mcs/mcs/namespace.cs

   1 //
   2 // namespace.cs: Tracks namespaces
   3 //
   4 // Author:
   5 //   Miguel de Icaza (miguel@ximian.com)
   6 //   Marek Safar (marek.safar@seznam.cz)
   7 //
   8 // Copyright 2001 Ximian, Inc.
   9 // Copyright 2003-2008 Novell, Inc.
  10 //
  11 using System;
  12 using System.Collections;
  13 using System.Collections.Specialized;
  14 using System.Reflection;
  15
  16 namespace Mono.CSharp {
  17
  18         public class RootNamespace : Namespace {
  19                 //
  20                 // Points to Mono's GetNamespaces method, an
  21                 // optimization when running on Mono to fetch all the
  22                 // namespaces in an assembly
  23                 //
  24                 static MethodInfo get_namespaces_method;
  25
  26                 string alias_name;
  27                 protected Assembly [] referenced_assemblies;
  28
  29                 Hashtable all_namespaces;
  30
  31                 static ListDictionary root_namespaces;
  32                 public static GlobalRootNamespace Global;
  33
  34                 static RootNamespace ()
  35                 {
  36                         get_namespaces_method = typeof (Assembly).GetMethod ("GetNamespaces", BindingFlags.Instance | BindingFlags.NonPublic);
  37
  38                         Reset ();
  39                 }
  40
  41                 public static void Reset ()
  42                 {
  43                         root_namespaces = new ListDictionary ();
  44                         Global = new GlobalRootNamespace ();
  45                         root_namespaces ["global"] = Global;
  46                 }
  47
  48                 protected RootNamespace (string alias_name)
  49                         : base (null, String.Empty)
  50                 {
  51                         this.alias_name = alias_name;
  52                         referenced_assemblies = new Assembly [0];
  53
  54                         all_namespaces = new Hashtable ();
  55                         all_namespaces.Add ("", this);
  56                 }
  57
  58                 public void AddAssemblyReference (Assembly a)
  59                 {
  60                         foreach (Assembly assembly in referenced_assemblies) {
  61                                 if (a == assembly)
  62                                         return;
  63                         }
  64
  65                         // How to test whether attribute exists without loading the assembly :-(
  66 #if NET_2_1
  67                         const string SystemCore = "System.Core, Version=2.0.5.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e";
  68 #else
  69                         const string SystemCore = "System.Core, Version=3.5.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089";
  70 #endif
  71                         if (TypeManager.extension_attribute_type == null &&
  72                                 a.FullName == SystemCore) {
  73                                 TypeManager.extension_attribute_type = a.GetType("System.Runtime.CompilerServices.ExtensionAttribute");
  74                         }
  75
  76                         int top = referenced_assemblies.Length;
  77                         Assembly [] n = new Assembly [top + 1];
  78                         referenced_assemblies.CopyTo (n, 0);
  79                         n [top] = a;
  80                         referenced_assemblies = n;
  81                 }
  82
  83                 public static void DefineRootNamespace (string alias, Assembly assembly)
  84                 {
  85                         if (alias == "global") {
  86                                 NamespaceEntry.Error_GlobalNamespaceRedefined (Location.Null);
  87                                 return;
  88                         }
  89
  90                         RootNamespace retval = GetRootNamespace (alias);
  91                         if (retval == null) {
  92                                 retval = new RootNamespace (alias);
  93                                 root_namespaces.Add (alias, retval);
  94                         }
  95
  96                         retval.AddAssemblyReference (assembly);
  97                 }
  98
  99                 public static RootNamespace GetRootNamespace (string name)
 100                 {
 101                         return (RootNamespace) root_namespaces [name];
 102                 }
 103
 104                 public static void ComputeNamespaces ()
 105                 {
 106                         foreach (RootNamespace rn in root_namespaces.Values) {
 107                                 foreach (Assembly a in rn.referenced_assemblies) {
 108                                         try {
 109                                                 rn.ComputeNamespaces (a);
 110                                         } catch (TypeLoadException e) {
 111                                                 Report.Error (11, Location.Null, e.Message);
 112                                         } catch (System.IO.FileNotFoundException) {
 113                                                 Report.Error (12, Location.Null, "An assembly `{0}' is used without being referenced",
 114                                                         a.FullName);
 115                                         }
 116                                 }
 117                         }
 118                 }
 119
 120                 public virtual Type LookupTypeReflection (string name, Location loc)
 121                 {
 122                         Type found_type = null;
 123
 124                         foreach (Assembly a in referenced_assemblies) {
 125                                 Type t = GetTypeInAssembly (a, name);
 126                                 if (t == null)
 127                                         continue;
 128
 129                                 if (found_type == null) {
 130                                         found_type = t;
 131                                         continue;
 132                                 }
 133
 134                                 Report.SymbolRelatedToPreviousError (found_type);
 135                                 Report.SymbolRelatedToPreviousError (t);
 136                                 Report.Error (433, loc, "The imported type `{0}' is defined multiple times", name);
 137
 138                                 return found_type;
 139                         }
 140
 141                         return found_type;
 142                 }
 143
 144                 public void RegisterNamespace (Namespace child)
 145                 {
 146                         if (child != this)
 147                                 all_namespaces.Add (child.Name, child);
 148                 }
 149
 150                 public bool IsNamespace (string name)
 151                 {
 152                         return all_namespaces.Contains (name);
 153                 }
 154
 155                 protected void RegisterNamespace (string dotted_name)
 156                 {
 157                         if (dotted_name != null && dotted_name.Length != 0 && ! IsNamespace (dotted_name))
 158                                 GetNamespace (dotted_name, true);
 159                 }
 160
 161                 void RegisterExtensionMethodClass (Type t)
 162                 {
 163                         string n = t.Namespace;
 164                         Namespace ns = n == null ? Global : (Namespace)all_namespaces [n];
 165                         if (ns == null)
 166                                 ns = GetNamespace (n, true);
 167
 168                         ns.RegisterExternalExtensionMethodClass (t);
 169                 }
 170
 171                 protected void ComputeNamespaces (Assembly assembly)
 172                 {
 173                         bool contains_extension_methods = TypeManager.extension_attribute_type != null &&
 174                                         assembly.IsDefined(TypeManager.extension_attribute_type, false);
 175
 176                         if (get_namespaces_method != null && !contains_extension_methods) {
 177                                 string [] namespaces = (string []) get_namespaces_method.Invoke (assembly, null);
 178                                 foreach (string ns in namespaces)
 179                                         RegisterNamespace (ns);
 180                                 return;
 181                         }
 182
 183                         foreach (Type t in assembly.GetExportedTypes ()) {
 184                                 if ((t.Attributes & Class.StaticClassAttribute) == Class.StaticClassAttribute &&
 185                                         contains_extension_methods && t.IsDefined (TypeManager.extension_attribute_type, false))
 186                                         RegisterExtensionMethodClass (t);
 187                                 else
 188                                         RegisterNamespace (t.Namespace);
 189                         }
 190                 }
 191
 192                 protected static Type GetTypeInAssembly (Assembly assembly, string name)
 193                 {
 194                         Type t = assembly.GetType (name);
 195                         if (t == null)
 196                                 return null;
 197
 198                         if (t.IsPointer)
 199                                 throw new InternalErrorException ("Use GetPointerType() to get a pointer");
 200
 201                         TypeAttributes ta = t.Attributes & TypeAttributes.VisibilityMask;
 202                         if (ta == TypeAttributes.NestedPrivate)
 203                                 return null;
 204
 205                         if ((ta == TypeAttributes.NotPublic ||
 206                              ta == TypeAttributes.NestedAssembly ||
 207                              ta == TypeAttributes.NestedFamANDAssem) &&
 208                             !TypeManager.IsThisOrFriendAssembly (t.Assembly))
 209                                 return null;
 210
 211                         return t;
 212                 }
 213
 214                 public override string ToString ()
 215                 {
 216                         return String.Format ("RootNamespace ({0}::)", alias_name);
 217                 }
 218
 219                 public override string GetSignatureForError ()
 220                 {
 221                         return alias_name + "::";
 222                 }
 223         }
 224
 225         public class GlobalRootNamespace : RootNamespace {
 226                 Module [] modules;
 227
 228                 public GlobalRootNamespace ()
 229                         : base ("global")
 230                 {
 231                 }
 232
 233                 public Assembly [] Assemblies {
 234                     get { return referenced_assemblies; }
 235                 }
 236
 237                 public Module [] Modules {
 238                         get { return modules; }
 239                 }
 240
 241                 public void AddModuleReference (Module m)
 242                 {
 243                         int top = modules != null ? modules.Length : 0;
 244                         Module [] n = new Module [top + 1];
 245                         if (modules != null)
 246                                 modules.CopyTo (n, 0);
 247                         n [top] = m;
 248                         modules = n;
 249
 250                         if (m == CodeGen.Module.Builder)
 251                                 return;
 252
 253                         foreach (Type t in m.GetTypes ())
 254                                 RegisterNamespace (t.Namespace);
 255                 }
 256
 257                 public override void Error_NamespaceDoesNotExist(DeclSpace ds, Location loc, string name)
 258                 {
 259                         Report.Error (400, loc, "The type or namespace name `{0}' could not be found in the global namespace (are you missing an assembly reference?)",
 260                                 name);
 261                 }
 262
 263                 public override Type LookupTypeReflection (string name, Location loc)
 264                 {
 265                         Type found_type = base.LookupTypeReflection (name, loc);
 266
 267                         if (modules != null) {
 268                                 foreach (Module module in modules) {
 269                                         Type t = module.GetType (name);
 270                                         if (t == null)
 271                                                 continue;
 272
 273                                         if (found_type == null) {
 274                                                 found_type = t;
 275                                                 continue;
 276                                         }
 277
 278                                         Report.SymbolRelatedToPreviousError (found_type);
 279                                         if (loc.IsNull) {
 280                                                 DeclSpace ds = TypeManager.LookupDeclSpace (t);
 281                                                 Report.Warning (1685, 1, ds.Location, "The type `{0}' conflicts with the predefined type `{1}' and will be ignored",
 282                                                         ds.GetSignatureForError (), TypeManager.CSharpName (found_type));
 283                                                 return found_type;
 284                                         }
 285                                         Report.SymbolRelatedToPreviousError (t);
 286                                         Report.Warning (436, 2, loc, "The type `{0}' conflicts with the imported type `{1}'. Ignoring the imported type definition",
 287                                                 TypeManager.CSharpName (t), TypeManager.CSharpName (found_type));
 288                                         return t;
 289                                 }
 290                         }
 291
 292                         return found_type;
 293                 }
 294         }
 295
 296         /// <summary>
 297         ///   Keeps track of the namespaces defined in the C# code.
 298         ///
 299         ///   This is an Expression to allow it to be referenced in the
 300         ///   compiler parse/intermediate tree during name resolution.
 301         /// </summary>
 302         public class Namespace : FullNamedExpression {
 303
 304                 Namespace parent;
 305                 string fullname;
 306                 IDictionary namespaces;
 307                 IDictionary declspaces;
 308                 Hashtable cached_types;
 309                 RootNamespace root;
 310                 ArrayList external_exmethod_classes;
 311
 312                 public readonly MemberName MemberName;
 313
 314                 /// <summary>
 315                 ///   Constructor Takes the current namespace and the
 316                 ///   name.  This is bootstrapped with parent == null
 317                 ///   and name = ""
 318                 /// </summary>
 319                 public Namespace (Namespace parent, string name)
 320                 {
 321                         // Expression members.
 322                         this.eclass = ExprClass.Namespace;
 323                         this.Type = typeof (Namespace);
 324                         this.loc = Location.Null;
 325
 326                         this.parent = parent;
 327
 328                         if (parent != null)
 329                                 this.root = parent.root;
 330                         else
 331                                 this.root = this as RootNamespace;
 332
 333                         if (this.root == null)
 334                                 throw new InternalErrorException ("Root namespaces must be created using RootNamespace");
 335
 336                         string pname = parent != null ? parent.fullname : "";
 337
 338                         if (pname == "")
 339                                 fullname = name;
 340                         else
 341                                 fullname = parent.fullname + "." + name;
 342
 343                         if (fullname == null)
 344                                 throw new InternalErrorException ("Namespace has a null fullname");
 345
 346                         if (parent != null && parent.MemberName != MemberName.Null)
 347                                 MemberName = new MemberName (parent.MemberName, name);
 348                         else if (name.Length == 0)
 349                                 MemberName = MemberName.Null;
 350                         else
 351                                 MemberName = new MemberName (name);
 352
 353                         namespaces = new HybridDictionary ();
 354                         cached_types = new Hashtable ();
 355
 356                         root.RegisterNamespace (this);
 357                 }
 358
 359                 public override Expression DoResolve (EmitContext ec)
 360                 {
 361                         return this;
 362                 }
 363
 364                 public virtual void Error_NamespaceDoesNotExist (DeclSpace ds, Location loc, string name)
 365                 {
 366                         if (name.IndexOf ('`') > 0) {
 367                                 FullNamedExpression retval = Lookup (ds, SimpleName.RemoveGenericArity (name), loc);
 368                                 if (retval != null) {
 369                                         Error_TypeArgumentsCannotBeUsed (retval, loc);
 370                                         return;
 371                                 }
 372                         } else {
 373                                 Type t = LookForAnyGenericType (name);
 374                                 if (t != null) {
 375                                         Error_InvalidNumberOfTypeArguments (t, loc);
 376                                         return;
 377                                 }
 378                         }
 379
 380                         Report.Error (234, loc, "The type or namespace name `{0}' does not exist in the namespace `{1}'. Are you missing an assembly reference?",
 381                                 name, GetSignatureForError ());
 382                 }
 383
 384                 public static void Error_InvalidNumberOfTypeArguments (Type t, Location loc)
 385                 {
 386                         Report.SymbolRelatedToPreviousError (t);
 387                         Report.Error (305, loc, "Using the generic type `{0}' requires `{1}' type argument(s)",
 388                                 TypeManager.CSharpName(t), TypeManager.GetNumberOfTypeArguments(t).ToString());
 389                 }
 390
 391                 public static void Error_TypeArgumentsCannotBeUsed (FullNamedExpression expr, Location loc)
 392                 {
 393                         if (expr is TypeExpr) {
 394                                 Report.SymbolRelatedToPreviousError (expr.Type);
 395                                 Error_TypeArgumentsCannotBeUsed (loc, "type", expr.GetSignatureForError ());
 396                         } else {
 397                                 expr.Error_ExpressionCannotBeGeneric (loc);
 398                         }
 399                 }
 400
 401                 public static void Error_TypeArgumentsCannotBeUsed (MethodBase mi, Location loc)
 402                 {
 403                         Report.SymbolRelatedToPreviousError (mi);
 404                         Error_TypeArgumentsCannotBeUsed (loc, "method", TypeManager.CSharpSignature (mi));
 405                 }
 406
 407                 static void Error_TypeArgumentsCannotBeUsed (Location loc, string type, string name)
 408                 {
 409                         Report.Error(308, loc, "The non-generic {0} `{1}' cannot be used with the type arguments",
 410                                 type, name);
 411                 }
 412
 413                 public override string GetSignatureForError ()
 414                 {
 415                         return fullname;
 416                 }
 417
 418                 public Namespace GetNamespace (string name, bool create)
 419                 {
 420                         int pos = name.IndexOf ('.');
 421
 422                         Namespace ns;
 423                         string first;
 424                         if (pos >= 0)
 425                                 first = name.Substring (0, pos);
 426                         else
 427                                 first = name;
 428
 429                         ns = (Namespace) namespaces [first];
 430                         if (ns == null) {
 431                                 if (!create)
 432                                         return null;
 433
 434                                 ns = new Namespace (this, first);
 435                                 namespaces.Add (first, ns);
 436                         }
 437
 438                         if (pos >= 0)
 439                                 ns = ns.GetNamespace (name.Substring (pos + 1), create);
 440
 441                         return ns;
 442                 }
 443
 444                 public bool HasDefinition (string name)
 445                 {
 446                         return declspaces != null && declspaces [name] != null;
 447                 }
 448
 449                 TypeExpr LookupType (string name, Location loc)
 450                 {
 451                         if (cached_types.Contains (name))
 452                                 return cached_types [name] as TypeExpr;
 453
 454                         Type t = null;
 455                         if (declspaces != null) {
 456                                 DeclSpace tdecl = declspaces [name] as DeclSpace;
 457                                 if (tdecl != null) {
 458                                         //
 459                                         // Note that this is not:
 460                                         //
 461                                         //   t = tdecl.DefineType ()
 462                                         //
 463                                         // This is to make it somewhat more useful when a DefineType
 464                                         // fails due to problems in nested types (more useful in the sense
 465                                         // of fewer misleading error messages)
 466                                         //
 467                                         tdecl.DefineType ();
 468                                         t = tdecl.TypeBuilder;
 469
 470                                         if (RootContext.EvalMode){
 471                                                 // Replace the TypeBuilder with a System.Type, as
 472                                                 // Reflection.Emit fails otherwise (we end up pretty
 473                                                 // much with Random type definitions later on).
 474                                                 Type tt = t.Assembly.GetType (t.Name);
 475                                                 if (tt != null)
 476                                                         t = tt;
 477                                         }
 478                                 }
 479                         }
 480                         string lookup = t != null ? t.FullName : (fullname.Length == 0 ? name : fullname + "." + name);
 481                         Type rt = root.LookupTypeReflection (lookup, loc);
 482
 483                         // HACK: loc.IsNull when the type is core type
 484                         if (t == null || (rt != null && loc.IsNull))
 485                                 t = rt;
 486
 487                         TypeExpr te = t == null ? null : new TypeExpression (t, Location.Null);
 488                         cached_types [name] = te;
 489                         return te;
 490                 }
 491
 492                 ///
 493                 /// Used for better error reporting only
 494                 ///
 495                 public Type LookForAnyGenericType (string typeName)
 496                 {
 497                         if (declspaces == null)
 498                                 return null;
 499
 500                         typeName = SimpleName.RemoveGenericArity (typeName);
 501
 502                         foreach (DictionaryEntry de in declspaces) {
 503                                 string type_item = (string) de.Key;
 504                                 int pos = type_item.LastIndexOf ('`');
 505                                 if (pos == typeName.Length && String.Compare (typeName, 0, type_item, 0, pos) == 0)
 506                                         return ((DeclSpace) de.Value).TypeBuilder;
 507                         }
 508                         return null;
 509                 }
 510
 511                 public FullNamedExpression Lookup (DeclSpace ds, string name, Location loc)
 512                 {
 513                         if (namespaces.Contains (name))
 514                                 return (Namespace) namespaces [name];
 515
 516                         return LookupType (name, loc);
 517                 }
 518
 519                 public void RegisterExternalExtensionMethodClass (Type type)
 520                 {
 521                         if (external_exmethod_classes == null)
 522                                 external_exmethod_classes = new ArrayList ();
 523
 524                         external_exmethod_classes.Add (type);
 525                 }
 526
 527                 ///
 528                 /// Looks for extension method in this namespace
 529                 ///
 530                 public ArrayList LookupExtensionMethod (Type extensionType, ClassOrStruct currentClass, string name)
 531                 {
 532                         ArrayList found = null;
 533
 534                         if (declspaces != null) {
 535                                 IEnumerator e = declspaces.Values.GetEnumerator ();
 536                                 e.Reset ();
 537                                 while (e.MoveNext ()) {
 538                                         Class c = e.Current as Class;
 539                                         if (c == null)
 540                                                 continue;
 541
 542                                         if (!c.IsStaticClass)
 543                                                 continue;
 544
 545                                         ArrayList res = c.MemberCache.FindExtensionMethods (extensionType, name, c != currentClass);
 546                                         if (res == null)
 547                                                 continue;
 548
 549                                         if (found == null)
 550                                                 found = res;
 551                                         else
 552                                                 found.AddRange (res);
 553                                 }
 554                         }
 555
 556                         if (external_exmethod_classes == null)
 557                                 return found;
 558
 559                         foreach (Type t in external_exmethod_classes) {
 560                                 MemberCache m = TypeHandle.GetMemberCache (t);
 561                                 ArrayList res = m.FindExtensionMethods (extensionType, name, true);
 562                                 if (res == null)
 563                                         continue;
 564
 565                                 if (found == null)
 566                                         found = res;
 567                                 else
 568                                         found.AddRange (res);
 569                         }
 570
 571                         return found;
 572                 }
 573
 574                 public void AddDeclSpace (string name, DeclSpace ds)
 575                 {
 576                         if (declspaces == null)
 577                                 declspaces = new HybridDictionary ();
 578                         declspaces.Add (name, ds);
 579                 }
 580
 581                 public void RemoveDeclSpace (string name)
 582                 {
 583                         declspaces.Remove (name);
 584                 }
 585
 586                 /// <summary>
 587                 ///   The qualified name of the current namespace
 588                 /// </summary>
 589                 public string Name {
 590                         get { return fullname; }
 591                 }
 592
 593                 /// <summary>
 594                 ///   The parent of this namespace, used by the parser to "Pop"
 595                 ///   the current namespace declaration
 596                 /// </summary>
 597                 public Namespace Parent {
 598                         get { return parent; }
 599                 }
 600         }
 601
 602         //
 603         // Namespace container as created by the parser
 604         //
 605         public class NamespaceEntry : IResolveContext {
 606
 607                 class UsingEntry {
 608                         readonly MemberName name;
 609                         Namespace resolved;
 610
 611                         public UsingEntry (MemberName name)
 612                         {
 613                                 this.name = name;
 614                         }
 615
 616                         public string GetSignatureForError ()
 617                         {
 618                                 return name.GetSignatureForError ();
 619                         }
 620
 621                         public Location Location {
 622                                 get { return name.Location; }
 623                         }
 624
 625                         public MemberName MemberName {
 626                                 get { return name; }
 627                         }
 628
 629                         public string Name {
 630                                 get { return GetSignatureForError (); }
 631                         }
 632
 633                         public Namespace Resolve (IResolveContext rc)
 634                         {
 635                                 if (resolved != null)
 636                                         return resolved;
 637
 638                                 FullNamedExpression fne = name.GetTypeExpression ().ResolveAsTypeStep (rc, false);
 639                                 if (fne == null)
 640                                         return null;
 641
 642                                 resolved = fne as Namespace;
 643                                 if (resolved == null) {
 644                                         Report.SymbolRelatedToPreviousError (fne.Type);
 645                                         Report.Error (138, Location,
 646                                                 "`{0}' is a type not a namespace. A using namespace directive can only be applied to namespaces",
 647                                                 GetSignatureForError ());
 648                                 }
 649                                 return resolved;
 650                         }
 651
 652                         public override string ToString ()
 653                         {
 654                                 return Name;
 655                         }
 656                 }
 657
 658                 class UsingAliasEntry {
 659                         public readonly string Alias;
 660                         public Location Location;
 661
 662                         public UsingAliasEntry (string alias, Location loc)
 663                         {
 664                                 this.Alias = alias;
 665                                 this.Location = loc;
 666                         }
 667
 668                         public virtual FullNamedExpression Resolve (IResolveContext rc)
 669                         {
 670                                 FullNamedExpression fne = RootNamespace.GetRootNamespace (Alias);
 671                                 if (fne == null) {
 672                                         Report.Error (430, Location,
 673                                                 "The extern alias `{0}' was not specified in -reference option",
 674                                                 Alias);
 675                                 }
 676
 677                                 return fne;
 678                         }
 679
 680                         public override string ToString ()
 681                         {
 682                                 return Alias;
 683                         }
 684
 685                 }
 686
 687                 class LocalUsingAliasEntry : UsingAliasEntry {
 688                         Expression resolved;
 689                         MemberName value;
 690
 691                         public LocalUsingAliasEntry (string alias, MemberName name, Location loc)
 692                                 : base (alias, loc)
 693                         {
 694                                 this.value = name;
 695                         }
 696
 697                         public override FullNamedExpression Resolve (IResolveContext rc)
 698                         {
 699                                 if (resolved != null || value == null)
 700                                         return (FullNamedExpression)resolved;
 701
 702                                 resolved = value.GetTypeExpression ().ResolveAsTypeStep (rc, false);
 703                                 if (resolved == null) {
 704                                         value = null;
 705                                         return null;
 706                                 }
 707
 708                                 // FIXME: This is quite wrong, the accessibility is not global
 709                                 if (resolved.Type != null) {
 710                                         TypeAttributes attr = resolved.Type.Attributes & TypeAttributes.VisibilityMask;
 711                                         if (attr == TypeAttributes.NestedPrivate || attr == TypeAttributes.NestedFamily ||
 712                                                 ((attr == TypeAttributes.NestedFamORAssem || attr == TypeAttributes.NestedAssembly) &&
 713                                                 TypeManager.LookupDeclSpace (resolved.Type) == null)) {
 714                                                 Expression.ErrorIsInaccesible (resolved.Location, resolved.GetSignatureForError ());
 715                                                 return null;
 716                                         }
 717                                 }
 718
 719                                 return (FullNamedExpression)resolved;
 720                         }
 721
 722                         public override string ToString ()
 723                         {
 724                                 return String.Format ("{0} = {1}", Alias, value.GetSignatureForError ());
 725                         }
 726                 }
 727
 728                 Namespace ns;
 729                 NamespaceEntry parent, implicit_parent;
 730                 CompilationUnit file;
 731                 int symfile_id;
 732
 733                 // Namespace using import block
 734                 ArrayList using_aliases;
 735                 ArrayList using_clauses;
 736                 public bool DeclarationFound = false;
 737                 // End
 738
 739                 public readonly bool IsImplicit;
 740                 public readonly DeclSpace SlaveDeclSpace;
 741                 static readonly Namespace [] empty_namespaces = new Namespace [0];
 742                 Namespace [] namespace_using_table;
 743
 744                 static ArrayList entries = new ArrayList ();
 745
 746                 public static void Reset ()
 747                 {
 748                         entries = new ArrayList ();
 749                 }
 750
 751                 public NamespaceEntry (NamespaceEntry parent, CompilationUnit file, string name)
 752                 {
 753                         this.parent = parent;
 754                         this.file = file;
 755                         entries.Add (this);
 756
 757                         if (parent != null)
 758                                 ns = parent.NS.GetNamespace (name, true);
 759                         else if (name != null)
 760                                 ns = RootNamespace.Global.GetNamespace (name, true);
 761                         else
 762                                 ns = RootNamespace.Global;
 763                         SlaveDeclSpace = new RootDeclSpace (this);
 764                 }
 765
 766                 private NamespaceEntry (NamespaceEntry parent, CompilationUnit file, Namespace ns, bool slave)
 767                 {
 768                         this.parent = parent;
 769                         this.file = file;
 770                         this.IsImplicit = true;
 771                         this.ns = ns;
 772                         this.SlaveDeclSpace = slave ? new RootDeclSpace (this) : null;
 773                 }
 774
 775                 //
 776                 // Populates the Namespace with some using declarations, used by the
 777                 // eval mode.
 778                 //
 779                 public void Populate (ArrayList source_using_aliases, ArrayList source_using_clauses)
 780                 {
 781                         foreach (UsingAliasEntry uae in source_using_aliases){
 782                                 if (using_aliases == null)
 783                                         using_aliases = new ArrayList ();
 784
 785                                 using_aliases.Add (uae);
 786                         }
 787
 788                         foreach (UsingEntry ue in source_using_clauses){
 789                                 if (using_clauses == null)
 790                                         using_clauses = new ArrayList ();
 791
 792                                 using_clauses.Add (ue);
 793                         }
 794                 }
 795
 796                 //
 797                 // Extracts the using alises and using clauses into a couple of
 798                 // arrays that might already have the same information;  Used by the
 799                 // C# Eval mode.
 800                 //
 801                 public void Extract (ArrayList out_using_aliases, ArrayList out_using_clauses)
 802                 {
 803                         if (using_aliases != null){
 804                                 foreach (UsingAliasEntry uae in using_aliases){
 805                                         bool replaced = false;
 806
 807                                         for (int i = 0; i < out_using_aliases.Count; i++){
 808                                                 UsingAliasEntry out_uea = (UsingAliasEntry) out_using_aliases [i];
 809
 810                                                 if (out_uea.Alias == uae.Alias){
 811                                                         out_using_aliases [i] = uae;
 812                                                         replaced = true;
 813                                                         break;
 814                                                 }
 815                                         }
 816                                         if (!replaced)
 817                                                 out_using_aliases.Add (uae);
 818                                 }
 819                         }
 820
 821                         if (using_clauses != null){
 822                                 foreach (UsingEntry ue in using_clauses){
 823                                         bool found = false;
 824
 825                                         foreach (UsingEntry out_ue in out_using_clauses)
 826                                                 if (out_ue.Name == ue.Name){
 827                                                         found = true;
 828                                                         break;
 829                                                 }
 830                                         if (!found)
 831                                                 out_using_clauses.Add (ue);
 832                                 }
 833                         }
 834                 }
 835
 836                 //
 837                 // According to section 16.3.1 (using-alias-directive), the namespace-or-type-name is
 838                 // resolved as if the immediately containing namespace body has no using-directives.
 839                 //
 840                 // Section 16.3.2 says that the same rule is applied when resolving the namespace-name
 841                 // in the using-namespace-directive.
 842                 //
 843                 // To implement these rules, the expressions in the using directives are resolved using
 844                 // the "doppelganger" (ghostly bodiless duplicate).
 845                 //
 846                 NamespaceEntry doppelganger;
 847                 NamespaceEntry Doppelganger {
 848                         get {
 849                                 if (!IsImplicit && doppelganger == null) {
 850                                         doppelganger = new NamespaceEntry (ImplicitParent, file, ns, true);
 851                                         doppelganger.using_aliases = using_aliases;
 852                                 }
 853                                 return doppelganger;
 854                         }
 855                 }
 856
 857                 public Namespace NS {
 858                         get { return ns; }
 859                 }
 860
 861                 public NamespaceEntry Parent {
 862                         get { return parent; }
 863                 }
 864
 865                 public NamespaceEntry ImplicitParent {
 866                         get {
 867                                 if (parent == null)
 868                                         return null;
 869                                 if (implicit_parent == null) {
 870                                         implicit_parent = (parent.NS == ns.Parent)
 871                                                 ? parent
 872                                                 : new NamespaceEntry (parent, file, ns.Parent, false);
 873                                 }
 874                                 return implicit_parent;
 875                         }
 876                 }
 877
 878                 /// <summary>
 879                 ///   Records a new namespace for resolving name references
 880                 /// </summary>
 881                 public void AddUsing (MemberName name, Location loc)
 882                 {
 883                         if (DeclarationFound){
 884                                 Report.Error (1529, loc, "A using clause must precede all other namespace elements except extern alias declarations");
 885                         }
 886
 887                         if (using_clauses == null) {
 888                                 using_clauses = new ArrayList ();
 889                         } else {
 890                                 foreach (UsingEntry old_entry in using_clauses) {
 891                                         if (name.Equals (old_entry.MemberName)) {
 892                                                 Report.SymbolRelatedToPreviousError (old_entry.Location, old_entry.GetSignatureForError ());
 893                                                 Report.Warning (105, 3, loc, "The using directive for `{0}' appeared previously in this namespace", name.GetSignatureForError ());
 894                                                 return;
 895                                         }
 896                                 }
 897                         }
 898
 899                         using_clauses.Add (new UsingEntry (name));
 900                 }
 901
 902                 public void AddUsingAlias (string alias, MemberName name, Location loc)
 903                 {
 904                         // TODO: This is parser bussines
 905                         if (DeclarationFound){
 906                                 Report.Error (1529, loc, "A using clause must precede all other namespace elements except extern alias declarations");
 907                         }
 908
 909                         if (RootContext.Version != LanguageVersion.ISO_1 && alias == "global")
 910                                 Report.Warning (440, 2, loc, "An alias named `global' will not be used when resolving 'global::';" +
 911                                         " the global namespace will be used instead");
 912
 913                         AddUsingAlias (new LocalUsingAliasEntry (alias, name, loc));
 914                 }
 915
 916                 public void AddUsingExternalAlias (string alias, Location loc)
 917                 {
 918                         // TODO: Do this in parser
 919                         bool not_first = using_clauses != null || DeclarationFound;
 920                         if (using_aliases != null && !not_first) {
 921                                 foreach (UsingAliasEntry uae in using_aliases) {
 922                                         if (uae is LocalUsingAliasEntry) {
 923                                                 not_first = true;
 924                                                 break;
 925                                         }
 926                                 }
 927                         }
 928
 929                         if (not_first)
 930                                 Report.Error (439, loc, "An extern alias declaration must precede all other elements");
 931
 932                         if (alias == "global") {
 933                                 Error_GlobalNamespaceRedefined (loc);
 934                                 return;
 935                         }
 936
 937                         AddUsingAlias (new UsingAliasEntry (alias, loc));
 938                 }
 939
 940                 void AddUsingAlias (UsingAliasEntry uae)
 941                 {
 942                         if (using_aliases == null) {
 943                                 using_aliases = new ArrayList ();
 944                         } else {
 945                                 foreach (UsingAliasEntry entry in using_aliases) {
 946                                         if (uae.Alias == entry.Alias) {
 947                                                 Report.SymbolRelatedToPreviousError (uae.Location, uae.Alias);
 948                                                 Report.Error (1537, entry.Location, "The using alias `{0}' appeared previously in this namespace",
 949                                                         entry.Alias);
 950                                                 return;
 951                                         }
 952                                 }
 953                         }
 954
 955                         using_aliases.Add (uae);
 956                 }
 957
 958                 ///
 959                 /// Does extension methods look up to find a method which matches name and extensionType.
 960                 /// Search starts from this namespace and continues hierarchically up to top level.
 961                 ///
 962                 public ExtensionMethodGroupExpr LookupExtensionMethod (Type extensionType, ClassOrStruct currentClass, string name, Location loc)
 963                 {
 964                         ArrayList candidates = null;
 965                         if (currentClass != null) {
 966                                 candidates = ns.LookupExtensionMethod (extensionType, currentClass, name);
 967                                 if (candidates != null)
 968                                         return new ExtensionMethodGroupExpr (candidates, this, extensionType, loc);
 969                         }
 970
 971                         foreach (Namespace n in GetUsingTable ()) {
 972                                 ArrayList a = n.LookupExtensionMethod (extensionType, null, name);
 973                                 if (a == null)
 974                                         continue;
 975
 976                                 if (candidates == null)
 977                                         candidates = a;
 978                                 else
 979                                         candidates.AddRange (a);
 980                         }
 981
 982                         if (candidates != null)
 983                                 return new ExtensionMethodGroupExpr (candidates, parent, extensionType, loc);
 984
 985                         if (parent == null)
 986                                 return null;
 987
 988                         //
 989                         // Inspect parent namespaces in namespace expression
 990                         //
 991                         Namespace parent_ns = ns.Parent;
 992                         do {
 993                                 candidates = parent_ns.LookupExtensionMethod (extensionType, null, name);
 994                                 if (candidates != null)
 995                                         return new ExtensionMethodGroupExpr (candidates, parent, extensionType, loc);
 996
 997                                 parent_ns = parent_ns.Parent;
 998                         } while (parent_ns != null);
 999
1000                         //
1001                         // Continue in parent scope
1002                         //
1003                         return parent.LookupExtensionMethod (extensionType, currentClass, name, loc);
1004                 }
1005
1006                 public FullNamedExpression LookupNamespaceOrType (DeclSpace ds, string name, Location loc, bool ignore_cs0104)
1007                 {
1008                         // Precondition: Only simple names (no dots) will be looked up with this function.
1009                         FullNamedExpression resolved = null;
1010                         for (NamespaceEntry curr_ns = this; curr_ns != null; curr_ns = curr_ns.ImplicitParent) {
1011                                 if ((resolved = curr_ns.Lookup (ds, name, loc, ignore_cs0104)) != null)
1012                                         break;
1013                         }
1014                         return resolved;
1015                 }
1016
1017                 static void Error_AmbiguousTypeReference (Location loc, string name, FullNamedExpression t1, FullNamedExpression t2)
1018                 {
1019                         Report.SymbolRelatedToPreviousError (t1.Type);
1020                         Report.SymbolRelatedToPreviousError (t2.Type);
1021                         Report.Error (104, loc, "`{0}' is an ambiguous reference between `{1}' and `{2}'",
1022                                 name, t1.GetSignatureForError (), t2.GetSignatureForError ());
1023                 }
1024
1025                 // Looks-up a alias named @name in this and surrounding namespace declarations
1026                 public FullNamedExpression LookupAlias (string name)
1027                 {
1028                         for (NamespaceEntry n = this; n != null; n = n.ImplicitParent) {
1029                                 if (n.using_aliases == null)
1030                                         continue;
1031
1032                                 foreach (UsingAliasEntry ue in n.using_aliases) {
1033                                         if (ue.Alias == name)
1034                                                 return ue.Resolve (Doppelganger);
1035                                 }
1036                         }
1037
1038                         return null;
1039                 }
1040
1041                 private FullNamedExpression Lookup (DeclSpace ds, string name, Location loc, bool ignore_cs0104)
1042                 {
1043                         //
1044                         // Check whether it's in the namespace.
1045                         //
1046                         FullNamedExpression fne = ns.Lookup (ds, name, loc);
1047
1048                         //
1049                         // Check aliases.
1050                         //
1051                         if (using_aliases != null) {
1052                                 foreach (UsingAliasEntry ue in using_aliases) {
1053                                         if (ue.Alias == name) {
1054                                                 if (fne != null) {
1055                                                         if (Doppelganger != null) {
1056                                                                 // TODO: Namespace has broken location
1057                                                                 //Report.SymbolRelatedToPreviousError (fne.Location, null);
1058                                                                 Report.SymbolRelatedToPreviousError (ue.Location, null);
1059                                                                 Report.Error (576, loc,
1060                                                                         "Namespace `{0}' contains a definition with same name as alias `{1}'",
1061                                                                         GetSignatureForError (), name);
1062                                                         } else {
1063                                                                 return fne;
1064                                                         }
1065                                                 }
1066
1067                                                 return ue.Resolve (Doppelganger);
1068                                         }
1069                                 }
1070                         }
1071
1072                         if (fne != null)
1073                                 return fne;
1074
1075                         if (IsImplicit)
1076                                 return null;
1077
1078                         //
1079                         // Check using entries.
1080                         //
1081                         FullNamedExpression match = null;
1082                         foreach (Namespace using_ns in GetUsingTable ()) {
1083                                 match = using_ns.Lookup (ds, name, loc);
1084                                 if (match == null || !(match is TypeExpr))
1085                                         continue;
1086                                 if (fne != null) {
1087                                         if (!ignore_cs0104)
1088                                                 Error_AmbiguousTypeReference (loc, name, fne, match);
1089                                         return null;
1090                                 }
1091                                 fne = match;
1092                         }
1093
1094                         return fne;
1095                 }
1096
1097                 Namespace [] GetUsingTable ()
1098                 {
1099                         if (namespace_using_table != null)
1100                                 return namespace_using_table;
1101
1102                         if (using_clauses == null) {
1103                                 namespace_using_table = empty_namespaces;
1104                                 return namespace_using_table;
1105                         }
1106
1107                         ArrayList list = new ArrayList (using_clauses.Count);
1108
1109                         foreach (UsingEntry ue in using_clauses) {
1110                                 Namespace using_ns = ue.Resolve (Doppelganger);
1111                                 if (using_ns == null)
1112                                         continue;
1113
1114                                 list.Add (using_ns);
1115                         }
1116
1117                         namespace_using_table = (Namespace[])list.ToArray (typeof (Namespace));
1118                         return namespace_using_table;
1119                 }
1120
1121                 static readonly string [] empty_using_list = new string [0];
1122
1123                 public int SymbolFileID {
1124                         get {
1125                                 if (symfile_id == 0 && file.SourceFileEntry != null) {
1126                                         int parent_id = parent == null ? 0 : parent.SymbolFileID;
1127
1128                                         string [] using_list = empty_using_list;
1129                                         if (using_clauses != null) {
1130                                                 using_list = new string [using_clauses.Count];
1131                                                 for (int i = 0; i < using_clauses.Count; i++)
1132                                                         using_list [i] = ((UsingEntry) using_clauses [i]).MemberName.GetName ();
1133                                         }
1134
1135                                         symfile_id = SymbolWriter.DefineNamespace (ns.Name, file.CompileUnitEntry, using_list, parent_id);
1136                                 }
1137                                 return symfile_id;
1138                         }
1139                 }
1140
1141                 static void MsgtryRef (string s)
1142                 {
1143                         Console.WriteLine ("    Try using -r:" + s);
1144                 }
1145
1146                 static void MsgtryPkg (string s)
1147                 {
1148                         Console.WriteLine ("    Try using -pkg:" + s);
1149                 }
1150
1151                 public static void Error_GlobalNamespaceRedefined (Location loc)
1152                 {
1153                         Report.Error (1681, loc, "You cannot redefine the global extern alias");
1154                 }
1155
1156                 public static void Error_NamespaceNotFound (Location loc, string name)
1157                 {
1158                         Report.Error (246, loc, "The type or namespace name `{0}' could not be found. Are you missing a using directive or an assembly reference?",
1159                                 name);
1160
1161                         switch (name) {
1162                         case "Gtk": case "GtkSharp":
1163                                 MsgtryPkg ("gtk-sharp");
1164                                 break;
1165
1166                         case "Gdk": case "GdkSharp":
1167                                 MsgtryPkg ("gdk-sharp");
1168                                 break;
1169
1170                         case "Glade": case "GladeSharp":
1171                                 MsgtryPkg ("glade-sharp");
1172                                 break;
1173
1174                         case "System.Drawing":
1175                         case "System.Web.Services":
1176                         case "System.Web":
1177                         case "System.Data":
1178                         case "System.Windows.Forms":
1179                                 MsgtryRef (name);
1180                                 break;
1181                         }
1182                 }
1183
1184                 /// <summary>
1185                 ///   Used to validate that all the using clauses are correct
1186                 ///   after we are finished parsing all the files.
1187                 /// </summary>
1188                 void VerifyUsing ()
1189                 {
1190                         if (using_aliases != null) {
1191                                 foreach (UsingAliasEntry ue in using_aliases)
1192                                         ue.Resolve (Doppelganger);
1193                         }
1194
1195                         if (using_clauses != null) {
1196                                 foreach (UsingEntry ue in using_clauses)
1197                                         ue.Resolve (Doppelganger);
1198                         }
1199                 }
1200
1201                 /// <summary>
1202                 ///   Used to validate that all the using clauses are correct
1203                 ///   after we are finished parsing all the files.
1204                 /// </summary>
1205                 static public void VerifyAllUsing ()
1206                 {
1207                         foreach (NamespaceEntry entry in entries)
1208                                 entry.VerifyUsing ();
1209                 }
1210
1211                 public string GetSignatureForError ()
1212                 {
1213                         return ns.GetSignatureForError ();
1214                 }
1215
1216                 public override string ToString ()
1217                 {
1218                         return ns.ToString ();
1219                 }
1220
1221                 #region IResolveContext Members
1222
1223                 public DeclSpace DeclContainer {
1224                         get { return SlaveDeclSpace; }
1225                 }
1226
1227                 public bool IsInObsoleteScope {
1228                         get { return SlaveDeclSpace.IsInObsoleteScope; }
1229                 }
1230
1231                 public bool IsInUnsafeScope {
1232                         get { return SlaveDeclSpace.IsInUnsafeScope; }
1233                 }
1234
1235                 public DeclSpace GenericDeclContainer {
1236                         get { return SlaveDeclSpace; }
1237                 }
1238
1239                 #endregion
1240         }
1241 }