mcs/mcs/namespace.cs

   1 //
   2 // namespace.cs: Tracks namespaces
   3 //
   4 // Author:
   5 //   Miguel de Icaza (miguel@ximian.com)
   6 //   Marek Safar (marek.safar@seznam.cz)
   7 //
   8 // Copyright 2001 Ximian, Inc.
   9 // Copyright 2003-2008 Novell, Inc.
  10 //
  11 using System;
  12 using System.Collections;
  13 using System.Collections.Specialized;
  14 using System.Reflection;
  15
  16 namespace Mono.CSharp {
  17
  18         public class RootNamespace : Namespace {
  19                 //
  20                 // Points to Mono's GetNamespaces method, an
  21                 // optimization when running on Mono to fetch all the
  22                 // namespaces in an assembly
  23                 //
  24                 static MethodInfo get_namespaces_method;
  25
  26                 string alias_name;
  27                 Assembly referenced_assembly;
  28
  29                 Hashtable all_namespaces;
  30
  31                 static Hashtable root_namespaces;
  32                 public static GlobalRootNamespace Global;
  33
  34                 static RootNamespace ()
  35                 {
  36                         get_namespaces_method = typeof (Assembly).GetMethod ("GetNamespaces", BindingFlags.Instance | BindingFlags.NonPublic);
  37
  38                         Reset ();
  39                 }
  40
  41                 public static void Reset ()
  42                 {
  43                         root_namespaces = new Hashtable ();
  44                         Global = new GlobalRootNamespace ();
  45                         root_namespaces ["global"] = Global;
  46                 }
  47
  48                 protected RootNamespace (string alias_name, Assembly assembly)
  49                         : base (null, String.Empty)
  50                 {
  51                         this.alias_name = alias_name;
  52                         referenced_assembly = assembly;
  53
  54                         all_namespaces = new Hashtable ();
  55                         all_namespaces.Add ("", this);
  56
  57                         if (referenced_assembly != null)
  58                                 ComputeNamespaces (this.referenced_assembly);
  59                 }
  60
  61                 public static void DefineRootNamespace (string name, Assembly assembly)
  62                 {
  63                         if (name == "global") {
  64                                 NamespaceEntry.Error_GlobalNamespaceRedefined (Location.Null);
  65                                 return;
  66                         }
  67                         RootNamespace retval = GetRootNamespace (name);
  68                         if (retval == null || retval.referenced_assembly != assembly)
  69                                 root_namespaces [name] = new RootNamespace (name, assembly);
  70                 }
  71
  72                 public static RootNamespace GetRootNamespace (string name)
  73                 {
  74                         return (RootNamespace) root_namespaces [name];
  75                 }
  76
  77                 public virtual Type LookupTypeReflection (string name, Location loc)
  78                 {
  79                         return GetTypeInAssembly (referenced_assembly, name);
  80                 }
  81
  82                 public void RegisterNamespace (Namespace child)
  83                 {
  84                         if (child != this)
  85                                 all_namespaces.Add (child.Name, child);
  86                 }
  87
  88                 public bool IsNamespace (string name)
  89                 {
  90                         return all_namespaces.Contains (name);
  91                 }
  92
  93                 protected void RegisterNamespace (string dotted_name)
  94                 {
  95                         if (dotted_name != null && dotted_name.Length != 0 && ! IsNamespace (dotted_name))
  96                                 GetNamespace (dotted_name, true);
  97                 }
  98
  99                 void RegisterExtensionMethodClass (Type t)
 100                 {
 101                         string n = t.Namespace;
 102                         Namespace ns = n == null ? Global : (Namespace)all_namespaces [n];
 103                         if (ns == null)
 104                                 ns = GetNamespace (n, true);
 105
 106                         ns.RegisterExternalExtensionMethodClass (t);
 107                 }
 108
 109                 protected void ComputeNamespaces (Assembly assembly)
 110                 {
 111                         // How to test whether attribute exists without loading the assembly :-(
 112 #if NET_2_1
 113                         const string SystemCore = "System.Core, Version=2.0.5.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e";
 114 #else
 115                         const string SystemCore = "System.Core, Version=3.5.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089";
 116 #endif
 117                         if (TypeManager.extension_attribute_type == null &&
 118                                 assembly.FullName == SystemCore) {
 119                                 TypeManager.extension_attribute_type = assembly.GetType("System.Runtime.CompilerServices.ExtensionAttribute");
 120                         }
 121
 122                         bool contains_extension_methods = TypeManager.extension_attribute_type != null &&
 123                                         assembly.IsDefined(TypeManager.extension_attribute_type, false);
 124
 125                         if (get_namespaces_method != null && !contains_extension_methods) {
 126                                 string [] namespaces = (string []) get_namespaces_method.Invoke (assembly, null);
 127                                 foreach (string ns in namespaces)
 128                                         RegisterNamespace (ns);
 129                                 return;
 130                         }
 131
 132                         foreach (Type t in assembly.GetExportedTypes ()) {
 133                                 if ((t.Attributes & Class.StaticClassAttribute) == Class.StaticClassAttribute &&
 134                                         contains_extension_methods && t.IsDefined (TypeManager.extension_attribute_type, false))
 135                                         RegisterExtensionMethodClass (t);
 136                                 else
 137                                         RegisterNamespace (t.Namespace);
 138                         }
 139                 }
 140
 141                 protected static Type GetTypeInAssembly (Assembly assembly, string name)
 142                 {
 143                         Type t = assembly.GetType (name);
 144                         if (t == null)
 145                                 return null;
 146
 147                         if (t.IsPointer)
 148                                 throw new InternalErrorException ("Use GetPointerType() to get a pointer");
 149
 150                         TypeAttributes ta = t.Attributes & TypeAttributes.VisibilityMask;
 151                         if (ta == TypeAttributes.NestedPrivate)
 152                                 return null;
 153
 154                         if ((ta == TypeAttributes.NotPublic ||
 155                              ta == TypeAttributes.NestedAssembly ||
 156                              ta == TypeAttributes.NestedFamANDAssem) &&
 157                             !TypeManager.IsThisOrFriendAssembly (t.Assembly))
 158                                 return null;
 159
 160                         return t;
 161                 }
 162
 163                 public override string ToString ()
 164                 {
 165                         return String.Format ("RootNamespace ({0}::)", alias_name);
 166                 }
 167
 168                 public override string GetSignatureForError ()
 169                 {
 170                         return alias_name + "::";
 171                 }
 172         }
 173
 174         public class GlobalRootNamespace : RootNamespace {
 175                 Assembly [] assemblies;
 176                 Module [] modules;
 177
 178                 public GlobalRootNamespace ()
 179                         : base ("global", null)
 180                 {
 181                         assemblies = new Assembly [0];
 182                 }
 183
 184                 public Assembly [] Assemblies {
 185                         get { return assemblies; }
 186                 }
 187
 188                 public Module [] Modules {
 189                         get { return modules; }
 190                 }
 191
 192                 public void AddAssemblyReference (Assembly a)
 193                 {
 194                         foreach (Assembly assembly in assemblies) {
 195                                 if (a == assembly)
 196                                         return;
 197                         }
 198
 199                         int top = assemblies.Length;
 200                         Assembly [] n = new Assembly [top + 1];
 201                         assemblies.CopyTo (n, 0);
 202                         n [top] = a;
 203                         assemblies = n;
 204
 205                         ComputeNamespaces (a);
 206                 }
 207
 208                 public void AddModuleReference (Module m)
 209                 {
 210                         int top = modules != null ? modules.Length : 0;
 211                         Module [] n = new Module [top + 1];
 212                         if (modules != null)
 213                                 modules.CopyTo (n, 0);
 214                         n [top] = m;
 215                         modules = n;
 216
 217                         if (m == CodeGen.Module.Builder)
 218                                 return;
 219
 220                         foreach (Type t in m.GetTypes ())
 221                                 RegisterNamespace (t.Namespace);
 222                 }
 223
 224                 public override void Error_NamespaceDoesNotExist(DeclSpace ds, Location loc, string name)
 225                 {
 226                         Report.Error (400, loc, "The type or namespace name `{0}' could not be found in the global namespace (are you missing an assembly reference?)",
 227                                 name);
 228                 }
 229
 230                 public override Type LookupTypeReflection (string name, Location loc)
 231                 {
 232                         Type found_type = null;
 233
 234                         foreach (Assembly a in assemblies) {
 235                                 Type t = GetTypeInAssembly (a, name);
 236                                 if (t == null)
 237                                         continue;
 238
 239                                 if (found_type == null) {
 240                                         found_type = t;
 241                                         continue;
 242                                 }
 243
 244                                 Report.SymbolRelatedToPreviousError (found_type);
 245                                 Report.SymbolRelatedToPreviousError (t);
 246                                 Report.Error (433, loc, "The imported type `{0}' is defined multiple times", name);
 247
 248                                 return found_type;
 249                         }
 250
 251                         if (modules != null) {
 252                                 foreach (Module module in modules) {
 253                                         Type t = module.GetType (name);
 254                                         if (t == null)
 255                                                 continue;
 256
 257                                         if (found_type == null) {
 258                                                 found_type = t;
 259                                                 continue;
 260                                         }
 261
 262                                         Report.SymbolRelatedToPreviousError (found_type);
 263                                         if (loc.IsNull) {
 264                                                 DeclSpace ds = TypeManager.LookupDeclSpace (t);
 265                                                 Report.Warning (1685, 1, ds.Location, "The type `{0}' conflicts with the predefined type `{1}' and will be ignored",
 266                                                         ds.GetSignatureForError (), TypeManager.CSharpName (found_type));
 267                                                 return found_type;
 268                                         }
 269                                         Report.SymbolRelatedToPreviousError (t);
 270                                         Report.Warning (436, 2, loc, "The type `{0}' conflicts with the imported type `{1}'. Ignoring the imported type definition",
 271                                                 TypeManager.CSharpName (t), TypeManager.CSharpName (found_type));
 272                                         return t;
 273                                 }
 274                         }
 275
 276                         return found_type;
 277                 }
 278         }
 279
 280         /// <summary>
 281         ///   Keeps track of the namespaces defined in the C# code.
 282         ///
 283         ///   This is an Expression to allow it to be referenced in the
 284         ///   compiler parse/intermediate tree during name resolution.
 285         /// </summary>
 286         public class Namespace : FullNamedExpression {
 287
 288                 Namespace parent;
 289                 string fullname;
 290                 IDictionary namespaces;
 291                 IDictionary declspaces;
 292                 Hashtable cached_types;
 293                 RootNamespace root;
 294                 ArrayList external_exmethod_classes;
 295
 296                 public readonly MemberName MemberName;
 297
 298                 /// <summary>
 299                 ///   Constructor Takes the current namespace and the
 300                 ///   name.  This is bootstrapped with parent == null
 301                 ///   and name = ""
 302                 /// </summary>
 303                 public Namespace (Namespace parent, string name)
 304                 {
 305                         // Expression members.
 306                         this.eclass = ExprClass.Namespace;
 307                         this.Type = typeof (Namespace);
 308                         this.loc = Location.Null;
 309
 310                         this.parent = parent;
 311
 312                         if (parent != null)
 313                                 this.root = parent.root;
 314                         else
 315                                 this.root = this as RootNamespace;
 316
 317                         if (this.root == null)
 318                                 throw new InternalErrorException ("Root namespaces must be created using RootNamespace");
 319
 320                         string pname = parent != null ? parent.fullname : "";
 321
 322                         if (pname == "")
 323                                 fullname = name;
 324                         else
 325                                 fullname = parent.fullname + "." + name;
 326
 327                         if (fullname == null)
 328                                 throw new InternalErrorException ("Namespace has a null fullname");
 329
 330                         if (parent != null && parent.MemberName != MemberName.Null)
 331                                 MemberName = new MemberName (parent.MemberName, name);
 332                         else if (name.Length == 0)
 333                                 MemberName = MemberName.Null;
 334                         else
 335                                 MemberName = new MemberName (name);
 336
 337                         namespaces = new HybridDictionary ();
 338                         cached_types = new Hashtable ();
 339
 340                         root.RegisterNamespace (this);
 341                 }
 342
 343                 public override Expression DoResolve (EmitContext ec)
 344                 {
 345                         return this;
 346                 }
 347
 348                 public virtual void Error_NamespaceDoesNotExist (DeclSpace ds, Location loc, string name)
 349                 {
 350                         if (name.IndexOf ('`') > 0) {
 351                                 FullNamedExpression retval = Lookup (ds, SimpleName.RemoveGenericArity (name), loc);
 352                                 if (retval != null) {
 353                                         Error_TypeArgumentsCannotBeUsed (retval.Type, loc);
 354                                         return;
 355                                 }
 356                         } else {
 357                                 Type t = LookForAnyGenericType (name);
 358                                 if (t != null) {
 359                                         Error_InvalidNumberOfTypeArguments (t, loc);
 360                                         return;
 361                                 }
 362                         }
 363
 364                         Report.Error (234, loc, "The type or namespace name `{0}' does not exist in the namespace `{1}'. Are you missing an assembly reference?",
 365                                 name, GetSignatureForError ());
 366                 }
 367
 368                 public static void Error_InvalidNumberOfTypeArguments (Type t, Location loc)
 369                 {
 370                         Report.SymbolRelatedToPreviousError (t);
 371                         Report.Error (305, loc, "Using the generic type `{0}' requires `{1}' type argument(s)",
 372                                 TypeManager.CSharpName(t), TypeManager.GetNumberOfTypeArguments(t).ToString());
 373                 }
 374
 375                 public static void Error_TypeArgumentsCannotBeUsed (Type t, Location loc)
 376                 {
 377                         Report.SymbolRelatedToPreviousError (t);
 378                         Error_TypeArgumentsCannotBeUsed (loc, "type", TypeManager.CSharpName (t));
 379                 }
 380
 381                 public static void Error_TypeArgumentsCannotBeUsed (MethodBase mi, Location loc)
 382                 {
 383                         Report.SymbolRelatedToPreviousError (mi);
 384                         Error_TypeArgumentsCannotBeUsed (loc, "method", TypeManager.CSharpSignature (mi));
 385                 }
 386
 387                 static void Error_TypeArgumentsCannotBeUsed (Location loc, string type, string name)
 388                 {
 389                         Report.Error(308, loc, "The non-generic {0} `{1}' cannot be used with the type arguments",
 390                                 type, name);
 391                 }
 392
 393                 public override string GetSignatureForError ()
 394                 {
 395                         return fullname;
 396                 }
 397
 398                 public Namespace GetNamespace (string name, bool create)
 399                 {
 400                         int pos = name.IndexOf ('.');
 401
 402                         Namespace ns;
 403                         string first;
 404                         if (pos >= 0)
 405                                 first = name.Substring (0, pos);
 406                         else
 407                                 first = name;
 408
 409                         ns = (Namespace) namespaces [first];
 410                         if (ns == null) {
 411                                 if (!create)
 412                                         return null;
 413
 414                                 ns = new Namespace (this, first);
 415                                 namespaces.Add (first, ns);
 416                         }
 417
 418                         if (pos >= 0)
 419                                 ns = ns.GetNamespace (name.Substring (pos + 1), create);
 420
 421                         return ns;
 422                 }
 423
 424                 TypeExpr LookupType (string name, Location loc)
 425                 {
 426                         if (cached_types.Contains (name))
 427                                 return cached_types [name] as TypeExpr;
 428
 429                         Type t = null;
 430                         if (declspaces != null) {
 431                                 DeclSpace tdecl = declspaces [name] as DeclSpace;
 432                                 if (tdecl != null) {
 433                                         //
 434                                         // Note that this is not:
 435                                         //
 436                                         //   t = tdecl.DefineType ()
 437                                         //
 438                                         // This is to make it somewhat more useful when a DefineType
 439                                         // fails due to problems in nested types (more useful in the sense
 440                                         // of fewer misleading error messages)
 441                                         //
 442                                         tdecl.DefineType ();
 443                                         t = tdecl.TypeBuilder;
 444                                 }
 445                         }
 446                         string lookup = t != null ? t.FullName : (fullname.Length == 0 ? name : fullname + "." + name);
 447                         Type rt = root.LookupTypeReflection (lookup, loc);
 448
 449                         // HACK: loc.IsNull when the type is core type
 450                         if (t == null || (rt != null && loc.IsNull))
 451                                 t = rt;
 452
 453                         TypeExpr te = t == null ? null : new TypeExpression (t, Location.Null);
 454                         cached_types [name] = te;
 455                         return te;
 456                 }
 457
 458                 ///
 459                 /// Used for better error reporting only
 460                 ///
 461                 public Type LookForAnyGenericType (string typeName)
 462                 {
 463                         if (declspaces == null)
 464                                 return null;
 465
 466                         typeName = SimpleName.RemoveGenericArity (typeName);
 467
 468                         foreach (DictionaryEntry de in declspaces) {
 469                                 string type_item = (string) de.Key;
 470                                 int pos = type_item.LastIndexOf ('`');
 471                                 if (pos == typeName.Length && String.Compare (typeName, 0, type_item, 0, pos) == 0)
 472                                         return ((DeclSpace) de.Value).TypeBuilder;
 473                         }
 474                         return null;
 475                 }
 476
 477                 public FullNamedExpression Lookup (DeclSpace ds, string name, Location loc)
 478                 {
 479                         if (namespaces.Contains (name))
 480                                 return (Namespace) namespaces [name];
 481
 482                         return LookupType (name, loc);
 483                 }
 484
 485                 public void RegisterExternalExtensionMethodClass (Type type)
 486                 {
 487                         if (external_exmethod_classes == null)
 488                                 external_exmethod_classes = new ArrayList ();
 489
 490                         external_exmethod_classes.Add (type);
 491                 }
 492
 493                 ///
 494                 /// Looks for extension method in this namespace
 495                 ///
 496                 public ArrayList LookupExtensionMethod (Type extensionType, ClassOrStruct currentClass, string name)
 497                 {
 498                         ArrayList found = null;
 499
 500                         if (declspaces != null) {
 501                                 IEnumerator e = declspaces.Values.GetEnumerator ();
 502                                 e.Reset ();
 503                                 while (e.MoveNext ()) {
 504                                         Class c = e.Current as Class;
 505                                         if (c == null)
 506                                                 continue;
 507
 508                                         if (!c.IsStaticClass)
 509                                                 continue;
 510
 511                                         ArrayList res = c.MemberCache.FindExtensionMethods (extensionType, name, c != currentClass);
 512                                         if (res == null)
 513                                                 continue;
 514
 515                                         if (found == null)
 516                                                 found = res;
 517                                         else
 518                                                 found.AddRange (res);
 519                                 }
 520                         }
 521
 522                         if (external_exmethod_classes == null)
 523                                 return found;
 524
 525                         foreach (Type t in external_exmethod_classes) {
 526                                 MemberCache m = TypeHandle.GetMemberCache (t);
 527                                 ArrayList res = m.FindExtensionMethods (extensionType, name, true);
 528                                 if (res == null)
 529                                         continue;
 530
 531                                 if (found == null)
 532                                         found = res;
 533                                 else
 534                                         found.AddRange (res);
 535                         }
 536
 537                         return found;
 538                 }
 539
 540                 public void AddDeclSpace (string name, DeclSpace ds)
 541                 {
 542                         if (declspaces == null)
 543                                 declspaces = new HybridDictionary ();
 544                         declspaces.Add (name, ds);
 545                 }
 546
 547                 /// <summary>
 548                 ///   The qualified name of the current namespace
 549                 /// </summary>
 550                 public string Name {
 551                         get { return fullname; }
 552                 }
 553
 554                 /// <summary>
 555                 ///   The parent of this namespace, used by the parser to "Pop"
 556                 ///   the current namespace declaration
 557                 /// </summary>
 558                 public Namespace Parent {
 559                         get { return parent; }
 560                 }
 561         }
 562
 563         //
 564         // Namespace container as created by the parser
 565         //
 566         public class NamespaceEntry : IResolveContext {
 567
 568                 class UsingEntry {
 569                         readonly MemberName name;
 570                         Namespace resolved;
 571
 572                         public UsingEntry (MemberName name)
 573                         {
 574                                 this.name = name;
 575                         }
 576
 577                         public string GetSignatureForError ()
 578                         {
 579                                 return name.GetSignatureForError ();
 580                         }
 581
 582                         public Location Location {
 583                                 get { return name.Location; }
 584                         }
 585
 586                         public MemberName MemberName {
 587                                 get { return name; }
 588                         }
 589
 590                         public string Name {
 591                                 get { return GetSignatureForError (); }
 592                         }
 593
 594                         public Namespace Resolve (IResolveContext rc)
 595                         {
 596                                 if (resolved != null)
 597                                         return resolved;
 598
 599                                 FullNamedExpression fne = name.GetTypeExpression ().ResolveAsTypeStep (rc, false);
 600                                 if (fne == null)
 601                                         return null;
 602
 603                                 resolved = fne as Namespace;
 604                                 if (resolved == null) {
 605                                         Report.SymbolRelatedToPreviousError (fne.Type);
 606                                         Report.Error (138, Location,
 607                                                 "`{0}' is a type not a namespace. A using namespace directive can only be applied to namespaces",
 608                                                 GetSignatureForError ());
 609                                 }
 610                                 return resolved;
 611                         }
 612                 }
 613
 614                 class UsingAliasEntry {
 615                         public readonly string Alias;
 616                         public Location Location;
 617
 618                         public UsingAliasEntry (string alias, Location loc)
 619                         {
 620                                 this.Alias = alias;
 621                                 this.Location = loc;
 622                         }
 623
 624                         public virtual FullNamedExpression Resolve (IResolveContext rc)
 625                         {
 626                                 FullNamedExpression fne = RootNamespace.GetRootNamespace (Alias);
 627                                 if (fne == null) {
 628                                         Report.Error (430, Location,
 629                                                 "The extern alias `{0}' was not specified in -reference option",
 630                                                 Alias);
 631                                 }
 632
 633                                 return fne;
 634                         }
 635                 }
 636
 637                 class LocalUsingAliasEntry : UsingAliasEntry {
 638                         Expression resolved;
 639                         MemberName value;
 640
 641                         public LocalUsingAliasEntry (string alias, MemberName name, Location loc)
 642                                 : base (alias, loc)
 643                         {
 644                                 this.value = name;
 645                         }
 646
 647                         public override FullNamedExpression Resolve (IResolveContext rc)
 648                         {
 649                                 if (resolved != null)
 650                                         return (FullNamedExpression)resolved;
 651
 652                                 resolved = value.GetTypeExpression ().ResolveAsTypeStep (rc, false);
 653                                 if (resolved == null)
 654                                         return null;
 655
 656                                 // FIXME: This is quite wrong, the accessibility is not global
 657                                 if (resolved.Type != null) {
 658                                         TypeAttributes attr = resolved.Type.Attributes & TypeAttributes.VisibilityMask;
 659                                         if (attr == TypeAttributes.NestedPrivate || attr == TypeAttributes.NestedFamily ||
 660                                                 ((attr == TypeAttributes.NestedFamORAssem || attr == TypeAttributes.NestedAssembly) &&
 661                                                 TypeManager.LookupDeclSpace (resolved.Type) == null)) {
 662                                                 Expression.ErrorIsInaccesible (resolved.Location, resolved.GetSignatureForError ());
 663                                                 return null;
 664                                         }
 665                                 }
 666
 667                                 return (FullNamedExpression)resolved;
 668                         }
 669                 }
 670
 671                 Namespace ns;
 672                 NamespaceEntry parent, implicit_parent;
 673                 CompilationUnit file;
 674                 int symfile_id;
 675
 676                 // Namespace using import block
 677                 ArrayList using_aliases;
 678                 ArrayList using_clauses;
 679                 public bool DeclarationFound = false;
 680                 // End
 681
 682                 public readonly bool IsImplicit;
 683                 public readonly DeclSpace SlaveDeclSpace;
 684                 static readonly Namespace [] empty_namespaces = new Namespace [0];
 685                 Namespace [] namespace_using_table;
 686
 687                 static ArrayList entries = new ArrayList ();
 688
 689                 public static void Reset ()
 690                 {
 691                         entries = new ArrayList ();
 692                 }
 693
 694                 public NamespaceEntry (NamespaceEntry parent, CompilationUnit file, string name)
 695                 {
 696                         this.parent = parent;
 697                         this.file = file;
 698                         entries.Add (this);
 699
 700                         if (parent != null)
 701                                 ns = parent.NS.GetNamespace (name, true);
 702                         else if (name != null)
 703                                 ns = RootNamespace.Global.GetNamespace (name, true);
 704                         else
 705                                 ns = RootNamespace.Global;
 706                         SlaveDeclSpace = new RootDeclSpace (this);
 707                 }
 708
 709                 private NamespaceEntry (NamespaceEntry parent, CompilationUnit file, Namespace ns, bool slave)
 710                 {
 711                         this.parent = parent;
 712                         this.file = file;
 713                         this.IsImplicit = true;
 714                         this.ns = ns;
 715                         this.SlaveDeclSpace = slave ? new RootDeclSpace (this) : null;
 716                 }
 717
 718                 //
 719                 // According to section 16.3.1 (using-alias-directive), the namespace-or-type-name is
 720                 // resolved as if the immediately containing namespace body has no using-directives.
 721                 //
 722                 // Section 16.3.2 says that the same rule is applied when resolving the namespace-name
 723                 // in the using-namespace-directive.
 724                 //
 725                 // To implement these rules, the expressions in the using directives are resolved using
 726                 // the "doppelganger" (ghostly bodiless duplicate).
 727                 //
 728                 NamespaceEntry doppelganger;
 729                 NamespaceEntry Doppelganger {
 730                         get {
 731                                 if (!IsImplicit && doppelganger == null) {
 732                                         doppelganger = new NamespaceEntry (ImplicitParent, file, ns, true);
 733                                         doppelganger.using_aliases = using_aliases;
 734                                 }
 735                                 return doppelganger;
 736                         }
 737                 }
 738
 739                 public Namespace NS {
 740                         get { return ns; }
 741                 }
 742
 743                 public NamespaceEntry Parent {
 744                         get { return parent; }
 745                 }
 746
 747                 public NamespaceEntry ImplicitParent {
 748                         get {
 749                                 if (parent == null)
 750                                         return null;
 751                                 if (implicit_parent == null) {
 752                                         implicit_parent = (parent.NS == ns.Parent)
 753                                                 ? parent
 754                                                 : new NamespaceEntry (parent, file, ns.Parent, false);
 755                                 }
 756                                 return implicit_parent;
 757                         }
 758                 }
 759
 760                 /// <summary>
 761                 ///   Records a new namespace for resolving name references
 762                 /// </summary>
 763                 public void AddUsing (MemberName name, Location loc)
 764                 {
 765                         if (DeclarationFound){
 766                                 Report.Error (1529, loc, "A using clause must precede all other namespace elements except extern alias declarations");
 767                         }
 768
 769                         if (using_clauses == null) {
 770                                 using_clauses = new ArrayList ();
 771                         } else {
 772                                 foreach (UsingEntry old_entry in using_clauses) {
 773                                         if (name.Equals (old_entry.MemberName)) {
 774                                                 Report.SymbolRelatedToPreviousError (old_entry.Location, old_entry.GetSignatureForError ());
 775                                                 Report.Warning (105, 3, loc, "The using directive for `{0}' appeared previously in this namespace", name.GetSignatureForError ());
 776                                                 return;
 777                                         }
 778                                 }
 779                         }
 780
 781                         using_clauses.Add (new UsingEntry (name));
 782                 }
 783
 784                 public void AddUsingAlias (string alias, MemberName name, Location loc)
 785                 {
 786                         // TODO: This is parser bussines
 787                         if (DeclarationFound){
 788                                 Report.Error (1529, loc, "A using clause must precede all other namespace elements except extern alias declarations");
 789                         }
 790
 791                         if (RootContext.Version != LanguageVersion.ISO_1 && alias == "global")
 792                                 Report.Warning (440, 2, loc, "An alias named `global' will not be used when resolving 'global::';" +
 793                                         " the global namespace will be used instead");
 794
 795                         AddUsingAlias (new LocalUsingAliasEntry (alias, name, loc));
 796                 }
 797
 798                 public void AddUsingExternalAlias (string alias, Location loc)
 799                 {
 800                         // TODO: Do this in parser
 801                         bool not_first = using_clauses != null || DeclarationFound;
 802                         if (using_aliases != null && !not_first) {
 803                                 foreach (UsingAliasEntry uae in using_aliases) {
 804                                         if (uae is LocalUsingAliasEntry) {
 805                                                 not_first = true;
 806                                                 break;
 807                                         }
 808                                 }
 809                         }
 810
 811                         if (not_first)
 812                                 Report.Error (439, loc, "An extern alias declaration must precede all other elements");
 813
 814                         if (alias == "global") {
 815                                 Error_GlobalNamespaceRedefined (loc);
 816                                 return;
 817                         }
 818
 819                         AddUsingAlias (new UsingAliasEntry (alias, loc));
 820                 }
 821
 822                 void AddUsingAlias (UsingAliasEntry uae)
 823                 {
 824                         if (using_aliases == null) {
 825                                 using_aliases = new ArrayList ();
 826                         } else {
 827                                 foreach (UsingAliasEntry entry in using_aliases) {
 828                                         if (uae.Alias == entry.Alias) {
 829                                                 Report.SymbolRelatedToPreviousError (uae.Location, uae.Alias);
 830                                                 Report.Error (1537, entry.Location, "The using alias `{0}' appeared previously in this namespace",
 831                                                         entry.Alias);
 832                                                 return;
 833                                         }
 834                                 }
 835                         }
 836
 837                         using_aliases.Add (uae);
 838                 }
 839
 840                 ///
 841                 /// Does extension methods look up to find a method which matches name and extensionType.
 842                 /// Search starts from this namespace and continues hierarchically up to top level.
 843                 ///
 844                 public ExtensionMethodGroupExpr LookupExtensionMethod (Type extensionType, ClassOrStruct currentClass, string name, Location loc)
 845                 {
 846                         ArrayList candidates = null;
 847                         if (currentClass != null) {
 848                                 candidates = ns.LookupExtensionMethod (extensionType, currentClass, name);
 849                                 if (candidates != null)
 850                                         return new ExtensionMethodGroupExpr (candidates, this, extensionType, loc);
 851                         }
 852
 853                         foreach (Namespace n in GetUsingTable ()) {
 854                                 ArrayList a = n.LookupExtensionMethod (extensionType, null, name);
 855                                 if (a == null)
 856                                         continue;
 857
 858                                 if (candidates == null)
 859                                         candidates = a;
 860                                 else
 861                                         candidates.AddRange (a);
 862                         }
 863
 864                         if (candidates != null)
 865                                 return new ExtensionMethodGroupExpr (candidates, parent, extensionType, loc);
 866
 867                         if (parent == null)
 868                                 return null;
 869
 870                         //
 871                         // Inspect parent namespaces in namespace expression
 872                         //
 873                         Namespace parent_ns = ns.Parent;
 874                         do {
 875                                 candidates = parent_ns.LookupExtensionMethod (extensionType, null, name);
 876                                 if (candidates != null)
 877                                         return new ExtensionMethodGroupExpr (candidates, parent, extensionType, loc);
 878
 879                                 parent_ns = parent_ns.Parent;
 880                         } while (parent_ns != null);
 881
 882                         //
 883                         // Continue in parent scope
 884                         //
 885                         return parent.LookupExtensionMethod (extensionType, currentClass, name, loc);
 886                 }
 887
 888                 public FullNamedExpression LookupNamespaceOrType (DeclSpace ds, string name, Location loc, bool ignore_cs0104)
 889                 {
 890                         // Precondition: Only simple names (no dots) will be looked up with this function.
 891                         FullNamedExpression resolved = null;
 892                         for (NamespaceEntry curr_ns = this; curr_ns != null; curr_ns = curr_ns.ImplicitParent) {
 893                                 if ((resolved = curr_ns.Lookup (ds, name, loc, ignore_cs0104)) != null)
 894                                         break;
 895                         }
 896                         return resolved;
 897                 }
 898
 899                 static void Error_AmbiguousTypeReference (Location loc, string name, FullNamedExpression t1, FullNamedExpression t2)
 900                 {
 901                         Report.SymbolRelatedToPreviousError (t1.Type);
 902                         Report.SymbolRelatedToPreviousError (t2.Type);
 903                         Report.Error (104, loc, "`{0}' is an ambiguous reference between `{1}' and `{2}'",
 904                                 name, t1.GetSignatureForError (), t2.GetSignatureForError ());
 905                 }
 906
 907                 // Looks-up a alias named @name in this and surrounding namespace declarations
 908                 public FullNamedExpression LookupAlias (string name)
 909                 {
 910                         for (NamespaceEntry n = this; n != null; n = n.ImplicitParent) {
 911                                 if (n.using_aliases == null)
 912                                         continue;
 913
 914                                 foreach (UsingAliasEntry ue in n.using_aliases) {
 915                                         if (ue.Alias == name)
 916                                                 return ue.Resolve (Doppelganger);
 917                                 }
 918                         }
 919
 920                         return null;
 921                 }
 922
 923                 private FullNamedExpression Lookup (DeclSpace ds, string name, Location loc, bool ignore_cs0104)
 924                 {
 925                         //
 926                         // Check whether it's in the namespace.
 927                         //
 928                         FullNamedExpression fne = ns.Lookup (ds, name, loc);
 929
 930                         //
 931                         // Check aliases.
 932                         //
 933                         if (using_aliases != null) {
 934                                 foreach (UsingAliasEntry ue in using_aliases) {
 935                                         if (ue.Alias == name) {
 936                                                 if (fne != null) {
 937                                                         if (Doppelganger != null) {
 938                                                                 // TODO: Namespace has broken location
 939                                                                 //Report.SymbolRelatedToPreviousError (fne.Location, null);
 940                                                                 Report.SymbolRelatedToPreviousError (ue.Location, null);
 941                                                                 Report.Error (576, loc,
 942                                                                         "Namespace `{0}' contains a definition with same name as alias `{1}'",
 943                                                                         GetSignatureForError (), name);
 944                                                         } else {
 945                                                                 return fne;
 946                                                         }
 947                                                 }
 948
 949                                                 return ue.Resolve (Doppelganger);
 950                                         }
 951                                 }
 952                         }
 953
 954                         if (fne != null)
 955                                 return fne;
 956
 957                         if (IsImplicit)
 958                                 return null;
 959
 960                         //
 961                         // Check using entries.
 962                         //
 963                         FullNamedExpression match = null;
 964                         foreach (Namespace using_ns in GetUsingTable ()) {
 965                                 match = using_ns.Lookup (ds, name, loc);
 966                                 if (match == null || !(match is TypeExpr))
 967                                         continue;
 968                                 if (fne != null) {
 969                                         if (!ignore_cs0104)
 970                                                 Error_AmbiguousTypeReference (loc, name, fne, match);
 971                                         return null;
 972                                 }
 973                                 fne = match;
 974                         }
 975
 976                         return fne;
 977                 }
 978
 979                 Namespace [] GetUsingTable ()
 980                 {
 981                         if (namespace_using_table != null)
 982                                 return namespace_using_table;
 983
 984                         if (using_clauses == null) {
 985                                 namespace_using_table = empty_namespaces;
 986                                 return namespace_using_table;
 987                         }
 988
 989                         ArrayList list = new ArrayList (using_clauses.Count);
 990
 991                         foreach (UsingEntry ue in using_clauses) {
 992                                 Namespace using_ns = ue.Resolve (Doppelganger);
 993                                 if (using_ns == null)
 994                                         continue;
 995
 996                                 list.Add (using_ns);
 997                         }
 998
 999                         namespace_using_table = (Namespace[])list.ToArray (typeof (Namespace));
1000                         return namespace_using_table;
1001                 }
1002
1003                 static readonly string [] empty_using_list = new string [0];
1004
1005                 public int SymbolFileID {
1006                         get {
1007                                 if (symfile_id == 0 && file.SourceFileEntry != null) {
1008                                         int parent_id = parent == null ? 0 : parent.SymbolFileID;
1009
1010                                         string [] using_list = empty_using_list;
1011                                         if (using_clauses != null) {
1012                                                 using_list = new string [using_clauses.Count];
1013                                                 for (int i = 0; i < using_clauses.Count; i++)
1014                                                         using_list [i] = ((UsingEntry) using_clauses [i]).MemberName.GetTypeName ();
1015                                         }
1016
1017                                         symfile_id = SymbolWriter.DefineNamespace (ns.Name, file.CompileUnitEntry, using_list, parent_id);
1018                                 }
1019                                 return symfile_id;
1020                         }
1021                 }
1022
1023                 static void MsgtryRef (string s)
1024                 {
1025                         Console.WriteLine ("    Try using -r:" + s);
1026                 }
1027
1028                 static void MsgtryPkg (string s)
1029                 {
1030                         Console.WriteLine ("    Try using -pkg:" + s);
1031                 }
1032
1033                 public static void Error_GlobalNamespaceRedefined (Location loc)
1034                 {
1035                         Report.Error (1681, loc, "You cannot redefine the global extern alias");
1036                 }
1037
1038                 public static void Error_NamespaceNotFound (Location loc, string name)
1039                 {
1040                         Report.Error (246, loc, "The type or namespace name `{0}' could not be found. Are you missing a using directive or an assembly reference?",
1041                                 name);
1042
1043                         switch (name) {
1044                         case "Gtk": case "GtkSharp":
1045                                 MsgtryPkg ("gtk-sharp");
1046                                 break;
1047
1048                         case "Gdk": case "GdkSharp":
1049                                 MsgtryPkg ("gdk-sharp");
1050                                 break;
1051
1052                         case "Glade": case "GladeSharp":
1053                                 MsgtryPkg ("glade-sharp");
1054                                 break;
1055
1056                         case "System.Drawing":
1057                         case "System.Web.Services":
1058                         case "System.Web":
1059                         case "System.Data":
1060                         case "System.Windows.Forms":
1061                                 MsgtryRef (name);
1062                                 break;
1063                         }
1064                 }
1065
1066                 /// <summary>
1067                 ///   Used to validate that all the using clauses are correct
1068                 ///   after we are finished parsing all the files.
1069                 /// </summary>
1070                 void VerifyUsing ()
1071                 {
1072                         if (using_aliases != null) {
1073                                 foreach (UsingAliasEntry ue in using_aliases)
1074                                         ue.Resolve (Doppelganger);
1075                         }
1076
1077                         if (using_clauses != null) {
1078                                 foreach (UsingEntry ue in using_clauses)
1079                                         ue.Resolve (Doppelganger);
1080                         }
1081                 }
1082
1083                 /// <summary>
1084                 ///   Used to validate that all the using clauses are correct
1085                 ///   after we are finished parsing all the files.
1086                 /// </summary>
1087                 static public void VerifyAllUsing ()
1088                 {
1089                         foreach (NamespaceEntry entry in entries)
1090                                 entry.VerifyUsing ();
1091                 }
1092
1093                 public string GetSignatureForError ()
1094                 {
1095                         return ns.GetSignatureForError ();
1096                 }
1097
1098                 public override string ToString ()
1099                 {
1100                         return ns.ToString ();
1101                 }
1102
1103                 #region IResolveContext Members
1104
1105                 public DeclSpace DeclContainer {
1106                         get { return SlaveDeclSpace; }
1107                 }
1108
1109                 public bool IsInObsoleteScope {
1110                         get { return SlaveDeclSpace.IsInObsoleteScope; }
1111                 }
1112
1113                 public bool IsInUnsafeScope {
1114                         get { return SlaveDeclSpace.IsInUnsafeScope; }
1115                 }
1116
1117                 public DeclSpace GenericDeclContainer {
1118                         get { return SlaveDeclSpace; }
1119                 }
1120
1121                 #endregion
1122         }
1123 }