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