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