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 using System.Linq;
  15
  16 namespace Mono.CSharp {
  17
  18         public class RootNamespace : Namespace {
  19
  20                 protected readonly string alias_name;
  21                 protected Assembly [] referenced_assemblies;
  22
  23                 Dictionary<string, Namespace> all_namespaces;
  24
  25                 public RootNamespace (string alias_name)
  26                         : base (null, String.Empty)
  27                 {
  28                         this.alias_name = alias_name;
  29                         referenced_assemblies = new Assembly [0];
  30
  31                         all_namespaces = new Dictionary<string, Namespace> ();
  32                         all_namespaces.Add ("", this);
  33                 }
  34
  35                 public void AddAssemblyReference (Assembly a)
  36                 {
  37                         foreach (Assembly assembly in referenced_assemblies) {
  38                                 if (a == assembly)
  39                                         return;
  40                         }
  41
  42                         int top = referenced_assemblies.Length;
  43                         Assembly [] n = new Assembly [top + 1];
  44                         referenced_assemblies.CopyTo (n, 0);
  45                         n [top] = a;
  46                         referenced_assemblies = n;
  47                 }
  48
  49                 public virtual void ImportTypes (CompilerContext ctx)
  50                 {
  51                         foreach (Assembly a in referenced_assemblies) {
  52                                 try {
  53                                         ctx.MetaImporter.ImportAssembly (a, this);
  54                                 } catch (TypeLoadException e) {
  55                                         ctx.Report.Error (11, Location.Null, e.Message);
  56                                 } catch (System.IO.FileNotFoundException) {
  57                                         ctx.Report.Error (12, Location.Null, "An assembly `{0}' is used without being referenced",
  58                                                 a.FullName);
  59                                 }
  60                         }
  61                 }
  62
  63                 public void RegisterNamespace (Namespace child)
  64                 {
  65                         if (child != this)
  66                                 all_namespaces.Add (child.Name, child);
  67                 }
  68
  69                 public bool IsNamespace (string name)
  70                 {
  71                         return all_namespaces.ContainsKey (name);
  72                 }
  73
  74                 protected void RegisterNamespace (string dotted_name)
  75                 {
  76                         if (dotted_name != null && dotted_name.Length != 0 && ! IsNamespace (dotted_name))
  77                                 GetNamespace (dotted_name, true);
  78                 }
  79
  80                 public override string GetSignatureForError ()
  81                 {
  82                         return alias_name + "::";
  83                 }
  84         }
  85
  86         // TODO: It should go to AssemblyClass or AssemblySpec
  87         public class GlobalRootNamespace : RootNamespace {
  88                 Module [] modules;
  89                 Dictionary<string, RootNamespace> root_namespaces;
  90
  91                 public GlobalRootNamespace ()
  92                         : base ("global")
  93                 {
  94                         root_namespaces = new Dictionary<string, RootNamespace> ();
  95                         root_namespaces.Add (alias_name, this);
  96                 }
  97
  98                 public Assembly [] Assemblies {
  99                     get { return referenced_assemblies; }
 100                 }
 101
 102                 public Module [] Modules {
 103                         get { return modules; }
 104                 }
 105
 106                 public void AddModuleReference (Module m)
 107                 {
 108                         int top = modules != null ? modules.Length : 0;
 109                         Module [] n = new Module [top + 1];
 110                         if (modules != null)
 111                                 modules.CopyTo (n, 0);
 112                         n [top] = m;
 113                         modules = n;
 114
 115                         if (m == RootContext.ToplevelTypes.Builder)
 116                                 return;
 117
 118                         foreach (var t in m.GetTypes ())
 119                                 RegisterNamespace (t.Namespace);
 120                 }
 121
 122                 public void ComputeNamespaces (CompilerContext ctx)
 123                 {
 124                         foreach (RootNamespace rn in root_namespaces.Values) {
 125                                 rn.ImportTypes (ctx);
 126                         }
 127                 }
 128
 129                 public void DefineRootNamespace (string alias, Assembly assembly, CompilerContext ctx)
 130                 {
 131                         if (alias == alias_name) {
 132                                 NamespaceEntry.Error_GlobalNamespaceRedefined (Location.Null, ctx.Report);
 133                                 return;
 134                         }
 135
 136                         RootNamespace retval = GetRootNamespace (alias);
 137                         if (retval == null) {
 138                                 retval = new RootNamespace (alias);
 139                                 root_namespaces.Add (alias, retval);
 140                         }
 141
 142                         retval.AddAssemblyReference (assembly);
 143                 }
 144
 145                 public override void Error_NamespaceDoesNotExist (Location loc, string name, int arity, IMemberContext ctx)
 146                 {
 147                         ctx.Compiler.Report.Error (400, loc,
 148                                 "The type or namespace name `{0}' could not be found in the global namespace (are you missing an assembly reference?)",
 149                                 name);
 150                 }
 151
 152                 public RootNamespace GetRootNamespace (string name)
 153                 {
 154                         RootNamespace rn;
 155                         if (!root_namespaces.TryGetValue (name, out rn))
 156                                 return null;
 157
 158                         return rn;
 159                 }
 160
 161                 public override void ImportTypes (CompilerContext ctx)
 162                 {
 163                         base.ImportTypes (ctx);
 164
 165                         if (modules != null) {
 166                                 // 0 is this module
 167                                 for (int i = 1; i < modules.Length; ++i) {
 168                                         ctx.MetaImporter.ImportModule (modules[i], this);
 169                                 }
 170                         }
 171                 }
 172         }
 173
 174         /// <summary>
 175         ///   Keeps track of the namespaces defined in the C# code.
 176         ///
 177         ///   This is an Expression to allow it to be referenced in the
 178         ///   compiler parse/intermediate tree during name resolution.
 179         /// </summary>
 180         public class Namespace : FullNamedExpression {
 181
 182                 Namespace parent;
 183                 string fullname;
 184                 protected Dictionary<string, Namespace> namespaces;
 185                 protected Dictionary<string, IList<TypeSpec>> types;
 186                 Dictionary<string, TypeExpr> cached_types;
 187                 RootNamespace root;
 188                 bool cls_checked;
 189
 190                 public readonly MemberName MemberName;
 191
 192                 /// <summary>
 193                 ///   Constructor Takes the current namespace and the
 194                 ///   name.  This is bootstrapped with parent == null
 195                 ///   and name = ""
 196                 /// </summary>
 197                 public Namespace (Namespace parent, string name)
 198                 {
 199                         // Expression members.
 200                         this.eclass = ExprClass.Namespace;
 201                         this.Type = InternalType.FakeInternalType;
 202                         this.loc = Location.Null;
 203
 204                         this.parent = parent;
 205
 206                         if (parent != null)
 207                                 this.root = parent.root;
 208                         else
 209                                 this.root = this as RootNamespace;
 210
 211                         if (this.root == null)
 212                                 throw new InternalErrorException ("Root namespaces must be created using RootNamespace");
 213
 214                         string pname = parent != null ? parent.fullname : "";
 215
 216                         if (pname == "")
 217                                 fullname = name;
 218                         else
 219                                 fullname = parent.fullname + "." + name;
 220
 221                         if (fullname == null)
 222                                 throw new InternalErrorException ("Namespace has a null fullname");
 223
 224                         if (parent != null && parent.MemberName != MemberName.Null)
 225                                 MemberName = new MemberName (parent.MemberName, name);
 226                         else if (name.Length == 0)
 227                                 MemberName = MemberName.Null;
 228                         else
 229                                 MemberName = new MemberName (name);
 230
 231                         namespaces = new Dictionary<string, Namespace> ();
 232                         cached_types = new Dictionary<string, TypeExpr> ();
 233
 234                         root.RegisterNamespace (this);
 235                 }
 236
 237                 #region Properties
 238
 239                 /// <summary>
 240                 ///   The qualified name of the current namespace
 241                 /// </summary>
 242                 public string Name {
 243                         get { return fullname; }
 244                 }
 245
 246                 /// <summary>
 247                 ///   The parent of this namespace, used by the parser to "Pop"
 248                 ///   the current namespace declaration
 249                 /// </summary>
 250                 public Namespace Parent {
 251                         get { return parent; }
 252                 }
 253
 254                 #endregion
 255
 256                 protected override Expression DoResolve (ResolveContext ec)
 257                 {
 258                         return this;
 259                 }
 260
 261                 public virtual void Error_NamespaceDoesNotExist (Location loc, string name, int arity, IMemberContext ctx)
 262                 {
 263                         FullNamedExpression retval = Lookup (ctx.Compiler, name, -System.Math.Max (1, arity), loc);
 264                         if (retval != null) {
 265                                 Error_TypeArgumentsCannotBeUsed (ctx.Compiler.Report, loc, retval.Type, arity);
 266                                 return;
 267                         }
 268
 269                         Namespace ns;
 270                         if (arity > 0 && namespaces.TryGetValue (name, out ns)) {
 271                                 ns.Error_TypeArgumentsCannotBeUsed (ctx.Compiler.Report, loc, null, arity);
 272                                 return;
 273                         }
 274
 275                         ctx.Compiler.Report.Error (234, loc,
 276                                 "The type or namespace name `{0}' does not exist in the namespace `{1}'. Are you missing an assembly reference?",
 277                                 name, GetSignatureForError ());
 278                 }
 279
 280                 public override string GetSignatureForError ()
 281                 {
 282                         return fullname;
 283                 }
 284
 285                 public Namespace GetNamespace (string name, bool create)
 286                 {
 287                         int pos = name.IndexOf ('.');
 288
 289                         Namespace ns;
 290                         string first;
 291                         if (pos >= 0)
 292                                 first = name.Substring (0, pos);
 293                         else
 294                                 first = name;
 295
 296                         if (!namespaces.TryGetValue (first, out ns)) {
 297                                 if (!create)
 298                                         return null;
 299
 300                                 ns = new Namespace (this, first);
 301                                 namespaces.Add (first, ns);
 302                         }
 303
 304                         if (pos >= 0)
 305                                 ns = ns.GetNamespace (name.Substring (pos + 1), create);
 306
 307                         return ns;
 308                 }
 309
 310                 public TypeExpr LookupType (CompilerContext ctx, string name, int arity, bool silent, Location loc)
 311                 {
 312                         if (types == null)
 313                                 return null;
 314
 315                         TypeExpr te;
 316                         if (arity == 0 && cached_types.TryGetValue (name, out te))
 317                                 return te;
 318
 319                         IList<TypeSpec> found;
 320                         if (!types.TryGetValue (name, out found))
 321                                 return null;
 322
 323                         TypeSpec best = null;
 324                         foreach (var ts in found) {
 325                                 if (ts.Arity == arity) {
 326                                         if (best == null) {
 327                                                 best = ts;
 328                                                 continue;
 329                                         }
 330
 331                                         var pts = best as PredefinedTypeSpec;
 332                                         if (pts == null)
 333                                                 pts = ts as PredefinedTypeSpec;
 334
 335                                         if (pts != null) {
 336                                                 ctx.Report.SymbolRelatedToPreviousError (best);
 337                                                 ctx.Report.SymbolRelatedToPreviousError (ts);
 338
 339                                                 // TODO: This should use different warning number but we want to be csc compatible
 340                                                 ctx.Report.Warning (1685, 1, loc,
 341                                                         "The predefined type `{0}.{1}' is redefined in the source code. Ignoring the local type definition",
 342                                                         pts.Namespace, pts.Name);
 343                                                 best = pts;
 344                                                 continue;
 345                                         }
 346
 347                                         if (best.MemberDefinition.IsImported && ts.MemberDefinition.IsImported) {
 348                                                 ctx.Report.SymbolRelatedToPreviousError (best);
 349                                                 ctx.Report.SymbolRelatedToPreviousError (ts);
 350                                                 if (silent) {
 351                                                         ctx.Report.Warning (1685, 1, loc,
 352                                                                 "The predefined type `{0}' is defined in multiple assemblies. Using definition from `{1}'",
 353                                                                 ts.GetSignatureForError (), best.Assembly.GetName ().Name);
 354                                                 } else {
 355                                                         ctx.Report.Error (433, loc, "The imported type `{0}' is defined multiple times", ts.GetSignatureForError ());
 356                                                 }
 357
 358                                                 break;
 359                                         }
 360
 361                                         if (best.MemberDefinition.IsImported)
 362                                                 best = ts;
 363
 364                                         if ((best.Modifiers & Modifiers.INTERNAL) != 0 && !TypeManager.IsThisOrFriendAssembly (CodeGen.Assembly.Builder, best.MemberDefinition.Assembly))
 365                                                 continue;
 366
 367                                         if (silent)
 368                                                 continue;
 369
 370                                         if (ts.MemberDefinition.IsImported)
 371                                                 ctx.Report.SymbolRelatedToPreviousError (ts);
 372
 373                                         ctx.Report.Warning (436, 2, loc,
 374                                                 "The type `{0}' conflicts with the imported type of same name'. Ignoring the imported type definition",
 375                                                 best.GetSignatureForError ());
 376                                 }
 377
 378                                 //
 379                                 // Lookup for the best candidate with closest arity match
 380                                 //
 381                                 if (arity < 0) {
 382                                         if (best == null) {
 383                                                 best = ts;
 384                                         } else if (System.Math.Abs (ts.Arity + arity) < System.Math.Abs (best.Arity + arity)) {
 385                                                 best = ts;
 386                                         }
 387                                 }
 388                         }
 389
 390                         if (best == null)
 391                                 return null;
 392
 393                         if ((best.Modifiers & Modifiers.INTERNAL) != 0 && !TypeManager.IsThisOrFriendAssembly (CodeGen.Assembly.Builder, best.MemberDefinition.Assembly))
 394                                 return null;
 395
 396                         te = new TypeExpression (best, Location.Null);
 397
 398                         // TODO MemberCache: Cache more
 399                         if (arity == 0 && !silent)
 400                                 cached_types.Add (name, te);
 401
 402                         return te;
 403                 }
 404
 405                 TypeSpec LookupType (string name, int arity)
 406                 {
 407                         if (types == null)
 408                                 return null;
 409
 410                         IList<TypeSpec> found;
 411                         if (types.TryGetValue (name, out found)) {
 412                                 TypeSpec best = null;
 413
 414                                 foreach (var ts in found) {
 415                                         if (ts.Arity == arity)
 416                                                 return ts;
 417
 418                                         //
 419                                         // Lookup for the best candidate with closest arity match
 420                                         //
 421                                         if (arity < 0) {
 422                                                 if (best == null) {
 423                                                         best = ts;
 424                                                 } else if (System.Math.Abs (ts.Arity + arity) < System.Math.Abs (best.Arity + arity)) {
 425                                                         best = ts;
 426                                                 }
 427                                         }
 428                                 }
 429
 430                                 return best;
 431                         }
 432
 433                         return null;
 434                 }
 435
 436                 public FullNamedExpression Lookup (CompilerContext ctx, string name, int arity, Location loc)
 437                 {
 438                         if (arity == 0 && namespaces.ContainsKey (name))
 439                                 return namespaces [name];
 440
 441                         return LookupType (ctx, name, arity, false, loc);
 442                 }
 443
 444                 //
 445                 // Completes types with the given `prefix'
 446                 //
 447                 public IEnumerable<string> CompletionGetTypesStartingWith (string prefix)
 448                 {
 449                         if (types == null)
 450                                 return Enumerable.Empty<string> ();
 451
 452                         var res = from item in types
 453                                           where item.Key.StartsWith (prefix) && item.Value.Any (l => (l.Modifiers & Modifiers.PUBLIC) != 0)
 454                                           select item.Key;
 455
 456                         if (namespaces != null)
 457                                 res = res.Concat (from item in namespaces where item.Key.StartsWith (prefix) select item.Key);
 458
 459                         return res;
 460                 }
 461
 462                 ///
 463                 /// Looks for extension method in this namespace
 464                 ///
 465                 public List<MethodSpec> LookupExtensionMethod (TypeSpec extensionType, ClassOrStruct currentClass, string name, int arity)
 466                 {
 467                         if (types == null)
 468                                 return null;
 469
 470                         List<MethodSpec> found = null;
 471
 472                         var invocation_type = currentClass == null ? InternalType.FakeInternalType : currentClass.CurrentType;
 473
 474                         // TODO: Add per namespace flag when at least 1 type has extension
 475
 476                         foreach (var tgroup in types.Values) {
 477                                 foreach (var ts in tgroup) {
 478                                         if ((ts.Modifiers & Modifiers.METHOD_EXTENSION) == 0)
 479                                                 continue;
 480
 481                                         var res = ts.MemberCache.FindExtensionMethods (invocation_type, extensionType, name, arity);
 482                                         if (res == null)
 483                                                 continue;
 484
 485                                         if (found == null) {
 486                                                 found = res;
 487                                         } else {
 488                                                 found.AddRange (res);
 489                                         }
 490                                 }
 491                         }
 492
 493                         return found;
 494                 }
 495
 496                 public void AddType (TypeSpec ts)
 497                 {
 498                         if (types == null) {
 499                                 types = new Dictionary<string, IList<TypeSpec>> (64);
 500                         }
 501
 502                         var name = ts.Name;
 503                         IList<TypeSpec> existing;
 504                         if (types.TryGetValue (name, out existing)) {
 505                                 TypeSpec better_type;
 506                                 TypeSpec found;
 507                                 if (existing.Count == 1) {
 508                                         found = existing[0];
 509                                         if (ts.Arity == found.Arity) {
 510                                                 better_type = IsImportedTypeOverride (ts, found);
 511                                                 if (better_type == found)
 512                                                         return;
 513
 514                                                 if (better_type != null) {
 515                                                         existing [0] = better_type;
 516                                                         return;
 517                                                 }
 518                                         }
 519
 520                                         existing = new List<TypeSpec> ();
 521                                         existing.Add (found);
 522                                         types[name] = existing;
 523                                 } else {
 524                                         for (int i = 0; i < existing.Count; ++i) {
 525                                                 found = existing[i];
 526                                                 if (ts.Arity != found.Arity)
 527                                                         continue;
 528
 529                                                 better_type = IsImportedTypeOverride (ts, found);
 530                                                 if (better_type == found)
 531                                                         return;
 532
 533                                                 if (better_type != null) {
 534                                                         existing.RemoveAt (i);
 535                                                         --i;
 536                                                         continue;
 537                                                 }
 538                                         }
 539                                 }
 540
 541                                 existing.Add (ts);
 542                         } else {
 543                                 types.Add (name, new TypeSpec[] { ts });
 544                         }
 545                 }
 546
 547                 //
 548                 // We import any types but in the situation there are same types
 549                 // but one has better visibility (either public or internal with friend)
 550                 // the less visible type is removed from the namespace cache
 551                 //
 552                 public static TypeSpec IsImportedTypeOverride (TypeSpec ts, TypeSpec found)
 553                 {
 554                         var ts_accessible = (ts.Modifiers & Modifiers.PUBLIC) != 0 || TypeManager.IsThisOrFriendAssembly (CodeGen.Assembly.Builder, ts.MemberDefinition.Assembly);
 555                         var found_accessible = (found.Modifiers & Modifiers.PUBLIC) != 0 || TypeManager.IsThisOrFriendAssembly (CodeGen.Assembly.Builder, found.MemberDefinition.Assembly);
 556
 557                         if (ts_accessible && !found_accessible)
 558                                 return ts;
 559
 560                         // found is better always better for accessible or inaccessible ts
 561                         if (!ts_accessible)
 562                                 return found;
 563
 564                         return null;
 565                 }
 566
 567                 public void RemoveDeclSpace (string name)
 568                 {
 569                         types.Remove (name);
 570                 }
 571
 572                 public void ReplaceTypeWithPredefined (TypeSpec ts, PredefinedTypeSpec pts)
 573                 {
 574                         var found = types [ts.Name];
 575                         cached_types.Remove (ts.Name);
 576                         if (found.Count == 1) {
 577                                 types[ts.Name][0] = pts;
 578                         } else {
 579                                 throw new NotImplementedException ();
 580                         }
 581                 }
 582
 583                 public void VerifyClsCompliance ()
 584                 {
 585                         if (types == null || cls_checked)
 586                                 return;
 587
 588                         cls_checked = true;
 589
 590                         // TODO: This is quite ugly way to check for CLS compliance at namespace level
 591
 592                         var locase_types = new Dictionary<string, List<TypeSpec>> (StringComparer.OrdinalIgnoreCase);
 593                         foreach (var tgroup in types.Values) {
 594                                 foreach (var tm in tgroup) {
 595                                         if ((tm.Modifiers & Modifiers.PUBLIC) == 0 || !tm.IsCLSCompliant ())
 596                                                 continue;
 597
 598                                         List<TypeSpec> found;
 599                                         if (!locase_types.TryGetValue (tm.Name, out found)) {
 600                                                 found = new List<TypeSpec> ();
 601                                                 locase_types.Add (tm.Name, found);
 602                                         }
 603
 604                                         found.Add (tm);
 605                                 }
 606                         }
 607
 608                         foreach (var locase in locase_types.Values) {
 609                                 if (locase.Count < 2)
 610                                         continue;
 611
 612                                 bool all_same = true;
 613                                 foreach (var notcompliant in locase) {
 614                                         all_same = notcompliant.Name == locase[0].Name;
 615                                         if (!all_same)
 616                                                 break;
 617                                 }
 618
 619                                 if (all_same)
 620                                         continue;
 621
 622                                 TypeContainer compiled = null;
 623                                 foreach (var notcompliant in locase) {
 624                                         if (!notcompliant.MemberDefinition.IsImported) {
 625                                                 if (compiled != null)
 626                                                         compiled.Compiler.Report.SymbolRelatedToPreviousError (compiled);
 627
 628                                                 compiled = notcompliant.MemberDefinition as TypeContainer;
 629                                         } else {
 630                                                 compiled.Compiler.Report.SymbolRelatedToPreviousError (notcompliant);
 631                                         }
 632                                 }
 633
 634                                 compiled.Compiler.Report.Warning (3005, 1, compiled.Location,
 635                                         "Identifier `{0}' differing only in case is not CLS-compliant", compiled.GetSignatureForError ());
 636                         }
 637                 }
 638         }
 639
 640         //
 641         // Namespace container as created by the parser
 642         //
 643         public class NamespaceEntry : IMemberContext {
 644
 645                 public class UsingEntry {
 646                         readonly MemberName name;
 647                         Namespace resolved;
 648
 649                         public UsingEntry (MemberName name)
 650                         {
 651                                 this.name = name;
 652                         }
 653
 654                         public string GetSignatureForError ()
 655                         {
 656                                 return name.GetSignatureForError ();
 657                         }
 658
 659                         public Location Location {
 660                                 get { return name.Location; }
 661                         }
 662
 663                         public MemberName MemberName {
 664                                 get { return name; }
 665                         }
 666
 667                         public string Name {
 668                                 get { return GetSignatureForError (); }
 669                         }
 670
 671                         public Namespace Resolve (IMemberContext rc)
 672                         {
 673                                 if (resolved != null)
 674                                         return resolved;
 675
 676                                 FullNamedExpression fne = name.GetTypeExpression ().ResolveAsTypeStep (rc, false);
 677                                 if (fne == null)
 678                                         return null;
 679
 680                                 resolved = fne as Namespace;
 681                                 if (resolved == null) {
 682                                         rc.Compiler.Report.SymbolRelatedToPreviousError (fne.Type);
 683                                         rc.Compiler.Report.Error (138, Location,
 684                                                 "`{0}' is a type not a namespace. A using namespace directive can only be applied to namespaces",
 685                                                 GetSignatureForError ());
 686                                 }
 687                                 return resolved;
 688                         }
 689
 690                         public override string ToString ()
 691                         {
 692                                 return Name;
 693                         }
 694                 }
 695
 696                 public class UsingAliasEntry {
 697                         public readonly string Alias;
 698                         public Location Location;
 699
 700                         public UsingAliasEntry (string alias, Location loc)
 701                         {
 702                                 this.Alias = alias;
 703                                 this.Location = loc;
 704                         }
 705
 706                         public virtual FullNamedExpression Resolve (IMemberContext rc, bool local)
 707                         {
 708                                 FullNamedExpression fne = rc.Compiler.GlobalRootNamespace.GetRootNamespace (Alias);
 709                                 if (fne == null) {
 710                                         rc.Compiler.Report.Error (430, Location,
 711                                                 "The extern alias `{0}' was not specified in -reference option",
 712                                                 Alias);
 713                                 }
 714
 715                                 return fne;
 716                         }
 717
 718                         public override string ToString ()
 719                         {
 720                                 return Alias;
 721                         }
 722
 723                 }
 724
 725                 class LocalUsingAliasEntry : UsingAliasEntry {
 726                         FullNamedExpression resolved;
 727                         MemberName value;
 728
 729                         public LocalUsingAliasEntry (string alias, MemberName name, Location loc)
 730                                 : base (alias, loc)
 731                         {
 732                                 this.value = name;
 733                         }
 734
 735                         public override FullNamedExpression Resolve (IMemberContext rc, bool local)
 736                         {
 737                                 if (resolved != null || value == null)
 738                                         return resolved;
 739
 740                                 if (local)
 741                                         return null;
 742
 743                                 resolved = value.GetTypeExpression ().ResolveAsTypeStep (rc, false);
 744                                 if (resolved == null) {
 745                                         value = null;
 746                                         return null;
 747                                 }
 748
 749                                 if (resolved is TypeExpr)
 750                                         resolved = resolved.ResolveAsTypeTerminal (rc, false);
 751
 752                                 return resolved;
 753                         }
 754
 755                         public override string ToString ()
 756                         {
 757                                 return String.Format ("{0} = {1}", Alias, value.GetSignatureForError ());
 758                         }
 759                 }
 760
 761                 Namespace ns;
 762                 NamespaceEntry parent, implicit_parent;
 763                 CompilationUnit file;
 764                 int symfile_id;
 765
 766                 // Namespace using import block
 767                 List<UsingAliasEntry> using_aliases;
 768                 List<UsingEntry> using_clauses;
 769                 public bool DeclarationFound;
 770                 // End
 771
 772                 public readonly bool IsImplicit;
 773                 public readonly DeclSpace SlaveDeclSpace;
 774                 static readonly Namespace [] empty_namespaces = new Namespace [0];
 775                 Namespace [] namespace_using_table;
 776                 CompilerContext ctx;
 777
 778                 static List<NamespaceEntry> entries = new List<NamespaceEntry> ();
 779
 780                 public static void Reset ()
 781                 {
 782                         entries = new List<NamespaceEntry> ();
 783                 }
 784
 785                 // TODO: ctx should be a module
 786                 public NamespaceEntry (CompilerContext ctx, NamespaceEntry parent, CompilationUnit file, string name)
 787                 {
 788                         this.ctx = ctx;
 789                         this.parent = parent;
 790                         this.file = file;
 791                         entries.Add (this);
 792
 793                         if (parent != null)
 794                                 ns = parent.NS.GetNamespace (name, true);
 795                         else if (name != null)
 796                                 ns = Compiler.GlobalRootNamespace.GetNamespace (name, true);
 797                         else
 798                                 ns = Compiler.GlobalRootNamespace;
 799                         SlaveDeclSpace = new RootDeclSpace (this);
 800                 }
 801
 802                 private NamespaceEntry (CompilerContext ctx, NamespaceEntry parent, CompilationUnit file, Namespace ns, bool slave)
 803                 {
 804                         this.ctx = ctx;
 805                         this.parent = parent;
 806                         this.file = file;
 807                         this.IsImplicit = true;
 808                         this.ns = ns;
 809                         this.SlaveDeclSpace = slave ? new RootDeclSpace (this) : null;
 810                 }
 811
 812                 //
 813                 // Populates the Namespace with some using declarations, used by the
 814                 // eval mode.
 815                 //
 816                 public void Populate (List<UsingAliasEntry> source_using_aliases, List<UsingEntry> source_using_clauses)
 817                 {
 818                         foreach (UsingAliasEntry uae in source_using_aliases){
 819                                 if (using_aliases == null)
 820                                         using_aliases = new List<UsingAliasEntry> ();
 821
 822                                 using_aliases.Add (uae);
 823                         }
 824
 825                         foreach (UsingEntry ue in source_using_clauses){
 826                                 if (using_clauses == null)
 827                                         using_clauses = new List<UsingEntry> ();
 828
 829                                 using_clauses.Add (ue);
 830                         }
 831                 }
 832
 833                 //
 834                 // Extracts the using alises and using clauses into a couple of
 835                 // arrays that might already have the same information;  Used by the
 836                 // C# Eval mode.
 837                 //
 838                 public void Extract (List<UsingAliasEntry> out_using_aliases, List<UsingEntry> out_using_clauses)
 839                 {
 840                         if (using_aliases != null){
 841                                 foreach (UsingAliasEntry uae in using_aliases){
 842                                         bool replaced = false;
 843
 844                                         for (int i = 0; i < out_using_aliases.Count; i++){
 845                                                 UsingAliasEntry out_uea = (UsingAliasEntry) out_using_aliases [i];
 846
 847                                                 if (out_uea.Alias == uae.Alias){
 848                                                         out_using_aliases [i] = uae;
 849                                                         replaced = true;
 850                                                         break;
 851                                                 }
 852                                         }
 853                                         if (!replaced)
 854                                                 out_using_aliases.Add (uae);
 855                                 }
 856                         }
 857
 858                         if (using_clauses != null){
 859                                 foreach (UsingEntry ue in using_clauses){
 860                                         bool found = false;
 861
 862                                         foreach (UsingEntry out_ue in out_using_clauses)
 863                                                 if (out_ue.Name == ue.Name){
 864                                                         found = true;
 865                                                         break;
 866                                                 }
 867                                         if (!found)
 868                                                 out_using_clauses.Add (ue);
 869                                 }
 870                         }
 871                 }
 872
 873                 //
 874                 // According to section 16.3.1 (using-alias-directive), the namespace-or-type-name is
 875                 // resolved as if the immediately containing namespace body has no using-directives.
 876                 //
 877                 // Section 16.3.2 says that the same rule is applied when resolving the namespace-name
 878                 // in the using-namespace-directive.
 879                 //
 880                 // To implement these rules, the expressions in the using directives are resolved using
 881                 // the "doppelganger" (ghostly bodiless duplicate).
 882                 //
 883                 NamespaceEntry doppelganger;
 884                 NamespaceEntry Doppelganger {
 885                         get {
 886                                 if (!IsImplicit && doppelganger == null) {
 887                                         doppelganger = new NamespaceEntry (ctx, ImplicitParent, file, ns, true);
 888                                         doppelganger.using_aliases = using_aliases;
 889                                 }
 890                                 return doppelganger;
 891                         }
 892                 }
 893
 894                 public Namespace NS {
 895                         get { return ns; }
 896                 }
 897
 898                 public NamespaceEntry Parent {
 899                         get { return parent; }
 900                 }
 901
 902                 public NamespaceEntry ImplicitParent {
 903                         get {
 904                                 if (parent == null)
 905                                         return null;
 906                                 if (implicit_parent == null) {
 907                                         implicit_parent = (parent.NS == ns.Parent)
 908                                                 ? parent
 909                                                 : new NamespaceEntry (ctx, parent, file, ns.Parent, false);
 910                                 }
 911                                 return implicit_parent;
 912                         }
 913                 }
 914
 915                 /// <summary>
 916                 ///   Records a new namespace for resolving name references
 917                 /// </summary>
 918                 public void AddUsing (MemberName name, Location loc)
 919                 {
 920                         if (DeclarationFound){
 921                                 Compiler.Report.Error (1529, loc, "A using clause must precede all other namespace elements except extern alias declarations");
 922                         }
 923
 924                         if (using_clauses == null) {
 925                                 using_clauses = new List<UsingEntry> ();
 926                         } else {
 927                                 foreach (UsingEntry old_entry in using_clauses) {
 928                                         if (name.Equals (old_entry.MemberName)) {
 929                                                 Compiler.Report.SymbolRelatedToPreviousError (old_entry.Location, old_entry.GetSignatureForError ());
 930                                                 Compiler.Report.Warning (105, 3, loc, "The using directive for `{0}' appeared previously in this namespace", name.GetSignatureForError ());
 931                                                 return;
 932                                         }
 933                                 }
 934                         }
 935
 936                         using_clauses.Add (new UsingEntry (name));
 937                 }
 938
 939                 public void AddUsingAlias (string alias, MemberName name, Location loc)
 940                 {
 941                         // TODO: This is parser bussines
 942                         if (DeclarationFound){
 943                                 Compiler.Report.Error (1529, loc, "A using clause must precede all other namespace elements except extern alias declarations");
 944                         }
 945
 946                         if (RootContext.Version != LanguageVersion.ISO_1 && alias == "global")
 947                                 Compiler.Report.Warning (440, 2, loc, "An alias named `global' will not be used when resolving 'global::';" +
 948                                         " the global namespace will be used instead");
 949
 950                         AddUsingAlias (new LocalUsingAliasEntry (alias, name, loc));
 951                 }
 952
 953                 public void AddUsingExternalAlias (string alias, Location loc, Report Report)
 954                 {
 955                         // TODO: Do this in parser
 956                         bool not_first = using_clauses != null || DeclarationFound;
 957                         if (using_aliases != null && !not_first) {
 958                                 foreach (UsingAliasEntry uae in using_aliases) {
 959                                         if (uae is LocalUsingAliasEntry) {
 960                                                 not_first = true;
 961                                                 break;
 962                                         }
 963                                 }
 964                         }
 965
 966                         if (not_first)
 967                                 Report.Error (439, loc, "An extern alias declaration must precede all other elements");
 968
 969                         if (alias == "global") {
 970                                 Error_GlobalNamespaceRedefined (loc, Report);
 971                                 return;
 972                         }
 973
 974                         AddUsingAlias (new UsingAliasEntry (alias, loc));
 975                 }
 976
 977                 void AddUsingAlias (UsingAliasEntry uae)
 978                 {
 979                         if (using_aliases == null) {
 980                                 using_aliases = new List<UsingAliasEntry> ();
 981                         } else {
 982                                 foreach (UsingAliasEntry entry in using_aliases) {
 983                                         if (uae.Alias == entry.Alias) {
 984                                                 Compiler.Report.SymbolRelatedToPreviousError (uae.Location, uae.Alias);
 985                                                 Compiler.Report.Error (1537, entry.Location, "The using alias `{0}' appeared previously in this namespace",
 986                                                         entry.Alias);
 987                                                 return;
 988                                         }
 989                                 }
 990                         }
 991
 992                         using_aliases.Add (uae);
 993                 }
 994
 995                 ///
 996                 /// Does extension methods look up to find a method which matches name and extensionType.
 997                 /// Search starts from this namespace and continues hierarchically up to top level.
 998                 ///
 999                 public IList<MethodSpec> LookupExtensionMethod (TypeSpec extensionType, string name, int arity, ref NamespaceEntry scope)
1000                 {
1001                         List<MethodSpec> candidates = null;
1002                         foreach (Namespace n in GetUsingTable ()) {
1003                                 var a = n.LookupExtensionMethod (extensionType, null, name, arity);
1004                                 if (a == null)
1005                                         continue;
1006
1007                                 if (candidates == null)
1008                                         candidates = a;
1009                                 else
1010                                         candidates.AddRange (a);
1011                         }
1012
1013                         scope = parent;
1014                         if (candidates != null)
1015                                 return candidates;
1016
1017                         if (parent == null)
1018                                 return null;
1019
1020                         //
1021                         // Inspect parent namespaces in namespace expression
1022                         //
1023                         Namespace parent_ns = ns.Parent;
1024                         do {
1025                                 candidates = parent_ns.LookupExtensionMethod (extensionType, null, name, arity);
1026                                 if (candidates != null)
1027                                         return candidates;
1028
1029                                 parent_ns = parent_ns.Parent;
1030                         } while (parent_ns != null);
1031
1032                         //
1033                         // Continue in parent scope
1034                         //
1035                         return parent.LookupExtensionMethod (extensionType, name, arity, ref scope);
1036                 }
1037
1038                 public FullNamedExpression LookupNamespaceOrType (string name, int arity, Location loc, bool ignore_cs0104)
1039                 {
1040                         // Precondition: Only simple names (no dots) will be looked up with this function.
1041                         FullNamedExpression resolved = null;
1042                         for (NamespaceEntry curr_ns = this; curr_ns != null; curr_ns = curr_ns.ImplicitParent) {
1043                                 if ((resolved = curr_ns.Lookup (name, arity, loc, ignore_cs0104)) != null)
1044                                         break;
1045                         }
1046
1047                         return resolved;
1048                 }
1049
1050                 public IList<string> CompletionGetTypesStartingWith (string prefix)
1051                 {
1052                         IEnumerable<string> all = Enumerable.Empty<string> ();
1053
1054                         for (NamespaceEntry curr_ns = this; curr_ns != null; curr_ns = curr_ns.ImplicitParent){
1055                                 foreach (Namespace using_ns in GetUsingTable ()){
1056                                         if (prefix.StartsWith (using_ns.Name)){
1057                                                 int ld = prefix.LastIndexOf ('.');
1058                                                 if (ld != -1){
1059                                                         string rest = prefix.Substring (ld+1);
1060
1061                                                         all = all.Concat (using_ns.CompletionGetTypesStartingWith (rest));
1062                                                 }
1063                                         }
1064                                         all = all.Concat (using_ns.CompletionGetTypesStartingWith (prefix));
1065                                 }
1066                         }
1067
1068                         return all.Distinct ().ToList ();
1069                 }
1070
1071                 // Looks-up a alias named @name in this and surrounding namespace declarations
1072                 public FullNamedExpression LookupNamespaceAlias (string name)
1073                 {
1074                         for (NamespaceEntry n = this; n != null; n = n.ImplicitParent) {
1075                                 if (n.using_aliases == null)
1076                                         continue;
1077
1078                                 foreach (UsingAliasEntry ue in n.using_aliases) {
1079                                         if (ue.Alias == name)
1080                                                 return ue.Resolve (Doppelganger ?? this, Doppelganger == null);
1081                                 }
1082                         }
1083
1084                         return null;
1085                 }
1086
1087                 private FullNamedExpression Lookup (string name, int arity, Location loc, bool ignore_cs0104)
1088                 {
1089                         //
1090                         // Check whether it's in the namespace.
1091                         //
1092                         FullNamedExpression fne = ns.Lookup (Compiler, name, arity, loc);
1093
1094                         //
1095                         // Check aliases.
1096                         //
1097                         if (using_aliases != null && arity == 0) {
1098                                 foreach (UsingAliasEntry ue in using_aliases) {
1099                                         if (ue.Alias == name) {
1100                                                 if (fne != null) {
1101                                                         if (Doppelganger != null) {
1102                                                                 // TODO: Namespace has broken location
1103                                                                 //Report.SymbolRelatedToPreviousError (fne.Location, null);
1104                                                                 Compiler.Report.SymbolRelatedToPreviousError (ue.Location, null);
1105                                                                 Compiler.Report.Error (576, loc,
1106                                                                         "Namespace `{0}' contains a definition with same name as alias `{1}'",
1107                                                                         GetSignatureForError (), name);
1108                                                         } else {
1109                                                                 return fne;
1110                                                         }
1111                                                 }
1112
1113                                                 return ue.Resolve (Doppelganger ?? this, Doppelganger == null);
1114                                         }
1115                                 }
1116                         }
1117
1118                         if (fne != null) {
1119                                 if (!((fne.Type.Modifiers & Modifiers.INTERNAL) != 0 && !TypeManager.IsThisOrFriendAssembly (CodeGen.Assembly.Builder, fne.Type.Assembly)))
1120                                         return fne;
1121                         }
1122
1123                         if (IsImplicit)
1124                                 return null;
1125
1126                         //
1127                         // Check using entries.
1128                         //
1129                         FullNamedExpression match = null;
1130                         foreach (Namespace using_ns in GetUsingTable ()) {
1131                                 // A using directive imports only types contained in the namespace, it
1132                                 // does not import any nested namespaces
1133                                 fne = using_ns.LookupType (Compiler, name, arity, false, loc);
1134                                 if (fne == null)
1135                                         continue;
1136
1137                                 if (match == null) {
1138                                         match = fne;
1139                                         continue;
1140                                 }
1141
1142                                 // Prefer types over namespaces
1143                                 var texpr_fne = fne as TypeExpr;
1144                                 var texpr_match = match as TypeExpr;
1145                                 if (texpr_fne != null && texpr_match == null) {
1146                                         match = fne;
1147                                         continue;
1148                                 } else if (texpr_fne == null) {
1149                                         continue;
1150                                 }
1151
1152                                 if (ignore_cs0104)
1153                                         return match;
1154
1155                                 // It can be top level accessibility only
1156                                 var better = Namespace.IsImportedTypeOverride (texpr_match.Type, texpr_fne.Type);
1157                                 if (better == null) {
1158                                         Compiler.Report.SymbolRelatedToPreviousError (texpr_match.Type);
1159                                         Compiler.Report.SymbolRelatedToPreviousError (texpr_fne.Type);
1160                                         Compiler.Report.Error (104, loc, "`{0}' is an ambiguous reference between `{1}' and `{2}'",
1161                                                 name, texpr_match.GetSignatureForError (), texpr_fne.GetSignatureForError ());
1162                                         return match;
1163                                 }
1164
1165                                 if (better == texpr_fne.Type)
1166                                         match = texpr_fne;
1167                         }
1168
1169                         return match;
1170                 }
1171
1172                 Namespace [] GetUsingTable ()
1173                 {
1174                         if (namespace_using_table != null)
1175                                 return namespace_using_table;
1176
1177                         if (using_clauses == null) {
1178                                 namespace_using_table = empty_namespaces;
1179                                 return namespace_using_table;
1180                         }
1181
1182                         var list = new List<Namespace> (using_clauses.Count);
1183
1184                         foreach (UsingEntry ue in using_clauses) {
1185                                 Namespace using_ns = ue.Resolve (Doppelganger);
1186                                 if (using_ns == null)
1187                                         continue;
1188
1189                                 list.Add (using_ns);
1190                         }
1191
1192                         namespace_using_table = list.ToArray ();
1193                         return namespace_using_table;
1194                 }
1195
1196                 static readonly string [] empty_using_list = new string [0];
1197
1198                 public int SymbolFileID {
1199                         get {
1200                                 if (symfile_id == 0 && file.SourceFileEntry != null) {
1201                                         int parent_id = parent == null ? 0 : parent.SymbolFileID;
1202
1203                                         string [] using_list = empty_using_list;
1204                                         if (using_clauses != null) {
1205                                                 using_list = new string [using_clauses.Count];
1206                                                 for (int i = 0; i < using_clauses.Count; i++)
1207                                                         using_list [i] = ((UsingEntry) using_clauses [i]).MemberName.GetName ();
1208                                         }
1209
1210                                         symfile_id = SymbolWriter.DefineNamespace (ns.Name, file.CompileUnitEntry, using_list, parent_id);
1211                                 }
1212                                 return symfile_id;
1213                         }
1214                 }
1215
1216                 static void MsgtryRef (string s)
1217                 {
1218                         Console.WriteLine ("    Try using -r:" + s);
1219                 }
1220
1221                 static void MsgtryPkg (string s)
1222                 {
1223                         Console.WriteLine ("    Try using -pkg:" + s);
1224                 }
1225
1226                 public static void Error_GlobalNamespaceRedefined (Location loc, Report Report)
1227                 {
1228                         Report.Error (1681, loc, "You cannot redefine the global extern alias");
1229                 }
1230
1231                 public static void Error_NamespaceNotFound (Location loc, string name, Report Report)
1232                 {
1233                         Report.Error (246, loc, "The type or namespace name `{0}' could not be found. Are you missing a using directive or an assembly reference?",
1234                                 name);
1235
1236                         switch (name) {
1237                         case "Gtk": case "GtkSharp":
1238                                 MsgtryPkg ("gtk-sharp");
1239                                 break;
1240
1241                         case "Gdk": case "GdkSharp":
1242                                 MsgtryPkg ("gdk-sharp");
1243                                 break;
1244
1245                         case "Glade": case "GladeSharp":
1246                                 MsgtryPkg ("glade-sharp");
1247                                 break;
1248
1249                         case "System.Drawing":
1250                         case "System.Web.Services":
1251                         case "System.Web":
1252                         case "System.Data":
1253                         case "System.Windows.Forms":
1254                                 MsgtryRef (name);
1255                                 break;
1256                         }
1257                 }
1258
1259                 /// <summary>
1260                 ///   Used to validate that all the using clauses are correct
1261                 ///   after we are finished parsing all the files.
1262                 /// </summary>
1263                 void VerifyUsing ()
1264                 {
1265                         if (using_aliases != null) {
1266                                 foreach (UsingAliasEntry ue in using_aliases)
1267                                         ue.Resolve (Doppelganger, Doppelganger == null);
1268                         }
1269
1270                         if (using_clauses != null) {
1271                                 foreach (UsingEntry ue in using_clauses)
1272                                         ue.Resolve (Doppelganger);
1273                         }
1274                 }
1275
1276                 /// <summary>
1277                 ///   Used to validate that all the using clauses are correct
1278                 ///   after we are finished parsing all the files.
1279                 /// </summary>
1280                 static public void VerifyAllUsing ()
1281                 {
1282                         foreach (NamespaceEntry entry in entries)
1283                                 entry.VerifyUsing ();
1284                 }
1285
1286                 public string GetSignatureForError ()
1287                 {
1288                         return ns.GetSignatureForError ();
1289                 }
1290
1291                 public override string ToString ()
1292                 {
1293                         return ns.ToString ();
1294                 }
1295
1296                 #region IMemberContext Members
1297
1298                 public CompilerContext Compiler {
1299                         get { return ctx; }
1300                 }
1301
1302                 public TypeSpec CurrentType {
1303                         get { return SlaveDeclSpace.CurrentType; }
1304                 }
1305
1306                 public MemberCore CurrentMemberDefinition {
1307                         get { return SlaveDeclSpace.CurrentMemberDefinition; }
1308                 }
1309
1310                 public TypeParameter[] CurrentTypeParameters {
1311                         get { return SlaveDeclSpace.CurrentTypeParameters; }
1312                 }
1313
1314                 // FIXME: It's false for expression types
1315                 public bool HasUnresolvedConstraints {
1316                         get { return true; }
1317                 }
1318
1319                 public bool IsObsolete {
1320                         get { return SlaveDeclSpace.IsObsolete; }
1321                 }
1322
1323                 public bool IsUnsafe {
1324                         get { return SlaveDeclSpace.IsUnsafe; }
1325                 }
1326
1327                 public bool IsStatic {
1328                         get { return SlaveDeclSpace.IsStatic; }
1329                 }
1330
1331                 #endregion
1332         }
1333 }