mcs/mcs/namespace.cs

   1 //
   2 // namespace.cs: Tracks namespaces
   3 //
   4 // Author:
   5 //   Miguel de Icaza (miguel@ximian.com)
   6 //   Marek Safar (marek.safar@seznam.cz)
   7 //
   8 // Copyright 2001 Ximian, Inc.
   9 // Copyright 2003-2008 Novell, Inc.
  10 //
  11 using System;
  12 using System.Collections;
  13 using System.Collections.Specialized;
  14 using System.Reflection;
  15
  16 namespace Mono.CSharp {
  17
  18         class RootNamespace : Namespace {
  19                 //
  20                 // Points to Mono's GetNamespaces method, an
  21                 // optimization when running on Mono to fetch all the
  22                 // namespaces in an assembly
  23                 //
  24                 static MethodInfo get_namespaces_method;
  25
  26                 protected readonly string alias_name;
  27                 protected Assembly [] referenced_assemblies;
  28
  29                 Hashtable all_namespaces;
  30
  31                 static RootNamespace ()
  32                 {
  33                         get_namespaces_method = typeof (Assembly).GetMethod ("GetNamespaces", BindingFlags.Instance | BindingFlags.NonPublic);
  34                 }
  35
  36                 public RootNamespace (string alias_name)
  37                         : base (null, String.Empty)
  38                 {
  39                         this.alias_name = alias_name;
  40                         referenced_assemblies = new Assembly [0];
  41
  42                         all_namespaces = new Hashtable ();
  43                         all_namespaces.Add ("", this);
  44                 }
  45
  46                 public void AddAssemblyReference (Assembly a)
  47                 {
  48                         foreach (Assembly assembly in referenced_assemblies) {
  49                                 if (a == assembly)
  50                                         return;
  51                         }
  52
  53                         int top = referenced_assemblies.Length;
  54                         Assembly [] n = new Assembly [top + 1];
  55                         referenced_assemblies.CopyTo (n, 0);
  56                         n [top] = a;
  57                         referenced_assemblies = n;
  58                 }
  59
  60                 public void ComputeNamespace (Type extensionType)
  61                 {
  62                         foreach (Assembly a in referenced_assemblies) {
  63                                 try {
  64                                         ComputeNamespaces (a, extensionType);
  65                                 } catch (TypeLoadException e) {
  66                                         Report.Error (11, Location.Null, e.Message);
  67                                 } catch (System.IO.FileNotFoundException) {
  68                                         Report.Error (12, Location.Null, "An assembly `{0}' is used without being referenced",
  69                                                 a.FullName);
  70                                 }
  71                         }
  72                 }
  73
  74                 public virtual Type LookupTypeReflection (string name, Location loc)
  75                 {
  76                         Type found_type = null;
  77
  78                         foreach (Assembly a in referenced_assemblies) {
  79                                 Type t = GetTypeInAssembly (a, name);
  80                                 if (t == null)
  81                                         continue;
  82
  83                                 if (found_type == null) {
  84                                         found_type = t;
  85                                         continue;
  86                                 }
  87
  88                                 Report.SymbolRelatedToPreviousError (found_type);
  89                                 Report.SymbolRelatedToPreviousError (t);
  90                                 Report.Error (433, loc, "The imported type `{0}' is defined multiple times", name);
  91
  92                                 return found_type;
  93                         }
  94
  95                         return found_type;
  96                 }
  97
  98                 public void RegisterNamespace (Namespace child)
  99                 {
 100                         if (child != this)
 101                                 all_namespaces.Add (child.Name, child);
 102                 }
 103
 104                 public bool IsNamespace (string name)
 105                 {
 106                         return all_namespaces.Contains (name);
 107                 }
 108
 109                 protected void RegisterNamespace (string dotted_name)
 110                 {
 111                         if (dotted_name != null && dotted_name.Length != 0 && ! IsNamespace (dotted_name))
 112                                 GetNamespace (dotted_name, true);
 113                 }
 114
 115                 void RegisterExtensionMethodClass (Type t)
 116                 {
 117                         string n = t.Namespace;
 118                         Namespace ns = n == null ? GlobalRootNamespace.Instance : (Namespace) all_namespaces[n];
 119                         if (ns == null)
 120                                 ns = GetNamespace (n, true);
 121
 122                         ns.RegisterExternalExtensionMethodClass (t);
 123                 }
 124
 125                 void ComputeNamespaces (Assembly assembly, Type extensionType)
 126                 {
 127                         bool contains_extension_methods = extensionType != null && assembly.IsDefined (extensionType, false);
 128
 129                         if (get_namespaces_method != null) {
 130                                 string [] namespaces = (string []) get_namespaces_method.Invoke (assembly, null);
 131                                 foreach (string ns in namespaces)
 132                                         RegisterNamespace (ns);
 133
 134                                 if (!contains_extension_methods)
 135                                         return;
 136                         }
 137
 138                         foreach (Type t in assembly.GetTypes ()) {
 139                                 if ((t.Attributes & Class.StaticClassAttribute) == Class.StaticClassAttribute &&
 140                                         contains_extension_methods && t.IsDefined (extensionType, false))
 141                                         RegisterExtensionMethodClass (t);
 142
 143                                 if (get_namespaces_method == null)
 144                                         RegisterNamespace (t.Namespace);
 145                         }
 146                 }
 147
 148                 protected static Type GetTypeInAssembly (Assembly assembly, string name)
 149                 {
 150                         Type t = assembly.GetType (name);
 151                         if (t == null)
 152                                 return null;
 153
 154                         if (t.IsPointer)
 155                                 throw new InternalErrorException ("Use GetPointerType() to get a pointer");
 156
 157                         TypeAttributes ta = t.Attributes & TypeAttributes.VisibilityMask;
 158                         if (ta == TypeAttributes.NestedPrivate)
 159                                 return null;
 160
 161                         if ((ta == TypeAttributes.NotPublic ||
 162                              ta == TypeAttributes.NestedAssembly ||
 163                              ta == TypeAttributes.NestedFamANDAssem) &&
 164                             !TypeManager.IsThisOrFriendAssembly (t.Assembly))
 165                                 return null;
 166
 167                         return t;
 168                 }
 169
 170                 public override string ToString ()
 171                 {
 172                         return String.Format ("RootNamespace ({0}::)", alias_name);
 173                 }
 174
 175                 public override string GetSignatureForError ()
 176                 {
 177                         return alias_name + "::";
 178                 }
 179         }
 180
 181         class GlobalRootNamespace : RootNamespace {
 182                 Module [] modules;
 183                 ListDictionary root_namespaces;
 184
 185                 public static GlobalRootNamespace Instance = new GlobalRootNamespace ();
 186
 187                 GlobalRootNamespace ()
 188                         : base ("global")
 189                 {
 190                         root_namespaces = new ListDictionary ();
 191                         root_namespaces.Add (alias_name, this);
 192                 }
 193
 194                 public static void Reset ()
 195                 {
 196                         Instance = new GlobalRootNamespace ();
 197                 }
 198
 199                 public Assembly [] Assemblies {
 200                     get { return referenced_assemblies; }
 201                 }
 202
 203                 public Module [] Modules {
 204                         get { return modules; }
 205                 }
 206
 207                 public void AddModuleReference (Module m)
 208                 {
 209                         int top = modules != null ? modules.Length : 0;
 210                         Module [] n = new Module [top + 1];
 211                         if (modules != null)
 212                                 modules.CopyTo (n, 0);
 213                         n [top] = m;
 214                         modules = n;
 215
 216                         if (m == RootContext.ToplevelTypes.Builder)
 217                                 return;
 218
 219                         foreach (Type t in m.GetTypes ())
 220                                 RegisterNamespace (t.Namespace);
 221                 }
 222
 223                 public void ComputeNamespaces ()
 224                 {
 225                         //
 226                         // Do very early lookup because type is required when we cache
 227                         // imported extension types in ComputeNamespaces
 228                         //
 229                         Type extension_attribute_type = TypeManager.CoreLookupType ("System.Runtime.CompilerServices", "ExtensionAttribute", Kind.Class, false);
 230
 231                         foreach (RootNamespace rn in root_namespaces.Values) {
 232                                 rn.ComputeNamespace (extension_attribute_type);
 233                         }
 234                 }
 235
 236                 public void DefineRootNamespace (string alias, Assembly assembly)
 237                 {
 238                         if (alias == alias_name) {
 239                                 NamespaceEntry.Error_GlobalNamespaceRedefined (Location.Null);
 240                                 return;
 241                         }
 242
 243                         RootNamespace retval = GetRootNamespace (alias);
 244                         if (retval == null) {
 245                                 retval = new RootNamespace (alias);
 246                                 root_namespaces.Add (alias, retval);
 247                         }
 248
 249                         retval.AddAssemblyReference (assembly);
 250                 }
 251
 252                 public override void Error_NamespaceDoesNotExist(DeclSpace ds, Location loc, string name)
 253                 {
 254                         Report.Error (400, loc, "The type or namespace name `{0}' could not be found in the global namespace (are you missing an assembly reference?)",
 255                                 name);
 256                 }
 257
 258                 public RootNamespace GetRootNamespace (string name)
 259                 {
 260                         return (RootNamespace) root_namespaces[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                         // Ignore, extension methods cannot be nested
 522                         if (type.DeclaringType != null)
 523                                 return;
 524
 525                         if (type.IsNotPublic && !TypeManager.IsThisOrFriendAssembly (type.Assembly))
 526                                 return;
 527
 528                         if (external_exmethod_classes == null)
 529                                 external_exmethod_classes = new ArrayList ();
 530
 531                         external_exmethod_classes.Add (type);
 532                 }
 533
 534                 ///
 535                 /// Looks for extension method in this namespace
 536                 ///
 537                 public ArrayList LookupExtensionMethod (Type extensionType, ClassOrStruct currentClass, string name)
 538                 {
 539                         ArrayList found = null;
 540
 541                         if (declspaces != null) {
 542                                 IEnumerator e = declspaces.Values.GetEnumerator ();
 543                                 e.Reset ();
 544                                 while (e.MoveNext ()) {
 545                                         Class c = e.Current as Class;
 546                                         if (c == null)
 547                                                 continue;
 548
 549                                         if ((c.ModFlags & Modifiers.METHOD_EXTENSION) == 0)
 550                                                 continue;
 551
 552                                         ArrayList res = c.MemberCache.FindExtensionMethods (extensionType, name, c != currentClass);
 553                                         if (res == null)
 554                                                 continue;
 555
 556                                         if (found == null)
 557                                                 found = res;
 558                                         else
 559                                                 found.AddRange (res);
 560                                 }
 561                         }
 562
 563                         if (external_exmethod_classes == null)
 564                                 return found;
 565
 566                         foreach (Type t in external_exmethod_classes) {
 567                                 MemberCache m = TypeHandle.GetMemberCache (t);
 568                                 ArrayList res = m.FindExtensionMethods (extensionType, name, true);
 569                                 if (res == null)
 570                                         continue;
 571
 572                                 if (found == null)
 573                                         found = res;
 574                                 else
 575                                         found.AddRange (res);
 576                         }
 577
 578                         return found;
 579                 }
 580
 581                 public void AddDeclSpace (string name, DeclSpace ds)
 582                 {
 583                         if (declspaces == null)
 584                                 declspaces = new HybridDictionary ();
 585                         declspaces.Add (name, ds);
 586                 }
 587
 588                 public void RemoveDeclSpace (string name)
 589                 {
 590                         declspaces.Remove (name);
 591                 }
 592
 593                 /// <summary>
 594                 ///   The qualified name of the current namespace
 595                 /// </summary>
 596                 public string Name {
 597                         get { return fullname; }
 598                 }
 599
 600                 /// <summary>
 601                 ///   The parent of this namespace, used by the parser to "Pop"
 602                 ///   the current namespace declaration
 603                 /// </summary>
 604                 public Namespace Parent {
 605                         get { return parent; }
 606                 }
 607         }
 608
 609         //
 610         // Namespace container as created by the parser
 611         //
 612         public class NamespaceEntry : IResolveContext {
 613
 614                 class UsingEntry {
 615                         readonly MemberName name;
 616                         Namespace resolved;
 617
 618                         public UsingEntry (MemberName name)
 619                         {
 620                                 this.name = name;
 621                         }
 622
 623                         public string GetSignatureForError ()
 624                         {
 625                                 return name.GetSignatureForError ();
 626                         }
 627
 628                         public Location Location {
 629                                 get { return name.Location; }
 630                         }
 631
 632                         public MemberName MemberName {
 633                                 get { return name; }
 634                         }
 635
 636                         public string Name {
 637                                 get { return GetSignatureForError (); }
 638                         }
 639
 640                         public Namespace Resolve (IResolveContext rc)
 641                         {
 642                                 if (resolved != null)
 643                                         return resolved;
 644
 645                                 FullNamedExpression fne = name.GetTypeExpression ().ResolveAsTypeStep (rc, false);
 646                                 if (fne == null)
 647                                         return null;
 648
 649                                 resolved = fne as Namespace;
 650                                 if (resolved == null) {
 651                                         Report.SymbolRelatedToPreviousError (fne.Type);
 652                                         Report.Error (138, Location,
 653                                                 "`{0}' is a type not a namespace. A using namespace directive can only be applied to namespaces",
 654                                                 GetSignatureForError ());
 655                                 }
 656                                 return resolved;
 657                         }
 658
 659                         public override string ToString ()
 660                         {
 661                                 return Name;
 662                         }
 663                 }
 664
 665                 class UsingAliasEntry {
 666                         public readonly string Alias;
 667                         public Location Location;
 668
 669                         public UsingAliasEntry (string alias, Location loc)
 670                         {
 671                                 this.Alias = alias;
 672                                 this.Location = loc;
 673                         }
 674
 675                         public virtual FullNamedExpression Resolve (IResolveContext rc)
 676                         {
 677                                 FullNamedExpression fne = GlobalRootNamespace.Instance.GetRootNamespace (Alias);
 678                                 if (fne == null) {
 679                                         Report.Error (430, Location,
 680                                                 "The extern alias `{0}' was not specified in -reference option",
 681                                                 Alias);
 682                                 }
 683
 684                                 return fne;
 685                         }
 686
 687                         public override string ToString ()
 688                         {
 689                                 return Alias;
 690                         }
 691
 692                 }
 693
 694                 class LocalUsingAliasEntry : UsingAliasEntry {
 695                         FullNamedExpression resolved;
 696                         MemberName value;
 697
 698                         public LocalUsingAliasEntry (string alias, MemberName name, Location loc)
 699                                 : base (alias, loc)
 700                         {
 701                                 this.value = name;
 702                         }
 703
 704                         public override FullNamedExpression Resolve (IResolveContext rc)
 705                         {
 706                                 if (resolved != null || value == null)
 707                                         return resolved;
 708
 709                                 resolved = value.GetTypeExpression ().ResolveAsTypeStep (rc, false);
 710                                 if (resolved == null) {
 711                                         value = null;
 712                                         return null;
 713                                 }
 714
 715                                 TypeExpr te = resolved as TypeExpr;
 716                                 if (te != null) {
 717                                         if (!te.CheckAccessLevel (rc.DeclContainer)) {
 718                                                 Report.SymbolRelatedToPreviousError (te.Type);
 719                                                 Expression.ErrorIsInaccesible (resolved.Location, resolved.GetSignatureForError ());
 720                                         }
 721                                 }
 722
 723                                 return resolved;
 724                         }
 725
 726                         public override string ToString ()
 727                         {
 728                                 return String.Format ("{0} = {1}", Alias, value.GetSignatureForError ());
 729                         }
 730                 }
 731
 732                 Namespace ns;
 733                 NamespaceEntry parent, implicit_parent;
 734                 CompilationUnit file;
 735                 int symfile_id;
 736
 737                 // Namespace using import block
 738                 ArrayList using_aliases;
 739                 ArrayList using_clauses;
 740                 public bool DeclarationFound = false;
 741                 // End
 742
 743                 public readonly bool IsImplicit;
 744                 public readonly DeclSpace SlaveDeclSpace;
 745                 static readonly Namespace [] empty_namespaces = new Namespace [0];
 746                 Namespace [] namespace_using_table;
 747
 748                 static ArrayList entries = new ArrayList ();
 749
 750                 public static void Reset ()
 751                 {
 752                         entries = new ArrayList ();
 753                 }
 754
 755                 public NamespaceEntry (NamespaceEntry parent, CompilationUnit file, string name)
 756                 {
 757                         this.parent = parent;
 758                         this.file = file;
 759                         entries.Add (this);
 760
 761                         if (parent != null)
 762                                 ns = parent.NS.GetNamespace (name, true);
 763                         else if (name != null)
 764                                 ns = GlobalRootNamespace.Instance.GetNamespace (name, true);
 765                         else
 766                                 ns = GlobalRootNamespace.Instance;
 767                         SlaveDeclSpace = new RootDeclSpace (this);
 768                 }
 769
 770                 private NamespaceEntry (NamespaceEntry parent, CompilationUnit file, Namespace ns, bool slave)
 771                 {
 772                         this.parent = parent;
 773                         this.file = file;
 774                         this.IsImplicit = true;
 775                         this.ns = ns;
 776                         this.SlaveDeclSpace = slave ? new RootDeclSpace (this) : null;
 777                 }
 778
 779                 //
 780                 // Populates the Namespace with some using declarations, used by the
 781                 // eval mode.
 782                 //
 783                 public void Populate (ArrayList source_using_aliases, ArrayList source_using_clauses)
 784                 {
 785                         foreach (UsingAliasEntry uae in source_using_aliases){
 786                                 if (using_aliases == null)
 787                                         using_aliases = new ArrayList ();
 788
 789                                 using_aliases.Add (uae);
 790                         }
 791
 792                         foreach (UsingEntry ue in source_using_clauses){
 793                                 if (using_clauses == null)
 794                                         using_clauses = new ArrayList ();
 795
 796                                 using_clauses.Add (ue);
 797                         }
 798                 }
 799
 800                 //
 801                 // Extracts the using alises and using clauses into a couple of
 802                 // arrays that might already have the same information;  Used by the
 803                 // C# Eval mode.
 804                 //
 805                 public void Extract (ArrayList out_using_aliases, ArrayList out_using_clauses)
 806                 {
 807                         if (using_aliases != null){
 808                                 foreach (UsingAliasEntry uae in using_aliases){
 809                                         bool replaced = false;
 810
 811                                         for (int i = 0; i < out_using_aliases.Count; i++){
 812                                                 UsingAliasEntry out_uea = (UsingAliasEntry) out_using_aliases [i];
 813
 814                                                 if (out_uea.Alias == uae.Alias){
 815                                                         out_using_aliases [i] = uae;
 816                                                         replaced = true;
 817                                                         break;
 818                                                 }
 819                                         }
 820                                         if (!replaced)
 821                                                 out_using_aliases.Add (uae);
 822                                 }
 823                         }
 824
 825                         if (using_clauses != null){
 826                                 foreach (UsingEntry ue in using_clauses){
 827                                         bool found = false;
 828
 829                                         foreach (UsingEntry out_ue in out_using_clauses)
 830                                                 if (out_ue.Name == ue.Name){
 831                                                         found = true;
 832                                                         break;
 833                                                 }
 834                                         if (!found)
 835                                                 out_using_clauses.Add (ue);
 836                                 }
 837                         }
 838                 }
 839
 840                 //
 841                 // According to section 16.3.1 (using-alias-directive), the namespace-or-type-name is
 842                 // resolved as if the immediately containing namespace body has no using-directives.
 843                 //
 844                 // Section 16.3.2 says that the same rule is applied when resolving the namespace-name
 845                 // in the using-namespace-directive.
 846                 //
 847                 // To implement these rules, the expressions in the using directives are resolved using
 848                 // the "doppelganger" (ghostly bodiless duplicate).
 849                 //
 850                 NamespaceEntry doppelganger;
 851                 NamespaceEntry Doppelganger {
 852                         get {
 853                                 if (!IsImplicit && doppelganger == null) {
 854                                         doppelganger = new NamespaceEntry (ImplicitParent, file, ns, true);
 855                                         doppelganger.using_aliases = using_aliases;
 856                                 }
 857                                 return doppelganger;
 858                         }
 859                 }
 860
 861                 public Namespace NS {
 862                         get { return ns; }
 863                 }
 864
 865                 public NamespaceEntry Parent {
 866                         get { return parent; }
 867                 }
 868
 869                 public NamespaceEntry ImplicitParent {
 870                         get {
 871                                 if (parent == null)
 872                                         return null;
 873                                 if (implicit_parent == null) {
 874                                         implicit_parent = (parent.NS == ns.Parent)
 875                                                 ? parent
 876                                                 : new NamespaceEntry (parent, file, ns.Parent, false);
 877                                 }
 878                                 return implicit_parent;
 879                         }
 880                 }
 881
 882                 /// <summary>
 883                 ///   Records a new namespace for resolving name references
 884                 /// </summary>
 885                 public void AddUsing (MemberName name, Location loc)
 886                 {
 887                         if (DeclarationFound){
 888                                 Report.Error (1529, loc, "A using clause must precede all other namespace elements except extern alias declarations");
 889                         }
 890
 891                         if (using_clauses == null) {
 892                                 using_clauses = new ArrayList ();
 893                         } else {
 894                                 foreach (UsingEntry old_entry in using_clauses) {
 895                                         if (name.Equals (old_entry.MemberName)) {
 896                                                 Report.SymbolRelatedToPreviousError (old_entry.Location, old_entry.GetSignatureForError ());
 897                                                 Report.Warning (105, 3, loc, "The using directive for `{0}' appeared previously in this namespace", name.GetSignatureForError ());
 898                                                 return;
 899                                         }
 900                                 }
 901                         }
 902
 903                         using_clauses.Add (new UsingEntry (name));
 904                 }
 905
 906                 public void AddUsingAlias (string alias, MemberName name, Location loc)
 907                 {
 908                         // TODO: This is parser bussines
 909                         if (DeclarationFound){
 910                                 Report.Error (1529, loc, "A using clause must precede all other namespace elements except extern alias declarations");
 911                         }
 912
 913                         if (RootContext.Version != LanguageVersion.ISO_1 && alias == "global")
 914                                 Report.Warning (440, 2, loc, "An alias named `global' will not be used when resolving 'global::';" +
 915                                         " the global namespace will be used instead");
 916
 917                         AddUsingAlias (new LocalUsingAliasEntry (alias, name, loc));
 918                 }
 919
 920                 public void AddUsingExternalAlias (string alias, Location loc)
 921                 {
 922                         // TODO: Do this in parser
 923                         bool not_first = using_clauses != null || DeclarationFound;
 924                         if (using_aliases != null && !not_first) {
 925                                 foreach (UsingAliasEntry uae in using_aliases) {
 926                                         if (uae is LocalUsingAliasEntry) {
 927                                                 not_first = true;
 928                                                 break;
 929                                         }
 930                                 }
 931                         }
 932
 933                         if (not_first)
 934                                 Report.Error (439, loc, "An extern alias declaration must precede all other elements");
 935
 936                         if (alias == "global") {
 937                                 Error_GlobalNamespaceRedefined (loc);
 938                                 return;
 939                         }
 940
 941                         AddUsingAlias (new UsingAliasEntry (alias, loc));
 942                 }
 943
 944                 void AddUsingAlias (UsingAliasEntry uae)
 945                 {
 946                         if (using_aliases == null) {
 947                                 using_aliases = new ArrayList ();
 948                         } else {
 949                                 foreach (UsingAliasEntry entry in using_aliases) {
 950                                         if (uae.Alias == entry.Alias) {
 951                                                 Report.SymbolRelatedToPreviousError (uae.Location, uae.Alias);
 952                                                 Report.Error (1537, entry.Location, "The using alias `{0}' appeared previously in this namespace",
 953                                                         entry.Alias);
 954                                                 return;
 955                                         }
 956                                 }
 957                         }
 958
 959                         using_aliases.Add (uae);
 960                 }
 961
 962                 ///
 963                 /// Does extension methods look up to find a method which matches name and extensionType.
 964                 /// Search starts from this namespace and continues hierarchically up to top level.
 965                 ///
 966                 public ExtensionMethodGroupExpr LookupExtensionMethod (Type extensionType, ClassOrStruct currentClass, string name, Location loc)
 967                 {
 968                         ArrayList candidates = null;
 969                         if (currentClass != null) {
 970                                 candidates = ns.LookupExtensionMethod (extensionType, currentClass, name);
 971                                 if (candidates != null)
 972                                         return new ExtensionMethodGroupExpr (candidates, this, extensionType, loc);
 973                         }
 974
 975                         foreach (Namespace n in GetUsingTable ()) {
 976                                 ArrayList a = n.LookupExtensionMethod (extensionType, null, name);
 977                                 if (a == null)
 978                                         continue;
 979
 980                                 if (candidates == null)
 981                                         candidates = a;
 982                                 else
 983                                         candidates.AddRange (a);
 984                         }
 985
 986                         if (candidates != null)
 987                                 return new ExtensionMethodGroupExpr (candidates, parent, extensionType, loc);
 988
 989                         if (parent == null)
 990                                 return null;
 991
 992                         //
 993                         // Inspect parent namespaces in namespace expression
 994                         //
 995                         Namespace parent_ns = ns.Parent;
 996                         do {
 997                                 candidates = parent_ns.LookupExtensionMethod (extensionType, null, name);
 998                                 if (candidates != null)
 999                                         return new ExtensionMethodGroupExpr (candidates, parent, extensionType, loc);
1000
1001                                 parent_ns = parent_ns.Parent;
1002                         } while (parent_ns != null);
1003
1004                         //
1005                         // Continue in parent scope
1006                         //
1007                         return parent.LookupExtensionMethod (extensionType, currentClass, name, loc);
1008                 }
1009
1010                 public FullNamedExpression LookupNamespaceOrType (DeclSpace ds, string name, Location loc, bool ignore_cs0104)
1011                 {
1012                         // Precondition: Only simple names (no dots) will be looked up with this function.
1013                         FullNamedExpression resolved = null;
1014                         for (NamespaceEntry curr_ns = this; curr_ns != null; curr_ns = curr_ns.ImplicitParent) {
1015                                 if ((resolved = curr_ns.Lookup (ds, name, loc, ignore_cs0104)) != null)
1016                                         break;
1017                         }
1018                         return resolved;
1019                 }
1020
1021                 static void Error_AmbiguousTypeReference (Location loc, string name, FullNamedExpression t1, FullNamedExpression t2)
1022                 {
1023                         Report.SymbolRelatedToPreviousError (t1.Type);
1024                         Report.SymbolRelatedToPreviousError (t2.Type);
1025                         Report.Error (104, loc, "`{0}' is an ambiguous reference between `{1}' and `{2}'",
1026                                 name, t1.GetSignatureForError (), t2.GetSignatureForError ());
1027                 }
1028
1029                 // Looks-up a alias named @name in this and surrounding namespace declarations
1030                 public FullNamedExpression LookupAlias (string name)
1031                 {
1032                         for (NamespaceEntry n = this; n != null; n = n.ImplicitParent) {
1033                                 if (n.using_aliases == null)
1034                                         continue;
1035
1036                                 foreach (UsingAliasEntry ue in n.using_aliases) {
1037                                         if (ue.Alias == name)
1038                                                 return ue.Resolve (Doppelganger);
1039                                 }
1040                         }
1041
1042                         return null;
1043                 }
1044
1045                 private FullNamedExpression Lookup (DeclSpace ds, string name, Location loc, bool ignore_cs0104)
1046                 {
1047                         //
1048                         // Check whether it's in the namespace.
1049                         //
1050                         FullNamedExpression fne = ns.Lookup (ds, name, loc);
1051
1052                         //
1053                         // Check aliases.
1054                         //
1055                         if (using_aliases != null) {
1056                                 foreach (UsingAliasEntry ue in using_aliases) {
1057                                         if (ue.Alias == name) {
1058                                                 if (fne != null) {
1059                                                         if (Doppelganger != null) {
1060                                                                 // TODO: Namespace has broken location
1061                                                                 //Report.SymbolRelatedToPreviousError (fne.Location, null);
1062                                                                 Report.SymbolRelatedToPreviousError (ue.Location, null);
1063                                                                 Report.Error (576, loc,
1064                                                                         "Namespace `{0}' contains a definition with same name as alias `{1}'",
1065                                                                         GetSignatureForError (), name);
1066                                                         } else {
1067                                                                 return fne;
1068                                                         }
1069                                                 }
1070
1071                                                 return ue.Resolve (Doppelganger);
1072                                         }
1073                                 }
1074                         }
1075
1076                         if (fne != null)
1077                                 return fne;
1078
1079                         if (IsImplicit)
1080                                 return null;
1081
1082                         //
1083                         // Check using entries.
1084                         //
1085                         FullNamedExpression match = null;
1086                         foreach (Namespace using_ns in GetUsingTable ()) {
1087                                 match = using_ns.Lookup (ds, name, loc);
1088                                 if (match == null || !(match is TypeExpr))
1089                                         continue;
1090                                 if (fne != null) {
1091                                         if (!ignore_cs0104)
1092                                                 Error_AmbiguousTypeReference (loc, name, fne, match);
1093                                         return null;
1094                                 }
1095                                 fne = match;
1096                         }
1097
1098                         return fne;
1099                 }
1100
1101                 Namespace [] GetUsingTable ()
1102                 {
1103                         if (namespace_using_table != null)
1104                                 return namespace_using_table;
1105
1106                         if (using_clauses == null) {
1107                                 namespace_using_table = empty_namespaces;
1108                                 return namespace_using_table;
1109                         }
1110
1111                         ArrayList list = new ArrayList (using_clauses.Count);
1112
1113                         foreach (UsingEntry ue in using_clauses) {
1114                                 Namespace using_ns = ue.Resolve (Doppelganger);
1115                                 if (using_ns == null)
1116                                         continue;
1117
1118                                 list.Add (using_ns);
1119                         }
1120
1121                         namespace_using_table = (Namespace[])list.ToArray (typeof (Namespace));
1122                         return namespace_using_table;
1123                 }
1124
1125                 static readonly string [] empty_using_list = new string [0];
1126
1127                 public int SymbolFileID {
1128                         get {
1129                                 if (symfile_id == 0 && file.SourceFileEntry != null) {
1130                                         int parent_id = parent == null ? 0 : parent.SymbolFileID;
1131
1132                                         string [] using_list = empty_using_list;
1133                                         if (using_clauses != null) {
1134                                                 using_list = new string [using_clauses.Count];
1135                                                 for (int i = 0; i < using_clauses.Count; i++)
1136                                                         using_list [i] = ((UsingEntry) using_clauses [i]).MemberName.GetName ();
1137                                         }
1138
1139                                         symfile_id = SymbolWriter.DefineNamespace (ns.Name, file.CompileUnitEntry, using_list, parent_id);
1140                                 }
1141                                 return symfile_id;
1142                         }
1143                 }
1144
1145                 static void MsgtryRef (string s)
1146                 {
1147                         Console.WriteLine ("    Try using -r:" + s);
1148                 }
1149
1150                 static void MsgtryPkg (string s)
1151                 {
1152                         Console.WriteLine ("    Try using -pkg:" + s);
1153                 }
1154
1155                 public static void Error_GlobalNamespaceRedefined (Location loc)
1156                 {
1157                         Report.Error (1681, loc, "You cannot redefine the global extern alias");
1158                 }
1159
1160                 public static void Error_NamespaceNotFound (Location loc, string name)
1161                 {
1162                         Report.Error (246, loc, "The type or namespace name `{0}' could not be found. Are you missing a using directive or an assembly reference?",
1163                                 name);
1164
1165                         switch (name) {
1166                         case "Gtk": case "GtkSharp":
1167                                 MsgtryPkg ("gtk-sharp");
1168                                 break;
1169
1170                         case "Gdk": case "GdkSharp":
1171                                 MsgtryPkg ("gdk-sharp");
1172                                 break;
1173
1174                         case "Glade": case "GladeSharp":
1175                                 MsgtryPkg ("glade-sharp");
1176                                 break;
1177
1178                         case "System.Drawing":
1179                         case "System.Web.Services":
1180                         case "System.Web":
1181                         case "System.Data":
1182                         case "System.Windows.Forms":
1183                                 MsgtryRef (name);
1184                                 break;
1185                         }
1186                 }
1187
1188                 /// <summary>
1189                 ///   Used to validate that all the using clauses are correct
1190                 ///   after we are finished parsing all the files.
1191                 /// </summary>
1192                 void VerifyUsing ()
1193                 {
1194                         if (using_aliases != null) {
1195                                 foreach (UsingAliasEntry ue in using_aliases)
1196                                         ue.Resolve (Doppelganger);
1197                         }
1198
1199                         if (using_clauses != null) {
1200                                 foreach (UsingEntry ue in using_clauses)
1201                                         ue.Resolve (Doppelganger);
1202                         }
1203                 }
1204
1205                 /// <summary>
1206                 ///   Used to validate that all the using clauses are correct
1207                 ///   after we are finished parsing all the files.
1208                 /// </summary>
1209                 static public void VerifyAllUsing ()
1210                 {
1211                         foreach (NamespaceEntry entry in entries)
1212                                 entry.VerifyUsing ();
1213                 }
1214
1215                 public string GetSignatureForError ()
1216                 {
1217                         return ns.GetSignatureForError ();
1218                 }
1219
1220                 public override string ToString ()
1221                 {
1222                         return ns.ToString ();
1223                 }
1224
1225                 #region IResolveContext Members
1226
1227                 public DeclSpace DeclContainer {
1228                         get { return SlaveDeclSpace; }
1229                 }
1230
1231                 public bool IsInObsoleteScope {
1232                         get { return SlaveDeclSpace.IsInObsoleteScope; }
1233                 }
1234
1235                 public bool IsInUnsafeScope {
1236                         get { return SlaveDeclSpace.IsInUnsafeScope; }
1237                 }
1238
1239                 public DeclSpace GenericDeclContainer {
1240                         get { return SlaveDeclSpace; }
1241                 }
1242
1243                 #endregion
1244         }
1245 }