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.Generic;
  13 using System.Reflection;
  14
  15 namespace Mono.CSharp {
  16
  17         public class RootNamespace : Namespace {
  18                 //
  19                 // Points to Mono's GetNamespaces method, an
  20                 // optimization when running on Mono to fetch all the
  21                 // namespaces in an assembly
  22                 //
  23                 static MethodInfo get_namespaces_method;
  24
  25                 protected readonly string alias_name;
  26                 protected Assembly [] referenced_assemblies;
  27
  28                 Dictionary<string, Namespace> all_namespaces;
  29
  30                 static RootNamespace ()
  31                 {
  32                         get_namespaces_method = typeof (Assembly).GetMethod ("GetNamespaces", BindingFlags.Instance | BindingFlags.NonPublic);
  33                 }
  34
  35                 public RootNamespace (string alias_name)
  36                         : base (null, String.Empty)
  37                 {
  38                         this.alias_name = alias_name;
  39                         referenced_assemblies = new Assembly [0];
  40
  41                         all_namespaces = new Dictionary<string, Namespace> ();
  42                         all_namespaces.Add ("", this);
  43                 }
  44
  45                 public void AddAssemblyReference (Assembly a)
  46                 {
  47                         foreach (Assembly assembly in referenced_assemblies) {
  48                                 if (a == assembly)
  49                                         return;
  50                         }
  51
  52                         int top = referenced_assemblies.Length;
  53                         Assembly [] n = new Assembly [top + 1];
  54                         referenced_assemblies.CopyTo (n, 0);
  55                         n [top] = a;
  56                         referenced_assemblies = n;
  57                 }
  58
  59                 public void ComputeNamespace (CompilerContext ctx, Type extensionType)
  60                 {
  61                         foreach (Assembly a in referenced_assemblies) {
  62                                 try {
  63                                         ComputeNamespaces (a, extensionType);
  64                                 } catch (TypeLoadException e) {
  65                                         ctx.Report.Error (11, Location.Null, e.Message);
  66                                 } catch (System.IO.FileNotFoundException) {
  67                                         ctx.Report.Error (12, Location.Null, "An assembly `{0}' is used without being referenced",
  68                                                 a.FullName);
  69                                 }
  70                         }
  71                 }
  72
  73                 public virtual Type LookupTypeReflection (CompilerContext ctx, string name, Location loc, bool must_be_unique)
  74                 {
  75                         // FIXME: Breaks dynamic
  76                         Assembly invocation_assembly = CodeGen.Assembly.Builder;
  77
  78                         Type found_type = null;
  79                         foreach (Assembly a in referenced_assemblies) {
  80                                 Type t = GetTypeInAssembly (invocation_assembly, a, name);
  81                                 if (t == null)
  82                                         continue;
  83
  84                                 if (!must_be_unique)
  85                                         return t;
  86
  87                                 if (found_type == null) {
  88                                         found_type = t;
  89                                         continue;
  90                                 }
  91
  92                                 // When type is forwarded
  93                                 if (t.Assembly == found_type.Assembly)
  94                                         continue;
  95
  96                                 ctx.Report.SymbolRelatedToPreviousError (found_type);
  97                                 ctx.Report.SymbolRelatedToPreviousError (t);
  98                                 if (loc.IsNull) {
  99                                         Error_AmbiguousPredefinedType (ctx, loc, name, found_type);
 100                                 } else {
 101                                         ctx.Report.Error (433, loc, "The imported type `{0}' is defined multiple times", name);
 102                                 }
 103
 104                                 return found_type;
 105                         }
 106
 107                         return found_type;
 108                 }
 109
 110                 //
 111                 // Returns the types starting with the given prefix
 112                 //
 113                 public ICollection<string> CompletionGetTypesStartingWith (string prefix)
 114                 {
 115                         Dictionary<string, string> result = null;
 116
 117                         foreach (Assembly a in referenced_assemblies){
 118                                 Type [] mtypes = a.GetTypes ();
 119
 120                                 foreach (Type t in mtypes){
 121                                         if (t.IsNotPublic)
 122                                                 continue;
 123
 124                                         string f = t.FullName;
 125
 126                                         if (f.StartsWith (prefix) && (result == null || !result.ContainsKey (f))){
 127                                                 if (result == null)
 128                                                         result = new Dictionary<string, string> ();
 129
 130                                                 result [f] = f;
 131                                         }
 132                                 }
 133                         }
 134                         return result == null ? null : result.Keys;
 135                 }
 136
 137                 protected static void Error_AmbiguousPredefinedType (CompilerContext ctx, Location loc, string name, Type type)
 138                 {
 139                         ctx.Report.Warning (1685, 1, loc,
 140                                 "The predefined type `{0}' is ambiguous. Using definition from `{1}'",
 141                                 name, type.Assembly.FullName);
 142                 }
 143
 144                 public void RegisterNamespace (Namespace child)
 145                 {
 146                         if (child != this)
 147                                 all_namespaces.Add (child.Name, child);
 148                 }
 149
 150                 public bool IsNamespace (string name)
 151                 {
 152                         return all_namespaces.ContainsKey (name);
 153                 }
 154
 155                 protected void RegisterNamespace (string dotted_name)
 156                 {
 157                         if (dotted_name != null && dotted_name.Length != 0 && ! IsNamespace (dotted_name))
 158                                 GetNamespace (dotted_name, true);
 159                 }
 160
 161                 void RegisterExtensionMethodClass (Type t)
 162                 {
 163                         string n = t.Namespace;
 164                         Namespace ns = null;
 165                         if (n == null)
 166                                 ns = GlobalRootNamespace.Instance;
 167                         else
 168                                 all_namespaces.TryGetValue (n, out ns);
 169
 170                         if (ns == null)
 171                                 ns = GetNamespace (n, true);
 172
 173                         ns.RegisterExternalExtensionMethodClass (t);
 174                 }
 175
 176                 void ComputeNamespaces (Assembly assembly, Type extensionType)
 177                 {
 178                         bool contains_extension_methods = extensionType != null && assembly.IsDefined (extensionType, false);
 179
 180                         if (get_namespaces_method != null) {
 181                                 string [] namespaces = (string []) get_namespaces_method.Invoke (assembly, null);
 182                                 foreach (string ns in namespaces)
 183                                         RegisterNamespace (ns);
 184
 185                                 if (!contains_extension_methods)
 186                                         return;
 187                         }
 188
 189                         foreach (Type t in assembly.GetTypes ()) {
 190                                 if ((t.Attributes & Class.StaticClassAttribute) == Class.StaticClassAttribute &&
 191                                         contains_extension_methods && t.IsDefined (extensionType, false))
 192                                         RegisterExtensionMethodClass (t);
 193
 194                                 if (get_namespaces_method == null)
 195                                         RegisterNamespace (t.Namespace);
 196                         }
 197                 }
 198
 199                 protected static Type GetTypeInAssembly (Assembly invocation, Assembly assembly, string name)
 200                 {
 201                         if (assembly == null)
 202                                 throw new ArgumentNullException ("assembly");
 203                         if (name == null)
 204                                 throw new ArgumentNullException ("name");
 205                         Type t = assembly.GetType (name);
 206                         if (t == null)
 207                                 return null;
 208
 209                         if (t.IsPointer)
 210                                 throw new InternalErrorException ("Use GetPointerType() to get a pointer");
 211
 212                         TypeAttributes ta = t.Attributes & TypeAttributes.VisibilityMask;
 213                         if (ta == TypeAttributes.NestedPrivate)
 214                                 return null;
 215
 216                         if ((ta == TypeAttributes.NotPublic ||
 217                              ta == TypeAttributes.NestedAssembly ||
 218                              ta == TypeAttributes.NestedFamANDAssem) &&
 219                             !TypeManager.IsThisOrFriendAssembly (invocation, t.Assembly))
 220                                 return null;
 221
 222                         return t;
 223                 }
 224
 225                 public override string ToString ()
 226                 {
 227                         return String.Format ("RootNamespace ({0}::)", alias_name);
 228                 }
 229
 230                 public override string GetSignatureForError ()
 231                 {
 232                         return alias_name + "::";
 233                 }
 234         }
 235
 236         public class GlobalRootNamespace : RootNamespace {
 237                 Module [] modules;
 238                 Dictionary<string, RootNamespace> root_namespaces;
 239
 240                 public static GlobalRootNamespace Instance = new GlobalRootNamespace ();
 241
 242                 GlobalRootNamespace ()
 243                         : base ("global")
 244                 {
 245                         root_namespaces = new Dictionary<string, RootNamespace> ();
 246                         root_namespaces.Add (alias_name, this);
 247                 }
 248
 249                 public static void Reset ()
 250                 {
 251                         Instance = new GlobalRootNamespace ();
 252                 }
 253
 254                 public Assembly [] Assemblies {
 255                     get { return referenced_assemblies; }
 256                 }
 257
 258                 public Module [] Modules {
 259                         get { return modules; }
 260                 }
 261
 262                 public void AddModuleReference (Module m)
 263                 {
 264                         int top = modules != null ? modules.Length : 0;
 265                         Module [] n = new Module [top + 1];
 266                         if (modules != null)
 267                                 modules.CopyTo (n, 0);
 268                         n [top] = m;
 269                         modules = n;
 270
 271                         if (m == RootContext.ToplevelTypes.Builder)
 272                                 return;
 273
 274                         foreach (Type t in m.GetTypes ())
 275                                 RegisterNamespace (t.Namespace);
 276                 }
 277
 278                 public void ComputeNamespaces (CompilerContext ctx)
 279                 {
 280                         //
 281                         // Do very early lookup because type is required when we cache
 282                         // imported extension types in ComputeNamespaces
 283                         //
 284                         Type extension_attribute_type = TypeManager.CoreLookupType (ctx, "System.Runtime.CompilerServices", "ExtensionAttribute", MemberKind.Class, false);
 285
 286                         foreach (RootNamespace rn in root_namespaces.Values) {
 287                                 rn.ComputeNamespace (ctx, extension_attribute_type);
 288                         }
 289                 }
 290
 291                 public void DefineRootNamespace (string alias, Assembly assembly, CompilerContext ctx)
 292                 {
 293                         if (alias == alias_name) {
 294                                 NamespaceEntry.Error_GlobalNamespaceRedefined (Location.Null, ctx.Report);
 295                                 return;
 296                         }
 297
 298                         RootNamespace retval = GetRootNamespace (alias);
 299                         if (retval == null) {
 300                                 retval = new RootNamespace (alias);
 301                                 root_namespaces.Add (alias, retval);
 302                         }
 303
 304                         retval.AddAssemblyReference (assembly);
 305                 }
 306
 307                 public override void Error_NamespaceDoesNotExist (Location loc, string name, IMemberContext ctx)
 308                 {
 309                         ctx.Compiler.Report.Error (400, loc,
 310                                 "The type or namespace name `{0}' could not be found in the global namespace (are you missing an assembly reference?)",
 311                                 name);
 312                 }
 313
 314                 public RootNamespace GetRootNamespace (string name)
 315                 {
 316                         RootNamespace rn;
 317                         if (!root_namespaces.TryGetValue (name, out rn))
 318                                 return null;
 319
 320                         return rn;
 321                 }
 322
 323                 public override Type LookupTypeReflection (CompilerContext ctx, string name, Location loc, bool must_be_unique)
 324                 {
 325                         Type found_type = base.LookupTypeReflection (ctx, name, loc, must_be_unique);
 326
 327                         if (modules != null) {
 328                                 foreach (Module module in modules) {
 329                                         Type t = module.GetType (name);
 330                                         if (t == null)
 331                                                 continue;
 332
 333                                         if (found_type == null) {
 334                                                 found_type = t;
 335                                                 continue;
 336                                         }
 337
 338                                         ctx.Report.SymbolRelatedToPreviousError (found_type);
 339                                         if (loc.IsNull) {
 340                                                 DeclSpace ds = TypeManager.LookupDeclSpace (t);
 341                                                 Error_AmbiguousPredefinedType (ctx, ds.Location, name, found_type);
 342                                                 return found_type;
 343                                         }
 344                                         ctx.Report.SymbolRelatedToPreviousError (t);
 345                                         ctx.Report.Warning (436, 2, loc, "The type `{0}' conflicts with the imported type `{1}'. Ignoring the imported type definition",
 346                                                 TypeManager.CSharpName (t), TypeManager.CSharpName (found_type));
 347                                         return t;
 348                                 }
 349                         }
 350
 351                         return found_type;
 352                 }
 353         }
 354
 355         /// <summary>
 356         ///   Keeps track of the namespaces defined in the C# code.
 357         ///
 358         ///   This is an Expression to allow it to be referenced in the
 359         ///   compiler parse/intermediate tree during name resolution.
 360         /// </summary>
 361         public class Namespace : FullNamedExpression {
 362
 363                 Namespace parent;
 364                 string fullname;
 365                 Dictionary<string, Namespace> namespaces;
 366                 Dictionary<string, DeclSpace> declspaces;
 367                 Dictionary<string, TypeExpr> cached_types;
 368                 RootNamespace root;
 369                 List<Type> external_exmethod_classes;
 370
 371                 public readonly MemberName MemberName;
 372
 373                 /// <summary>
 374                 ///   Constructor Takes the current namespace and the
 375                 ///   name.  This is bootstrapped with parent == null
 376                 ///   and name = ""
 377                 /// </summary>
 378                 public Namespace (Namespace parent, string name)
 379                 {
 380                         // Expression members.
 381                         this.eclass = ExprClass.Namespace;
 382                         this.Type = typeof (Namespace);
 383                         this.loc = Location.Null;
 384
 385                         this.parent = parent;
 386
 387                         if (parent != null)
 388                                 this.root = parent.root;
 389                         else
 390                                 this.root = this as RootNamespace;
 391
 392                         if (this.root == null)
 393                                 throw new InternalErrorException ("Root namespaces must be created using RootNamespace");
 394
 395                         string pname = parent != null ? parent.fullname : "";
 396
 397                         if (pname == "")
 398                                 fullname = name;
 399                         else
 400                                 fullname = parent.fullname + "." + name;
 401
 402                         if (fullname == null)
 403                                 throw new InternalErrorException ("Namespace has a null fullname");
 404
 405                         if (parent != null && parent.MemberName != MemberName.Null)
 406                                 MemberName = new MemberName (parent.MemberName, name);
 407                         else if (name.Length == 0)
 408                                 MemberName = MemberName.Null;
 409                         else
 410                                 MemberName = new MemberName (name);
 411
 412                         namespaces = new Dictionary<string, Namespace> ();
 413                         cached_types = new Dictionary<string, TypeExpr> ();
 414
 415                         root.RegisterNamespace (this);
 416                 }
 417
 418                 protected override Expression DoResolve (ResolveContext ec)
 419                 {
 420                         return this;
 421                 }
 422
 423                 public virtual void Error_NamespaceDoesNotExist (Location loc, string name, IMemberContext ctx)
 424                 {
 425                         if (name.IndexOf ('`') > 0) {
 426                                 FullNamedExpression retval = Lookup (ctx.Compiler, SimpleName.RemoveGenericArity (name), loc);
 427                                 if (retval != null) {
 428                                         retval.Error_TypeArgumentsCannotBeUsed (ctx.Compiler.Report, loc);
 429                                         return;
 430                                 }
 431                         } else {
 432                                 Type t = LookForAnyGenericType (name);
 433                                 if (t != null) {
 434                                         Error_InvalidNumberOfTypeArguments (ctx.Compiler.Report, t, loc);
 435                                         return;
 436                                 }
 437                         }
 438
 439                         ctx.Compiler.Report.Error (234, loc,
 440                                 "The type or namespace name `{0}' does not exist in the namespace `{1}'. Are you missing an assembly reference?",
 441                                 name, GetSignatureForError ());
 442                 }
 443
 444                 public static void Error_InvalidNumberOfTypeArguments (Report report, Type t, Location loc)
 445                 {
 446                         report.SymbolRelatedToPreviousError (t);
 447                         report.Error (305, loc, "Using the generic type `{0}' requires `{1}' type argument(s)",
 448                                 TypeManager.CSharpName(t), TypeManager.GetNumberOfTypeArguments(t).ToString());
 449                 }
 450
 451                 public override string GetSignatureForError ()
 452                 {
 453                         return fullname;
 454                 }
 455
 456                 public Namespace GetNamespace (string name, bool create)
 457                 {
 458                         int pos = name.IndexOf ('.');
 459
 460                         Namespace ns;
 461                         string first;
 462                         if (pos >= 0)
 463                                 first = name.Substring (0, pos);
 464                         else
 465                                 first = name;
 466
 467                         if (!namespaces.TryGetValue (first, out ns)) {
 468                                 if (!create)
 469                                         return null;
 470
 471                                 ns = new Namespace (this, first);
 472                                 namespaces.Add (first, ns);
 473                         }
 474
 475                         if (pos >= 0)
 476                                 ns = ns.GetNamespace (name.Substring (pos + 1), create);
 477
 478                         return ns;
 479                 }
 480
 481                 public bool HasDefinition (string name)
 482                 {
 483                         return declspaces != null && declspaces.ContainsKey (name);
 484                 }
 485
 486                 TypeExpr LookupType (CompilerContext ctx, string name, Location loc)
 487                 {
 488                         TypeExpr te;
 489                         if (cached_types.TryGetValue (name, out te))
 490                                 return te;
 491
 492                         Type t = null;
 493                         if (declspaces != null) {
 494                                 DeclSpace tdecl;
 495                                 if (declspaces.TryGetValue (name, out tdecl)) {
 496                                         //
 497                                         // Note that this is not:
 498                                         //
 499                                         //   t = tdecl.DefineType ()
 500                                         //
 501                                         // This is to make it somewhat more useful when a DefineType
 502                                         // fails due to problems in nested types (more useful in the sense
 503                                         // of fewer misleading error messages)
 504                                         //
 505                                         tdecl.DefineType ();
 506                                         t = tdecl.TypeBuilder;
 507
 508                                         if (RootContext.EvalMode){
 509                                                 // Replace the TypeBuilder with a System.Type, as
 510                                                 // Reflection.Emit fails otherwise (we end up pretty
 511                                                 // much with Random type definitions later on).
 512                                                 Type tt = t.Assembly.GetType (t.Name);
 513                                                 if (tt != null)
 514                                                         t = tt;
 515                                         }
 516                                 }
 517                         }
 518                         string lookup = t != null ? t.FullName : (fullname.Length == 0 ? name : fullname + "." + name);
 519                         Type rt = root.LookupTypeReflection (ctx, lookup, loc, t == null);
 520
 521                         // HACK: loc.IsNull when the type is core type
 522                         if (t == null || (rt != null && loc.IsNull))
 523                                 t = rt;
 524
 525                         te = t == null ? null : new TypeExpression (t, Location.Null);
 526                         cached_types [name] = te;
 527                         return te;
 528                 }
 529
 530                 ///
 531                 /// Used for better error reporting only
 532                 ///
 533                 public Type LookForAnyGenericType (string typeName)
 534                 {
 535                         if (declspaces == null)
 536                                 return null;
 537
 538                         typeName = SimpleName.RemoveGenericArity (typeName);
 539
 540                         foreach (var de in declspaces) {
 541                                 string type_item = de.Key;
 542                                 int pos = type_item.LastIndexOf ('`');
 543                                 if (pos == typeName.Length && String.Compare (typeName, 0, type_item, 0, pos) == 0)
 544                                         return de.Value.TypeBuilder;
 545                         }
 546                         return null;
 547                 }
 548
 549                 public FullNamedExpression Lookup (CompilerContext ctx, string name, Location loc)
 550                 {
 551                         if (namespaces.ContainsKey (name))
 552                                 return namespaces [name];
 553
 554                         return LookupType (ctx, name, loc);
 555                 }
 556
 557                 //
 558                 // Completes types with the given `prefix' and stores the results in `result'
 559                 //
 560                 public void CompletionGetTypesStartingWith (string prefix, Dictionary<string, string> result)
 561                 {
 562                         int l = fullname.Length + 1;
 563                         var res = root.CompletionGetTypesStartingWith (fullname + "." + prefix);
 564
 565                         if (res == null)
 566                                 return;
 567
 568                         foreach (string match in res){
 569                                 string x = match.Substring (l);
 570
 571                                 // Turn reflection nested classes foo+bar into foo.bar
 572                                 x = x.Replace ('+', '.');
 573
 574                                 // Only get the first name element, no point in adding anything beyond the first dot.
 575                                 int p = x.IndexOf ('.');
 576                                 if (p != -1)
 577                                         x = x.Substring (0, p);
 578
 579                                 // Turn Foo`N into Foo<
 580                                 p = x.IndexOf ('`');
 581                                 if (p != -1)
 582                                         x = x.Substring (0, p) + "<";
 583
 584                                 if (!result.ContainsKey (x))
 585                                         result [x] = x;
 586                         }
 587                 }
 588
 589                 public void RegisterExternalExtensionMethodClass (Type type)
 590                 {
 591                         // Ignore, extension methods cannot be nested
 592                         if (type.DeclaringType != null)
 593                                 return;
 594
 595                         // TODO: CodeGen.Assembly.Builder is global
 596                         if (type.IsNotPublic && !TypeManager.IsThisOrFriendAssembly (CodeGen.Assembly.Builder, type.Assembly))
 597                                 return;
 598
 599                         if (external_exmethod_classes == null)
 600                                 external_exmethod_classes = new List<Type> ();
 601
 602                         external_exmethod_classes.Add (type);
 603                 }
 604
 605                 ///
 606                 /// Looks for extension method in this namespace
 607                 ///
 608                 public List<MethodSpec> LookupExtensionMethod (Type extensionType, ClassOrStruct currentClass, string name)
 609                 {
 610                         List<MethodSpec> found = null;
 611
 612                         // TODO: problematic
 613                         var invocation_assembly = CodeGen.Assembly.Builder;
 614
 615                         if (declspaces != null) {
 616                                 var e = declspaces.Values.GetEnumerator ();
 617                                 while (e.MoveNext ()) {
 618                                         Class c = e.Current as Class;
 619                                         if (c == null)
 620                                                 continue;
 621
 622                                         if ((c.ModFlags & Modifiers.METHOD_EXTENSION) == 0)
 623                                                 continue;
 624
 625                                         var res = c.MemberCache.FindExtensionMethods (invocation_assembly, extensionType, name, c != currentClass);
 626                                         if (res == null)
 627                                                 continue;
 628
 629                                         if (found == null)
 630                                                 found = res;
 631                                         else
 632                                                 found.AddRange (res);
 633                                 }
 634                         }
 635
 636                         if (external_exmethod_classes == null)
 637                                 return found;
 638
 639                         foreach (Type t in external_exmethod_classes) {
 640                                 MemberCache m = TypeHandle.GetMemberCache (t);
 641                                 var res = m.FindExtensionMethods (invocation_assembly, extensionType, name, true);
 642                                 if (res == null)
 643                                         continue;
 644
 645                                 if (found == null)
 646                                         found = res;
 647                                 else
 648                                         found.AddRange (res);
 649                         }
 650
 651                         return found;
 652                 }
 653
 654                 public void AddDeclSpace (string name, DeclSpace ds)
 655                 {
 656                         if (declspaces == null)
 657                                 declspaces = new Dictionary<string, DeclSpace> ();
 658                         declspaces.Add (name, ds);
 659                 }
 660
 661                 public void RemoveDeclSpace (string name)
 662                 {
 663                         declspaces.Remove (name);
 664                 }
 665
 666                 /// <summary>
 667                 ///   The qualified name of the current namespace
 668                 /// </summary>
 669                 public string Name {
 670                         get { return fullname; }
 671                 }
 672
 673                 /// <summary>
 674                 ///   The parent of this namespace, used by the parser to "Pop"
 675                 ///   the current namespace declaration
 676                 /// </summary>
 677                 public Namespace Parent {
 678                         get { return parent; }
 679                 }
 680         }
 681
 682         //
 683         // Namespace container as created by the parser
 684         //
 685         public class NamespaceEntry : IMemberContext {
 686
 687                 public class UsingEntry {
 688                         readonly MemberName name;
 689                         Namespace resolved;
 690
 691                         public UsingEntry (MemberName name)
 692                         {
 693                                 this.name = name;
 694                         }
 695
 696                         public string GetSignatureForError ()
 697                         {
 698                                 return name.GetSignatureForError ();
 699                         }
 700
 701                         public Location Location {
 702                                 get { return name.Location; }
 703                         }
 704
 705                         public MemberName MemberName {
 706                                 get { return name; }
 707                         }
 708
 709                         public string Name {
 710                                 get { return GetSignatureForError (); }
 711                         }
 712
 713                         public Namespace Resolve (IMemberContext rc)
 714                         {
 715                                 if (resolved != null)
 716                                         return resolved;
 717
 718                                 FullNamedExpression fne = name.GetTypeExpression ().ResolveAsTypeStep (rc, false);
 719                                 if (fne == null)
 720                                         return null;
 721
 722                                 resolved = fne as Namespace;
 723                                 if (resolved == null) {
 724                                         rc.Compiler.Report.SymbolRelatedToPreviousError (fne.Type);
 725                                         rc.Compiler.Report.Error (138, Location,
 726                                                 "`{0}' is a type not a namespace. A using namespace directive can only be applied to namespaces",
 727                                                 GetSignatureForError ());
 728                                 }
 729                                 return resolved;
 730                         }
 731
 732                         public override string ToString ()
 733                         {
 734                                 return Name;
 735                         }
 736                 }
 737
 738                 public class UsingAliasEntry {
 739                         public readonly string Alias;
 740                         public Location Location;
 741
 742                         public UsingAliasEntry (string alias, Location loc)
 743                         {
 744                                 this.Alias = alias;
 745                                 this.Location = loc;
 746                         }
 747
 748                         public virtual FullNamedExpression Resolve (IMemberContext rc)
 749                         {
 750                                 FullNamedExpression fne = GlobalRootNamespace.Instance.GetRootNamespace (Alias);
 751                                 if (fne == null) {
 752                                         rc.Compiler.Report.Error (430, Location,
 753                                                 "The extern alias `{0}' was not specified in -reference option",
 754                                                 Alias);
 755                                 }
 756
 757                                 return fne;
 758                         }
 759
 760                         public override string ToString ()
 761                         {
 762                                 return Alias;
 763                         }
 764
 765                 }
 766
 767                 class LocalUsingAliasEntry : UsingAliasEntry {
 768                         FullNamedExpression resolved;
 769                         MemberName value;
 770
 771                         public LocalUsingAliasEntry (string alias, MemberName name, Location loc)
 772                                 : base (alias, loc)
 773                         {
 774                                 this.value = name;
 775                         }
 776
 777                         public override FullNamedExpression Resolve (IMemberContext rc)
 778                         {
 779                                 if (resolved != null || value == null)
 780                                         return resolved;
 781
 782                                 if (rc == null)
 783                                         return null;
 784
 785                                 resolved = value.GetTypeExpression ().ResolveAsTypeStep (rc, false);
 786                                 if (resolved == null) {
 787                                         value = null;
 788                                         return null;
 789                                 }
 790
 791                                 if (resolved is TypeExpr)
 792                                         resolved = resolved.ResolveAsBaseTerminal (rc, false);
 793
 794                                 return resolved;
 795                         }
 796
 797                         public override string ToString ()
 798                         {
 799                                 return String.Format ("{0} = {1}", Alias, value.GetSignatureForError ());
 800                         }
 801                 }
 802
 803                 Namespace ns;
 804                 NamespaceEntry parent, implicit_parent;
 805                 CompilationUnit file;
 806                 int symfile_id;
 807
 808                 // Namespace using import block
 809                 List<UsingAliasEntry> using_aliases;
 810                 List<UsingEntry> using_clauses;
 811                 public bool DeclarationFound;
 812                 // End
 813
 814                 public readonly bool IsImplicit;
 815                 public readonly DeclSpace SlaveDeclSpace;
 816                 static readonly Namespace [] empty_namespaces = new Namespace [0];
 817                 Namespace [] namespace_using_table;
 818
 819                 static List<NamespaceEntry> entries = new List<NamespaceEntry> ();
 820
 821                 public static void Reset ()
 822                 {
 823                         entries = new List<NamespaceEntry> ();
 824                 }
 825
 826                 public NamespaceEntry (NamespaceEntry parent, CompilationUnit file, string name)
 827                 {
 828                         this.parent = parent;
 829                         this.file = file;
 830                         entries.Add (this);
 831
 832                         if (parent != null)
 833                                 ns = parent.NS.GetNamespace (name, true);
 834                         else if (name != null)
 835                                 ns = GlobalRootNamespace.Instance.GetNamespace (name, true);
 836                         else
 837                                 ns = GlobalRootNamespace.Instance;
 838                         SlaveDeclSpace = new RootDeclSpace (this);
 839                 }
 840
 841                 private NamespaceEntry (NamespaceEntry parent, CompilationUnit file, Namespace ns, bool slave)
 842                 {
 843                         this.parent = parent;
 844                         this.file = file;
 845                         this.IsImplicit = true;
 846                         this.ns = ns;
 847                         this.SlaveDeclSpace = slave ? new RootDeclSpace (this) : null;
 848                 }
 849
 850                 //
 851                 // Populates the Namespace with some using declarations, used by the
 852                 // eval mode.
 853                 //
 854                 public void Populate (List<UsingAliasEntry> source_using_aliases, List<UsingEntry> source_using_clauses)
 855                 {
 856                         foreach (UsingAliasEntry uae in source_using_aliases){
 857                                 if (using_aliases == null)
 858                                         using_aliases = new List<UsingAliasEntry> ();
 859
 860                                 using_aliases.Add (uae);
 861                         }
 862
 863                         foreach (UsingEntry ue in source_using_clauses){
 864                                 if (using_clauses == null)
 865                                         using_clauses = new List<UsingEntry> ();
 866
 867                                 using_clauses.Add (ue);
 868                         }
 869                 }
 870
 871                 //
 872                 // Extracts the using alises and using clauses into a couple of
 873                 // arrays that might already have the same information;  Used by the
 874                 // C# Eval mode.
 875                 //
 876                 public void Extract (List<UsingAliasEntry> out_using_aliases, List<UsingEntry> out_using_clauses)
 877                 {
 878                         if (using_aliases != null){
 879                                 foreach (UsingAliasEntry uae in using_aliases){
 880                                         bool replaced = false;
 881
 882                                         for (int i = 0; i < out_using_aliases.Count; i++){
 883                                                 UsingAliasEntry out_uea = (UsingAliasEntry) out_using_aliases [i];
 884
 885                                                 if (out_uea.Alias == uae.Alias){
 886                                                         out_using_aliases [i] = uae;
 887                                                         replaced = true;
 888                                                         break;
 889                                                 }
 890                                         }
 891                                         if (!replaced)
 892                                                 out_using_aliases.Add (uae);
 893                                 }
 894                         }
 895
 896                         if (using_clauses != null){
 897                                 foreach (UsingEntry ue in using_clauses){
 898                                         bool found = false;
 899
 900                                         foreach (UsingEntry out_ue in out_using_clauses)
 901                                                 if (out_ue.Name == ue.Name){
 902                                                         found = true;
 903                                                         break;
 904                                                 }
 905                                         if (!found)
 906                                                 out_using_clauses.Add (ue);
 907                                 }
 908                         }
 909                 }
 910
 911                 //
 912                 // According to section 16.3.1 (using-alias-directive), the namespace-or-type-name is
 913                 // resolved as if the immediately containing namespace body has no using-directives.
 914                 //
 915                 // Section 16.3.2 says that the same rule is applied when resolving the namespace-name
 916                 // in the using-namespace-directive.
 917                 //
 918                 // To implement these rules, the expressions in the using directives are resolved using
 919                 // the "doppelganger" (ghostly bodiless duplicate).
 920                 //
 921                 NamespaceEntry doppelganger;
 922                 NamespaceEntry Doppelganger {
 923                         get {
 924                                 if (!IsImplicit && doppelganger == null) {
 925                                         doppelganger = new NamespaceEntry (ImplicitParent, file, ns, true);
 926                                         doppelganger.using_aliases = using_aliases;
 927                                 }
 928                                 return doppelganger;
 929                         }
 930                 }
 931
 932                 public Namespace NS {
 933                         get { return ns; }
 934                 }
 935
 936                 public NamespaceEntry Parent {
 937                         get { return parent; }
 938                 }
 939
 940                 public NamespaceEntry ImplicitParent {
 941                         get {
 942                                 if (parent == null)
 943                                         return null;
 944                                 if (implicit_parent == null) {
 945                                         implicit_parent = (parent.NS == ns.Parent)
 946                                                 ? parent
 947                                                 : new NamespaceEntry (parent, file, ns.Parent, false);
 948                                 }
 949                                 return implicit_parent;
 950                         }
 951                 }
 952
 953                 /// <summary>
 954                 ///   Records a new namespace for resolving name references
 955                 /// </summary>
 956                 public void AddUsing (MemberName name, Location loc)
 957                 {
 958                         if (DeclarationFound){
 959                                 Compiler.Report.Error (1529, loc, "A using clause must precede all other namespace elements except extern alias declarations");
 960                         }
 961
 962                         if (using_clauses == null) {
 963                                 using_clauses = new List<UsingEntry> ();
 964                         } else {
 965                                 foreach (UsingEntry old_entry in using_clauses) {
 966                                         if (name.Equals (old_entry.MemberName)) {
 967                                                 Compiler.Report.SymbolRelatedToPreviousError (old_entry.Location, old_entry.GetSignatureForError ());
 968                                                 Compiler.Report.Warning (105, 3, loc, "The using directive for `{0}' appeared previously in this namespace", name.GetSignatureForError ());
 969                                                 return;
 970                                         }
 971                                 }
 972                         }
 973
 974                         using_clauses.Add (new UsingEntry (name));
 975                 }
 976
 977                 public void AddUsingAlias (string alias, MemberName name, Location loc)
 978                 {
 979                         // TODO: This is parser bussines
 980                         if (DeclarationFound){
 981                                 Compiler.Report.Error (1529, loc, "A using clause must precede all other namespace elements except extern alias declarations");
 982                         }
 983
 984                         if (RootContext.Version != LanguageVersion.ISO_1 && alias == "global")
 985                                 Compiler.Report.Warning (440, 2, loc, "An alias named `global' will not be used when resolving 'global::';" +
 986                                         " the global namespace will be used instead");
 987
 988                         AddUsingAlias (new LocalUsingAliasEntry (alias, name, loc));
 989                 }
 990
 991                 public void AddUsingExternalAlias (string alias, Location loc, Report Report)
 992                 {
 993                         // TODO: Do this in parser
 994                         bool not_first = using_clauses != null || DeclarationFound;
 995                         if (using_aliases != null && !not_first) {
 996                                 foreach (UsingAliasEntry uae in using_aliases) {
 997                                         if (uae is LocalUsingAliasEntry) {
 998                                                 not_first = true;
 999                                                 break;
1000                                         }
1001                                 }
1002                         }
1003
1004                         if (not_first)
1005                                 Report.Error (439, loc, "An extern alias declaration must precede all other elements");
1006
1007                         if (alias == "global") {
1008                                 Error_GlobalNamespaceRedefined (loc, Report);
1009                                 return;
1010                         }
1011
1012                         AddUsingAlias (new UsingAliasEntry (alias, loc));
1013                 }
1014
1015                 void AddUsingAlias (UsingAliasEntry uae)
1016                 {
1017                         if (using_aliases == null) {
1018                                 using_aliases = new List<UsingAliasEntry> ();
1019                         } else {
1020                                 foreach (UsingAliasEntry entry in using_aliases) {
1021                                         if (uae.Alias == entry.Alias) {
1022                                                 Compiler.Report.SymbolRelatedToPreviousError (uae.Location, uae.Alias);
1023                                                 Compiler.Report.Error (1537, entry.Location, "The using alias `{0}' appeared previously in this namespace",
1024                                                         entry.Alias);
1025                                                 return;
1026                                         }
1027                                 }
1028                         }
1029
1030                         using_aliases.Add (uae);
1031                 }
1032
1033                 ///
1034                 /// Does extension methods look up to find a method which matches name and extensionType.
1035                 /// Search starts from this namespace and continues hierarchically up to top level.
1036                 ///
1037                 public ExtensionMethodGroupExpr LookupExtensionMethod (Type extensionType, string name, Location loc)
1038                 {
1039                         List<MethodSpec> candidates = null;
1040                         foreach (Namespace n in GetUsingTable ()) {
1041                                 var a = n.LookupExtensionMethod (extensionType, null, name);
1042                                 if (a == null)
1043                                         continue;
1044
1045                                 if (candidates == null)
1046                                         candidates = a;
1047                                 else
1048                                         candidates.AddRange (a);
1049                         }
1050
1051                         if (candidates != null)
1052                                 return new ExtensionMethodGroupExpr (candidates, parent, extensionType, loc);
1053
1054                         if (parent == null)
1055                                 return null;
1056
1057                         //
1058                         // Inspect parent namespaces in namespace expression
1059                         //
1060                         Namespace parent_ns = ns.Parent;
1061                         do {
1062                                 candidates = parent_ns.LookupExtensionMethod (extensionType, null, name);
1063                                 if (candidates != null)
1064                                         return new ExtensionMethodGroupExpr (candidates, parent, extensionType, loc);
1065
1066                                 parent_ns = parent_ns.Parent;
1067                         } while (parent_ns != null);
1068
1069                         //
1070                         // Continue in parent scope
1071                         //
1072                         return parent.LookupExtensionMethod (extensionType, name, loc);
1073                 }
1074
1075                 public FullNamedExpression LookupNamespaceOrType (string name, Location loc, bool ignore_cs0104)
1076                 {
1077                         // Precondition: Only simple names (no dots) will be looked up with this function.
1078                         FullNamedExpression resolved = null;
1079                         for (NamespaceEntry curr_ns = this; curr_ns != null; curr_ns = curr_ns.ImplicitParent) {
1080                                 if ((resolved = curr_ns.Lookup (name, loc, ignore_cs0104)) != null)
1081                                         break;
1082                         }
1083                         return resolved;
1084                 }
1085
1086                 public ICollection<string> CompletionGetTypesStartingWith (string prefix)
1087                 {
1088                         var result = new Dictionary<string, string> ();
1089
1090                         for (NamespaceEntry curr_ns = this; curr_ns != null; curr_ns = curr_ns.ImplicitParent){
1091                                 foreach (Namespace using_ns in GetUsingTable ()){
1092                                         if (prefix.StartsWith (using_ns.Name)){
1093                                                 int ld = prefix.LastIndexOf ('.');
1094                                                 if (ld != -1){
1095                                                         string rest = prefix.Substring (ld+1);
1096
1097                                                         using_ns.CompletionGetTypesStartingWith (rest, result);
1098                                                 }
1099                                         }
1100                                         using_ns.CompletionGetTypesStartingWith (prefix, result);
1101                                 }
1102                         }
1103
1104                         return result.Keys;
1105                 }
1106
1107                 void Error_AmbiguousTypeReference (Location loc, string name, FullNamedExpression t1, FullNamedExpression t2)
1108                 {
1109                         Compiler.Report.SymbolRelatedToPreviousError (t1.Type);
1110                         Compiler.Report.SymbolRelatedToPreviousError (t2.Type);
1111                         Compiler.Report.Error (104, loc, "`{0}' is an ambiguous reference between `{1}' and `{2}'",
1112                                 name, t1.GetSignatureForError (), t2.GetSignatureForError ());
1113                 }
1114
1115                 // Looks-up a alias named @name in this and surrounding namespace declarations
1116                 public FullNamedExpression LookupNamespaceAlias (string name)
1117                 {
1118                         for (NamespaceEntry n = this; n != null; n = n.ImplicitParent) {
1119                                 if (n.using_aliases == null)
1120                                         continue;
1121
1122                                 foreach (UsingAliasEntry ue in n.using_aliases) {
1123                                         if (ue.Alias == name)
1124                                                 return ue.Resolve (Doppelganger);
1125                                 }
1126                         }
1127
1128                         return null;
1129                 }
1130
1131                 private FullNamedExpression Lookup (string name, Location loc, bool ignore_cs0104)
1132                 {
1133                         //
1134                         // Check whether it's in the namespace.
1135                         //
1136                         FullNamedExpression fne = ns.Lookup (Compiler, name, loc);
1137
1138                         //
1139                         // Check aliases.
1140                         //
1141                         if (using_aliases != null) {
1142                                 foreach (UsingAliasEntry ue in using_aliases) {
1143                                         if (ue.Alias == name) {
1144                                                 if (fne != null) {
1145                                                         if (Doppelganger != null) {
1146                                                                 // TODO: Namespace has broken location
1147                                                                 //Report.SymbolRelatedToPreviousError (fne.Location, null);
1148                                                                 Compiler.Report.SymbolRelatedToPreviousError (ue.Location, null);
1149                                                                 Compiler.Report.Error (576, loc,
1150                                                                         "Namespace `{0}' contains a definition with same name as alias `{1}'",
1151                                                                         GetSignatureForError (), name);
1152                                                         } else {
1153                                                                 return fne;
1154                                                         }
1155                                                 }
1156
1157                                                 return ue.Resolve (Doppelganger);
1158                                         }
1159                                 }
1160                         }
1161
1162                         if (fne != null)
1163                                 return fne;
1164
1165                         if (IsImplicit)
1166                                 return null;
1167
1168                         //
1169                         // Check using entries.
1170                         //
1171                         FullNamedExpression match = null;
1172                         foreach (Namespace using_ns in GetUsingTable ()) {
1173                                 match = using_ns.Lookup (Compiler, name, loc);
1174                                 if (match == null || !(match is TypeExpr))
1175                                         continue;
1176                                 if (fne != null) {
1177                                         if (!ignore_cs0104)
1178                                                 Error_AmbiguousTypeReference (loc, name, fne, match);
1179                                         return null;
1180                                 }
1181                                 fne = match;
1182                         }
1183
1184                         return fne;
1185                 }
1186
1187                 Namespace [] GetUsingTable ()
1188                 {
1189                         if (namespace_using_table != null)
1190                                 return namespace_using_table;
1191
1192                         if (using_clauses == null) {
1193                                 namespace_using_table = empty_namespaces;
1194                                 return namespace_using_table;
1195                         }
1196
1197                         var list = new List<Namespace> (using_clauses.Count);
1198
1199                         foreach (UsingEntry ue in using_clauses) {
1200                                 Namespace using_ns = ue.Resolve (Doppelganger);
1201                                 if (using_ns == null)
1202                                         continue;
1203
1204                                 list.Add (using_ns);
1205                         }
1206
1207                         namespace_using_table = list.ToArray ();
1208                         return namespace_using_table;
1209                 }
1210
1211                 static readonly string [] empty_using_list = new string [0];
1212
1213                 public int SymbolFileID {
1214                         get {
1215                                 if (symfile_id == 0 && file.SourceFileEntry != null) {
1216                                         int parent_id = parent == null ? 0 : parent.SymbolFileID;
1217
1218                                         string [] using_list = empty_using_list;
1219                                         if (using_clauses != null) {
1220                                                 using_list = new string [using_clauses.Count];
1221                                                 for (int i = 0; i < using_clauses.Count; i++)
1222                                                         using_list [i] = ((UsingEntry) using_clauses [i]).MemberName.GetName ();
1223                                         }
1224
1225                                         symfile_id = SymbolWriter.DefineNamespace (ns.Name, file.CompileUnitEntry, using_list, parent_id);
1226                                 }
1227                                 return symfile_id;
1228                         }
1229                 }
1230
1231                 static void MsgtryRef (string s)
1232                 {
1233                         Console.WriteLine ("    Try using -r:" + s);
1234                 }
1235
1236                 static void MsgtryPkg (string s)
1237                 {
1238                         Console.WriteLine ("    Try using -pkg:" + s);
1239                 }
1240
1241                 public static void Error_GlobalNamespaceRedefined (Location loc, Report Report)
1242                 {
1243                         Report.Error (1681, loc, "You cannot redefine the global extern alias");
1244                 }
1245
1246                 public static void Error_NamespaceNotFound (Location loc, string name, Report Report)
1247                 {
1248                         Report.Error (246, loc, "The type or namespace name `{0}' could not be found. Are you missing a using directive or an assembly reference?",
1249                                 name);
1250
1251                         switch (name) {
1252                         case "Gtk": case "GtkSharp":
1253                                 MsgtryPkg ("gtk-sharp");
1254                                 break;
1255
1256                         case "Gdk": case "GdkSharp":
1257                                 MsgtryPkg ("gdk-sharp");
1258                                 break;
1259
1260                         case "Glade": case "GladeSharp":
1261                                 MsgtryPkg ("glade-sharp");
1262                                 break;
1263
1264                         case "System.Drawing":
1265                         case "System.Web.Services":
1266                         case "System.Web":
1267                         case "System.Data":
1268                         case "System.Windows.Forms":
1269                                 MsgtryRef (name);
1270                                 break;
1271                         }
1272                 }
1273
1274                 /// <summary>
1275                 ///   Used to validate that all the using clauses are correct
1276                 ///   after we are finished parsing all the files.
1277                 /// </summary>
1278                 void VerifyUsing ()
1279                 {
1280                         if (using_aliases != null) {
1281                                 foreach (UsingAliasEntry ue in using_aliases)
1282                                         ue.Resolve (Doppelganger);
1283                         }
1284
1285                         if (using_clauses != null) {
1286                                 foreach (UsingEntry ue in using_clauses)
1287                                         ue.Resolve (Doppelganger);
1288                         }
1289                 }
1290
1291                 /// <summary>
1292                 ///   Used to validate that all the using clauses are correct
1293                 ///   after we are finished parsing all the files.
1294                 /// </summary>
1295                 static public void VerifyAllUsing ()
1296                 {
1297                         foreach (NamespaceEntry entry in entries)
1298                                 entry.VerifyUsing ();
1299                 }
1300
1301                 public string GetSignatureForError ()
1302                 {
1303                         return ns.GetSignatureForError ();
1304                 }
1305
1306                 public override string ToString ()
1307                 {
1308                         return ns.ToString ();
1309                 }
1310
1311                 #region IMemberContext Members
1312
1313                 public CompilerContext Compiler {
1314                         get { return RootContext.ToplevelTypes.Compiler; }
1315                 }
1316
1317                 public Type CurrentType {
1318                         get { return SlaveDeclSpace.CurrentType; }
1319                 }
1320
1321                 public TypeContainer CurrentTypeDefinition {
1322                         get { return SlaveDeclSpace.CurrentTypeDefinition; }
1323                 }
1324
1325                 public TypeParameter[] CurrentTypeParameters {
1326                         get { return SlaveDeclSpace.CurrentTypeParameters; }
1327                 }
1328
1329                 public bool IsObsolete {
1330                         get { return SlaveDeclSpace.IsObsolete; }
1331                 }
1332
1333                 public bool IsUnsafe {
1334                         get { return SlaveDeclSpace.IsUnsafe; }
1335                 }
1336
1337                 public bool IsStatic {
1338                         get { return SlaveDeclSpace.IsStatic; }
1339                 }
1340
1341                 #endregion
1342         }
1343 }