1130                 }
1131
1132                 public bool Contains (object value)
1133                 {
1134                         return List.Contains (value);
1135                 }
1136
1137                 public int IndexOf (object value)
1138                 {
1139                         return List.IndexOf (value);
1140                 }
1141
1142                 public void Insert (int index, object value)
1143                 {
1144                         throw new NotSupportedException ();
1145                 }
1146
1147                 public void Remove (object value)
1148                 {
1149                         throw new NotSupportedException ();
1150                 }
1151
1152                 public void RemoveAt (int index)
1153                 {
1154                         throw new NotSupportedException ();
1155                 }
1156         }
1157
1158         /// <summary>
1159         ///   This interface is used to get all members of a class when creating the
1160         ///   member cache.  It must be implemented by all DeclSpace derivatives which
1161         ///   want to support the member cache and by TypeHandle to get caching of
1162         ///   non-dynamic types.
1163         /// </summary>
1164         public interface IMemberContainer {
1165                 /// <summary>
1166                 ///   The name of the IMemberContainer.  This is only used for
1167                 ///   debugging purposes.
1168                 /// </summary>
1169                 string Name {
1170                         get;
1171                 }
1172
1173                 /// <summary>
1174                 ///   The type of this IMemberContainer.
1175                 /// </summary>
1176                 Type Type {
1177                         get;
1178                 }
1179
1180                 /// <summary>
1181                 ///   Returns the IMemberContainer of the base class or null if this
1182                 ///   is an interface or TypeManger.object_type.
1183                 ///   This is used when creating the member cache for a class to get all
1184                 ///   members from the base class.
1185                 /// </summary>
1186                 MemberCache BaseCache {
1187                         get;
1188                 }
1189
1190                 /// <summary>
1191                 ///   Whether this is an interface.
1192                 /// </summary>
1193                 bool IsInterface {
1194                         get;
1195                 }
1196
1197                 /// <summary>
1198                 ///   Returns all members of this class with the corresponding MemberTypes
1199                 ///   and BindingFlags.
1200                 /// </summary>
1201                 /// <remarks>
1202                 ///   When implementing this method, make sure not to return any inherited
1203                 ///   members and check the MemberTypes and BindingFlags properly.
1204                 ///   Unfortunately, System.Reflection is lame and doesn't provide a way to
1205                 ///   get the BindingFlags (static/non-static,public/non-public) in the
1206                 ///   MemberInfo class, but the cache needs this information.  That's why
1207                 ///   this method is called multiple times with different BindingFlags.
1208                 /// </remarks>
1209                 MemberList GetMembers (MemberTypes mt, BindingFlags bf);
1210
1211                 /// <summary>
1212                 ///   Return the container's member cache.
1213                 /// </summary>
1214                 MemberCache MemberCache {
1215                         get;
1216                 }
1217         }
1218
1219         /// <summary>
1220         ///   The MemberCache is used by dynamic and non-dynamic types to speed up
1221         ///   member lookups.  It has a member name based hash table; it maps each member
1222         ///   name to a list of CacheEntry objects.  Each CacheEntry contains a MemberInfo
1223         ///   and the BindingFlags that were initially used to get it.  The cache contains
1224         ///   all members of the current class and all inherited members.  If this cache is
1225         ///   for an interface types, it also contains all inherited members.
1226         ///
1227         ///   There are two ways to get a MemberCache:
1228         ///   * if this is a dynamic type, lookup the corresponding DeclSpace and then
1229         ///     use the DeclSpace.MemberCache property.
1230         ///   * if this not a dynamic type, call TypeHandle.GetTypeHandle() to get a
1231         ///     TypeHandle instance for the type and then use TypeHandle.MemberCache.
1232         /// </summary>
1233         public class MemberCache {
1234                 public readonly IMemberContainer Container;
1235                 protected Hashtable member_hash;
1236                 protected Hashtable method_hash;
1237
1238                 /// <summary>
1239                 ///   Create a new MemberCache for the given IMemberContainer `container'.
1240                 /// </summary>
1241                 public MemberCache (IMemberContainer container)
1242                 {
1243                         this.Container = container;
1244
1245                         Timer.IncrementCounter (CounterType.MemberCache);
1246                         Timer.StartTimer (TimerType.CacheInit);
1247
1248                         // If we have a base class (we have a base class unless we're
1249                         // TypeManager.object_type), we deep-copy its MemberCache here.
1250                         if (Container.BaseCache != null)
1251                                 member_hash = SetupCache (Container.BaseCache);
1252                         else
1253                                 member_hash = new Hashtable ();
1254
1255                         // If this is neither a dynamic type nor an interface, create a special
1256                         // method cache with all declared and inherited methods.
1257                         Type type = container.Type;
1258                         if (!(type is TypeBuilder) && !type.IsInterface &&
1259                             (Container.BaseCache == null || Container.BaseCache.method_hash != null)) {
1260                                 method_hash = new Hashtable ();
1261                                 AddMethods (type);
1262                         }
1263
1264                         // Add all members from the current class.
1265                         AddMembers (Container);
1266
1267                         Timer.StopTimer (TimerType.CacheInit);
1268                 }
1269
1270                 public MemberCache (Type[] ifaces)
1271                 {
1272                         //
1273                         // The members of this cache all belong to other caches.  
1274                         // So, 'Container' will not be used.
1275                         //
1276                         this.Container = null;
1277
1278                         member_hash = new Hashtable ();
1279                         if (ifaces == null)
1280                                 return;
1281
1282                         foreach (Type itype in ifaces)
1283                                 AddCacheContents (TypeManager.LookupMemberCache (itype));
1284                 }
1285
1286                 /// <summary>
1287                 ///   Bootstrap this member cache by doing a deep-copy of our base.
1288                 /// </summary>
1289                 Hashtable SetupCache (MemberCache base_class)
1290                 {
1291                         Hashtable hash = new Hashtable ();
1292
1293                         if (base_class == null)
1294                                 return hash;
1295
1296                         IDictionaryEnumerator it = base_class.member_hash.GetEnumerator ();
1297                         while (it.MoveNext ()) {
1298                                 hash [it.Key] = ((ArrayList) it.Value).Clone ();
1299                          }
1300                                 
1301                         return hash;
1302                 }
1303
1304                 /// <summary>
1305                 ///   Add the contents of `cache' to the member_hash.
1306                 /// </summary>
1307                 void AddCacheContents (MemberCache cache)
1308                 {
1309                         IDictionaryEnumerator it = cache.member_hash.GetEnumerator ();
1310                         while (it.MoveNext ()) {
1311                                 ArrayList list = (ArrayList) member_hash [it.Key];
1312                                 if (list == null)
1313                                         member_hash [it.Key] = list = new ArrayList ();
1314
1315                                 ArrayList entries = (ArrayList) it.Value;
1316                                 for (int i = entries.Count-1; i >= 0; i--) {
1317                                         CacheEntry entry = (CacheEntry) entries [i];
1318
1319                                         if (entry.Container != cache.Container)
1320                                                 break;
1321                                         list.Add (entry);
1322                                 }
1323                         }
1324                 }
1325
1326                 /// <summary>
1327                 ///   Add all members from class `container' to the cache.
1328                 /// </summary>
1329                 void AddMembers (IMemberContainer container)
1330                 {
1331                         // We need to call AddMembers() with a single member type at a time
1332                         // to get the member type part of CacheEntry.EntryType right.
1333                         if (!container.IsInterface) {
1334                                 AddMembers (MemberTypes.Constructor, container);
1335                                 AddMembers (MemberTypes.Field, container);
1336                         }
1337                         AddMembers (MemberTypes.Method, container);
1338                         AddMembers (MemberTypes.Property, container);
1339                         AddMembers (MemberTypes.Event, container);
1340                         // Nested types are returned by both Static and Instance searches.
1341                         AddMembers (MemberTypes.NestedType,
1342                                     BindingFlags.Static | BindingFlags.Public, container);
1343                         AddMembers (MemberTypes.NestedType,
1344                                     BindingFlags.Static | BindingFlags.NonPublic, container);
1345                 }
1346
1347                 void AddMembers (MemberTypes mt, IMemberContainer container)
1348                 {
1349                         AddMembers (mt, BindingFlags.Static | BindingFlags.Public, container);
1350                         AddMembers (mt, BindingFlags.Static | BindingFlags.NonPublic, container);
1351                         AddMembers (mt, BindingFlags.Instance | BindingFlags.Public, container);
1352                         AddMembers (mt, BindingFlags.Instance | BindingFlags.NonPublic, container);
1353                 }
1354
1355                 /// <summary>
1356                 ///   Add all members from class `container' with the requested MemberTypes and
1357                 ///   BindingFlags to the cache.  This method is called multiple times with different
1358                 ///   MemberTypes and BindingFlags.
1359                 /// </summary>
1360                 void AddMembers (MemberTypes mt, BindingFlags bf, IMemberContainer container)
1361                 {
1362                         MemberList members = container.GetMembers (mt, bf);
1363
1364                         foreach (MemberInfo member in members) {
1365                                 string name = member.Name;
1366
1367                                 // We use a name-based hash table of ArrayList's.
1368                                 ArrayList list = (ArrayList) member_hash [name];
1369                                 if (list == null) {
1370                                         list = new ArrayList ();
1371                                         member_hash.Add (name, list);
1372                                 }
1373
1374                                 // When this method is called for the current class, the list will
1375                                 // already contain all inherited members from our base classes.
1376                                 // We cannot add new members in front of the list since this'd be an
1377                                 // expensive operation, that's why the list is sorted in reverse order
1378                                 // (ie. members from the current class are coming last).
1379                                 list.Add (new CacheEntry (container, member, mt, bf));
1380                         }
1381                 }
1382
1383                 /// <summary>
1384                 ///   Add all declared and inherited methods from class `type' to the method cache.
1385                 /// </summary>
1386                 void AddMethods (Type type)
1387                 {
1388                         AddMethods (BindingFlags.Static | BindingFlags.Public |
1389                                     BindingFlags.FlattenHierarchy, type);
1390                         AddMethods (BindingFlags.Static | BindingFlags.NonPublic |
1391                                     BindingFlags.FlattenHierarchy, type);
1392                         AddMethods (BindingFlags.Instance | BindingFlags.Public, type);
1393                         AddMethods (BindingFlags.Instance | BindingFlags.NonPublic, type);
1394                 }
1395
1396                 void AddMethods (BindingFlags bf, Type type)
1397                 {
1398                         //
1399                         // Consider the case:
1400                         //
1401                         //   class X { public virtual int f() {} }
1402                         //   class Y : X {}
1403                         // 
1404                         // When processing 'Y', the method_cache will already have a copy of 'f', 
1405                         // with ReflectedType == X.  However, we want to ensure that its ReflectedType == Y
1406                         // 
1407                         MethodBase [] members = type.GetMethods (bf);
1408
1409                         Array.Reverse (members);
1410
1411                         foreach (MethodBase member in members) {
1412                                 string name = member.Name;
1413
1414                                 // We use a name-based hash table of ArrayList's.
1415                                 ArrayList list = (ArrayList) method_hash [name];
1416                                 if (list == null) {
1417                                         list = new ArrayList ();
1418                                         method_hash.Add (name, list);
1419                                 }
1420
1421                                 if (member.IsVirtual &&
1422                                     (member.Attributes & MethodAttributes.NewSlot) == 0) {
1423                                         MethodInfo base_method = ((MethodInfo) member).GetBaseDefinition ();
1424
1425                                         if (base_method == member) {
1426                                                 //
1427                                                 // Both mcs and CSC 1.1 seem to emit a somewhat broken
1428                                                 // ...Invoke () function for delegates: it's missing a 'newslot'.
1429                                                 // CSC 2.0 emits a 'newslot' for a delegate's Invoke.
1430                                                 //
1431                                                 if (member.Name != "Invoke" ||
1432                                                     !type.IsSubclassOf (TypeManager.multicast_delegate_type)) {
1433                                                         Report.SymbolRelatedToPreviousError (base_method);
1434                                                         Report.Warning (-28, 
1435                                                                 "The method '{0}' is marked 'override'," + 
1436                                                                 " but doesn't appear to override any virtual or abstract method:" + 
1437                                                                 " it may be ignored during overload resolution",
1438                                                                 TypeManager.CSharpSignature (base_method));
1439                                                 }
1440                                                 goto skip;
1441                                         }
1442
1443                                         for (;;) {
1444                                                 list.Add (new CacheEntry (null, base_method, MemberTypes.Method, bf));
1445                                                 if ((base_method.Attributes & MethodAttributes.NewSlot) != 0)
1446                                                         break;
1447
1448                                                 //
1449                                                 // Shouldn't get here.  Mono appears to be buggy.
1450                                                 //
1451                                                 MethodInfo new_base_method = base_method.GetBaseDefinition ();
1452                                                 if (new_base_method == base_method) {
1453                                                         Report.SymbolRelatedToPreviousError (base_method);
1454                                                         Report.Warning (-28, 
1455                                                                 "The method '{0}' is marked 'override'," +
1456                                                                 " but doesn't appear to overrided any virtual or abstract method:" + 
1457                                                                 " it may be ignored during overload resolution",
1458                                                                 TypeManager.CSharpSignature (base_method));
1459                                                         break;
1460                                                 }
1461                                                 base_method = new_base_method;
1462                                         }
1463
1464
1465                                 }
1466                         skip:
1467
1468                                 // Unfortunately, the elements returned by Type.GetMethods() aren't
1469                                 // sorted so we need to do this check for every member.
1470                                 BindingFlags new_bf = bf;
1471                                 if (member.DeclaringType == type)
1472                                         new_bf |= BindingFlags.DeclaredOnly;
1473
1474                                 list.Add (new CacheEntry (Container, member, MemberTypes.Method, new_bf));
1475                         }
1476                 }
1477
1478                 /// <summary>
1479                 ///   Compute and return a appropriate `EntryType' magic number for the given
1480                 ///   MemberTypes and BindingFlags.
1481                 /// </summary>
1482                 protected static EntryType GetEntryType (MemberTypes mt, BindingFlags bf)
1483                 {
1484                         EntryType type = EntryType.None;
1485
1486                         if ((mt & MemberTypes.Constructor) != 0)
1487                                 type |= EntryType.Constructor;
1488                         if ((mt & MemberTypes.Event) != 0)
1489                                 type |= EntryType.Event;
1490                         if ((mt & MemberTypes.Field) != 0)
1491                                 type |= EntryType.Field;
1492                         if ((mt & MemberTypes.Method) != 0)
1493                                 type |= EntryType.Method;
1494                         if ((mt & MemberTypes.Property) != 0)
1495                                 type |= EntryType.Property;
1496                         // Nested types are returned by static and instance searches.
1497                         if ((mt & MemberTypes.NestedType) != 0)
1498                                 type |= EntryType.NestedType | EntryType.Static | EntryType.Instance;
1499
1500                         if ((bf & BindingFlags.Instance) != 0)
1501                                 type |= EntryType.Instance;
1502                         if ((bf & BindingFlags.Static) != 0)
1503                                 type |= EntryType.Static;
1504                         if ((bf & BindingFlags.Public) != 0)
1505                                 type |= EntryType.Public;
1506                         if ((bf & BindingFlags.NonPublic) != 0)
1507                                 type |= EntryType.NonPublic;
1508                         if ((bf & BindingFlags.DeclaredOnly) != 0)
1509                                 type |= EntryType.Declared;
1510
1511                         return type;
1512                 }
1513
1514                 /// <summary>
1515                 ///   The `MemberTypes' enumeration type is a [Flags] type which means that it may
1516                 ///   denote multiple member types.  Returns true if the given flags value denotes a
1517                 ///   single member types.
1518                 /// </summary>
1519                 public static bool IsSingleMemberType (MemberTypes mt)
1520                 {
1521                         switch (mt) {
1522                         case MemberTypes.Constructor:
1523                         case MemberTypes.Event:
1524                         case MemberTypes.Field:
1525                         case MemberTypes.Method:
1526                         case MemberTypes.Property:
1527                         case MemberTypes.NestedType:
1528                                 return true;
1529
1530                         default:
1531                                 return false;
1532                         }
1533                 }
1534
1535                 /// <summary>
1536                 ///   We encode the MemberTypes and BindingFlags of each members in a "magic"
1537                 ///   number to speed up the searching process.
1538                 /// </summary>
1539                 [Flags]
1540                 protected enum EntryType {
1541                         None            = 0x000,
1542
1543                         Instance        = 0x001,
1544                         Static          = 0x002,
1545                         MaskStatic      = Instance|Static,
1546
1547                         Public          = 0x004,
1548                         NonPublic       = 0x008,
1549                         MaskProtection  = Public|NonPublic,
1550
1551                         Declared        = 0x010,
1552
1553                         Constructor     = 0x020,
1554                         Event           = 0x040,
1555                         Field           = 0x080,
1556                         Method          = 0x100,
1557                         Property        = 0x200,
1558                         NestedType      = 0x400,
1559
1560                         MaskType        = Constructor|Event|Field|Method|Property|NestedType
1561                 }
1562
1563                 protected class CacheEntry {
1564                         public readonly IMemberContainer Container;
1565                         public readonly EntryType EntryType;
1566                         public readonly MemberInfo Member;
1567
1568                         public CacheEntry (IMemberContainer container, MemberInfo member,
1569                                            MemberTypes mt, BindingFlags bf)
1570                         {
1571                                 this.Container = container;
1572                                 this.Member = member;
1573                                 this.EntryType = GetEntryType (mt, bf);
1574                         }
1575
1576                         public override string ToString ()
1577                         {
1578                                 return String.Format ("CacheEntry ({0}:{1}:{2})", Container.Name,
1579                                                       EntryType, Member);
1580                         }
1581                 }
1582
1583                 /// <summary>
1584                 ///   This is called each time we're walking up one level in the class hierarchy
1585                 ///   and checks whether we can abort the search since we've already found what
1586                 ///   we were looking for.
1587                 /// </summary>
1588                 protected bool DoneSearching (ArrayList list)
1589                 {
1590                         //
1591                         // We've found exactly one member in the current class and it's not
1592                         // a method or constructor.
1593                         //
1594                         if (list.Count == 1 && !(list [0] is MethodBase))
1595                                 return true;
1596
1597                         //
1598                         // Multiple properties: we query those just to find out the indexer
1599                         // name
1600                         //
1601                         if ((list.Count > 0) && (list [0] is PropertyInfo))
1602                                 return true;
1603
1604                         return false;
1605                 }
1606
1607                 /// <summary>
1608                 ///   Looks up members with name `name'.  If you provide an optional
1609                 ///   filter function, it'll only be called with members matching the
1610                 ///   requested member name.
1611                 ///
1612                 ///   This method will try to use the cache to do the lookup if possible.
1613                 ///
1614                 ///   Unlike other FindMembers implementations, this method will always
1615                 ///   check all inherited members - even when called on an interface type.
1616                 ///
1617                 ///   If you know that you're only looking for methods, you should use
1618                 ///   MemberTypes.Method alone since this speeds up the lookup a bit.
1619                 ///   When doing a method-only search, it'll try to use a special method
1620                 ///   cache (unless it's a dynamic type or an interface) and the returned
1621                 ///   MemberInfo's will have the correct ReflectedType for inherited methods.
1622                 ///   The lookup process will automatically restart itself in method-only
1623                 ///   search mode if it discovers that it's about to return methods.
1624                 /// </summary>
1625                 ArrayList global = new ArrayList ();
1626                 bool using_global = false;
1627                 
1628                 static MemberInfo [] emptyMemberInfo = new MemberInfo [0];
1629                 
1630                 public MemberInfo [] FindMembers (MemberTypes mt, BindingFlags bf, string name,
1631                                                   MemberFilter filter, object criteria)
1632                 {
1633                         if (using_global)
1634                                 throw new Exception ();
1635                         
1636                         bool declared_only = (bf & BindingFlags.DeclaredOnly) != 0;
1637                         bool method_search = mt == MemberTypes.Method;
1638                         // If we have a method cache and we aren't already doing a method-only search,
1639                         // then we restart a method search if the first match is a method.
1640                         bool do_method_search = !method_search && (method_hash != null);
1641
1642                         ArrayList applicable;
1643
1644                         // If this is a method-only search, we try to use the method cache if
1645                         // possible; a lookup in the method cache will return a MemberInfo with
1646                         // the correct ReflectedType for inherited methods.
1647                         
1648                         if (method_search && (method_hash != null))
1649                                 applicable = (ArrayList) method_hash [name];
1650                         else
1651                                 applicable = (ArrayList) member_hash [name];
1652
1653                         if (applicable == null)
1654                                 return emptyMemberInfo;
1655
1656                         //
1657                         // 32  slots gives 53 rss/54 size
1658                         // 2/4 slots gives 55 rss
1659                         //
1660                         // Strange: from 25,000 calls, only 1,800
1661                         // are above 2.  Why does this impact it?
1662                         //
1663                         global.Clear ();
1664                         using_global = true;
1665
1666                         Timer.StartTimer (TimerType.CachedLookup);
1667
1668                         EntryType type = GetEntryType (mt, bf);
1669
1670                         IMemberContainer current = Container;
1671
1672
1673                         // `applicable' is a list of all members with the given member name `name'
1674                         // in the current class and all its base classes.  The list is sorted in
1675                         // reverse order due to the way how the cache is initialy created (to speed
1676                         // things up, we're doing a deep-copy of our base).
1677
1678                         for (int i = applicable.Count-1; i >= 0; i--) {
1679                                 CacheEntry entry = (CacheEntry) applicable [i];
1680
1681                                 // This happens each time we're walking one level up in the class
1682                                 // hierarchy.  If we're doing a DeclaredOnly search, we must abort
1683                                 // the first time this happens (this may already happen in the first
1684                                 // iteration of this loop if there are no members with the name we're
1685                                 // looking for in the current class).
1686                                 if (entry.Container != current) {
1687                                         if (declared_only || DoneSearching (global))
1688                                                 break;
1689
1690                                         current = entry.Container;
1691                                 }
1692
1693                                 // Is the member of the correct type ?
1694                                 if ((entry.EntryType & type & EntryType.MaskType) == 0)
1695                                         continue;
1696
1697                                 // Is the member static/non-static ?
1698                                 if ((entry.EntryType & type & EntryType.MaskStatic) == 0)
1699                                         continue;
1700
1701                                 // Apply the filter to it.
1702                                 if (filter (entry.Member, criteria)) {
1703                                         if ((entry.EntryType & EntryType.MaskType) != EntryType.Method)
1704                                                 do_method_search = false;
1705                                         global.Add (entry.Member);
1706                                 }
1707                         }
1708
1709                         Timer.StopTimer (TimerType.CachedLookup);
1710
1711                         // If we have a method cache and we aren't already doing a method-only
1712                         // search, we restart in method-only search mode if the first match is
1713                         // a method.  This ensures that we return a MemberInfo with the correct
1714                         // ReflectedType for inherited methods.
1715                         if (do_method_search && (global.Count > 0)){
1716                                 using_global = false;
1717
1718                                 return FindMembers (MemberTypes.Method, bf, name, filter, criteria);
1719                         }
1720
1721                         using_global = false;
1722                         MemberInfo [] copy = new MemberInfo [global.Count];
1723                         global.CopyTo (copy);
1724                         return copy;
1725                 }
1726                 
1727                 // find the nested type @name in @this.
1728                 public Type FindNestedType (string name)
1729                 {
1730                         ArrayList applicable = (ArrayList) member_hash [name];
1731                         if (applicable == null)
1732                                 return null;
1733                         
1734                         for (int i = applicable.Count-1; i >= 0; i--) {
1735                                 CacheEntry entry = (CacheEntry) applicable [i];
1736                                 if ((entry.EntryType & EntryType.NestedType & EntryType.MaskType) != 0)
1737                                         return (Type) entry.Member;
1738                         }
1739                         
1740                         return null;
1741                 }
1742                 
1743                 //
1744                 // This finds the method or property for us to override. invocationType is the type where
1745                 // the override is going to be declared, name is the name of the method/property, and
1746                 // paramTypes is the parameters, if any to the method or property
1747                 //
1748                 // Because the MemberCache holds members from this class and all the base classes,
1749                 // we can avoid tons of reflection stuff.
1750                 //
1751                 public MemberInfo FindMemberToOverride (Type invocationType, string name, Type [] paramTypes, bool is_property)
1752                 {
1753                         ArrayList applicable;
1754                         if (method_hash != null && !is_property)
1755                                 applicable = (ArrayList) method_hash [name];
1756                         else
1757                                 applicable = (ArrayList) member_hash [name];
1758                         
1759                         if (applicable == null)
1760                                 return null;
1761                         //
1762                         // Walk the chain of methods, starting from the top.
1763                         //
1764                         for (int i = applicable.Count - 1; i >= 0; i--) {
1765                                 CacheEntry entry = (CacheEntry) applicable [i];
1766                                 
1767                                 if ((entry.EntryType & (is_property ? (EntryType.Property | EntryType.Field) : EntryType.Method)) == 0)
1768                                         continue;
1769
1770                                 PropertyInfo pi = null;
1771                                 MethodInfo mi = null;
1772                                 FieldInfo fi = null;
1773                                 Type [] cmpAttrs = null;
1774                                 
1775                                 if (is_property) {
1776                                         if ((entry.EntryType & EntryType.Field) != 0) {
1777                                                 fi = (FieldInfo)entry.Member;
1778
1779                                                 // TODO: For this case we ignore member type
1780                                                 //fb = TypeManager.GetField (fi);
1781                                                 //cmpAttrs = new Type[] { fb.MemberType };
1782                                         } else {
1783                                                 pi = (PropertyInfo) entry.Member;
1784                                                 cmpAttrs = TypeManager.GetArgumentTypes (pi);
1785                                         }
1786                                 } else {
1787                                         mi = (MethodInfo) entry.Member;
1788                                         cmpAttrs = TypeManager.GetArgumentTypes (mi);
1789                                 }
1790
1791                                 if (fi != null) {
1792                                         // TODO: Almost duplicate !
1793                                         // Check visibility
1794                                         switch (fi.Attributes & FieldAttributes.FieldAccessMask) {
1795                                                 case FieldAttributes.Private:
1796                                                         //
1797                                                         // A private method is Ok if we are a nested subtype.
1798                                                         // The spec actually is not very clear about this, see bug 52458.
1799                                                         //
1800                                                         if (invocationType != entry.Container.Type &
1801                                                                 TypeManager.IsNestedChildOf (invocationType, entry.Container.Type))
1802                                                                 continue;
1803
1804                                                         break;
1805                                                 case FieldAttributes.FamANDAssem:
1806                                                 case FieldAttributes.Assembly:
1807                                                         //
1808                                                         // Check for assembly methods
1809                                                         //
1810                                                         if (mi.DeclaringType.Assembly != CodeGen.Assembly.Builder)
1811                                                                 continue;
1812                                                         break;
1813                                         }
1814                                         return entry.Member;
1815                                 }
1816
1817                                 //
1818                                 // Check the arguments
1819                                 //
1820                                 if (cmpAttrs.Length != paramTypes.Length)
1821                                         continue;
1822         
1823                                 for (int j = cmpAttrs.Length - 1; j >= 0; j --)
1824                                         if (paramTypes [j] != cmpAttrs [j])
1825                                                 goto next;
1826                                 
1827                                 //
1828                                 // get one of the methods because this has the visibility info.
1829                                 //
1830                                 if (is_property) {
1831                                         mi = pi.GetGetMethod (true);
1832                                         if (mi == null)
1833                                                 mi = pi.GetSetMethod (true);
1834                                 }
1835                                 
1836                                 //
1837                                 // Check visibility
1838                                 //
1839                                 switch (mi.Attributes & MethodAttributes.MemberAccessMask) {
1840                                 case MethodAttributes.Private:
1841                                         //
1842                                         // A private method is Ok if we are a nested subtype.
1843                                         // The spec actually is not very clear about this, see bug 52458.
1844                                         //
1845                                         if (invocationType == entry.Container.Type ||
1846                                             TypeManager.IsNestedChildOf (invocationType, entry.Container.Type))
1847                                                 return entry.Member;
1848                                         
1849                                         break;
1850                                 case MethodAttributes.FamANDAssem:
1851                                 case MethodAttributes.Assembly:
1852                                         //
1853                                         // Check for assembly methods
1854                                         //
1855                                         if (mi.DeclaringType.Assembly == CodeGen.Assembly.Builder)
1856                                                 return entry.Member;
1857                                         
1858                                         break;
1859                                 default:
1860                                         //
1861                                         // A protected method is ok, because we are overriding.
1862                                         // public is always ok.
1863                                         //
1864                                         return entry.Member;
1865                                 }
1866                         next:
1867                                 ;
1868                         }
1869                         
1870                         return null;
1871                 }
1872
1873                 /// <summary>
1874                 /// The method is looking for conflict with inherited symbols (errors CS0108, CS0109).
1875                 /// We handle two cases. The first is for types without parameters (events, field, properties).
1876                 /// The second are methods, indexers and this is why ignore_complex_types is here.
1877                 /// The latest param is temporary hack. See DoDefineMembers method for more info.
1878                 /// </summary>
1879                 public MemberInfo FindMemberWithSameName (string name, bool ignore_complex_types, MemberInfo ignore_member)
1880                 {
1881                         ArrayList applicable = null;
1882  
1883                         if (method_hash != null)
1884                                 applicable = (ArrayList) method_hash [name];
1885  
1886                         if (applicable != null) {
1887                                 for (int i = applicable.Count - 1; i >= 0; i--) {
1888                                         CacheEntry entry = (CacheEntry) applicable [i];
1889                                         if ((entry.EntryType & EntryType.Public) != 0)
1890                                                 return entry.Member;
1891                                 }
1892                         }
1893  
1894                         if (member_hash == null)
1895                                 return null;
1896                         applicable = (ArrayList) member_hash [name];
1897                         
1898                         if (applicable != null) {
1899                                 for (int i = applicable.Count - 1; i >= 0; i--) {
1900                                         CacheEntry entry = (CacheEntry) applicable [i];
1901                                         if ((entry.EntryType & EntryType.Public) != 0 & entry.Member != ignore_member) {
1902                                                 if (ignore_complex_types) {
1903                                                         if ((entry.EntryType & EntryType.Method) != 0)
1904                                                                 continue;
1905  
1906                                                         // Does exist easier way how to detect indexer ?
1907                                                         if ((entry.EntryType & EntryType.Property) != 0) {
1908                                                                 Type[] arg_types = TypeManager.GetArgumentTypes ((PropertyInfo)entry.Member);
1909                                                                 if (arg_types.Length > 0)
1910                                                                         continue;
1911                                                         }
1912                                                 }
1913                                                 return entry.Member;
1914                                         }
1915                                 }
1916                         }
1917                         return null;
1918                 }
1919
1920                 Hashtable locase_table;
1921  
1922                 /// <summary>
1923                 /// Builds low-case table for CLS Compliance test
1924                 /// </summary>
1925                 public Hashtable GetPublicMembers ()
1926                 {
1927                         if (locase_table != null)
1928                                 return locase_table;
1929  
1930                         locase_table = new Hashtable ();
1931                         foreach (DictionaryEntry entry in member_hash) {
1932                                 ArrayList members = (ArrayList)entry.Value;
1933                                 for (int ii = 0; ii < members.Count; ++ii) {
1934                                         CacheEntry member_entry = (CacheEntry) members [ii];
1935  
1936                                         if ((member_entry.EntryType & EntryType.Public) == 0)
1937                                                 continue;
1938  
1939                                         // TODO: Does anyone know easier way how to detect that member is internal ?
1940                                         switch (member_entry.EntryType & EntryType.MaskType) {
1941                                                 case EntryType.Constructor:
1942                                                         continue;
1943  
1944                                                 case EntryType.Field:
1945                                                         if ((((FieldInfo)member_entry.Member).Attributes & (FieldAttributes.Assembly | FieldAttributes.Public)) == FieldAttributes.Assembly)
1946                                                                 continue;
1947                                                         break;
1948  
1949                                                 case EntryType.Method:
1950                                                         if ((((MethodInfo)member_entry.Member).Attributes & (MethodAttributes.Assembly | MethodAttributes.Public)) == MethodAttributes.Assembly)
1951                                                                 continue;
1952                                                         break;
1953  
1954                                                 case EntryType.Property:
1955                                                         PropertyInfo pi = (PropertyInfo)member_entry.Member;
1956                                                         if (pi.GetSetMethod () == null && pi.GetGetMethod () == null)
1957                                                                 continue;
1958                                                         break;
1959  
1960                                                 case EntryType.Event:
1961                                                         EventInfo ei = (EventInfo)member_entry.Member;
1962                                                         MethodInfo mi = ei.GetAddMethod ();
1963                                                         if ((mi.Attributes & (MethodAttributes.Assembly | MethodAttributes.Public)) == MethodAttributes.Assembly)
1964                                                                 continue;
1965                                                         break;
1966                                         }
1967                                         string lcase = ((string)entry.Key).ToLower (System.Globalization.CultureInfo.InvariantCulture);
1968                                         locase_table [lcase] = member_entry.Member;
1969                                         break;
1970                                 }
1971                         }
1972                         return locase_table;
1973                 }
1974  
1975                 public Hashtable Members {
1976                         get {
1977                                 return member_hash;
1978                         }
1979                 }
1980  
1981                 /// <summary>
1982                 /// Cls compliance check whether methods or constructors parameters differing only in ref or out, or in array rank
1983                 /// </summary>
1984                 public void VerifyClsParameterConflict (ArrayList al, MethodCore method, MemberInfo this_builder)
1985                 {
1986                         EntryType tested_type = (method is Constructor ? EntryType.Constructor : EntryType.Method) | EntryType.Public;
1987  
1988                         for (int i = 0; i < al.Count; ++i) {
1989                                 MemberCache.CacheEntry entry = (MemberCache.CacheEntry) al [i];
1990                 
1991                                 // skip itself
1992                                 if (entry.Member == this_builder)
1993                                         continue;
1994                 
1995                                 if ((entry.EntryType & tested_type) != tested_type)
1996                                         continue;
1997                 
1998                                 MethodBase method_to_compare = (MethodBase)entry.Member;
1999                                 if (AttributeTester.AreOverloadedMethodParamsClsCompliant (method.ParameterTypes, TypeManager.GetArgumentTypes (method_to_compare)))
2000                                         continue;
2001
2002                                 IMethodData md = TypeManager.GetMethod (method_to_compare);
2003
2004                                 // TODO: now we are ignoring CLSCompliance(false) on method from other assembly which is buggy.
2005                                 // However it is exactly what csc does.
2006                                 if (md != null && !md.IsClsCompliaceRequired (method.Parent))
2007                                         continue;
2008                 
2009                                 Report.SymbolRelatedToPreviousError (entry.Member);
2010                                 Report.Error (3006, method.Location, "Overloaded method '{0}' differing only in ref or out, or in array rank, is not CLS-compliant", method.GetSignatureForError ());
2011                         }
2012                 }
2013         }
2014 }