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         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                 protected readonly string alias_name;
  27                 protected Assembly [] referenced_assemblies;
  28
  29                 Hashtable all_namespaces;
  30
  31                 static RootNamespace ()
  32                 {
  33                         get_namespaces_method = typeof (Assembly).GetMethod ("GetNamespaces", BindingFlags.Instance | BindingFlags.NonPublic);
  34                 }
  35
  36                 public RootNamespace (string alias_name)
  37                         : base (null, String.Empty)
  38                 {
  39                         this.alias_name = alias_name;
  40                         referenced_assemblies = new Assembly [0];
  41
  42                         all_namespaces = new Hashtable ();
  43                         all_namespaces.Add ("", this);
  44                 }
  45
  46                 public void AddAssemblyReference (Assembly a)
  47                 {
  48                         foreach (Assembly assembly in referenced_assemblies) {
  49                                 if (a == assembly)
  50                                         return;
  51                         }
  52
  53                         int top = referenced_assemblies.Length;
  54                         Assembly [] n = new Assembly [top + 1];
  55                         referenced_assemblies.CopyTo (n, 0);
  56                         n [top] = a;
  57                         referenced_assemblies = n;
  58                 }
  59
  60                 public void ComputeNamespace (Type extensionType)
  61                 {
  62                         foreach (Assembly a in referenced_assemblies) {
  63                                 try {
  64                                         ComputeNamespaces (a, extensionType);
  65                                 } catch (TypeLoadException e) {
  66                                         Report.Error (11, Location.Null, e.Message);
  67                                 } catch (System.IO.FileNotFoundException) {
  68                                         Report.Error (12, Location.Null, "An assembly `{0}' is used without being referenced",
  69                                                 a.FullName);
  70                                 }
  71                         }
  72                 }
  73
  74                 public virtual Type LookupTypeReflection (string name, Location loc, bool must_be_unique)
  75                 {
  76                         Type found_type = null;
  77
  78                         foreach (Assembly a in referenced_assemblies) {
  79                                 Type t = GetTypeInAssembly (a, name);
  80                                 if (t == null)
  81                                         continue;
  82
  83                                 if (!must_be_unique)
  84                                         return t;
  85
  86                                 if (found_type == null) {
  87                                         found_type = t;
  88                                         continue;
  89                                 }
  90
  91                                 // When type is forwarded
  92                                 if (t.Assembly == found_type.Assembly)
  93                                         continue;
  94
  95                                 Report.SymbolRelatedToPreviousError (found_type);
  96                                 Report.SymbolRelatedToPreviousError (t);
  97                                 if (loc.IsNull) {
  98                                         Error_AmbiguousPredefinedType (loc, name, found_type);
  99                                 } else {
 100                                         Report.Error (433, loc, "The imported type `{0}' is defined multiple times", name);
 101                                 }
 102
 103                                 return found_type;
 104                         }
 105
 106                         return found_type;
 107                 }
 108
 109                 //
 110                 // Returns the types starting with the given prefix
 111                 //
 112                 public ICollection CompletionGetTypesStartingWith (string prefix)
 113                 {
 114                         Hashtable result = null;
 115
 116                         foreach (Assembly a in referenced_assemblies){
 117                                 Type [] mtypes = a.GetTypes ();
 118
 119                                 foreach (Type t in mtypes){
 120                                         string f = t.FullName;
 121
 122                                         if (f.StartsWith (prefix) && (result == null || !result.Contains (f))){
 123                                                 if (result == null)
 124                                                         result = new Hashtable ();
 125
 126                                                 result [f] = f;
 127                                         }
 128                                 }
 129                         }
 130                         return result == null ? result : result.Keys;
 131                 }
 132
 133                 protected void Error_AmbiguousPredefinedType (Location loc, string name, Type type)
 134                 {
 135                         Report.Warning (1685, 1, loc,
 136                                 "The predefined type `{0}' is ambiguous. Using definition from `{1}'",
 137                                 name, type.Assembly.FullName);
 138                 }
 139
 140                 public void RegisterNamespace (Namespace child)
 141                 {
 142                         if (child != this)
 143                                 all_namespaces.Add (child.Name, child);
 144                 }
 145
 146                 public bool IsNamespace (string name)
 147                 {
 148                         return all_namespaces.Contains (name);
 149                 }
 150
 151                 protected void RegisterNamespace (string dotted_name)
 152                 {
 153                         if (dotted_name != null && dotted_name.Length != 0 && ! IsNamespace (dotted_name))
 154                                 GetNamespace (dotted_name, true);
 155                 }
 156
 157                 void RegisterExtensionMethodClass (Type t)
 158                 {
 159                         string n = t.Namespace;
 160                         Namespace ns = n == null ? GlobalRootNamespace.Instance : (Namespace) all_namespaces[n];
 161                         if (ns == null)
 162                                 ns = GetNamespace (n, true);
 163
 164                         ns.RegisterExternalExtensionMethodClass (t);
 165                 }
 166
 167                 void ComputeNamespaces (Assembly assembly, Type extensionType)
 168                 {
 169                         bool contains_extension_methods = extensionType != null && assembly.IsDefined (extensionType, false);
 170
 171                         if (get_namespaces_method != null) {
 172                                 string [] namespaces = (string []) get_namespaces_method.Invoke (assembly, null);
 173                                 foreach (string ns in namespaces)
 174                                         RegisterNamespace (ns);
 175
 176                                 if (!contains_extension_methods)
 177                                         return;
 178                         }
 179
 180                         foreach (Type t in assembly.GetTypes ()) {
 181                                 if ((t.Attributes & Class.StaticClassAttribute) == Class.StaticClassAttribute &&
 182                                         contains_extension_methods && t.IsDefined (extensionType, false))
 183                                         RegisterExtensionMethodClass (t);
 184
 185                                 if (get_namespaces_method == null)
 186                                         RegisterNamespace (t.Namespace);
 187                         }
 188                 }
 189
 190                 protected static Type GetTypeInAssembly (Assembly assembly, string name)
 191                 {
 192                         if (assembly == null)
 193                                 throw new ArgumentNullException ("assembly");
 194                         if (name == null)
 195                                 throw new ArgumentNullException ("name");
 196                         Type t = assembly.GetType (name);
 197                         if (t == null)
 198                                 return null;
 199
 200                         if (t.IsPointer)
 201                                 throw new InternalErrorException ("Use GetPointerType() to get a pointer");
 202
 203                         TypeAttributes ta = t.Attributes & TypeAttributes.VisibilityMask;
 204                         if (ta == TypeAttributes.NestedPrivate)
 205                                 return null;
 206
 207                         if ((ta == TypeAttributes.NotPublic ||
 208                              ta == TypeAttributes.NestedAssembly ||
 209                              ta == TypeAttributes.NestedFamANDAssem) &&
 210                             !TypeManager.IsThisOrFriendAssembly (t.Assembly))
 211                                 return null;
 212
 213                         return t;
 214                 }
 215
 216                 public override string ToString ()
 217                 {
 218                         return String.Format ("RootNamespace ({0}::)", alias_name);
 219                 }
 220
 221                 public override string GetSignatureForError ()
 222                 {
 223                         return alias_name + "::";
 224                 }
 225         }
 226
 227         class GlobalRootNamespace : RootNamespace {
 228                 Module [] modules;
 229                 ListDictionary root_namespaces;
 230
 231                 public static GlobalRootNamespace Instance = new GlobalRootNamespace ();
 232
 233                 GlobalRootNamespace ()
 234                         : base ("global")
 235                 {
 236                         root_namespaces = new ListDictionary ();
 237                         root_namespaces.Add (alias_name, this);
 238                 }
 239
 240                 public static void Reset ()
 241                 {
 242                         Instance = new GlobalRootNamespace ();
 243                 }
 244
 245                 public Assembly [] Assemblies {
 246                     get { return referenced_assemblies; }
 247                 }
 248
 249                 public Module [] Modules {
 250                         get { return modules; }
 251                 }
 252
 253                 public void AddModuleReference (Module m)
 254                 {
 255                         int top = modules != null ? modules.Length : 0;
 256                         Module [] n = new Module [top + 1];
 257                         if (modules != null)
 258                                 modules.CopyTo (n, 0);
 259                         n [top] = m;
 260                         modules = n;
 261
 262                         if (m == RootContext.ToplevelTypes.Builder)
 263                                 return;
 264
 265                         foreach (Type t in m.GetTypes ())
 266                                 RegisterNamespace (t.Namespace);
 267                 }
 268
 269                 public void ComputeNamespaces ()
 270                 {
 271                         //
 272                         // Do very early lookup because type is required when we cache
 273                         // imported extension types in ComputeNamespaces
 274                         //
 275                         Type extension_attribute_type = TypeManager.CoreLookupType ("System.Runtime.CompilerServices", "ExtensionAttribute", Kind.Class, false);
 276
 277                         foreach (RootNamespace rn in root_namespaces.Values) {
 278                                 rn.ComputeNamespace (extension_attribute_type);
 279                         }
 280                 }
 281
 282                 public void DefineRootNamespace (string alias, Assembly assembly)
 283                 {
 284                         if (alias == alias_name) {
 285                                 NamespaceEntry.Error_GlobalNamespaceRedefined (Location.Null);
 286                                 return;
 287                         }
 288
 289                         RootNamespace retval = GetRootNamespace (alias);
 290                         if (retval == null) {
 291                                 retval = new RootNamespace (alias);
 292                                 root_namespaces.Add (alias, retval);
 293                         }
 294
 295                         retval.AddAssemblyReference (assembly);
 296                 }
 297
 298                 public override void Error_NamespaceDoesNotExist (Location loc, string name)
 299                 {
 300                         Report.Error (400, loc, "The type or namespace name `{0}' could not be found in the global namespace (are you missing an assembly reference?)",
 301                                 name);
 302                 }
 303
 304                 public RootNamespace GetRootNamespace (string name)
 305                 {
 306                         return (RootNamespace) root_namespaces[name];
 307                 }
 308
 309                 public override Type LookupTypeReflection (string name, Location loc, bool must_be_unique)
 310                 {
 311                         Type found_type = base.LookupTypeReflection (name, loc, must_be_unique);
 312
 313                         if (modules != null) {
 314                                 foreach (Module module in modules) {
 315                                         Type t = module.GetType (name);
 316                                         if (t == null)
 317                                                 continue;
 318
 319                                         if (found_type == null) {
 320                                                 found_type = t;
 321                                                 continue;
 322                                         }
 323
 324                                         Report.SymbolRelatedToPreviousError (found_type);
 325                                         if (loc.IsNull) {
 326                                                 DeclSpace ds = TypeManager.LookupDeclSpace (t);
 327                                                 Error_AmbiguousPredefinedType (ds.Location, name, found_type);
 328                                                 return found_type;
 329                                         }
 330                                         Report.SymbolRelatedToPreviousError (t);
 331                                         Report.Warning (436, 2, loc, "The type `{0}' conflicts with the imported type `{1}'. Ignoring the imported type definition",
 332                                                 TypeManager.CSharpName (t), TypeManager.CSharpName (found_type));
 333                                         return t;
 334                                 }
 335                         }
 336
 337                         return found_type;
 338                 }
 339         }
 340
 341         /// <summary>
 342         ///   Keeps track of the namespaces defined in the C# code.
 343         ///
 344         ///   This is an Expression to allow it to be referenced in the
 345         ///   compiler parse/intermediate tree during name resolution.
 346         /// </summary>
 347         public class Namespace : FullNamedExpression {
 348
 349                 Namespace parent;
 350                 string fullname;
 351                 IDictionary namespaces;
 352                 IDictionary declspaces;
 353                 Hashtable cached_types;
 354                 RootNamespace root;
 355                 ArrayList external_exmethod_classes;
 356
 357                 public readonly MemberName MemberName;
 358
 359                 /// <summary>
 360                 ///   Constructor Takes the current namespace and the
 361                 ///   name.  This is bootstrapped with parent == null
 362                 ///   and name = ""
 363                 /// </summary>
 364                 public Namespace (Namespace parent, string name)
 365                 {
 366                         // Expression members.
 367                         this.eclass = ExprClass.Namespace;
 368                         this.Type = typeof (Namespace);
 369                         this.loc = Location.Null;
 370
 371                         this.parent = parent;
 372
 373                         if (parent != null)
 374                                 this.root = parent.root;
 375                         else
 376                                 this.root = this as RootNamespace;
 377
 378                         if (this.root == null)
 379                                 throw new InternalErrorException ("Root namespaces must be created using RootNamespace");
 380
 381                         string pname = parent != null ? parent.fullname : "";
 382
 383                         if (pname == "")
 384                                 fullname = name;
 385                         else
 386                                 fullname = parent.fullname + "." + name;
 387
 388                         if (fullname == null)
 389                                 throw new InternalErrorException ("Namespace has a null fullname");
 390
 391                         if (parent != null && parent.MemberName != MemberName.Null)
 392                                 MemberName = new MemberName (parent.MemberName, name);
 393                         else if (name.Length == 0)
 394                                 MemberName = MemberName.Null;
 395                         else
 396                                 MemberName = new MemberName (name);
 397
 398                         namespaces = new HybridDictionary ();
 399                         cached_types = new Hashtable ();
 400
 401                         root.RegisterNamespace (this);
 402                 }
 403
 404                 public override Expression DoResolve (ResolveContext ec)
 405                 {
 406                         return this;
 407                 }
 408
 409                 public virtual void Error_NamespaceDoesNotExist (Location loc, string name)
 410                 {
 411                         if (name.IndexOf ('`') > 0) {
 412                                 FullNamedExpression retval = Lookup (SimpleName.RemoveGenericArity (name), loc);
 413                                 if (retval != null) {
 414                                         Error_TypeArgumentsCannotBeUsed (retval, loc);
 415                                         return;
 416                                 }
 417                         } else {
 418                                 Type t = LookForAnyGenericType (name);
 419                                 if (t != null) {
 420                                         Error_InvalidNumberOfTypeArguments (t, loc);
 421                                         return;
 422                                 }
 423                         }
 424
 425                         Report.Error (234, loc, "The type or namespace name `{0}' does not exist in the namespace `{1}'. Are you missing an assembly reference?",
 426                                 name, GetSignatureForError ());
 427                 }
 428
 429                 public static void Error_InvalidNumberOfTypeArguments (Type t, Location loc)
 430                 {
 431                         Report.SymbolRelatedToPreviousError (t);
 432                         Report.Error (305, loc, "Using the generic type `{0}' requires `{1}' type argument(s)",
 433                                 TypeManager.CSharpName(t), TypeManager.GetNumberOfTypeArguments(t).ToString());
 434                 }
 435
 436                 public static void Error_TypeArgumentsCannotBeUsed (FullNamedExpression expr, Location loc)
 437                 {
 438                         if (expr is TypeExpr) {
 439                                 Report.SymbolRelatedToPreviousError (expr.Type);
 440                                 Error_TypeArgumentsCannotBeUsed (loc, "type", expr.GetSignatureForError ());
 441                         } else {
 442                                 expr.Error_ExpressionCannotBeGeneric (loc);
 443                         }
 444                 }
 445
 446                 public static void Error_TypeArgumentsCannotBeUsed (MethodBase mi, Location loc)
 447                 {
 448                         Report.SymbolRelatedToPreviousError (mi);
 449                         Error_TypeArgumentsCannotBeUsed (loc, "method", TypeManager.CSharpSignature (mi));
 450                 }
 451
 452                 static void Error_TypeArgumentsCannotBeUsed (Location loc, string type, string name)
 453                 {
 454                         Report.Error(308, loc, "The non-generic {0} `{1}' cannot be used with the type arguments",
 455                                 type, name);
 456                 }
 457
 458                 public override string GetSignatureForError ()
 459                 {
 460                         return fullname;
 461                 }
 462
 463                 public Namespace GetNamespace (string name, bool create)
 464                 {
 465                         int pos = name.IndexOf ('.');
 466
 467                         Namespace ns;
 468                         string first;
 469                         if (pos >= 0)
 470                                 first = name.Substring (0, pos);
 471                         else
 472                                 first = name;
 473
 474                         ns = (Namespace) namespaces [first];
 475                         if (ns == null) {
 476                                 if (!create)
 477                                         return null;
 478
 479                                 ns = new Namespace (this, first);
 480                                 namespaces.Add (first, ns);
 481                         }
 482
 483                         if (pos >= 0)
 484                                 ns = ns.GetNamespace (name.Substring (pos + 1), create);
 485
 486                         return ns;
 487                 }
 488
 489                 public bool HasDefinition (string name)
 490                 {
 491                         return declspaces != null && declspaces [name] != null;
 492                 }
 493
 494                 TypeExpr LookupType (string name, Location loc)
 495                 {
 496                         if (cached_types.Contains (name))
 497                                 return cached_types [name] as TypeExpr;
 498
 499                         Type t = null;
 500                         if (declspaces != null) {
 501                                 DeclSpace tdecl = declspaces [name] as DeclSpace;
 502                                 if (tdecl != null) {
 503                                         //
 504                                         // Note that this is not:
 505                                         //
 506                                         //   t = tdecl.DefineType ()
 507                                         //
 508                                         // This is to make it somewhat more useful when a DefineType
 509                                         // fails due to problems in nested types (more useful in the sense
 510                                         // of fewer misleading error messages)
 511                                         //
 512                                         tdecl.DefineType ();
 513                                         t = tdecl.TypeBuilder;
 514
 515                                         if (RootContext.EvalMode){
 516                                                 // Replace the TypeBuilder with a System.Type, as
 517                                                 // Reflection.Emit fails otherwise (we end up pretty
 518                                                 // much with Random type definitions later on).
 519                                                 Type tt = t.Assembly.GetType (t.Name);
 520                                                 if (tt != null)
 521                                                         t = tt;
 522                                         }
 523                                 }
 524                         }
 525                         string lookup = t != null ? t.FullName : (fullname.Length == 0 ? name : fullname + "." + name);
 526                         Type rt = root.LookupTypeReflection (lookup, loc, t == null);
 527
 528                         // HACK: loc.IsNull when the type is core type
 529                         if (t == null || (rt != null && loc.IsNull))
 530                                 t = rt;
 531
 532                         TypeExpr te = t == null ? null : new TypeExpression (t, Location.Null);
 533                         cached_types [name] = te;
 534                         return te;
 535                 }
 536
 537                 ///
 538                 /// Used for better error reporting only
 539                 ///
 540                 public Type LookForAnyGenericType (string typeName)
 541                 {
 542                         if (declspaces == null)
 543                                 return null;
 544
 545                         typeName = SimpleName.RemoveGenericArity (typeName);
 546
 547                         foreach (DictionaryEntry de in declspaces) {
 548                                 string type_item = (string) de.Key;
 549                                 int pos = type_item.LastIndexOf ('`');
 550                                 if (pos == typeName.Length && String.Compare (typeName, 0, type_item, 0, pos) == 0)
 551                                         return ((DeclSpace) de.Value).TypeBuilder;
 552                         }
 553                         return null;
 554                 }
 555
 556                 public FullNamedExpression Lookup (string name, Location loc)
 557                 {
 558                         if (namespaces.Contains (name))
 559                                 return (Namespace) namespaces [name];
 560
 561                         return LookupType (name, loc);
 562                 }
 563
 564                 //
 565                 // Completes types with the given `prefix' and stores the results in `result'
 566                 //
 567                 public void CompletionGetTypesStartingWith (string prefix, Hashtable result)
 568                 {
 569                         int l = fullname.Length + 1;
 570                         ICollection res = root.CompletionGetTypesStartingWith (fullname + "." + prefix);
 571
 572                         if (res == null)
 573                                 return;
 574
 575                         foreach (string match in res){
 576                                 string x = match.Substring (l);
 577
 578                                 // Turn reflection nested classes foo+bar into foo.bar
 579                                 x = x.Replace ('+', '.');
 580
 581                                 // Only get the first name element, no point in adding anything beyond the first dot.
 582                                 int p = x.IndexOf ('.');
 583                                 if (p != -1)
 584                                         x = x.Substring (0, p);
 585
 586                                 // Turn Foo`N into Foo<
 587                                 p = x.IndexOf ('`');
 588                                 if (p != -1)
 589                                         x = x.Substring (0, p) + "<";
 590
 591                                 if (!result.Contains (x))
 592                                         result [x] = x;
 593                         }
 594                 }
 595
 596                 public void RegisterExternalExtensionMethodClass (Type type)
 597                 {
 598                         // Ignore, extension methods cannot be nested
 599                         if (type.DeclaringType != null)
 600                                 return;
 601
 602                         if (type.IsNotPublic && !TypeManager.IsThisOrFriendAssembly (type.Assembly))
 603                                 return;
 604
 605                         if (external_exmethod_classes == null)
 606                                 external_exmethod_classes = new ArrayList ();
 607
 608                         external_exmethod_classes.Add (type);
 609                 }
 610
 611                 ///
 612                 /// Looks for extension method in this namespace
 613                 ///
 614                 public ArrayList LookupExtensionMethod (Type extensionType, ClassOrStruct currentClass, string name)
 615                 {
 616                         ArrayList found = null;
 617
 618                         if (declspaces != null) {
 619                                 IEnumerator e = declspaces.Values.GetEnumerator ();
 620                                 e.Reset ();
 621                                 while (e.MoveNext ()) {
 622                                         Class c = e.Current as Class;
 623                                         if (c == null)
 624                                                 continue;
 625
 626                                         if ((c.ModFlags & Modifiers.METHOD_EXTENSION) == 0)
 627                                                 continue;
 628
 629                                         ArrayList res = c.MemberCache.FindExtensionMethods (extensionType, name, c != currentClass);
 630                                         if (res == null)
 631                                                 continue;
 632
 633                                         if (found == null)
 634                                                 found = res;
 635                                         else
 636                                                 found.AddRange (res);
 637                                 }
 638                         }
 639
 640                         if (external_exmethod_classes == null)
 641                                 return found;
 642
 643                         foreach (Type t in external_exmethod_classes) {
 644                                 MemberCache m = TypeHandle.GetMemberCache (t);
 645                                 ArrayList res = m.FindExtensionMethods (extensionType, name, true);
 646                                 if (res == null)
 647                                         continue;
 648
 649                                 if (found == null)
 650                                         found = res;
 651                                 else
 652                                         found.AddRange (res);
 653                         }
 654
 655                         return found;
 656                 }
 657
 658                 public void AddDeclSpace (string name, DeclSpace ds)
 659                 {
 660                         if (declspaces == null)
 661                                 declspaces = new HybridDictionary ();
 662                         declspaces.Add (name, ds);
 663                 }
 664
 665                 public void RemoveDeclSpace (string name)
 666                 {
 667                         declspaces.Remove (name);
 668                 }
 669
 670                 /// <summary>
 671                 ///   The qualified name of the current namespace
 672                 /// </summary>
 673                 public string Name {
 674                         get { return fullname; }
 675                 }
 676
 677                 /// <summary>
 678                 ///   The parent of this namespace, used by the parser to "Pop"
 679                 ///   the current namespace declaration
 680                 /// </summary>
 681                 public Namespace Parent {
 682                         get { return parent; }
 683                 }
 684         }
 685
 686         //
 687         // Namespace container as created by the parser
 688         //
 689         public class NamespaceEntry : IMemberContext {
 690
 691                 class UsingEntry {
 692                         readonly MemberName name;
 693                         Namespace resolved;
 694
 695                         public UsingEntry (MemberName name)
 696                         {
 697                                 this.name = name;
 698                         }
 699
 700                         public string GetSignatureForError ()
 701                         {
 702                                 return name.GetSignatureForError ();
 703                         }
 704
 705                         public Location Location {
 706                                 get { return name.Location; }
 707                         }
 708
 709                         public MemberName MemberName {
 710                                 get { return name; }
 711                         }
 712
 713                         public string Name {
 714                                 get { return GetSignatureForError (); }
 715                         }
 716
 717                         public Namespace Resolve (IMemberContext rc)
 718                         {
 719                                 if (resolved != null)
 720                                         return resolved;
 721
 722                                 FullNamedExpression fne = name.GetTypeExpression ().ResolveAsTypeStep (rc, false);
 723                                 if (fne == null)
 724                                         return null;
 725
 726                                 resolved = fne as Namespace;
 727                                 if (resolved == null) {
 728                                         Report.SymbolRelatedToPreviousError (fne.Type);
 729                                         Report.Error (138, Location,
 730                                                 "`{0}' is a type not a namespace. A using namespace directive can only be applied to namespaces",
 731                                                 GetSignatureForError ());
 732                                 }
 733                                 return resolved;
 734                         }
 735
 736                         public override string ToString ()
 737                         {
 738                                 return Name;
 739                         }
 740                 }
 741
 742                 class UsingAliasEntry {
 743                         public readonly string Alias;
 744                         public Location Location;
 745
 746                         public UsingAliasEntry (string alias, Location loc)
 747                         {
 748                                 this.Alias = alias;
 749                                 this.Location = loc;
 750                         }
 751
 752                         public virtual FullNamedExpression Resolve (IMemberContext rc)
 753                         {
 754                                 FullNamedExpression fne = GlobalRootNamespace.Instance.GetRootNamespace (Alias);
 755                                 if (fne == null) {
 756                                         Report.Error (430, Location,
 757                                                 "The extern alias `{0}' was not specified in -reference option",
 758                                                 Alias);
 759                                 }
 760
 761                                 return fne;
 762                         }
 763
 764                         public override string ToString ()
 765                         {
 766                                 return Alias;
 767                         }
 768
 769                 }
 770
 771                 class LocalUsingAliasEntry : UsingAliasEntry {
 772                         FullNamedExpression resolved;
 773                         MemberName value;
 774
 775                         public LocalUsingAliasEntry (string alias, MemberName name, Location loc)
 776                                 : base (alias, loc)
 777                         {
 778                                 this.value = name;
 779                         }
 780
 781                         public override FullNamedExpression Resolve (IMemberContext rc)
 782                         {
 783                                 if (resolved != null || value == null)
 784                                         return resolved;
 785
 786                                 if (rc == null)
 787                                         return null;
 788
 789                                 resolved = value.GetTypeExpression ().ResolveAsTypeStep (rc, false);
 790                                 if (resolved == null) {
 791                                         value = null;
 792                                         return null;
 793                                 }
 794
 795                                 if (resolved is TypeExpr)
 796                                         resolved = resolved.ResolveAsBaseTerminal (rc, false);
 797
 798                                 return resolved;
 799                         }
 800
 801                         public override string ToString ()
 802                         {
 803                                 return String.Format ("{0} = {1}", Alias, value.GetSignatureForError ());
 804                         }
 805                 }
 806
 807                 Namespace ns;
 808                 NamespaceEntry parent, implicit_parent;
 809                 CompilationUnit file;
 810                 int symfile_id;
 811
 812                 // Namespace using import block
 813                 ArrayList using_aliases;
 814                 ArrayList using_clauses;
 815                 public bool DeclarationFound = false;
 816                 // End
 817
 818                 public readonly bool IsImplicit;
 819                 public readonly DeclSpace SlaveDeclSpace;
 820                 static readonly Namespace [] empty_namespaces = new Namespace [0];
 821                 Namespace [] namespace_using_table;
 822
 823                 static ArrayList entries = new ArrayList ();
 824
 825                 public static void Reset ()
 826                 {
 827                         entries = new ArrayList ();
 828                 }
 829
 830                 public NamespaceEntry (NamespaceEntry parent, CompilationUnit file, string name)
 831                 {
 832                         this.parent = parent;
 833                         this.file = file;
 834                         entries.Add (this);
 835
 836                         if (parent != null)
 837                                 ns = parent.NS.GetNamespace (name, true);
 838                         else if (name != null)
 839                                 ns = GlobalRootNamespace.Instance.GetNamespace (name, true);
 840                         else
 841                                 ns = GlobalRootNamespace.Instance;
 842                         SlaveDeclSpace = new RootDeclSpace (this);
 843                 }
 844
 845                 private NamespaceEntry (NamespaceEntry parent, CompilationUnit file, Namespace ns, bool slave)
 846                 {
 847                         this.parent = parent;
 848                         this.file = file;
 849                         this.IsImplicit = true;
 850                         this.ns = ns;
 851                         this.SlaveDeclSpace = slave ? new RootDeclSpace (this) : null;
 852                 }
 853
 854                 //
 855                 // Populates the Namespace with some using declarations, used by the
 856                 // eval mode.
 857                 //
 858                 public void Populate (ArrayList source_using_aliases, ArrayList source_using_clauses)
 859                 {
 860                         foreach (UsingAliasEntry uae in source_using_aliases){
 861                                 if (using_aliases == null)
 862                                         using_aliases = new ArrayList ();
 863
 864                                 using_aliases.Add (uae);
 865                         }
 866
 867                         foreach (UsingEntry ue in source_using_clauses){
 868                                 if (using_clauses == null)
 869                                         using_clauses = new ArrayList ();
 870
 871                                 using_clauses.Add (ue);
 872                         }
 873                 }
 874
 875                 //
 876                 // Extracts the using alises and using clauses into a couple of
 877                 // arrays that might already have the same information;  Used by the
 878                 // C# Eval mode.
 879                 //
 880                 public void Extract (ArrayList out_using_aliases, ArrayList out_using_clauses)
 881                 {
 882                         if (using_aliases != null){
 883                                 foreach (UsingAliasEntry uae in using_aliases){
 884                                         bool replaced = false;
 885
 886                                         for (int i = 0; i < out_using_aliases.Count; i++){
 887                                                 UsingAliasEntry out_uea = (UsingAliasEntry) out_using_aliases [i];
 888
 889                                                 if (out_uea.Alias == uae.Alias){
 890                                                         out_using_aliases [i] = uae;
 891                                                         replaced = true;
 892                                                         break;
 893                                                 }
 894                                         }
 895                                         if (!replaced)
 896                                                 out_using_aliases.Add (uae);
 897                                 }
 898                         }
 899
 900                         if (using_clauses != null){
 901                                 foreach (UsingEntry ue in using_clauses){
 902                                         bool found = false;
 903
 904                                         foreach (UsingEntry out_ue in out_using_clauses)
 905                                                 if (out_ue.Name == ue.Name){
 906                                                         found = true;
 907                                                         break;
 908                                                 }
 909                                         if (!found)
 910                                                 out_using_clauses.Add (ue);
 911                                 }
 912                         }
 913                 }
 914
 915                 //
 916                 // According to section 16.3.1 (using-alias-directive), the namespace-or-type-name is
 917                 // resolved as if the immediately containing namespace body has no using-directives.
 918                 //
 919                 // Section 16.3.2 says that the same rule is applied when resolving the namespace-name
 920                 // in the using-namespace-directive.
 921                 //
 922                 // To implement these rules, the expressions in the using directives are resolved using
 923                 // the "doppelganger" (ghostly bodiless duplicate).
 924                 //
 925                 NamespaceEntry doppelganger;
 926                 NamespaceEntry Doppelganger {
 927                         get {
 928                                 if (!IsImplicit && doppelganger == null) {
 929                                         doppelganger = new NamespaceEntry (ImplicitParent, file, ns, true);
 930                                         doppelganger.using_aliases = using_aliases;
 931                                 }
 932                                 return doppelganger;
 933                         }
 934                 }
 935
 936                 public Namespace NS {
 937                         get { return ns; }
 938                 }
 939
 940                 public NamespaceEntry Parent {
 941                         get { return parent; }
 942                 }
 943
 944                 public NamespaceEntry ImplicitParent {
 945                         get {
 946                                 if (parent == null)
 947                                         return null;
 948                                 if (implicit_parent == null) {
 949                                         implicit_parent = (parent.NS == ns.Parent)
 950                                                 ? parent
 951                                                 : new NamespaceEntry (parent, file, ns.Parent, false);
 952                                 }
 953                                 return implicit_parent;
 954                         }
 955                 }
 956
 957                 /// <summary>
 958                 ///   Records a new namespace for resolving name references
 959                 /// </summary>
 960                 public void AddUsing (MemberName name, Location loc)
 961                 {
 962                         if (DeclarationFound){
 963                                 Report.Error (1529, loc, "A using clause must precede all other namespace elements except extern alias declarations");
 964                         }
 965
 966                         if (using_clauses == null) {
 967                                 using_clauses = new ArrayList ();
 968                         } else {
 969                                 foreach (UsingEntry old_entry in using_clauses) {
 970                                         if (name.Equals (old_entry.MemberName)) {
 971                                                 Report.SymbolRelatedToPreviousError (old_entry.Location, old_entry.GetSignatureForError ());
 972                                                 Report.Warning (105, 3, loc, "The using directive for `{0}' appeared previously in this namespace", name.GetSignatureForError ());
 973                                                 return;
 974                                         }
 975                                 }
 976                         }
 977
 978                         using_clauses.Add (new UsingEntry (name));
 979                 }
 980
 981                 public void AddUsingAlias (string alias, MemberName name, Location loc)
 982                 {
 983                         // TODO: This is parser bussines
 984                         if (DeclarationFound){
 985                                 Report.Error (1529, loc, "A using clause must precede all other namespace elements except extern alias declarations");
 986                         }
 987
 988                         if (RootContext.Version != LanguageVersion.ISO_1 && alias == "global")
 989                                 Report.Warning (440, 2, loc, "An alias named `global' will not be used when resolving 'global::';" +
 990                                         " the global namespace will be used instead");
 991
 992                         AddUsingAlias (new LocalUsingAliasEntry (alias, name, loc));
 993                 }
 994
 995                 public void AddUsingExternalAlias (string alias, Location loc)
 996                 {
 997                         // TODO: Do this in parser
 998                         bool not_first = using_clauses != null || DeclarationFound;
 999                         if (using_aliases != null && !not_first) {
1000                                 foreach (UsingAliasEntry uae in using_aliases) {
1001                                         if (uae is LocalUsingAliasEntry) {
1002                                                 not_first = true;
1003                                                 break;
1004                                         }
1005                                 }
1006                         }
1007
1008                         if (not_first)
1009                                 Report.Error (439, loc, "An extern alias declaration must precede all other elements");
1010
1011                         if (alias == "global") {
1012                                 Error_GlobalNamespaceRedefined (loc);
1013                                 return;
1014                         }
1015
1016                         AddUsingAlias (new UsingAliasEntry (alias, loc));
1017                 }
1018
1019                 void AddUsingAlias (UsingAliasEntry uae)
1020                 {
1021                         if (using_aliases == null) {
1022                                 using_aliases = new ArrayList ();
1023                         } else {
1024                                 foreach (UsingAliasEntry entry in using_aliases) {
1025                                         if (uae.Alias == entry.Alias) {
1026                                                 Report.SymbolRelatedToPreviousError (uae.Location, uae.Alias);
1027                                                 Report.Error (1537, entry.Location, "The using alias `{0}' appeared previously in this namespace",
1028                                                         entry.Alias);
1029                                                 return;
1030                                         }
1031                                 }
1032                         }
1033
1034                         using_aliases.Add (uae);
1035                 }
1036
1037                 ///
1038                 /// Does extension methods look up to find a method which matches name and extensionType.
1039                 /// Search starts from this namespace and continues hierarchically up to top level.
1040                 ///
1041                 public ExtensionMethodGroupExpr LookupExtensionMethod (Type extensionType, string name, Location loc)
1042                 {
1043                         ArrayList candidates = null;
1044                         foreach (Namespace n in GetUsingTable ()) {
1045                                 ArrayList a = n.LookupExtensionMethod (extensionType, null, name);
1046                                 if (a == null)
1047                                         continue;
1048
1049                                 if (candidates == null)
1050                                         candidates = a;
1051                                 else
1052                                         candidates.AddRange (a);
1053                         }
1054
1055                         if (candidates != null)
1056                                 return new ExtensionMethodGroupExpr (candidates, parent, extensionType, loc);
1057
1058                         if (parent == null)
1059                                 return null;
1060
1061                         //
1062                         // Inspect parent namespaces in namespace expression
1063                         //
1064                         Namespace parent_ns = ns.Parent;
1065                         do {
1066                                 candidates = parent_ns.LookupExtensionMethod (extensionType, null, name);
1067                                 if (candidates != null)
1068                                         return new ExtensionMethodGroupExpr (candidates, parent, extensionType, loc);
1069
1070                                 parent_ns = parent_ns.Parent;
1071                         } while (parent_ns != null);
1072
1073                         //
1074                         // Continue in parent scope
1075                         //
1076                         return parent.LookupExtensionMethod (extensionType, name, loc);
1077                 }
1078
1079                 public FullNamedExpression LookupNamespaceOrType (string name, Location loc, bool ignore_cs0104)
1080                 {
1081                         // Precondition: Only simple names (no dots) will be looked up with this function.
1082                         FullNamedExpression resolved = null;
1083                         for (NamespaceEntry curr_ns = this; curr_ns != null; curr_ns = curr_ns.ImplicitParent) {
1084                                 if ((resolved = curr_ns.Lookup (name, loc, ignore_cs0104)) != null)
1085                                         break;
1086                         }
1087                         return resolved;
1088                 }
1089
1090                 public ICollection CompletionGetTypesStartingWith (string prefix)
1091                 {
1092                         Hashtable result = new Hashtable ();
1093
1094                         for (NamespaceEntry curr_ns = this; curr_ns != null; curr_ns = curr_ns.ImplicitParent){
1095                                 foreach (Namespace using_ns in GetUsingTable ()){
1096                                         if (prefix.StartsWith (using_ns.Name)){
1097                                                 int ld = prefix.LastIndexOf ('.');
1098                                                 if (ld != -1){
1099                                                         string rest = prefix.Substring (ld+1);
1100
1101                                                         using_ns.CompletionGetTypesStartingWith (rest, result);
1102                                                 }
1103                                         }
1104                                         using_ns.CompletionGetTypesStartingWith (prefix, result);
1105                                 }
1106                         }
1107
1108                         return result.Keys;
1109                 }
1110
1111                 static void Error_AmbiguousTypeReference (Location loc, string name, FullNamedExpression t1, FullNamedExpression t2)
1112                 {
1113                         Report.SymbolRelatedToPreviousError (t1.Type);
1114                         Report.SymbolRelatedToPreviousError (t2.Type);
1115                         Report.Error (104, loc, "`{0}' is an ambiguous reference between `{1}' and `{2}'",
1116                                 name, t1.GetSignatureForError (), t2.GetSignatureForError ());
1117                 }
1118
1119                 // Looks-up a alias named @name in this and surrounding namespace declarations
1120                 public FullNamedExpression LookupNamespaceAlias (string name)
1121                 {
1122                         for (NamespaceEntry n = this; n != null; n = n.ImplicitParent) {
1123                                 if (n.using_aliases == null)
1124                                         continue;
1125
1126                                 foreach (UsingAliasEntry ue in n.using_aliases) {
1127                                         if (ue.Alias == name)
1128                                                 return ue.Resolve (Doppelganger);
1129                                 }
1130                         }
1131
1132                         return null;
1133                 }
1134
1135                 private FullNamedExpression Lookup (string name, Location loc, bool ignore_cs0104)
1136                 {
1137                         //
1138                         // Check whether it's in the namespace.
1139                         //
1140                         FullNamedExpression fne = ns.Lookup (name, loc);
1141
1142                         //
1143                         // Check aliases.
1144                         //
1145                         if (using_aliases != null) {
1146                                 foreach (UsingAliasEntry ue in using_aliases) {
1147                                         if (ue.Alias == name) {
1148                                                 if (fne != null) {
1149                                                         if (Doppelganger != null) {
1150                                                                 // TODO: Namespace has broken location
1151                                                                 //Report.SymbolRelatedToPreviousError (fne.Location, null);
1152                                                                 Report.SymbolRelatedToPreviousError (ue.Location, null);
1153                                                                 Report.Error (576, loc,
1154                                                                         "Namespace `{0}' contains a definition with same name as alias `{1}'",
1155                                                                         GetSignatureForError (), name);
1156                                                         } else {
1157                                                                 return fne;
1158                                                         }
1159                                                 }
1160
1161                                                 return ue.Resolve (Doppelganger);
1162                                         }
1163                                 }
1164                         }
1165
1166                         if (fne != null)
1167                                 return fne;
1168
1169                         if (IsImplicit)
1170                                 return null;
1171
1172                         //
1173                         // Check using entries.
1174                         //
1175                         FullNamedExpression match = null;
1176                         foreach (Namespace using_ns in GetUsingTable ()) {
1177                                 match = using_ns.Lookup (name, loc);
1178                                 if (match == null || !(match is TypeExpr))
1179                                         continue;
1180                                 if (fne != null) {
1181                                         if (!ignore_cs0104)
1182                                                 Error_AmbiguousTypeReference (loc, name, fne, match);
1183                                         return null;
1184                                 }
1185                                 fne = match;
1186                         }
1187
1188                         return fne;
1189                 }
1190
1191                 Namespace [] GetUsingTable ()
1192                 {
1193                         if (namespace_using_table != null)
1194                                 return namespace_using_table;
1195
1196                         if (using_clauses == null) {
1197                                 namespace_using_table = empty_namespaces;
1198                                 return namespace_using_table;
1199                         }
1200
1201                         ArrayList list = new ArrayList (using_clauses.Count);
1202
1203                         foreach (UsingEntry ue in using_clauses) {
1204                                 Namespace using_ns = ue.Resolve (Doppelganger);
1205                                 if (using_ns == null)
1206                                         continue;
1207
1208                                 list.Add (using_ns);
1209                         }
1210
1211                         namespace_using_table = (Namespace[])list.ToArray (typeof (Namespace));
1212                         return namespace_using_table;
1213                 }
1214
1215                 static readonly string [] empty_using_list = new string [0];
1216
1217                 public int SymbolFileID {
1218                         get {
1219                                 if (symfile_id == 0 && file.SourceFileEntry != null) {
1220                                         int parent_id = parent == null ? 0 : parent.SymbolFileID;
1221
1222                                         string [] using_list = empty_using_list;
1223                                         if (using_clauses != null) {
1224                                                 using_list = new string [using_clauses.Count];
1225                                                 for (int i = 0; i < using_clauses.Count; i++)
1226                                                         using_list [i] = ((UsingEntry) using_clauses [i]).MemberName.GetName ();
1227                                         }
1228
1229                                         symfile_id = SymbolWriter.DefineNamespace (ns.Name, file.CompileUnitEntry, using_list, parent_id);
1230                                 }
1231                                 return symfile_id;
1232                         }
1233                 }
1234
1235                 static void MsgtryRef (string s)
1236                 {
1237                         Console.WriteLine ("    Try using -r:" + s);
1238                 }
1239
1240                 static void MsgtryPkg (string s)
1241                 {
1242                         Console.WriteLine ("    Try using -pkg:" + s);
1243                 }
1244
1245                 public static void Error_GlobalNamespaceRedefined (Location loc)
1246                 {
1247                         Report.Error (1681, loc, "You cannot redefine the global extern alias");
1248                 }
1249
1250                 public static void Error_NamespaceNotFound (Location loc, string name)
1251                 {
1252                         Report.Error (246, loc, "The type or namespace name `{0}' could not be found. Are you missing a using directive or an assembly reference?",
1253                                 name);
1254
1255                         switch (name) {
1256                         case "Gtk": case "GtkSharp":
1257                                 MsgtryPkg ("gtk-sharp");
1258                                 break;
1259
1260                         case "Gdk": case "GdkSharp":
1261                                 MsgtryPkg ("gdk-sharp");
1262                                 break;
1263
1264                         case "Glade": case "GladeSharp":
1265                                 MsgtryPkg ("glade-sharp");
1266                                 break;
1267
1268                         case "System.Drawing":
1269                         case "System.Web.Services":
1270                         case "System.Web":
1271                         case "System.Data":
1272                         case "System.Windows.Forms":
1273                                 MsgtryRef (name);
1274                                 break;
1275                         }
1276                 }
1277
1278                 /// <summary>
1279                 ///   Used to validate that all the using clauses are correct
1280                 ///   after we are finished parsing all the files.
1281                 /// </summary>
1282                 void VerifyUsing ()
1283                 {
1284                         if (using_aliases != null) {
1285                                 foreach (UsingAliasEntry ue in using_aliases)
1286                                         ue.Resolve (Doppelganger);
1287                         }
1288
1289                         if (using_clauses != null) {
1290                                 foreach (UsingEntry ue in using_clauses)
1291                                         ue.Resolve (Doppelganger);
1292                         }
1293                 }
1294
1295                 /// <summary>
1296                 ///   Used to validate that all the using clauses are correct
1297                 ///   after we are finished parsing all the files.
1298                 /// </summary>
1299                 static public void VerifyAllUsing ()
1300                 {
1301                         foreach (NamespaceEntry entry in entries)
1302                                 entry.VerifyUsing ();
1303                 }
1304
1305                 public string GetSignatureForError ()
1306                 {
1307                         return ns.GetSignatureForError ();
1308                 }
1309
1310                 public override string ToString ()
1311                 {
1312                         return ns.ToString ();
1313                 }
1314
1315                 #region IMemberContext Members
1316
1317                 public Type CurrentType {
1318                         get { return SlaveDeclSpace.CurrentType; }
1319                 }
1320
1321                 public TypeContainer CurrentTypeDefinition {
1322                         get { return SlaveDeclSpace.CurrentTypeDefinition; }
1323                 }
1324
1325                 public TypeParameter[] CurrentTypeParameters {
1326                         get { return SlaveDeclSpace.CurrentTypeParameters; }
1327                 }
1328
1329                 public bool IsObsolete {
1330                         get { return SlaveDeclSpace.IsObsolete; }
1331                 }
1332
1333                 public bool IsUnsafe {
1334                         get { return SlaveDeclSpace.IsUnsafe; }
1335                 }
1336
1337                 public bool IsStatic {
1338                         get { return SlaveDeclSpace.IsStatic; }
1339                 }
1340
1341                 #endregion
1342         }
1343 }