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                 public bool HasDefinition (string name)
 425                 {
 426                         return declspaces != null && declspaces [name] != null;
 427                 }
 428
 429                 TypeExpr LookupType (string name, Location loc)
 430                 {
 431                         if (cached_types.Contains (name))
 432                                 return cached_types [name] as TypeExpr;
 433
 434                         Type t = null;
 435                         if (declspaces != null) {
 436                                 DeclSpace tdecl = declspaces [name] as DeclSpace;
 437                                 if (tdecl != null) {
 438                                         //
 439                                         // Note that this is not:
 440                                         //
 441                                         //   t = tdecl.DefineType ()
 442                                         //
 443                                         // This is to make it somewhat more useful when a DefineType
 444                                         // fails due to problems in nested types (more useful in the sense
 445                                         // of fewer misleading error messages)
 446                                         //
 447                                         tdecl.DefineType ();
 448                                         t = tdecl.TypeBuilder;
 449
 450                                         if (RootContext.EvalMode){
 451                                                 // Replace the TypeBuilder with a System.Type, as
 452                                                 // Reflection.Emit fails otherwise (we end up pretty
 453                                                 // much with Random type definitions later on).
 454                                                 Type tt = t.Assembly.GetType (t.Name);
 455                                                 if (tt != null)
 456                                                         t = tt;
 457                                         }
 458                                 }
 459                         }
 460                         string lookup = t != null ? t.FullName : (fullname.Length == 0 ? name : fullname + "." + name);
 461                         Type rt = root.LookupTypeReflection (lookup, loc);
 462
 463                         // HACK: loc.IsNull when the type is core type
 464                         if (t == null || (rt != null && loc.IsNull))
 465                                 t = rt;
 466
 467                         TypeExpr te = t == null ? null : new TypeExpression (t, Location.Null);
 468                         cached_types [name] = te;
 469                         return te;
 470                 }
 471
 472                 ///
 473                 /// Used for better error reporting only
 474                 ///
 475                 public Type LookForAnyGenericType (string typeName)
 476                 {
 477                         if (declspaces == null)
 478                                 return null;
 479
 480                         typeName = SimpleName.RemoveGenericArity (typeName);
 481
 482                         foreach (DictionaryEntry de in declspaces) {
 483                                 string type_item = (string) de.Key;
 484                                 int pos = type_item.LastIndexOf ('`');
 485                                 if (pos == typeName.Length && String.Compare (typeName, 0, type_item, 0, pos) == 0)
 486                                         return ((DeclSpace) de.Value).TypeBuilder;
 487                         }
 488                         return null;
 489                 }
 490
 491                 public FullNamedExpression Lookup (DeclSpace ds, string name, Location loc)
 492                 {
 493                         if (namespaces.Contains (name))
 494                                 return (Namespace) namespaces [name];
 495
 496                         return LookupType (name, loc);
 497                 }
 498
 499                 public void RegisterExternalExtensionMethodClass (Type type)
 500                 {
 501                         if (external_exmethod_classes == null)
 502                                 external_exmethod_classes = new ArrayList ();
 503
 504                         external_exmethod_classes.Add (type);
 505                 }
 506
 507                 ///
 508                 /// Looks for extension method in this namespace
 509                 ///
 510                 public ArrayList LookupExtensionMethod (Type extensionType, ClassOrStruct currentClass, string name)
 511                 {
 512                         ArrayList found = null;
 513
 514                         if (declspaces != null) {
 515                                 IEnumerator e = declspaces.Values.GetEnumerator ();
 516                                 e.Reset ();
 517                                 while (e.MoveNext ()) {
 518                                         Class c = e.Current as Class;
 519                                         if (c == null)
 520                                                 continue;
 521
 522                                         if (!c.IsStaticClass)
 523                                                 continue;
 524
 525                                         ArrayList res = c.MemberCache.FindExtensionMethods (extensionType, name, c != currentClass);
 526                                         if (res == null)
 527                                                 continue;
 528
 529                                         if (found == null)
 530                                                 found = res;
 531                                         else
 532                                                 found.AddRange (res);
 533                                 }
 534                         }
 535
 536                         if (external_exmethod_classes == null)
 537                                 return found;
 538
 539                         foreach (Type t in external_exmethod_classes) {
 540                                 MemberCache m = TypeHandle.GetMemberCache (t);
 541                                 ArrayList res = m.FindExtensionMethods (extensionType, name, true);
 542                                 if (res == null)
 543                                         continue;
 544
 545                                 if (found == null)
 546                                         found = res;
 547                                 else
 548                                         found.AddRange (res);
 549                         }
 550
 551                         return found;
 552                 }
 553
 554                 public void AddDeclSpace (string name, DeclSpace ds)
 555                 {
 556                         if (declspaces == null)
 557                                 declspaces = new HybridDictionary ();
 558                         declspaces.Add (name, ds);
 559                 }
 560
 561                 public void RemoveDeclSpace (string name)
 562                 {
 563                         declspaces.Remove (name);
 564                 }
 565
 566                 /// <summary>
 567                 ///   The qualified name of the current namespace
 568                 /// </summary>
 569                 public string Name {
 570                         get { return fullname; }
 571                 }
 572
 573                 /// <summary>
 574                 ///   The parent of this namespace, used by the parser to "Pop"
 575                 ///   the current namespace declaration
 576                 /// </summary>
 577                 public Namespace Parent {
 578                         get { return parent; }
 579                 }
 580         }
 581
 582         //
 583         // Namespace container as created by the parser
 584         //
 585         public class NamespaceEntry : IResolveContext {
 586
 587                 class UsingEntry {
 588                         readonly MemberName name;
 589                         Namespace resolved;
 590
 591                         public UsingEntry (MemberName name)
 592                         {
 593                                 this.name = name;
 594                         }
 595
 596                         public string GetSignatureForError ()
 597                         {
 598                                 return name.GetSignatureForError ();
 599                         }
 600
 601                         public Location Location {
 602                                 get { return name.Location; }
 603                         }
 604
 605                         public MemberName MemberName {
 606                                 get { return name; }
 607                         }
 608
 609                         public string Name {
 610                                 get { return GetSignatureForError (); }
 611                         }
 612
 613                         public Namespace Resolve (IResolveContext rc)
 614                         {
 615                                 if (resolved != null)
 616                                         return resolved;
 617
 618                                 FullNamedExpression fne = name.GetTypeExpression ().ResolveAsTypeStep (rc, false);
 619                                 if (fne == null)
 620                                         return null;
 621
 622                                 resolved = fne as Namespace;
 623                                 if (resolved == null) {
 624                                         Report.SymbolRelatedToPreviousError (fne.Type);
 625                                         Report.Error (138, Location,
 626                                                 "`{0}' is a type not a namespace. A using namespace directive can only be applied to namespaces",
 627                                                 GetSignatureForError ());
 628                                 }
 629                                 return resolved;
 630                         }
 631
 632                         public override string ToString ()
 633                         {
 634                                 return Name;
 635                         }
 636                 }
 637
 638                 class UsingAliasEntry {
 639                         public readonly string Alias;
 640                         public Location Location;
 641
 642                         public UsingAliasEntry (string alias, Location loc)
 643                         {
 644                                 this.Alias = alias;
 645                                 this.Location = loc;
 646                         }
 647
 648                         public virtual FullNamedExpression Resolve (IResolveContext rc)
 649                         {
 650                                 FullNamedExpression fne = RootNamespace.GetRootNamespace (Alias);
 651                                 if (fne == null) {
 652                                         Report.Error (430, Location,
 653                                                 "The extern alias `{0}' was not specified in -reference option",
 654                                                 Alias);
 655                                 }
 656
 657                                 return fne;
 658                         }
 659
 660                         public override string ToString ()
 661                         {
 662                                 return Alias;
 663                         }
 664
 665                 }
 666
 667                 class LocalUsingAliasEntry : UsingAliasEntry {
 668                         Expression resolved;
 669                         MemberName value;
 670
 671                         public LocalUsingAliasEntry (string alias, MemberName name, Location loc)
 672                                 : base (alias, loc)
 673                         {
 674                                 this.value = name;
 675                         }
 676
 677                         public override FullNamedExpression Resolve (IResolveContext rc)
 678                         {
 679                                 if (resolved != null)
 680                                         return (FullNamedExpression)resolved;
 681
 682                                 resolved = value.GetTypeExpression ().ResolveAsTypeStep (rc, false);
 683                                 if (resolved == null)
 684                                         return null;
 685
 686                                 // FIXME: This is quite wrong, the accessibility is not global
 687                                 if (resolved.Type != null) {
 688                                         TypeAttributes attr = resolved.Type.Attributes & TypeAttributes.VisibilityMask;
 689                                         if (attr == TypeAttributes.NestedPrivate || attr == TypeAttributes.NestedFamily ||
 690                                                 ((attr == TypeAttributes.NestedFamORAssem || attr == TypeAttributes.NestedAssembly) &&
 691                                                 TypeManager.LookupDeclSpace (resolved.Type) == null)) {
 692                                                 Expression.ErrorIsInaccesible (resolved.Location, resolved.GetSignatureForError ());
 693                                                 return null;
 694                                         }
 695                                 }
 696
 697                                 return (FullNamedExpression)resolved;
 698                         }
 699
 700                         public override string ToString ()
 701                         {
 702                                 return String.Format ("{0} = {1}", Alias, value.GetSignatureForError ());
 703                         }
 704                 }
 705
 706                 Namespace ns;
 707                 NamespaceEntry parent, implicit_parent;
 708                 CompilationUnit file;
 709                 int symfile_id;
 710
 711                 // Namespace using import block
 712                 ArrayList using_aliases;
 713                 ArrayList using_clauses;
 714                 public bool DeclarationFound = false;
 715                 // End
 716
 717                 public readonly bool IsImplicit;
 718                 public readonly DeclSpace SlaveDeclSpace;
 719                 static readonly Namespace [] empty_namespaces = new Namespace [0];
 720                 Namespace [] namespace_using_table;
 721
 722                 static ArrayList entries = new ArrayList ();
 723
 724                 public static void Reset ()
 725                 {
 726                         entries = new ArrayList ();
 727                 }
 728
 729                 public NamespaceEntry (NamespaceEntry parent, CompilationUnit file, string name)
 730                 {
 731                         this.parent = parent;
 732                         this.file = file;
 733                         entries.Add (this);
 734
 735                         if (parent != null)
 736                                 ns = parent.NS.GetNamespace (name, true);
 737                         else if (name != null)
 738                                 ns = RootNamespace.Global.GetNamespace (name, true);
 739                         else
 740                                 ns = RootNamespace.Global;
 741                         SlaveDeclSpace = new RootDeclSpace (this);
 742                 }
 743
 744                 private NamespaceEntry (NamespaceEntry parent, CompilationUnit file, Namespace ns, bool slave)
 745                 {
 746                         this.parent = parent;
 747                         this.file = file;
 748                         this.IsImplicit = true;
 749                         this.ns = ns;
 750                         this.SlaveDeclSpace = slave ? new RootDeclSpace (this) : null;
 751                 }
 752
 753                 //
 754                 // Populates the Namespace with some using declarations, used by the
 755                 // eval mode.
 756                 //
 757                 public void Populate (ArrayList source_using_aliases, ArrayList source_using_clauses)
 758                 {
 759                         foreach (UsingAliasEntry uae in source_using_aliases){
 760                                 if (using_aliases == null)
 761                                         using_aliases = new ArrayList ();
 762
 763                                 using_aliases.Add (uae);
 764                         }
 765
 766                         foreach (UsingEntry ue in source_using_clauses){
 767                                 if (using_clauses == null)
 768                                         using_clauses = new ArrayList ();
 769
 770                                 using_clauses.Add (ue);
 771                         }
 772                 }
 773
 774                 //
 775                 // Extracts the using alises and using clauses into a couple of
 776                 // arrays that might already have the same information;  Used by the
 777                 // C# Eval mode.
 778                 //
 779                 public void Extract (ArrayList out_using_aliases, ArrayList out_using_clauses)
 780                 {
 781                         if (using_aliases != null){
 782                                 foreach (UsingAliasEntry uae in using_aliases){
 783                                         bool replaced = false;
 784
 785                                         for (int i = 0; i < out_using_aliases.Count; i++){
 786                                                 UsingAliasEntry out_uea = (UsingAliasEntry) out_using_aliases [i];
 787
 788                                                 if (out_uea.Alias == uae.Alias){
 789                                                         out_using_aliases [i] = uae;
 790                                                         replaced = true;
 791                                                         break;
 792                                                 }
 793                                         }
 794                                         if (!replaced)
 795                                                 out_using_aliases.Add (uae);
 796                                 }
 797                         }
 798
 799                         if (using_clauses != null){
 800                                 foreach (UsingEntry ue in using_clauses){
 801                                         bool found = false;
 802
 803                                         foreach (UsingEntry out_ue in out_using_clauses)
 804                                                 if (out_ue.Name == ue.Name){
 805                                                         found = true;
 806                                                         break;
 807                                                 }
 808                                         if (!found)
 809                                                 out_using_clauses.Add (ue);
 810                                 }
 811                         }
 812                 }
 813
 814                 //
 815                 // According to section 16.3.1 (using-alias-directive), the namespace-or-type-name is
 816                 // resolved as if the immediately containing namespace body has no using-directives.
 817                 //
 818                 // Section 16.3.2 says that the same rule is applied when resolving the namespace-name
 819                 // in the using-namespace-directive.
 820                 //
 821                 // To implement these rules, the expressions in the using directives are resolved using
 822                 // the "doppelganger" (ghostly bodiless duplicate).
 823                 //
 824                 NamespaceEntry doppelganger;
 825                 NamespaceEntry Doppelganger {
 826                         get {
 827                                 if (!IsImplicit && doppelganger == null) {
 828                                         doppelganger = new NamespaceEntry (ImplicitParent, file, ns, true);
 829                                         doppelganger.using_aliases = using_aliases;
 830                                 }
 831                                 return doppelganger;
 832                         }
 833                 }
 834
 835                 public Namespace NS {
 836                         get { return ns; }
 837                 }
 838
 839                 public NamespaceEntry Parent {
 840                         get { return parent; }
 841                 }
 842
 843                 public NamespaceEntry ImplicitParent {
 844                         get {
 845                                 if (parent == null)
 846                                         return null;
 847                                 if (implicit_parent == null) {
 848                                         implicit_parent = (parent.NS == ns.Parent)
 849                                                 ? parent
 850                                                 : new NamespaceEntry (parent, file, ns.Parent, false);
 851                                 }
 852                                 return implicit_parent;
 853                         }
 854                 }
 855
 856                 /// <summary>
 857                 ///   Records a new namespace for resolving name references
 858                 /// </summary>
 859                 public void AddUsing (MemberName name, Location loc)
 860                 {
 861                         if (DeclarationFound){
 862                                 Report.Error (1529, loc, "A using clause must precede all other namespace elements except extern alias declarations");
 863                         }
 864
 865                         if (using_clauses == null) {
 866                                 using_clauses = new ArrayList ();
 867                         } else {
 868                                 foreach (UsingEntry old_entry in using_clauses) {
 869                                         if (name.Equals (old_entry.MemberName)) {
 870                                                 Report.SymbolRelatedToPreviousError (old_entry.Location, old_entry.GetSignatureForError ());
 871                                                 Report.Warning (105, 3, loc, "The using directive for `{0}' appeared previously in this namespace", name.GetSignatureForError ());
 872                                                 return;
 873                                         }
 874                                 }
 875                         }
 876
 877                         using_clauses.Add (new UsingEntry (name));
 878                 }
 879
 880                 public void AddUsingAlias (string alias, MemberName name, Location loc)
 881                 {
 882                         // TODO: This is parser bussines
 883                         if (DeclarationFound){
 884                                 Report.Error (1529, loc, "A using clause must precede all other namespace elements except extern alias declarations");
 885                         }
 886
 887                         if (RootContext.Version != LanguageVersion.ISO_1 && alias == "global")
 888                                 Report.Warning (440, 2, loc, "An alias named `global' will not be used when resolving 'global::';" +
 889                                         " the global namespace will be used instead");
 890
 891                         AddUsingAlias (new LocalUsingAliasEntry (alias, name, loc));
 892                 }
 893
 894                 public void AddUsingExternalAlias (string alias, Location loc)
 895                 {
 896                         // TODO: Do this in parser
 897                         bool not_first = using_clauses != null || DeclarationFound;
 898                         if (using_aliases != null && !not_first) {
 899                                 foreach (UsingAliasEntry uae in using_aliases) {
 900                                         if (uae is LocalUsingAliasEntry) {
 901                                                 not_first = true;
 902                                                 break;
 903                                         }
 904                                 }
 905                         }
 906
 907                         if (not_first)
 908                                 Report.Error (439, loc, "An extern alias declaration must precede all other elements");
 909
 910                         if (alias == "global") {
 911                                 Error_GlobalNamespaceRedefined (loc);
 912                                 return;
 913                         }
 914
 915                         AddUsingAlias (new UsingAliasEntry (alias, loc));
 916                 }
 917
 918                 void AddUsingAlias (UsingAliasEntry uae)
 919                 {
 920                         if (using_aliases == null) {
 921                                 using_aliases = new ArrayList ();
 922                         } else {
 923                                 foreach (UsingAliasEntry entry in using_aliases) {
 924                                         if (uae.Alias == entry.Alias) {
 925                                                 Report.SymbolRelatedToPreviousError (uae.Location, uae.Alias);
 926                                                 Report.Error (1537, entry.Location, "The using alias `{0}' appeared previously in this namespace",
 927                                                         entry.Alias);
 928                                                 return;
 929                                         }
 930                                 }
 931                         }
 932
 933                         using_aliases.Add (uae);
 934                 }
 935
 936                 ///
 937                 /// Does extension methods look up to find a method which matches name and extensionType.
 938                 /// Search starts from this namespace and continues hierarchically up to top level.
 939                 ///
 940                 public ExtensionMethodGroupExpr LookupExtensionMethod (Type extensionType, ClassOrStruct currentClass, string name, Location loc)
 941                 {
 942                         ArrayList candidates = null;
 943                         if (currentClass != null) {
 944                                 candidates = ns.LookupExtensionMethod (extensionType, currentClass, name);
 945                                 if (candidates != null)
 946                                         return new ExtensionMethodGroupExpr (candidates, this, extensionType, loc);
 947                         }
 948
 949                         foreach (Namespace n in GetUsingTable ()) {
 950                                 ArrayList a = n.LookupExtensionMethod (extensionType, null, name);
 951                                 if (a == null)
 952                                         continue;
 953
 954                                 if (candidates == null)
 955                                         candidates = a;
 956                                 else
 957                                         candidates.AddRange (a);
 958                         }
 959
 960                         if (candidates != null)
 961                                 return new ExtensionMethodGroupExpr (candidates, parent, extensionType, loc);
 962
 963                         if (parent == null)
 964                                 return null;
 965
 966                         //
 967                         // Inspect parent namespaces in namespace expression
 968                         //
 969                         Namespace parent_ns = ns.Parent;
 970                         do {
 971                                 candidates = parent_ns.LookupExtensionMethod (extensionType, null, name);
 972                                 if (candidates != null)
 973                                         return new ExtensionMethodGroupExpr (candidates, parent, extensionType, loc);
 974
 975                                 parent_ns = parent_ns.Parent;
 976                         } while (parent_ns != null);
 977
 978                         //
 979                         // Continue in parent scope
 980                         //
 981                         return parent.LookupExtensionMethod (extensionType, currentClass, name, loc);
 982                 }
 983
 984                 public FullNamedExpression LookupNamespaceOrType (DeclSpace ds, string name, Location loc, bool ignore_cs0104)
 985                 {
 986                         // Precondition: Only simple names (no dots) will be looked up with this function.
 987                         FullNamedExpression resolved = null;
 988                         for (NamespaceEntry curr_ns = this; curr_ns != null; curr_ns = curr_ns.ImplicitParent) {
 989                                 if ((resolved = curr_ns.Lookup (ds, name, loc, ignore_cs0104)) != null)
 990                                         break;
 991                         }
 992                         return resolved;
 993                 }
 994
 995                 static void Error_AmbiguousTypeReference (Location loc, string name, FullNamedExpression t1, FullNamedExpression t2)
 996                 {
 997                         Report.SymbolRelatedToPreviousError (t1.Type);
 998                         Report.SymbolRelatedToPreviousError (t2.Type);
 999                         Report.Error (104, loc, "`{0}' is an ambiguous reference between `{1}' and `{2}'",
1000                                 name, t1.GetSignatureForError (), t2.GetSignatureForError ());
1001                 }
1002
1003                 // Looks-up a alias named @name in this and surrounding namespace declarations
1004                 public FullNamedExpression LookupAlias (string name)
1005                 {
1006                         for (NamespaceEntry n = this; n != null; n = n.ImplicitParent) {
1007                                 if (n.using_aliases == null)
1008                                         continue;
1009
1010                                 foreach (UsingAliasEntry ue in n.using_aliases) {
1011                                         if (ue.Alias == name)
1012                                                 return ue.Resolve (Doppelganger);
1013                                 }
1014                         }
1015
1016                         return null;
1017                 }
1018
1019                 private FullNamedExpression Lookup (DeclSpace ds, string name, Location loc, bool ignore_cs0104)
1020                 {
1021                         //
1022                         // Check whether it's in the namespace.
1023                         //
1024                         FullNamedExpression fne = ns.Lookup (ds, name, loc);
1025
1026                         //
1027                         // Check aliases.
1028                         //
1029                         if (using_aliases != null) {
1030                                 foreach (UsingAliasEntry ue in using_aliases) {
1031                                         if (ue.Alias == name) {
1032                                                 if (fne != null) {
1033                                                         if (Doppelganger != null) {
1034                                                                 // TODO: Namespace has broken location
1035                                                                 //Report.SymbolRelatedToPreviousError (fne.Location, null);
1036                                                                 Report.SymbolRelatedToPreviousError (ue.Location, null);
1037                                                                 Report.Error (576, loc,
1038                                                                         "Namespace `{0}' contains a definition with same name as alias `{1}'",
1039                                                                         GetSignatureForError (), name);
1040                                                         } else {
1041                                                                 return fne;
1042                                                         }
1043                                                 }
1044
1045                                                 return ue.Resolve (Doppelganger);
1046                                         }
1047                                 }
1048                         }
1049
1050                         if (fne != null)
1051                                 return fne;
1052
1053                         if (IsImplicit)
1054                                 return null;
1055
1056                         //
1057                         // Check using entries.
1058                         //
1059                         FullNamedExpression match = null;
1060                         foreach (Namespace using_ns in GetUsingTable ()) {
1061                                 match = using_ns.Lookup (ds, name, loc);
1062                                 if (match == null || !(match is TypeExpr))
1063                                         continue;
1064                                 if (fne != null) {
1065                                         if (!ignore_cs0104)
1066                                                 Error_AmbiguousTypeReference (loc, name, fne, match);
1067                                         return null;
1068                                 }
1069                                 fne = match;
1070                         }
1071
1072                         return fne;
1073                 }
1074
1075                 Namespace [] GetUsingTable ()
1076                 {
1077                         if (namespace_using_table != null)
1078                                 return namespace_using_table;
1079
1080                         if (using_clauses == null) {
1081                                 namespace_using_table = empty_namespaces;
1082                                 return namespace_using_table;
1083                         }
1084
1085                         ArrayList list = new ArrayList (using_clauses.Count);
1086
1087                         foreach (UsingEntry ue in using_clauses) {
1088                                 Namespace using_ns = ue.Resolve (Doppelganger);
1089                                 if (using_ns == null)
1090                                         continue;
1091
1092                                 list.Add (using_ns);
1093                         }
1094
1095                         namespace_using_table = (Namespace[])list.ToArray (typeof (Namespace));
1096                         return namespace_using_table;
1097                 }
1098
1099                 static readonly string [] empty_using_list = new string [0];
1100
1101                 public int SymbolFileID {
1102                         get {
1103                                 if (symfile_id == 0 && file.SourceFileEntry != null) {
1104                                         int parent_id = parent == null ? 0 : parent.SymbolFileID;
1105
1106                                         string [] using_list = empty_using_list;
1107                                         if (using_clauses != null) {
1108                                                 using_list = new string [using_clauses.Count];
1109                                                 for (int i = 0; i < using_clauses.Count; i++)
1110                                                         using_list [i] = ((UsingEntry) using_clauses [i]).MemberName.GetTypeName ();
1111                                         }
1112
1113                                         symfile_id = SymbolWriter.DefineNamespace (ns.Name, file.CompileUnitEntry, using_list, parent_id);
1114                                 }
1115                                 return symfile_id;
1116                         }
1117                 }
1118
1119                 static void MsgtryRef (string s)
1120                 {
1121                         Console.WriteLine ("    Try using -r:" + s);
1122                 }
1123
1124                 static void MsgtryPkg (string s)
1125                 {
1126                         Console.WriteLine ("    Try using -pkg:" + s);
1127                 }
1128
1129                 public static void Error_GlobalNamespaceRedefined (Location loc)
1130                 {
1131                         Report.Error (1681, loc, "You cannot redefine the global extern alias");
1132                 }
1133
1134                 public static void Error_NamespaceNotFound (Location loc, string name)
1135                 {
1136                         if (RootContext.EvalMode){
1137                                 // Do not report this, it might be an error on the eval side, and we are lax there.
1138                                 return;
1139                         }
1140
1141                         Report.Error (246, loc, "The type or namespace name `{0}' could not be found. Are you missing a using directive or an assembly reference?",
1142                                 name);
1143
1144                         switch (name) {
1145                         case "Gtk": case "GtkSharp":
1146                                 MsgtryPkg ("gtk-sharp");
1147                                 break;
1148
1149                         case "Gdk": case "GdkSharp":
1150                                 MsgtryPkg ("gdk-sharp");
1151                                 break;
1152
1153                         case "Glade": case "GladeSharp":
1154                                 MsgtryPkg ("glade-sharp");
1155                                 break;
1156
1157                         case "System.Drawing":
1158                         case "System.Web.Services":
1159                         case "System.Web":
1160                         case "System.Data":
1161                         case "System.Windows.Forms":
1162                                 MsgtryRef (name);
1163                                 break;
1164                         }
1165                 }
1166
1167                 /// <summary>
1168                 ///   Used to validate that all the using clauses are correct
1169                 ///   after we are finished parsing all the files.
1170                 /// </summary>
1171                 void VerifyUsing ()
1172                 {
1173                         if (using_aliases != null) {
1174                                 foreach (UsingAliasEntry ue in using_aliases)
1175                                         ue.Resolve (Doppelganger);
1176                         }
1177
1178                         if (using_clauses != null) {
1179                                 foreach (UsingEntry ue in using_clauses)
1180                                         ue.Resolve (Doppelganger);
1181                         }
1182                 }
1183
1184                 /// <summary>
1185                 ///   Used to validate that all the using clauses are correct
1186                 ///   after we are finished parsing all the files.
1187                 /// </summary>
1188                 static public void VerifyAllUsing ()
1189                 {
1190                         foreach (NamespaceEntry entry in entries)
1191                                 entry.VerifyUsing ();
1192                 }
1193
1194                 public string GetSignatureForError ()
1195                 {
1196                         return ns.GetSignatureForError ();
1197                 }
1198
1199                 public override string ToString ()
1200                 {
1201                         return ns.ToString ();
1202                 }
1203
1204                 #region IResolveContext Members
1205
1206                 public DeclSpace DeclContainer {
1207                         get { return SlaveDeclSpace; }
1208                 }
1209
1210                 public bool IsInObsoleteScope {
1211                         get { return SlaveDeclSpace.IsInObsoleteScope; }
1212                 }
1213
1214                 public bool IsInUnsafeScope {
1215                         get { return SlaveDeclSpace.IsInUnsafeScope; }
1216                 }
1217
1218                 public DeclSpace GenericDeclContainer {
1219                         get { return SlaveDeclSpace; }
1220                 }
1221
1222                 #endregion
1223         }
1224 }