mcs/mcs/namespace.cs

   1 //
   2 // namespace.cs: Tracks namespaces
   3 //
   4 // Author:
   5 //   Miguel de Icaza (miguel@ximian.com)
   6 //   Marek Safar (marek.safar@seznam.cz)
   7 //
   8 // Copyright 2001 Ximian, Inc.
   9 // Copyright 2003-2008 Novell, Inc.
  10 //
  11 using System;
  12 using System.Collections;
  13 using System.Collections.Specialized;
  14 using System.Reflection;
  15
  16 namespace Mono.CSharp {
  17
  18         public class RootNamespace : Namespace {
  19                 //
  20                 // Points to Mono's GetNamespaces method, an
  21                 // optimization when running on Mono to fetch all the
  22                 // namespaces in an assembly
  23                 //
  24                 static MethodInfo get_namespaces_method;
  25
  26                 string alias_name;
  27                 protected Assembly [] referenced_assemblies;
  28
  29                 Hashtable all_namespaces;
  30
  31                 static ListDictionary root_namespaces;
  32                 public static GlobalRootNamespace Global;
  33
  34                 static RootNamespace ()
  35                 {
  36                         get_namespaces_method = typeof (Assembly).GetMethod ("GetNamespaces", BindingFlags.Instance | BindingFlags.NonPublic);
  37
  38                         Reset ();
  39                 }
  40
  41                 public static void Reset ()
  42                 {
  43                         root_namespaces = new ListDictionary ();
  44                         Global = new GlobalRootNamespace ();
  45                         root_namespaces ["global"] = Global;
  46                 }
  47
  48                 protected RootNamespace (string alias_name)
  49                         : base (null, String.Empty)
  50                 {
  51                         this.alias_name = alias_name;
  52                         referenced_assemblies = new Assembly [0];
  53
  54                         all_namespaces = new Hashtable ();
  55                         all_namespaces.Add ("", this);
  56                 }
  57
  58                 public void AddAssemblyReference (Assembly a)
  59                 {
  60                         foreach (Assembly assembly in referenced_assemblies) {
  61                                 if (a == assembly)
  62                                         return;
  63                         }
  64
  65                         int top = referenced_assemblies.Length;
  66                         Assembly [] n = new Assembly [top + 1];
  67                         referenced_assemblies.CopyTo (n, 0);
  68                         n [top] = a;
  69                         referenced_assemblies = n;
  70                 }
  71
  72                 public static void DefineRootNamespace (string alias, Assembly assembly)
  73                 {
  74                         if (alias == "global") {
  75                                 NamespaceEntry.Error_GlobalNamespaceRedefined (Location.Null);
  76                                 return;
  77                         }
  78
  79                         RootNamespace retval = GetRootNamespace (alias);
  80                         if (retval == null) {
  81                                 retval = new RootNamespace (alias);
  82                                 root_namespaces.Add (alias, retval);
  83                         }
  84
  85                         retval.AddAssemblyReference (assembly);
  86                 }
  87
  88                 public static RootNamespace GetRootNamespace (string name)
  89                 {
  90                         return (RootNamespace) root_namespaces [name];
  91                 }
  92
  93                 public static void ComputeNamespaces ()
  94                 {
  95                         //
  96                         // Do very early lookup because type is required when we cache
  97                         // imported extension types in ComputeNamespaces
  98                         //
  99                         TypeManager.extension_attribute_type = TypeManager.CoreLookupType ("System.Runtime.CompilerServices", "ExtensionAttribute", Kind.Class, false);
 100
 101                         foreach (RootNamespace rn in root_namespaces.Values) {
 102                                 foreach (Assembly a in rn.referenced_assemblies) {
 103                                         try {
 104                                                 rn.ComputeNamespaces (a);
 105                                         } catch (TypeLoadException e) {
 106                                                 Report.Error (11, Location.Null, e.Message);
 107                                         } catch (System.IO.FileNotFoundException) {
 108                                                 Report.Error (12, Location.Null, "An assembly `{0}' is used without being referenced",
 109                                                         a.FullName);
 110                                         }
 111                                 }
 112                         }
 113                 }
 114
 115                 public virtual Type LookupTypeReflection (string name, Location loc)
 116                 {
 117                         Type found_type = null;
 118
 119                         foreach (Assembly a in referenced_assemblies) {
 120                                 Type t = GetTypeInAssembly (a, name);
 121                                 if (t == null)
 122                                         continue;
 123
 124                                 if (found_type == null) {
 125                                         found_type = t;
 126                                         continue;
 127                                 }
 128
 129                                 Report.SymbolRelatedToPreviousError (found_type);
 130                                 Report.SymbolRelatedToPreviousError (t);
 131                                 Report.Error (433, loc, "The imported type `{0}' is defined multiple times", name);
 132
 133                                 return found_type;
 134                         }
 135
 136                         return found_type;
 137                 }
 138
 139                 public void RegisterNamespace (Namespace child)
 140                 {
 141                         if (child != this)
 142                                 all_namespaces.Add (child.Name, child);
 143                 }
 144
 145                 public bool IsNamespace (string name)
 146                 {
 147                         return all_namespaces.Contains (name);
 148                 }
 149
 150                 protected void RegisterNamespace (string dotted_name)
 151                 {
 152                         if (dotted_name != null && dotted_name.Length != 0 && ! IsNamespace (dotted_name))
 153                                 GetNamespace (dotted_name, true);
 154                 }
 155
 156                 void RegisterExtensionMethodClass (Type t)
 157                 {
 158                         string n = t.Namespace;
 159                         Namespace ns = n == null ? Global : (Namespace)all_namespaces [n];
 160                         if (ns == null)
 161                                 ns = GetNamespace (n, true);
 162
 163                         ns.RegisterExternalExtensionMethodClass (t);
 164                 }
 165
 166                 protected void ComputeNamespaces (Assembly assembly)
 167                 {
 168                         bool contains_extension_methods = TypeManager.extension_attribute_type != null &&
 169                                         assembly.IsDefined(TypeManager.extension_attribute_type, false);
 170
 171                         if (get_namespaces_method != null) {
 172                                 string [] namespaces = (string []) get_namespaces_method.Invoke (assembly, null);
 173                                 foreach (string ns in namespaces)
 174                                         RegisterNamespace (ns);
 175
 176                                 if (!contains_extension_methods)
 177                                         return;
 178                         }
 179
 180                         foreach (Type t in assembly.GetTypes ()) {
 181                                 if ((t.Attributes & Class.StaticClassAttribute) == Class.StaticClassAttribute &&
 182                                         contains_extension_methods && t.IsDefined (TypeManager.extension_attribute_type, false))
 183                                         RegisterExtensionMethodClass (t);
 184
 185                                 if (get_namespaces_method == null)
 186                                         RegisterNamespace (t.Namespace);
 187                         }
 188                 }
 189
 190                 protected static Type GetTypeInAssembly (Assembly assembly, string name)
 191                 {
 192                         Type t = assembly.GetType (name);
 193                         if (t == null)
 194                                 return null;
 195
 196                         if (t.IsPointer)
 197                                 throw new InternalErrorException ("Use GetPointerType() to get a pointer");
 198
 199                         TypeAttributes ta = t.Attributes & TypeAttributes.VisibilityMask;
 200                         if (ta == TypeAttributes.NestedPrivate)
 201                                 return null;
 202
 203                         if ((ta == TypeAttributes.NotPublic ||
 204                              ta == TypeAttributes.NestedAssembly ||
 205                              ta == TypeAttributes.NestedFamANDAssem) &&
 206                             !TypeManager.IsThisOrFriendAssembly (t.Assembly))
 207                                 return null;
 208
 209                         return t;
 210                 }
 211
 212                 public override string ToString ()
 213                 {
 214                         return String.Format ("RootNamespace ({0}::)", alias_name);
 215                 }
 216
 217                 public override string GetSignatureForError ()
 218                 {
 219                         return alias_name + "::";
 220                 }
 221         }
 222
 223         public class GlobalRootNamespace : RootNamespace {
 224                 Module [] modules;
 225
 226                 public GlobalRootNamespace ()
 227                         : base ("global")
 228                 {
 229                 }
 230
 231                 public Assembly [] Assemblies {
 232                     get { return referenced_assemblies; }
 233                 }
 234
 235                 public Module [] Modules {
 236                         get { return modules; }
 237                 }
 238
 239                 public void AddModuleReference (Module m)
 240                 {
 241                         int top = modules != null ? modules.Length : 0;
 242                         Module [] n = new Module [top + 1];
 243                         if (modules != null)
 244                                 modules.CopyTo (n, 0);
 245                         n [top] = m;
 246                         modules = n;
 247
 248                         if (m == CodeGen.Module.Builder)
 249                                 return;
 250
 251                         foreach (Type t in m.GetTypes ())
 252                                 RegisterNamespace (t.Namespace);
 253                 }
 254
 255                 public override void Error_NamespaceDoesNotExist(DeclSpace ds, Location loc, string name)
 256                 {
 257                         Report.Error (400, loc, "The type or namespace name `{0}' could not be found in the global namespace (are you missing an assembly reference?)",
 258                                 name);
 259                 }
 260
 261                 public override Type LookupTypeReflection (string name, Location loc)
 262                 {
 263                         Type found_type = base.LookupTypeReflection (name, loc);
 264
 265                         if (modules != null) {
 266                                 foreach (Module module in modules) {
 267                                         Type t = module.GetType (name);
 268                                         if (t == null)
 269                                                 continue;
 270
 271                                         if (found_type == null) {
 272                                                 found_type = t;
 273                                                 continue;
 274                                         }
 275
 276                                         Report.SymbolRelatedToPreviousError (found_type);
 277                                         if (loc.IsNull) {
 278                                                 DeclSpace ds = TypeManager.LookupDeclSpace (t);
 279                                                 Report.Warning (1685, 1, ds.Location, "The type `{0}' conflicts with the predefined type `{1}' and will be ignored",
 280                                                         ds.GetSignatureForError (), TypeManager.CSharpName (found_type));
 281                                                 return found_type;
 282                                         }
 283                                         Report.SymbolRelatedToPreviousError (t);
 284                                         Report.Warning (436, 2, loc, "The type `{0}' conflicts with the imported type `{1}'. Ignoring the imported type definition",
 285                                                 TypeManager.CSharpName (t), TypeManager.CSharpName (found_type));
 286                                         return t;
 287                                 }
 288                         }
 289
 290                         return found_type;
 291                 }
 292         }
 293
 294         /// <summary>
 295         ///   Keeps track of the namespaces defined in the C# code.
 296         ///
 297         ///   This is an Expression to allow it to be referenced in the
 298         ///   compiler parse/intermediate tree during name resolution.
 299         /// </summary>
 300         public class Namespace : FullNamedExpression {
 301
 302                 Namespace parent;
 303                 string fullname;
 304                 IDictionary namespaces;
 305                 IDictionary declspaces;
 306                 Hashtable cached_types;
 307                 RootNamespace root;
 308                 ArrayList external_exmethod_classes;
 309
 310                 public readonly MemberName MemberName;
 311
 312                 /// <summary>
 313                 ///   Constructor Takes the current namespace and the
 314                 ///   name.  This is bootstrapped with parent == null
 315                 ///   and name = ""
 316                 /// </summary>
 317                 public Namespace (Namespace parent, string name)
 318                 {
 319                         // Expression members.
 320                         this.eclass = ExprClass.Namespace;
 321                         this.Type = typeof (Namespace);
 322                         this.loc = Location.Null;
 323
 324                         this.parent = parent;
 325
 326                         if (parent != null)
 327                                 this.root = parent.root;
 328                         else
 329                                 this.root = this as RootNamespace;
 330
 331                         if (this.root == null)
 332                                 throw new InternalErrorException ("Root namespaces must be created using RootNamespace");
 333
 334                         string pname = parent != null ? parent.fullname : "";
 335
 336                         if (pname == "")
 337                                 fullname = name;
 338                         else
 339                                 fullname = parent.fullname + "." + name;
 340
 341                         if (fullname == null)
 342                                 throw new InternalErrorException ("Namespace has a null fullname");
 343
 344                         if (parent != null && parent.MemberName != MemberName.Null)
 345                                 MemberName = new MemberName (parent.MemberName, name);
 346                         else if (name.Length == 0)
 347                                 MemberName = MemberName.Null;
 348                         else
 349                                 MemberName = new MemberName (name);
 350
 351                         namespaces = new HybridDictionary ();
 352                         cached_types = new Hashtable ();
 353
 354                         root.RegisterNamespace (this);
 355                 }
 356
 357                 public override Expression DoResolve (EmitContext ec)
 358                 {
 359                         return this;
 360                 }
 361
 362                 public virtual void Error_NamespaceDoesNotExist (DeclSpace ds, Location loc, string name)
 363                 {
 364                         if (name.IndexOf ('`') > 0) {
 365                                 FullNamedExpression retval = Lookup (ds, SimpleName.RemoveGenericArity (name), loc);
 366                                 if (retval != null) {
 367                                         Error_TypeArgumentsCannotBeUsed (retval, loc);
 368                                         return;
 369                                 }
 370                         } else {
 371                                 Type t = LookForAnyGenericType (name);
 372                                 if (t != null) {
 373                                         Error_InvalidNumberOfTypeArguments (t, loc);
 374                                         return;
 375                                 }
 376                         }
 377
 378                         Report.Error (234, loc, "The type or namespace name `{0}' does not exist in the namespace `{1}'. Are you missing an assembly reference?",
 379                                 name, GetSignatureForError ());
 380                 }
 381
 382                 public static void Error_InvalidNumberOfTypeArguments (Type t, Location loc)
 383                 {
 384                         Report.SymbolRelatedToPreviousError (t);
 385                         Report.Error (305, loc, "Using the generic type `{0}' requires `{1}' type argument(s)",
 386                                 TypeManager.CSharpName(t), TypeManager.GetNumberOfTypeArguments(t).ToString());
 387                 }
 388
 389                 public static void Error_TypeArgumentsCannotBeUsed (FullNamedExpression expr, Location loc)
 390                 {
 391                         if (expr is TypeExpr) {
 392                                 Report.SymbolRelatedToPreviousError (expr.Type);
 393                                 Error_TypeArgumentsCannotBeUsed (loc, "type", expr.GetSignatureForError ());
 394                         } else {
 395                                 expr.Error_ExpressionCannotBeGeneric (loc);
 396                         }
 397                 }
 398
 399                 public static void Error_TypeArgumentsCannotBeUsed (MethodBase mi, Location loc)
 400                 {
 401                         Report.SymbolRelatedToPreviousError (mi);
 402                         Error_TypeArgumentsCannotBeUsed (loc, "method", TypeManager.CSharpSignature (mi));
 403                 }
 404
 405                 static void Error_TypeArgumentsCannotBeUsed (Location loc, string type, string name)
 406                 {
 407                         Report.Error(308, loc, "The non-generic {0} `{1}' cannot be used with the type arguments",
 408                                 type, name);
 409                 }
 410
 411                 public override string GetSignatureForError ()
 412                 {
 413                         return fullname;
 414                 }
 415
 416                 public Namespace GetNamespace (string name, bool create)
 417                 {
 418                         int pos = name.IndexOf ('.');
 419
 420                         Namespace ns;
 421                         string first;
 422                         if (pos >= 0)
 423                                 first = name.Substring (0, pos);
 424                         else
 425                                 first = name;
 426
 427                         ns = (Namespace) namespaces [first];
 428                         if (ns == null) {
 429                                 if (!create)
 430                                         return null;
 431
 432                                 ns = new Namespace (this, first);
 433                                 namespaces.Add (first, ns);
 434                         }
 435
 436                         if (pos >= 0)
 437                                 ns = ns.GetNamespace (name.Substring (pos + 1), create);
 438
 439                         return ns;
 440                 }
 441
 442                 public bool HasDefinition (string name)
 443                 {
 444                         return declspaces != null && declspaces [name] != null;
 445                 }
 446
 447                 TypeExpr LookupType (string name, Location loc)
 448                 {
 449                         if (cached_types.Contains (name))
 450                                 return cached_types [name] as TypeExpr;
 451
 452                         Type t = null;
 453                         if (declspaces != null) {
 454                                 DeclSpace tdecl = declspaces [name] as DeclSpace;
 455                                 if (tdecl != null) {
 456                                         //
 457                                         // Note that this is not:
 458                                         //
 459                                         //   t = tdecl.DefineType ()
 460                                         //
 461                                         // This is to make it somewhat more useful when a DefineType
 462                                         // fails due to problems in nested types (more useful in the sense
 463                                         // of fewer misleading error messages)
 464                                         //
 465                                         tdecl.DefineType ();
 466                                         t = tdecl.TypeBuilder;
 467
 468                                         if (RootContext.EvalMode){
 469                                                 // Replace the TypeBuilder with a System.Type, as
 470                                                 // Reflection.Emit fails otherwise (we end up pretty
 471                                                 // much with Random type definitions later on).
 472                                                 Type tt = t.Assembly.GetType (t.Name);
 473                                                 if (tt != null)
 474                                                         t = tt;
 475                                         }
 476                                 }
 477                         }
 478                         string lookup = t != null ? t.FullName : (fullname.Length == 0 ? name : fullname + "." + name);
 479                         Type rt = root.LookupTypeReflection (lookup, loc);
 480
 481                         // HACK: loc.IsNull when the type is core type
 482                         if (t == null || (rt != null && loc.IsNull))
 483                                 t = rt;
 484
 485                         TypeExpr te = t == null ? null : new TypeExpression (t, Location.Null);
 486                         cached_types [name] = te;
 487                         return te;
 488                 }
 489
 490                 ///
 491                 /// Used for better error reporting only
 492                 ///
 493                 public Type LookForAnyGenericType (string typeName)
 494                 {
 495                         if (declspaces == null)
 496                                 return null;
 497
 498                         typeName = SimpleName.RemoveGenericArity (typeName);
 499
 500                         foreach (DictionaryEntry de in declspaces) {
 501                                 string type_item = (string) de.Key;
 502                                 int pos = type_item.LastIndexOf ('`');
 503                                 if (pos == typeName.Length && String.Compare (typeName, 0, type_item, 0, pos) == 0)
 504                                         return ((DeclSpace) de.Value).TypeBuilder;
 505                         }
 506                         return null;
 507                 }
 508
 509                 public FullNamedExpression Lookup (DeclSpace ds, string name, Location loc)
 510                 {
 511                         if (namespaces.Contains (name))
 512                                 return (Namespace) namespaces [name];
 513
 514                         return LookupType (name, loc);
 515                 }
 516
 517                 public void RegisterExternalExtensionMethodClass (Type type)
 518                 {
 519                         // Ignore, extension methods cannot be nested
 520                         if (type.DeclaringType != null)
 521                                 return;
 522
 523                         if (type.IsNotPublic && !TypeManager.IsThisOrFriendAssembly (type.Assembly))
 524                                 return;
 525
 526                         if (external_exmethod_classes == null)
 527                                 external_exmethod_classes = new ArrayList ();
 528
 529                         external_exmethod_classes.Add (type);
 530                 }
 531
 532                 ///
 533                 /// Looks for extension method in this namespace
 534                 ///
 535                 public ArrayList LookupExtensionMethod (Type extensionType, ClassOrStruct currentClass, string name)
 536                 {
 537                         ArrayList found = null;
 538
 539                         if (declspaces != null) {
 540                                 IEnumerator e = declspaces.Values.GetEnumerator ();
 541                                 e.Reset ();
 542                                 while (e.MoveNext ()) {
 543                                         Class c = e.Current as Class;
 544                                         if (c == null)
 545                                                 continue;
 546
 547                                         if ((c.ModFlags & Modifiers.METHOD_EXTENSION) == 0)
 548                                                 continue;
 549
 550                                         ArrayList res = c.MemberCache.FindExtensionMethods (extensionType, name, c != currentClass);
 551                                         if (res == null)
 552                                                 continue;
 553
 554                                         if (found == null)
 555                                                 found = res;
 556                                         else
 557                                                 found.AddRange (res);
 558                                 }
 559                         }
 560
 561                         if (external_exmethod_classes == null)
 562                                 return found;
 563
 564                         foreach (Type t in external_exmethod_classes) {
 565                                 MemberCache m = TypeHandle.GetMemberCache (t);
 566                                 ArrayList res = m.FindExtensionMethods (extensionType, name, true);
 567                                 if (res == null)
 568                                         continue;
 569
 570                                 if (found == null)
 571                                         found = res;
 572                                 else
 573                                         found.AddRange (res);
 574                         }
 575
 576                         return found;
 577                 }
 578
 579                 public void AddDeclSpace (string name, DeclSpace ds)
 580                 {
 581                         if (declspaces == null)
 582                                 declspaces = new HybridDictionary ();
 583                         declspaces.Add (name, ds);
 584                 }
 585
 586                 public void RemoveDeclSpace (string name)
 587                 {
 588                         declspaces.Remove (name);
 589                 }
 590
 591                 /// <summary>
 592                 ///   The qualified name of the current namespace
 593                 /// </summary>
 594                 public string Name {
 595                         get { return fullname; }
 596                 }
 597
 598                 /// <summary>
 599                 ///   The parent of this namespace, used by the parser to "Pop"
 600                 ///   the current namespace declaration
 601                 /// </summary>
 602                 public Namespace Parent {
 603                         get { return parent; }
 604                 }
 605         }
 606
 607         //
 608         // Namespace container as created by the parser
 609         //
 610         public class NamespaceEntry : IResolveContext {
 611
 612                 class UsingEntry {
 613                         readonly MemberName name;
 614                         Namespace resolved;
 615
 616                         public UsingEntry (MemberName name)
 617                         {
 618                                 this.name = name;
 619                         }
 620
 621                         public string GetSignatureForError ()
 622                         {
 623                                 return name.GetSignatureForError ();
 624                         }
 625
 626                         public Location Location {
 627                                 get { return name.Location; }
 628                         }
 629
 630                         public MemberName MemberName {
 631                                 get { return name; }
 632                         }
 633
 634                         public string Name {
 635                                 get { return GetSignatureForError (); }
 636                         }
 637
 638                         public Namespace Resolve (IResolveContext rc)
 639                         {
 640                                 if (resolved != null)
 641                                         return resolved;
 642
 643                                 FullNamedExpression fne = name.GetTypeExpression ().ResolveAsTypeStep (rc, false);
 644                                 if (fne == null)
 645                                         return null;
 646
 647                                 resolved = fne as Namespace;
 648                                 if (resolved == null) {
 649                                         Report.SymbolRelatedToPreviousError (fne.Type);
 650                                         Report.Error (138, Location,
 651                                                 "`{0}' is a type not a namespace. A using namespace directive can only be applied to namespaces",
 652                                                 GetSignatureForError ());
 653                                 }
 654                                 return resolved;
 655                         }
 656
 657                         public override string ToString ()
 658                         {
 659                                 return Name;
 660                         }
 661                 }
 662
 663                 class UsingAliasEntry {
 664                         public readonly string Alias;
 665                         public Location Location;
 666
 667                         public UsingAliasEntry (string alias, Location loc)
 668                         {
 669                                 this.Alias = alias;
 670                                 this.Location = loc;
 671                         }
 672
 673                         public virtual FullNamedExpression Resolve (IResolveContext rc)
 674                         {
 675                                 FullNamedExpression fne = RootNamespace.GetRootNamespace (Alias);
 676                                 if (fne == null) {
 677                                         Report.Error (430, Location,
 678                                                 "The extern alias `{0}' was not specified in -reference option",
 679                                                 Alias);
 680                                 }
 681
 682                                 return fne;
 683                         }
 684
 685                         public override string ToString ()
 686                         {
 687                                 return Alias;
 688                         }
 689
 690                 }
 691
 692                 class LocalUsingAliasEntry : UsingAliasEntry {
 693                         FullNamedExpression resolved;
 694                         MemberName value;
 695
 696                         public LocalUsingAliasEntry (string alias, MemberName name, Location loc)
 697                                 : base (alias, loc)
 698                         {
 699                                 this.value = name;
 700                         }
 701
 702                         public override FullNamedExpression Resolve (IResolveContext rc)
 703                         {
 704                                 if (resolved != null || value == null)
 705                                         return resolved;
 706
 707                                 resolved = value.GetTypeExpression ().ResolveAsTypeStep (rc, false);
 708                                 if (resolved == null) {
 709                                         value = null;
 710                                         return null;
 711                                 }
 712
 713                                 TypeExpr te = resolved as TypeExpr;
 714                                 if (te != null) {
 715                                         if (!te.CheckAccessLevel (rc.DeclContainer)) {
 716                                                 Report.SymbolRelatedToPreviousError (te.Type);
 717                                                 Expression.ErrorIsInaccesible (resolved.Location, resolved.GetSignatureForError ());
 718                                         }
 719                                 }
 720
 721                                 return resolved;
 722                         }
 723
 724                         public override string ToString ()
 725                         {
 726                                 return String.Format ("{0} = {1}", Alias, value.GetSignatureForError ());
 727                         }
 728                 }
 729
 730                 Namespace ns;
 731                 NamespaceEntry parent, implicit_parent;
 732                 CompilationUnit file;
 733                 int symfile_id;
 734
 735                 // Namespace using import block
 736                 ArrayList using_aliases;
 737                 ArrayList using_clauses;
 738                 public bool DeclarationFound = false;
 739                 // End
 740
 741                 public readonly bool IsImplicit;
 742                 public readonly DeclSpace SlaveDeclSpace;
 743                 static readonly Namespace [] empty_namespaces = new Namespace [0];
 744                 Namespace [] namespace_using_table;
 745
 746                 static ArrayList entries = new ArrayList ();
 747
 748                 public static void Reset ()
 749                 {
 750                         entries = new ArrayList ();
 751                 }
 752
 753                 public NamespaceEntry (NamespaceEntry parent, CompilationUnit file, string name)
 754                 {
 755                         this.parent = parent;
 756                         this.file = file;
 757                         entries.Add (this);
 758
 759                         if (parent != null)
 760                                 ns = parent.NS.GetNamespace (name, true);
 761                         else if (name != null)
 762                                 ns = RootNamespace.Global.GetNamespace (name, true);
 763                         else
 764                                 ns = RootNamespace.Global;
 765                         SlaveDeclSpace = new RootDeclSpace (this);
 766                 }
 767
 768                 private NamespaceEntry (NamespaceEntry parent, CompilationUnit file, Namespace ns, bool slave)
 769                 {
 770                         this.parent = parent;
 771                         this.file = file;
 772                         this.IsImplicit = true;
 773                         this.ns = ns;
 774                         this.SlaveDeclSpace = slave ? new RootDeclSpace (this) : null;
 775                 }
 776
 777                 //
 778                 // Populates the Namespace with some using declarations, used by the
 779                 // eval mode.
 780                 //
 781                 public void Populate (ArrayList source_using_aliases, ArrayList source_using_clauses)
 782                 {
 783                         foreach (UsingAliasEntry uae in source_using_aliases){
 784                                 if (using_aliases == null)
 785                                         using_aliases = new ArrayList ();
 786
 787                                 using_aliases.Add (uae);
 788                         }
 789
 790                         foreach (UsingEntry ue in source_using_clauses){
 791                                 if (using_clauses == null)
 792                                         using_clauses = new ArrayList ();
 793
 794                                 using_clauses.Add (ue);
 795                         }
 796                 }
 797
 798                 //
 799                 // Extracts the using alises and using clauses into a couple of
 800                 // arrays that might already have the same information;  Used by the
 801                 // C# Eval mode.
 802                 //
 803                 public void Extract (ArrayList out_using_aliases, ArrayList out_using_clauses)
 804                 {
 805                         if (using_aliases != null){
 806                                 foreach (UsingAliasEntry uae in using_aliases){
 807                                         bool replaced = false;
 808
 809                                         for (int i = 0; i < out_using_aliases.Count; i++){
 810                                                 UsingAliasEntry out_uea = (UsingAliasEntry) out_using_aliases [i];
 811
 812                                                 if (out_uea.Alias == uae.Alias){
 813                                                         out_using_aliases [i] = uae;
 814                                                         replaced = true;
 815                                                         break;
 816                                                 }
 817                                         }
 818                                         if (!replaced)
 819                                                 out_using_aliases.Add (uae);
 820                                 }
 821                         }
 822
 823                         if (using_clauses != null){
 824                                 foreach (UsingEntry ue in using_clauses){
 825                                         bool found = false;
 826
 827                                         foreach (UsingEntry out_ue in out_using_clauses)
 828                                                 if (out_ue.Name == ue.Name){
 829                                                         found = true;
 830                                                         break;
 831                                                 }
 832                                         if (!found)
 833                                                 out_using_clauses.Add (ue);
 834                                 }
 835                         }
 836                 }
 837
 838                 //
 839                 // According to section 16.3.1 (using-alias-directive), the namespace-or-type-name is
 840                 // resolved as if the immediately containing namespace body has no using-directives.
 841                 //
 842                 // Section 16.3.2 says that the same rule is applied when resolving the namespace-name
 843                 // in the using-namespace-directive.
 844                 //
 845                 // To implement these rules, the expressions in the using directives are resolved using
 846                 // the "doppelganger" (ghostly bodiless duplicate).
 847                 //
 848                 NamespaceEntry doppelganger;
 849                 NamespaceEntry Doppelganger {
 850                         get {
 851                                 if (!IsImplicit && doppelganger == null) {
 852                                         doppelganger = new NamespaceEntry (ImplicitParent, file, ns, true);
 853                                         doppelganger.using_aliases = using_aliases;
 854                                 }
 855                                 return doppelganger;
 856                         }
 857                 }
 858
 859                 public Namespace NS {
 860                         get { return ns; }
 861                 }
 862
 863                 public NamespaceEntry Parent {
 864                         get { return parent; }
 865                 }
 866
 867                 public NamespaceEntry ImplicitParent {
 868                         get {
 869                                 if (parent == null)
 870                                         return null;
 871                                 if (implicit_parent == null) {
 872                                         implicit_parent = (parent.NS == ns.Parent)
 873                                                 ? parent
 874                                                 : new NamespaceEntry (parent, file, ns.Parent, false);
 875                                 }
 876                                 return implicit_parent;
 877                         }
 878                 }
 879
 880                 /// <summary>
 881                 ///   Records a new namespace for resolving name references
 882                 /// </summary>
 883                 public void AddUsing (MemberName name, Location loc)
 884                 {
 885                         if (DeclarationFound){
 886                                 Report.Error (1529, loc, "A using clause must precede all other namespace elements except extern alias declarations");
 887                         }
 888
 889                         if (using_clauses == null) {
 890                                 using_clauses = new ArrayList ();
 891                         } else {
 892                                 foreach (UsingEntry old_entry in using_clauses) {
 893                                         if (name.Equals (old_entry.MemberName)) {
 894                                                 Report.SymbolRelatedToPreviousError (old_entry.Location, old_entry.GetSignatureForError ());
 895                                                 Report.Warning (105, 3, loc, "The using directive for `{0}' appeared previously in this namespace", name.GetSignatureForError ());
 896                                                 return;
 897                                         }
 898                                 }
 899                         }
 900
 901                         using_clauses.Add (new UsingEntry (name));
 902                 }
 903
 904                 public void AddUsingAlias (string alias, MemberName name, Location loc)
 905                 {
 906                         // TODO: This is parser bussines
 907                         if (DeclarationFound){
 908                                 Report.Error (1529, loc, "A using clause must precede all other namespace elements except extern alias declarations");
 909                         }
 910
 911                         if (RootContext.Version != LanguageVersion.ISO_1 && alias == "global")
 912                                 Report.Warning (440, 2, loc, "An alias named `global' will not be used when resolving 'global::';" +
 913                                         " the global namespace will be used instead");
 914
 915                         AddUsingAlias (new LocalUsingAliasEntry (alias, name, loc));
 916                 }
 917
 918                 public void AddUsingExternalAlias (string alias, Location loc)
 919                 {
 920                         // TODO: Do this in parser
 921                         bool not_first = using_clauses != null || DeclarationFound;
 922                         if (using_aliases != null && !not_first) {
 923                                 foreach (UsingAliasEntry uae in using_aliases) {
 924                                         if (uae is LocalUsingAliasEntry) {
 925                                                 not_first = true;
 926                                                 break;
 927                                         }
 928                                 }
 929                         }
 930
 931                         if (not_first)
 932                                 Report.Error (439, loc, "An extern alias declaration must precede all other elements");
 933
 934                         if (alias == "global") {
 935                                 Error_GlobalNamespaceRedefined (loc);
 936                                 return;
 937                         }
 938
 939                         AddUsingAlias (new UsingAliasEntry (alias, loc));
 940                 }
 941
 942                 void AddUsingAlias (UsingAliasEntry uae)
 943                 {
 944                         if (using_aliases == null) {
 945                                 using_aliases = new ArrayList ();
 946                         } else {
 947                                 foreach (UsingAliasEntry entry in using_aliases) {
 948                                         if (uae.Alias == entry.Alias) {
 949                                                 Report.SymbolRelatedToPreviousError (uae.Location, uae.Alias);
 950                                                 Report.Error (1537, entry.Location, "The using alias `{0}' appeared previously in this namespace",
 951                                                         entry.Alias);
 952                                                 return;
 953                                         }
 954                                 }
 955                         }
 956
 957                         using_aliases.Add (uae);
 958                 }
 959
 960                 ///
 961                 /// Does extension methods look up to find a method which matches name and extensionType.
 962                 /// Search starts from this namespace and continues hierarchically up to top level.
 963                 ///
 964                 public ExtensionMethodGroupExpr LookupExtensionMethod (Type extensionType, ClassOrStruct currentClass, string name, Location loc)
 965                 {
 966                         ArrayList candidates = null;
 967                         if (currentClass != null) {
 968                                 candidates = ns.LookupExtensionMethod (extensionType, currentClass, name);
 969                                 if (candidates != null)
 970                                         return new ExtensionMethodGroupExpr (candidates, this, extensionType, loc);
 971                         }
 972
 973                         foreach (Namespace n in GetUsingTable ()) {
 974                                 ArrayList a = n.LookupExtensionMethod (extensionType, null, name);
 975                                 if (a == null)
 976                                         continue;
 977
 978                                 if (candidates == null)
 979                                         candidates = a;
 980                                 else
 981                                         candidates.AddRange (a);
 982                         }
 983
 984                         if (candidates != null)
 985                                 return new ExtensionMethodGroupExpr (candidates, parent, extensionType, loc);
 986
 987                         if (parent == null)
 988                                 return null;
 989
 990                         //
 991                         // Inspect parent namespaces in namespace expression
 992                         //
 993                         Namespace parent_ns = ns.Parent;
 994                         do {
 995                                 candidates = parent_ns.LookupExtensionMethod (extensionType, null, name);
 996                                 if (candidates != null)
 997                                         return new ExtensionMethodGroupExpr (candidates, parent, extensionType, loc);
 998
 999                                 parent_ns = parent_ns.Parent;
1000                         } while (parent_ns != null);
1001
1002                         //
1003                         // Continue in parent scope
1004                         //
1005                         return parent.LookupExtensionMethod (extensionType, currentClass, name, loc);
1006                 }
1007
1008                 public FullNamedExpression LookupNamespaceOrType (DeclSpace ds, string name, Location loc, bool ignore_cs0104)
1009                 {
1010                         // Precondition: Only simple names (no dots) will be looked up with this function.
1011                         FullNamedExpression resolved = null;
1012                         for (NamespaceEntry curr_ns = this; curr_ns != null; curr_ns = curr_ns.ImplicitParent) {
1013                                 if ((resolved = curr_ns.Lookup (ds, name, loc, ignore_cs0104)) != null)
1014                                         break;
1015                         }
1016                         return resolved;
1017                 }
1018
1019                 static void Error_AmbiguousTypeReference (Location loc, string name, FullNamedExpression t1, FullNamedExpression t2)
1020                 {
1021                         Report.SymbolRelatedToPreviousError (t1.Type);
1022                         Report.SymbolRelatedToPreviousError (t2.Type);
1023                         Report.Error (104, loc, "`{0}' is an ambiguous reference between `{1}' and `{2}'",
1024                                 name, t1.GetSignatureForError (), t2.GetSignatureForError ());
1025                 }
1026
1027                 // Looks-up a alias named @name in this and surrounding namespace declarations
1028                 public FullNamedExpression LookupAlias (string name)
1029                 {
1030                         for (NamespaceEntry n = this; n != null; n = n.ImplicitParent) {
1031                                 if (n.using_aliases == null)
1032                                         continue;
1033
1034                                 foreach (UsingAliasEntry ue in n.using_aliases) {
1035                                         if (ue.Alias == name)
1036                                                 return ue.Resolve (Doppelganger);
1037                                 }
1038                         }
1039
1040                         return null;
1041                 }
1042
1043                 private FullNamedExpression Lookup (DeclSpace ds, string name, Location loc, bool ignore_cs0104)
1044                 {
1045                         //
1046                         // Check whether it's in the namespace.
1047                         //
1048                         FullNamedExpression fne = ns.Lookup (ds, name, loc);
1049
1050                         //
1051                         // Check aliases.
1052                         //
1053                         if (using_aliases != null) {
1054                                 foreach (UsingAliasEntry ue in using_aliases) {
1055                                         if (ue.Alias == name) {
1056                                                 if (fne != null) {
1057                                                         if (Doppelganger != null) {
1058                                                                 // TODO: Namespace has broken location
1059                                                                 //Report.SymbolRelatedToPreviousError (fne.Location, null);
1060                                                                 Report.SymbolRelatedToPreviousError (ue.Location, null);
1061                                                                 Report.Error (576, loc,
1062                                                                         "Namespace `{0}' contains a definition with same name as alias `{1}'",
1063                                                                         GetSignatureForError (), name);
1064                                                         } else {
1065                                                                 return fne;
1066                                                         }
1067                                                 }
1068
1069                                                 return ue.Resolve (Doppelganger);
1070                                         }
1071                                 }
1072                         }
1073
1074                         if (fne != null)
1075                                 return fne;
1076
1077                         if (IsImplicit)
1078                                 return null;
1079
1080                         //
1081                         // Check using entries.
1082                         //
1083                         FullNamedExpression match = null;
1084                         foreach (Namespace using_ns in GetUsingTable ()) {
1085                                 match = using_ns.Lookup (ds, name, loc);
1086                                 if (match == null || !(match is TypeExpr))
1087                                         continue;
1088                                 if (fne != null) {
1089                                         if (!ignore_cs0104)
1090                                                 Error_AmbiguousTypeReference (loc, name, fne, match);
1091                                         return null;
1092                                 }
1093                                 fne = match;
1094                         }
1095
1096                         return fne;
1097                 }
1098
1099                 Namespace [] GetUsingTable ()
1100                 {
1101                         if (namespace_using_table != null)
1102                                 return namespace_using_table;
1103
1104                         if (using_clauses == null) {
1105                                 namespace_using_table = empty_namespaces;
1106                                 return namespace_using_table;
1107                         }
1108
1109                         ArrayList list = new ArrayList (using_clauses.Count);
1110
1111                         foreach (UsingEntry ue in using_clauses) {
1112                                 Namespace using_ns = ue.Resolve (Doppelganger);
1113                                 if (using_ns == null)
1114                                         continue;
1115
1116                                 list.Add (using_ns);
1117                         }
1118
1119                         namespace_using_table = (Namespace[])list.ToArray (typeof (Namespace));
1120                         return namespace_using_table;
1121                 }
1122
1123                 static readonly string [] empty_using_list = new string [0];
1124
1125                 public int SymbolFileID {
1126                         get {
1127                                 if (symfile_id == 0 && file.SourceFileEntry != null) {
1128                                         int parent_id = parent == null ? 0 : parent.SymbolFileID;
1129
1130                                         string [] using_list = empty_using_list;
1131                                         if (using_clauses != null) {
1132                                                 using_list = new string [using_clauses.Count];
1133                                                 for (int i = 0; i < using_clauses.Count; i++)
1134                                                         using_list [i] = ((UsingEntry) using_clauses [i]).MemberName.GetName ();
1135                                         }
1136
1137                                         symfile_id = SymbolWriter.DefineNamespace (ns.Name, file.CompileUnitEntry, using_list, parent_id);
1138                                 }
1139                                 return symfile_id;
1140                         }
1141                 }
1142
1143                 static void MsgtryRef (string s)
1144                 {
1145                         Console.WriteLine ("    Try using -r:" + s);
1146                 }
1147
1148                 static void MsgtryPkg (string s)
1149                 {
1150                         Console.WriteLine ("    Try using -pkg:" + s);
1151                 }
1152
1153                 public static void Error_GlobalNamespaceRedefined (Location loc)
1154                 {
1155                         Report.Error (1681, loc, "You cannot redefine the global extern alias");
1156                 }
1157
1158                 public static void Error_NamespaceNotFound (Location loc, string name)
1159                 {
1160                         Report.Error (246, loc, "The type or namespace name `{0}' could not be found. Are you missing a using directive or an assembly reference?",
1161                                 name);
1162
1163                         switch (name) {
1164                         case "Gtk": case "GtkSharp":
1165                                 MsgtryPkg ("gtk-sharp");
1166                                 break;
1167
1168                         case "Gdk": case "GdkSharp":
1169                                 MsgtryPkg ("gdk-sharp");
1170                                 break;
1171
1172                         case "Glade": case "GladeSharp":
1173                                 MsgtryPkg ("glade-sharp");
1174                                 break;
1175
1176                         case "System.Drawing":
1177                         case "System.Web.Services":
1178                         case "System.Web":
1179                         case "System.Data":
1180                         case "System.Windows.Forms":
1181                                 MsgtryRef (name);
1182                                 break;
1183                         }
1184                 }
1185
1186                 /// <summary>
1187                 ///   Used to validate that all the using clauses are correct
1188                 ///   after we are finished parsing all the files.
1189                 /// </summary>
1190                 void VerifyUsing ()
1191                 {
1192                         if (using_aliases != null) {
1193                                 foreach (UsingAliasEntry ue in using_aliases)
1194                                         ue.Resolve (Doppelganger);
1195                         }
1196
1197                         if (using_clauses != null) {
1198                                 foreach (UsingEntry ue in using_clauses)
1199                                         ue.Resolve (Doppelganger);
1200                         }
1201                 }
1202
1203                 /// <summary>
1204                 ///   Used to validate that all the using clauses are correct
1205                 ///   after we are finished parsing all the files.
1206                 /// </summary>
1207                 static public void VerifyAllUsing ()
1208                 {
1209                         foreach (NamespaceEntry entry in entries)
1210                                 entry.VerifyUsing ();
1211                 }
1212
1213                 public string GetSignatureForError ()
1214                 {
1215                         return ns.GetSignatureForError ();
1216                 }
1217
1218                 public override string ToString ()
1219                 {
1220                         return ns.ToString ();
1221                 }
1222
1223                 #region IResolveContext Members
1224
1225                 public DeclSpace DeclContainer {
1226                         get { return SlaveDeclSpace; }
1227                 }
1228
1229                 public bool IsInObsoleteScope {
1230                         get { return SlaveDeclSpace.IsInObsoleteScope; }
1231                 }
1232
1233                 public bool IsInUnsafeScope {
1234                         get { return SlaveDeclSpace.IsInUnsafeScope; }
1235                 }
1236
1237                 public DeclSpace GenericDeclContainer {
1238                         get { return SlaveDeclSpace; }
1239                 }
1240
1241                 #endregion
1242         }
1243 }