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                 protected Assembly [] referenced_assemblies;
  28
  29                 Hashtable all_namespaces;
  30
  31                 static ListDictionary 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 ListDictionary ();
  44                         Global = new GlobalRootNamespace ();
  45                         root_namespaces ["global"] = Global;
  46                 }
  47
  48                 protected RootNamespace (string alias_name)
  49                         : base (null, String.Empty)
  50                 {
  51                         this.alias_name = alias_name;
  52                         referenced_assemblies = new Assembly [0];
  53
  54                         all_namespaces = new Hashtable ();
  55                         all_namespaces.Add ("", this);
  56                 }
  57
  58                 public void AddAssemblyReference (Assembly a)
  59                 {
  60                         foreach (Assembly assembly in referenced_assemblies) {
  61                                 if (a == assembly)
  62                                         return;
  63                         }
  64
  65                         int top = referenced_assemblies.Length;
  66                         Assembly [] n = new Assembly [top + 1];
  67                         referenced_assemblies.CopyTo (n, 0);
  68                         n [top] = a;
  69                         referenced_assemblies = n;
  70                 }
  71
  72                 public static void DefineRootNamespace (string alias, Assembly assembly)
  73                 {
  74                         if (alias == "global") {
  75                                 NamespaceEntry.Error_GlobalNamespaceRedefined (Location.Null);
  76                                 return;
  77                         }
  78
  79                         RootNamespace retval = GetRootNamespace (alias);
  80                         if (retval == null) {
  81                                 retval = new RootNamespace (alias);
  82                                 root_namespaces.Add (alias, retval);
  83                         }
  84
  85                         retval.AddAssemblyReference (assembly);
  86                 }
  87
  88                 public static RootNamespace GetRootNamespace (string name)
  89                 {
  90                         return (RootNamespace) root_namespaces [name];
  91                 }
  92
  93                 public static void ComputeNamespaces ()
  94                 {
  95                         //
  96                         // Do very early lookup because type is required when we cache
  97                         // imported extension types in ComputeNamespaces
  98                         //
  99                         TypeManager.extension_attribute_type = TypeManager.CoreLookupType ("System.Runtime.CompilerServices", "ExtensionAttribute", Kind.Class, false);
 100
 101                         foreach (RootNamespace rn in root_namespaces.Values) {
 102                                 foreach (Assembly a in rn.referenced_assemblies) {
 103                                         try {
 104                                                 rn.ComputeNamespaces (a);
 105                                         } catch (TypeLoadException e) {
 106                                                 Report.Error (11, Location.Null, e.Message);
 107                                         } catch (System.IO.FileNotFoundException) {
 108                                                 Report.Error (12, Location.Null, "An assembly `{0}' is used without being referenced",
 109                                                         a.FullName);
 110                                         }
 111                                 }
 112                         }
 113                 }
 114
 115                 public virtual Type LookupTypeReflection (string name, Location loc)
 116                 {
 117                         Type found_type = null;
 118
 119                         foreach (Assembly a in referenced_assemblies) {
 120                                 Type t = GetTypeInAssembly (a, name);
 121                                 if (t == null)
 122                                         continue;
 123
 124                                 if (found_type == null) {
 125                                         found_type = t;
 126                                         continue;
 127                                 }
 128
 129                                 Report.SymbolRelatedToPreviousError (found_type);
 130                                 Report.SymbolRelatedToPreviousError (t);
 131                                 Report.Error (433, loc, "The imported type `{0}' is defined multiple times", name);
 132
 133                                 return found_type;
 134                         }
 135
 136                         return found_type;
 137                 }
 138
 139                 public void RegisterNamespace (Namespace child)
 140                 {
 141                         if (child != this)
 142                                 all_namespaces.Add (child.Name, child);
 143                 }
 144
 145                 public bool IsNamespace (string name)
 146                 {
 147                         return all_namespaces.Contains (name);
 148                 }
 149
 150                 protected void RegisterNamespace (string dotted_name)
 151                 {
 152                         if (dotted_name != null && dotted_name.Length != 0 && ! IsNamespace (dotted_name))
 153                                 GetNamespace (dotted_name, true);
 154                 }
 155
 156                 void RegisterExtensionMethodClass (Type t)
 157                 {
 158                         string n = t.Namespace;
 159                         Namespace ns = n == null ? Global : (Namespace)all_namespaces [n];
 160                         if (ns == null)
 161                                 ns = GetNamespace (n, true);
 162
 163                         ns.RegisterExternalExtensionMethodClass (t);
 164                 }
 165
 166                 protected void ComputeNamespaces (Assembly assembly)
 167                 {
 168                         bool contains_extension_methods = TypeManager.extension_attribute_type != null &&
 169                                         assembly.IsDefined(TypeManager.extension_attribute_type, false);
 170
 171                         if (get_namespaces_method != null && !contains_extension_methods) {
 172                                 string [] namespaces = (string []) get_namespaces_method.Invoke (assembly, null);
 173                                 foreach (string ns in namespaces)
 174                                         RegisterNamespace (ns);
 175                                 return;
 176                         }
 177
 178                         foreach (Type t in assembly.GetExportedTypes ()) {
 179                                 if ((t.Attributes & Class.StaticClassAttribute) == Class.StaticClassAttribute &&
 180                                         contains_extension_methods && t.IsDefined (TypeManager.extension_attribute_type, false))
 181                                         RegisterExtensionMethodClass (t);
 182                                 else
 183                                         RegisterNamespace (t.Namespace);
 184                         }
 185                 }
 186
 187                 protected static Type GetTypeInAssembly (Assembly assembly, string name)
 188                 {
 189                         Type t = assembly.GetType (name);
 190                         if (t == null)
 191                                 return null;
 192
 193                         if (t.IsPointer)
 194                                 throw new InternalErrorException ("Use GetPointerType() to get a pointer");
 195
 196                         TypeAttributes ta = t.Attributes & TypeAttributes.VisibilityMask;
 197                         if (ta == TypeAttributes.NestedPrivate)
 198                                 return null;
 199
 200                         if ((ta == TypeAttributes.NotPublic ||
 201                              ta == TypeAttributes.NestedAssembly ||
 202                              ta == TypeAttributes.NestedFamANDAssem) &&
 203                             !TypeManager.IsThisOrFriendAssembly (t.Assembly))
 204                                 return null;
 205
 206                         return t;
 207                 }
 208
 209                 public override string ToString ()
 210                 {
 211                         return String.Format ("RootNamespace ({0}::)", alias_name);
 212                 }
 213
 214                 public override string GetSignatureForError ()
 215                 {
 216                         return alias_name + "::";
 217                 }
 218         }
 219
 220         public class GlobalRootNamespace : RootNamespace {
 221                 Module [] modules;
 222
 223                 public GlobalRootNamespace ()
 224                         : base ("global")
 225                 {
 226                 }
 227
 228                 public Assembly [] Assemblies {
 229                     get { return referenced_assemblies; }
 230                 }
 231
 232                 public Module [] Modules {
 233                         get { return modules; }
 234                 }
 235
 236                 public void AddModuleReference (Module m)
 237                 {
 238                         int top = modules != null ? modules.Length : 0;
 239                         Module [] n = new Module [top + 1];
 240                         if (modules != null)
 241                                 modules.CopyTo (n, 0);
 242                         n [top] = m;
 243                         modules = n;
 244
 245                         if (m == CodeGen.Module.Builder)
 246                                 return;
 247
 248                         foreach (Type t in m.GetTypes ())
 249                                 RegisterNamespace (t.Namespace);
 250                 }
 251
 252                 public override void Error_NamespaceDoesNotExist(DeclSpace ds, Location loc, string name)
 253                 {
 254                         Report.Error (400, loc, "The type or namespace name `{0}' could not be found in the global namespace (are you missing an assembly reference?)",
 255                                 name);
 256                 }
 257
 258                 public override Type LookupTypeReflection (string name, Location loc)
 259                 {
 260                         Type found_type = base.LookupTypeReflection (name, loc);
 261
 262                         if (modules != null) {
 263                                 foreach (Module module in modules) {
 264                                         Type t = module.GetType (name);
 265                                         if (t == null)
 266                                                 continue;
 267
 268                                         if (found_type == null) {
 269                                                 found_type = t;
 270                                                 continue;
 271                                         }
 272
 273                                         Report.SymbolRelatedToPreviousError (found_type);
 274                                         if (loc.IsNull) {
 275                                                 DeclSpace ds = TypeManager.LookupDeclSpace (t);
 276                                                 Report.Warning (1685, 1, ds.Location, "The type `{0}' conflicts with the predefined type `{1}' and will be ignored",
 277                                                         ds.GetSignatureForError (), TypeManager.CSharpName (found_type));
 278                                                 return found_type;
 279                                         }
 280                                         Report.SymbolRelatedToPreviousError (t);
 281                                         Report.Warning (436, 2, loc, "The type `{0}' conflicts with the imported type `{1}'. Ignoring the imported type definition",
 282                                                 TypeManager.CSharpName (t), TypeManager.CSharpName (found_type));
 283                                         return t;
 284                                 }
 285                         }
 286
 287                         return found_type;
 288                 }
 289         }
 290
 291         /// <summary>
 292         ///   Keeps track of the namespaces defined in the C# code.
 293         ///
 294         ///   This is an Expression to allow it to be referenced in the
 295         ///   compiler parse/intermediate tree during name resolution.
 296         /// </summary>
 297         public class Namespace : FullNamedExpression {
 298
 299                 Namespace parent;
 300                 string fullname;
 301                 IDictionary namespaces;
 302                 IDictionary declspaces;
 303                 Hashtable cached_types;
 304                 RootNamespace root;
 305                 ArrayList external_exmethod_classes;
 306
 307                 public readonly MemberName MemberName;
 308
 309                 /// <summary>
 310                 ///   Constructor Takes the current namespace and the
 311                 ///   name.  This is bootstrapped with parent == null
 312                 ///   and name = ""
 313                 /// </summary>
 314                 public Namespace (Namespace parent, string name)
 315                 {
 316                         // Expression members.
 317                         this.eclass = ExprClass.Namespace;
 318                         this.Type = typeof (Namespace);
 319                         this.loc = Location.Null;
 320
 321                         this.parent = parent;
 322
 323                         if (parent != null)
 324                                 this.root = parent.root;
 325                         else
 326                                 this.root = this as RootNamespace;
 327
 328                         if (this.root == null)
 329                                 throw new InternalErrorException ("Root namespaces must be created using RootNamespace");
 330
 331                         string pname = parent != null ? parent.fullname : "";
 332
 333                         if (pname == "")
 334                                 fullname = name;
 335                         else
 336                                 fullname = parent.fullname + "." + name;
 337
 338                         if (fullname == null)
 339                                 throw new InternalErrorException ("Namespace has a null fullname");
 340
 341                         if (parent != null && parent.MemberName != MemberName.Null)
 342                                 MemberName = new MemberName (parent.MemberName, name);
 343                         else if (name.Length == 0)
 344                                 MemberName = MemberName.Null;
 345                         else
 346                                 MemberName = new MemberName (name);
 347
 348                         namespaces = new HybridDictionary ();
 349                         cached_types = new Hashtable ();
 350
 351                         root.RegisterNamespace (this);
 352                 }
 353
 354                 public override Expression DoResolve (EmitContext ec)
 355                 {
 356                         return this;
 357                 }
 358
 359                 public virtual void Error_NamespaceDoesNotExist (DeclSpace ds, Location loc, string name)
 360                 {
 361                         if (name.IndexOf ('`') > 0) {
 362                                 FullNamedExpression retval = Lookup (ds, SimpleName.RemoveGenericArity (name), loc);
 363                                 if (retval != null) {
 364                                         Error_TypeArgumentsCannotBeUsed (retval, loc);
 365                                         return;
 366                                 }
 367                         } else {
 368                                 Type t = LookForAnyGenericType (name);
 369                                 if (t != null) {
 370                                         Error_InvalidNumberOfTypeArguments (t, loc);
 371                                         return;
 372                                 }
 373                         }
 374
 375                         Report.Error (234, loc, "The type or namespace name `{0}' does not exist in the namespace `{1}'. Are you missing an assembly reference?",
 376                                 name, GetSignatureForError ());
 377                 }
 378
 379                 public static void Error_InvalidNumberOfTypeArguments (Type t, Location loc)
 380                 {
 381                         Report.SymbolRelatedToPreviousError (t);
 382                         Report.Error (305, loc, "Using the generic type `{0}' requires `{1}' type argument(s)",
 383                                 TypeManager.CSharpName(t), TypeManager.GetNumberOfTypeArguments(t).ToString());
 384                 }
 385
 386                 public static void Error_TypeArgumentsCannotBeUsed (FullNamedExpression expr, Location loc)
 387                 {
 388                         if (expr is TypeExpr) {
 389                                 Report.SymbolRelatedToPreviousError (expr.Type);
 390                                 Error_TypeArgumentsCannotBeUsed (loc, "type", expr.GetSignatureForError ());
 391                         } else {
 392                                 expr.Error_ExpressionCannotBeGeneric (loc);
 393                         }
 394                 }
 395
 396                 public static void Error_TypeArgumentsCannotBeUsed (MethodBase mi, Location loc)
 397                 {
 398                         Report.SymbolRelatedToPreviousError (mi);
 399                         Error_TypeArgumentsCannotBeUsed (loc, "method", TypeManager.CSharpSignature (mi));
 400                 }
 401
 402                 static void Error_TypeArgumentsCannotBeUsed (Location loc, string type, string name)
 403                 {
 404                         Report.Error(308, loc, "The non-generic {0} `{1}' cannot be used with the type arguments",
 405                                 type, name);
 406                 }
 407
 408                 public override string GetSignatureForError ()
 409                 {
 410                         return fullname;
 411                 }
 412
 413                 public Namespace GetNamespace (string name, bool create)
 414                 {
 415                         int pos = name.IndexOf ('.');
 416
 417                         Namespace ns;
 418                         string first;
 419                         if (pos >= 0)
 420                                 first = name.Substring (0, pos);
 421                         else
 422                                 first = name;
 423
 424                         ns = (Namespace) namespaces [first];
 425                         if (ns == null) {
 426                                 if (!create)
 427                                         return null;
 428
 429                                 ns = new Namespace (this, first);
 430                                 namespaces.Add (first, ns);
 431                         }
 432
 433                         if (pos >= 0)
 434                                 ns = ns.GetNamespace (name.Substring (pos + 1), create);
 435
 436                         return ns;
 437                 }
 438
 439                 public bool HasDefinition (string name)
 440                 {
 441                         return declspaces != null && declspaces [name] != null;
 442                 }
 443
 444                 TypeExpr LookupType (string name, Location loc)
 445                 {
 446                         if (cached_types.Contains (name))
 447                                 return cached_types [name] as TypeExpr;
 448
 449                         Type t = null;
 450                         if (declspaces != null) {
 451                                 DeclSpace tdecl = declspaces [name] as DeclSpace;
 452                                 if (tdecl != null) {
 453                                         //
 454                                         // Note that this is not:
 455                                         //
 456                                         //   t = tdecl.DefineType ()
 457                                         //
 458                                         // This is to make it somewhat more useful when a DefineType
 459                                         // fails due to problems in nested types (more useful in the sense
 460                                         // of fewer misleading error messages)
 461                                         //
 462                                         tdecl.DefineType ();
 463                                         t = tdecl.TypeBuilder;
 464
 465                                         if (RootContext.EvalMode){
 466                                                 // Replace the TypeBuilder with a System.Type, as
 467                                                 // Reflection.Emit fails otherwise (we end up pretty
 468                                                 // much with Random type definitions later on).
 469                                                 Type tt = t.Assembly.GetType (t.Name);
 470                                                 if (tt != null)
 471                                                         t = tt;
 472                                         }
 473                                 }
 474                         }
 475                         string lookup = t != null ? t.FullName : (fullname.Length == 0 ? name : fullname + "." + name);
 476                         Type rt = root.LookupTypeReflection (lookup, loc);
 477
 478                         // HACK: loc.IsNull when the type is core type
 479                         if (t == null || (rt != null && loc.IsNull))
 480                                 t = rt;
 481
 482                         TypeExpr te = t == null ? null : new TypeExpression (t, Location.Null);
 483                         cached_types [name] = te;
 484                         return te;
 485                 }
 486
 487                 ///
 488                 /// Used for better error reporting only
 489                 ///
 490                 public Type LookForAnyGenericType (string typeName)
 491                 {
 492                         if (declspaces == null)
 493                                 return null;
 494
 495                         typeName = SimpleName.RemoveGenericArity (typeName);
 496
 497                         foreach (DictionaryEntry de in declspaces) {
 498                                 string type_item = (string) de.Key;
 499                                 int pos = type_item.LastIndexOf ('`');
 500                                 if (pos == typeName.Length && String.Compare (typeName, 0, type_item, 0, pos) == 0)
 501                                         return ((DeclSpace) de.Value).TypeBuilder;
 502                         }
 503                         return null;
 504                 }
 505
 506                 public FullNamedExpression Lookup (DeclSpace ds, string name, Location loc)
 507                 {
 508                         if (namespaces.Contains (name))
 509                                 return (Namespace) namespaces [name];
 510
 511                         return LookupType (name, loc);
 512                 }
 513
 514                 public void RegisterExternalExtensionMethodClass (Type type)
 515                 {
 516                         if (external_exmethod_classes == null)
 517                                 external_exmethod_classes = new ArrayList ();
 518
 519                         external_exmethod_classes.Add (type);
 520                 }
 521
 522                 ///
 523                 /// Looks for extension method in this namespace
 524                 ///
 525                 public ArrayList LookupExtensionMethod (Type extensionType, ClassOrStruct currentClass, string name)
 526                 {
 527                         ArrayList found = null;
 528
 529                         if (declspaces != null) {
 530                                 IEnumerator e = declspaces.Values.GetEnumerator ();
 531                                 e.Reset ();
 532                                 while (e.MoveNext ()) {
 533                                         Class c = e.Current as Class;
 534                                         if (c == null)
 535                                                 continue;
 536
 537                                         if (!c.IsStaticClass)
 538                                                 continue;
 539
 540                                         ArrayList res = c.MemberCache.FindExtensionMethods (extensionType, name, c != currentClass);
 541                                         if (res == null)
 542                                                 continue;
 543
 544                                         if (found == null)
 545                                                 found = res;
 546                                         else
 547                                                 found.AddRange (res);
 548                                 }
 549                         }
 550
 551                         if (external_exmethod_classes == null)
 552                                 return found;
 553
 554                         foreach (Type t in external_exmethod_classes) {
 555                                 MemberCache m = TypeHandle.GetMemberCache (t);
 556                                 ArrayList res = m.FindExtensionMethods (extensionType, name, true);
 557                                 if (res == null)
 558                                         continue;
 559
 560                                 if (found == null)
 561                                         found = res;
 562                                 else
 563                                         found.AddRange (res);
 564                         }
 565
 566                         return found;
 567                 }
 568
 569                 public void AddDeclSpace (string name, DeclSpace ds)
 570                 {
 571                         if (declspaces == null)
 572                                 declspaces = new HybridDictionary ();
 573                         declspaces.Add (name, ds);
 574                 }
 575
 576                 public void RemoveDeclSpace (string name)
 577                 {
 578                         declspaces.Remove (name);
 579                 }
 580
 581                 /// <summary>
 582                 ///   The qualified name of the current namespace
 583                 /// </summary>
 584                 public string Name {
 585                         get { return fullname; }
 586                 }
 587
 588                 /// <summary>
 589                 ///   The parent of this namespace, used by the parser to "Pop"
 590                 ///   the current namespace declaration
 591                 /// </summary>
 592                 public Namespace Parent {
 593                         get { return parent; }
 594                 }
 595         }
 596
 597         //
 598         // Namespace container as created by the parser
 599         //
 600         public class NamespaceEntry : IResolveContext {
 601
 602                 class UsingEntry {
 603                         readonly MemberName name;
 604                         Namespace resolved;
 605
 606                         public UsingEntry (MemberName name)
 607                         {
 608                                 this.name = name;
 609                         }
 610
 611                         public string GetSignatureForError ()
 612                         {
 613                                 return name.GetSignatureForError ();
 614                         }
 615
 616                         public Location Location {
 617                                 get { return name.Location; }
 618                         }
 619
 620                         public MemberName MemberName {
 621                                 get { return name; }
 622                         }
 623
 624                         public string Name {
 625                                 get { return GetSignatureForError (); }
 626                         }
 627
 628                         public Namespace Resolve (IResolveContext rc)
 629                         {
 630                                 if (resolved != null)
 631                                         return resolved;
 632
 633                                 FullNamedExpression fne = name.GetTypeExpression ().ResolveAsTypeStep (rc, false);
 634                                 if (fne == null)
 635                                         return null;
 636
 637                                 resolved = fne as Namespace;
 638                                 if (resolved == null) {
 639                                         Report.SymbolRelatedToPreviousError (fne.Type);
 640                                         Report.Error (138, Location,
 641                                                 "`{0}' is a type not a namespace. A using namespace directive can only be applied to namespaces",
 642                                                 GetSignatureForError ());
 643                                 }
 644                                 return resolved;
 645                         }
 646
 647                         public override string ToString ()
 648                         {
 649                                 return Name;
 650                         }
 651                 }
 652
 653                 class UsingAliasEntry {
 654                         public readonly string Alias;
 655                         public Location Location;
 656
 657                         public UsingAliasEntry (string alias, Location loc)
 658                         {
 659                                 this.Alias = alias;
 660                                 this.Location = loc;
 661                         }
 662
 663                         public virtual FullNamedExpression Resolve (IResolveContext rc)
 664                         {
 665                                 FullNamedExpression fne = RootNamespace.GetRootNamespace (Alias);
 666                                 if (fne == null) {
 667                                         Report.Error (430, Location,
 668                                                 "The extern alias `{0}' was not specified in -reference option",
 669                                                 Alias);
 670                                 }
 671
 672                                 return fne;
 673                         }
 674
 675                         public override string ToString ()
 676                         {
 677                                 return Alias;
 678                         }
 679
 680                 }
 681
 682                 class LocalUsingAliasEntry : UsingAliasEntry {
 683                         FullNamedExpression resolved;
 684                         MemberName value;
 685
 686                         public LocalUsingAliasEntry (string alias, MemberName name, Location loc)
 687                                 : base (alias, loc)
 688                         {
 689                                 this.value = name;
 690                         }
 691
 692                         public override FullNamedExpression Resolve (IResolveContext rc)
 693                         {
 694                                 if (resolved != null || value == null)
 695                                         return resolved;
 696
 697                                 resolved = value.GetTypeExpression ().ResolveAsTypeStep (rc, false);
 698                                 if (resolved == null) {
 699                                         value = null;
 700                                         return null;
 701                                 }
 702
 703                                 TypeExpr te = resolved as TypeExpr;
 704                                 if (te != null) {
 705                                         if (!te.CheckAccessLevel (rc.DeclContainer)) {
 706                                                 Report.SymbolRelatedToPreviousError (te.Type);
 707                                                 Expression.ErrorIsInaccesible (resolved.Location, resolved.GetSignatureForError ());
 708                                         }
 709                                 }
 710
 711                                 return resolved;
 712                         }
 713
 714                         public override string ToString ()
 715                         {
 716                                 return String.Format ("{0} = {1}", Alias, value.GetSignatureForError ());
 717                         }
 718                 }
 719
 720                 Namespace ns;
 721                 NamespaceEntry parent, implicit_parent;
 722                 CompilationUnit file;
 723                 int symfile_id;
 724
 725                 // Namespace using import block
 726                 ArrayList using_aliases;
 727                 ArrayList using_clauses;
 728                 public bool DeclarationFound = false;
 729                 // End
 730
 731                 public readonly bool IsImplicit;
 732                 public readonly DeclSpace SlaveDeclSpace;
 733                 static readonly Namespace [] empty_namespaces = new Namespace [0];
 734                 Namespace [] namespace_using_table;
 735
 736                 static ArrayList entries = new ArrayList ();
 737
 738                 public static void Reset ()
 739                 {
 740                         entries = new ArrayList ();
 741                 }
 742
 743                 public NamespaceEntry (NamespaceEntry parent, CompilationUnit file, string name)
 744                 {
 745                         this.parent = parent;
 746                         this.file = file;
 747                         entries.Add (this);
 748
 749                         if (parent != null)
 750                                 ns = parent.NS.GetNamespace (name, true);
 751                         else if (name != null)
 752                                 ns = RootNamespace.Global.GetNamespace (name, true);
 753                         else
 754                                 ns = RootNamespace.Global;
 755                         SlaveDeclSpace = new RootDeclSpace (this);
 756                 }
 757
 758                 private NamespaceEntry (NamespaceEntry parent, CompilationUnit file, Namespace ns, bool slave)
 759                 {
 760                         this.parent = parent;
 761                         this.file = file;
 762                         this.IsImplicit = true;
 763                         this.ns = ns;
 764                         this.SlaveDeclSpace = slave ? new RootDeclSpace (this) : null;
 765                 }
 766
 767                 //
 768                 // Populates the Namespace with some using declarations, used by the
 769                 // eval mode.
 770                 //
 771                 public void Populate (ArrayList source_using_aliases, ArrayList source_using_clauses)
 772                 {
 773                         foreach (UsingAliasEntry uae in source_using_aliases){
 774                                 if (using_aliases == null)
 775                                         using_aliases = new ArrayList ();
 776
 777                                 using_aliases.Add (uae);
 778                         }
 779
 780                         foreach (UsingEntry ue in source_using_clauses){
 781                                 if (using_clauses == null)
 782                                         using_clauses = new ArrayList ();
 783
 784                                 using_clauses.Add (ue);
 785                         }
 786                 }
 787
 788                 //
 789                 // Extracts the using alises and using clauses into a couple of
 790                 // arrays that might already have the same information;  Used by the
 791                 // C# Eval mode.
 792                 //
 793                 public void Extract (ArrayList out_using_aliases, ArrayList out_using_clauses)
 794                 {
 795                         if (using_aliases != null){
 796                                 foreach (UsingAliasEntry uae in using_aliases){
 797                                         bool replaced = false;
 798
 799                                         for (int i = 0; i < out_using_aliases.Count; i++){
 800                                                 UsingAliasEntry out_uea = (UsingAliasEntry) out_using_aliases [i];
 801
 802                                                 if (out_uea.Alias == uae.Alias){
 803                                                         out_using_aliases [i] = uae;
 804                                                         replaced = true;
 805                                                         break;
 806                                                 }
 807                                         }
 808                                         if (!replaced)
 809                                                 out_using_aliases.Add (uae);
 810                                 }
 811                         }
 812
 813                         if (using_clauses != null){
 814                                 foreach (UsingEntry ue in using_clauses){
 815                                         bool found = false;
 816
 817                                         foreach (UsingEntry out_ue in out_using_clauses)
 818                                                 if (out_ue.Name == ue.Name){
 819                                                         found = true;
 820                                                         break;
 821                                                 }
 822                                         if (!found)
 823                                                 out_using_clauses.Add (ue);
 824                                 }
 825                         }
 826                 }
 827
 828                 //
 829                 // According to section 16.3.1 (using-alias-directive), the namespace-or-type-name is
 830                 // resolved as if the immediately containing namespace body has no using-directives.
 831                 //
 832                 // Section 16.3.2 says that the same rule is applied when resolving the namespace-name
 833                 // in the using-namespace-directive.
 834                 //
 835                 // To implement these rules, the expressions in the using directives are resolved using
 836                 // the "doppelganger" (ghostly bodiless duplicate).
 837                 //
 838                 NamespaceEntry doppelganger;
 839                 NamespaceEntry Doppelganger {
 840                         get {
 841                                 if (!IsImplicit && doppelganger == null) {
 842                                         doppelganger = new NamespaceEntry (ImplicitParent, file, ns, true);
 843                                         doppelganger.using_aliases = using_aliases;
 844                                 }
 845                                 return doppelganger;
 846                         }
 847                 }
 848
 849                 public Namespace NS {
 850                         get { return ns; }
 851                 }
 852
 853                 public NamespaceEntry Parent {
 854                         get { return parent; }
 855                 }
 856
 857                 public NamespaceEntry ImplicitParent {
 858                         get {
 859                                 if (parent == null)
 860                                         return null;
 861                                 if (implicit_parent == null) {
 862                                         implicit_parent = (parent.NS == ns.Parent)
 863                                                 ? parent
 864                                                 : new NamespaceEntry (parent, file, ns.Parent, false);
 865                                 }
 866                                 return implicit_parent;
 867                         }
 868                 }
 869
 870                 /// <summary>
 871                 ///   Records a new namespace for resolving name references
 872                 /// </summary>
 873                 public void AddUsing (MemberName name, Location loc)
 874                 {
 875                         if (DeclarationFound){
 876                                 Report.Error (1529, loc, "A using clause must precede all other namespace elements except extern alias declarations");
 877                         }
 878
 879                         if (using_clauses == null) {
 880                                 using_clauses = new ArrayList ();
 881                         } else {
 882                                 foreach (UsingEntry old_entry in using_clauses) {
 883                                         if (name.Equals (old_entry.MemberName)) {
 884                                                 Report.SymbolRelatedToPreviousError (old_entry.Location, old_entry.GetSignatureForError ());
 885                                                 Report.Warning (105, 3, loc, "The using directive for `{0}' appeared previously in this namespace", name.GetSignatureForError ());
 886                                                 return;
 887                                         }
 888                                 }
 889                         }
 890
 891                         using_clauses.Add (new UsingEntry (name));
 892                 }
 893
 894                 public void AddUsingAlias (string alias, MemberName name, Location loc)
 895                 {
 896                         // TODO: This is parser bussines
 897                         if (DeclarationFound){
 898                                 Report.Error (1529, loc, "A using clause must precede all other namespace elements except extern alias declarations");
 899                         }
 900
 901                         if (RootContext.Version != LanguageVersion.ISO_1 && alias == "global")
 902                                 Report.Warning (440, 2, loc, "An alias named `global' will not be used when resolving 'global::';" +
 903                                         " the global namespace will be used instead");
 904
 905                         AddUsingAlias (new LocalUsingAliasEntry (alias, name, loc));
 906                 }
 907
 908                 public void AddUsingExternalAlias (string alias, Location loc)
 909                 {
 910                         // TODO: Do this in parser
 911                         bool not_first = using_clauses != null || DeclarationFound;
 912                         if (using_aliases != null && !not_first) {
 913                                 foreach (UsingAliasEntry uae in using_aliases) {
 914                                         if (uae is LocalUsingAliasEntry) {
 915                                                 not_first = true;
 916                                                 break;
 917                                         }
 918                                 }
 919                         }
 920
 921                         if (not_first)
 922                                 Report.Error (439, loc, "An extern alias declaration must precede all other elements");
 923
 924                         if (alias == "global") {
 925                                 Error_GlobalNamespaceRedefined (loc);
 926                                 return;
 927                         }
 928
 929                         AddUsingAlias (new UsingAliasEntry (alias, loc));
 930                 }
 931
 932                 void AddUsingAlias (UsingAliasEntry uae)
 933                 {
 934                         if (using_aliases == null) {
 935                                 using_aliases = new ArrayList ();
 936                         } else {
 937                                 foreach (UsingAliasEntry entry in using_aliases) {
 938                                         if (uae.Alias == entry.Alias) {
 939                                                 Report.SymbolRelatedToPreviousError (uae.Location, uae.Alias);
 940                                                 Report.Error (1537, entry.Location, "The using alias `{0}' appeared previously in this namespace",
 941                                                         entry.Alias);
 942                                                 return;
 943                                         }
 944                                 }
 945                         }
 946
 947                         using_aliases.Add (uae);
 948                 }
 949
 950                 ///
 951                 /// Does extension methods look up to find a method which matches name and extensionType.
 952                 /// Search starts from this namespace and continues hierarchically up to top level.
 953                 ///
 954                 public ExtensionMethodGroupExpr LookupExtensionMethod (Type extensionType, ClassOrStruct currentClass, string name, Location loc)
 955                 {
 956                         ArrayList candidates = null;
 957                         if (currentClass != null) {
 958                                 candidates = ns.LookupExtensionMethod (extensionType, currentClass, name);
 959                                 if (candidates != null)
 960                                         return new ExtensionMethodGroupExpr (candidates, this, extensionType, loc);
 961                         }
 962
 963                         foreach (Namespace n in GetUsingTable ()) {
 964                                 ArrayList a = n.LookupExtensionMethod (extensionType, null, name);
 965                                 if (a == null)
 966                                         continue;
 967
 968                                 if (candidates == null)
 969                                         candidates = a;
 970                                 else
 971                                         candidates.AddRange (a);
 972                         }
 973
 974                         if (candidates != null)
 975                                 return new ExtensionMethodGroupExpr (candidates, parent, extensionType, loc);
 976
 977                         if (parent == null)
 978                                 return null;
 979
 980                         //
 981                         // Inspect parent namespaces in namespace expression
 982                         //
 983                         Namespace parent_ns = ns.Parent;
 984                         do {
 985                                 candidates = parent_ns.LookupExtensionMethod (extensionType, null, name);
 986                                 if (candidates != null)
 987                                         return new ExtensionMethodGroupExpr (candidates, parent, extensionType, loc);
 988
 989                                 parent_ns = parent_ns.Parent;
 990                         } while (parent_ns != null);
 991
 992                         //
 993                         // Continue in parent scope
 994                         //
 995                         return parent.LookupExtensionMethod (extensionType, currentClass, name, loc);
 996                 }
 997
 998                 public FullNamedExpression LookupNamespaceOrType (DeclSpace ds, string name, Location loc, bool ignore_cs0104)
 999                 {
1000                         // Precondition: Only simple names (no dots) will be looked up with this function.
1001                         FullNamedExpression resolved = null;
1002                         for (NamespaceEntry curr_ns = this; curr_ns != null; curr_ns = curr_ns.ImplicitParent) {
1003                                 if ((resolved = curr_ns.Lookup (ds, name, loc, ignore_cs0104)) != null)
1004                                         break;
1005                         }
1006                         return resolved;
1007                 }
1008
1009                 static void Error_AmbiguousTypeReference (Location loc, string name, FullNamedExpression t1, FullNamedExpression t2)
1010                 {
1011                         Report.SymbolRelatedToPreviousError (t1.Type);
1012                         Report.SymbolRelatedToPreviousError (t2.Type);
1013                         Report.Error (104, loc, "`{0}' is an ambiguous reference between `{1}' and `{2}'",
1014                                 name, t1.GetSignatureForError (), t2.GetSignatureForError ());
1015                 }
1016
1017                 // Looks-up a alias named @name in this and surrounding namespace declarations
1018                 public FullNamedExpression LookupAlias (string name)
1019                 {
1020                         for (NamespaceEntry n = this; n != null; n = n.ImplicitParent) {
1021                                 if (n.using_aliases == null)
1022                                         continue;
1023
1024                                 foreach (UsingAliasEntry ue in n.using_aliases) {
1025                                         if (ue.Alias == name)
1026                                                 return ue.Resolve (Doppelganger);
1027                                 }
1028                         }
1029
1030                         return null;
1031                 }
1032
1033                 private FullNamedExpression Lookup (DeclSpace ds, string name, Location loc, bool ignore_cs0104)
1034                 {
1035                         //
1036                         // Check whether it's in the namespace.
1037                         //
1038                         FullNamedExpression fne = ns.Lookup (ds, name, loc);
1039
1040                         //
1041                         // Check aliases.
1042                         //
1043                         if (using_aliases != null) {
1044                                 foreach (UsingAliasEntry ue in using_aliases) {
1045                                         if (ue.Alias == name) {
1046                                                 if (fne != null) {
1047                                                         if (Doppelganger != null) {
1048                                                                 // TODO: Namespace has broken location
1049                                                                 //Report.SymbolRelatedToPreviousError (fne.Location, null);
1050                                                                 Report.SymbolRelatedToPreviousError (ue.Location, null);
1051                                                                 Report.Error (576, loc,
1052                                                                         "Namespace `{0}' contains a definition with same name as alias `{1}'",
1053                                                                         GetSignatureForError (), name);
1054                                                         } else {
1055                                                                 return fne;
1056                                                         }
1057                                                 }
1058
1059                                                 return ue.Resolve (Doppelganger);
1060                                         }
1061                                 }
1062                         }
1063
1064                         if (fne != null)
1065                                 return fne;
1066
1067                         if (IsImplicit)
1068                                 return null;
1069
1070                         //
1071                         // Check using entries.
1072                         //
1073                         FullNamedExpression match = null;
1074                         foreach (Namespace using_ns in GetUsingTable ()) {
1075                                 match = using_ns.Lookup (ds, name, loc);
1076                                 if (match == null || !(match is TypeExpr))
1077                                         continue;
1078                                 if (fne != null) {
1079                                         if (!ignore_cs0104)
1080                                                 Error_AmbiguousTypeReference (loc, name, fne, match);
1081                                         return null;
1082                                 }
1083                                 fne = match;
1084                         }
1085
1086                         return fne;
1087                 }
1088
1089                 Namespace [] GetUsingTable ()
1090                 {
1091                         if (namespace_using_table != null)
1092                                 return namespace_using_table;
1093
1094                         if (using_clauses == null) {
1095                                 namespace_using_table = empty_namespaces;
1096                                 return namespace_using_table;
1097                         }
1098
1099                         ArrayList list = new ArrayList (using_clauses.Count);
1100
1101                         foreach (UsingEntry ue in using_clauses) {
1102                                 Namespace using_ns = ue.Resolve (Doppelganger);
1103                                 if (using_ns == null)
1104                                         continue;
1105
1106                                 list.Add (using_ns);
1107                         }
1108
1109                         namespace_using_table = (Namespace[])list.ToArray (typeof (Namespace));
1110                         return namespace_using_table;
1111                 }
1112
1113                 static readonly string [] empty_using_list = new string [0];
1114
1115                 public int SymbolFileID {
1116                         get {
1117                                 if (symfile_id == 0 && file.SourceFileEntry != null) {
1118                                         int parent_id = parent == null ? 0 : parent.SymbolFileID;
1119
1120                                         string [] using_list = empty_using_list;
1121                                         if (using_clauses != null) {
1122                                                 using_list = new string [using_clauses.Count];
1123                                                 for (int i = 0; i < using_clauses.Count; i++)
1124                                                         using_list [i] = ((UsingEntry) using_clauses [i]).MemberName.GetName ();
1125                                         }
1126
1127                                         symfile_id = SymbolWriter.DefineNamespace (ns.Name, file.CompileUnitEntry, using_list, parent_id);
1128                                 }
1129                                 return symfile_id;
1130                         }
1131                 }
1132
1133                 static void MsgtryRef (string s)
1134                 {
1135                         Console.WriteLine ("    Try using -r:" + s);
1136                 }
1137
1138                 static void MsgtryPkg (string s)
1139                 {
1140                         Console.WriteLine ("    Try using -pkg:" + s);
1141                 }
1142
1143                 public static void Error_GlobalNamespaceRedefined (Location loc)
1144                 {
1145                         Report.Error (1681, loc, "You cannot redefine the global extern alias");
1146                 }
1147
1148                 public static void Error_NamespaceNotFound (Location loc, string name)
1149                 {
1150                         Report.Error (246, loc, "The type or namespace name `{0}' could not be found. Are you missing a using directive or an assembly reference?",
1151                                 name);
1152
1153                         switch (name) {
1154                         case "Gtk": case "GtkSharp":
1155                                 MsgtryPkg ("gtk-sharp");
1156                                 break;
1157
1158                         case "Gdk": case "GdkSharp":
1159                                 MsgtryPkg ("gdk-sharp");
1160                                 break;
1161
1162                         case "Glade": case "GladeSharp":
1163                                 MsgtryPkg ("glade-sharp");
1164                                 break;
1165
1166                         case "System.Drawing":
1167                         case "System.Web.Services":
1168                         case "System.Web":
1169                         case "System.Data":
1170                         case "System.Windows.Forms":
1171                                 MsgtryRef (name);
1172                                 break;
1173                         }
1174                 }
1175
1176                 /// <summary>
1177                 ///   Used to validate that all the using clauses are correct
1178                 ///   after we are finished parsing all the files.
1179                 /// </summary>
1180                 void VerifyUsing ()
1181                 {
1182                         if (using_aliases != null) {
1183                                 foreach (UsingAliasEntry ue in using_aliases)
1184                                         ue.Resolve (Doppelganger);
1185                         }
1186
1187                         if (using_clauses != null) {
1188                                 foreach (UsingEntry ue in using_clauses)
1189                                         ue.Resolve (Doppelganger);
1190                         }
1191                 }
1192
1193                 /// <summary>
1194                 ///   Used to validate that all the using clauses are correct
1195                 ///   after we are finished parsing all the files.
1196                 /// </summary>
1197                 static public void VerifyAllUsing ()
1198                 {
1199                         foreach (NamespaceEntry entry in entries)
1200                                 entry.VerifyUsing ();
1201                 }
1202
1203                 public string GetSignatureForError ()
1204                 {
1205                         return ns.GetSignatureForError ();
1206                 }
1207
1208                 public override string ToString ()
1209                 {
1210                         return ns.ToString ();
1211                 }
1212
1213                 #region IResolveContext Members
1214
1215                 public DeclSpace DeclContainer {
1216                         get { return SlaveDeclSpace; }
1217                 }
1218
1219                 public bool IsInObsoleteScope {
1220                         get { return SlaveDeclSpace.IsInObsoleteScope; }
1221                 }
1222
1223                 public bool IsInUnsafeScope {
1224                         get { return SlaveDeclSpace.IsInUnsafeScope; }
1225                 }
1226
1227                 public DeclSpace GenericDeclContainer {
1228                         get { return SlaveDeclSpace; }
1229                 }
1230
1231                 #endregion
1232         }
1233 }