mcs/gmcs/namespace.cs

   1 //
   2 // namespace.cs: Tracks namespaces
   3 //
   4 // Author:
   5 //   Miguel de Icaza (miguel@ximian.com)
   6 //
   7 // (C) 2001 Ximian, Inc.
   8 //
   9 using System;
  10 using System.Collections;
  11
  12 namespace Mono.CSharp {
  13
  14         /// <summary>
  15         ///   Keeps track of the namespaces defined in the C# code.
  16         ///
  17         ///   This is an Expression to allow it to be referenced in the
  18         ///   compiler parse/intermediate tree during name resolution.
  19         /// </summary>
  20         public class Namespace : FullNamedExpression, IAlias {
  21                 static ArrayList all_namespaces = new ArrayList ();
  22                 static Hashtable namespaces_map = new Hashtable ();
  23
  24                 Namespace parent;
  25                 string fullname;
  26                 ArrayList entries;
  27                 Hashtable namespaces;
  28                 Hashtable defined_names;
  29
  30                 /// <summary>
  31                 ///   Constructor Takes the current namespace and the
  32                 ///   name.  This is bootstrapped with parent == null
  33                 ///   and name = ""
  34                 /// </summary>
  35                 public Namespace (Namespace parent, string name)
  36                 {
  37                         // Expression members.
  38                         this.eclass = ExprClass.Namespace;
  39                         this.Type = null;
  40                         this.loc = Location.Null;
  41
  42                         this.parent = parent;
  43
  44                         string pname = parent != null ? parent.Name : "";
  45
  46                         if (pname == "")
  47                                 fullname = name;
  48                         else
  49                                 fullname = parent.Name + "." + name;
  50
  51                         entries = new ArrayList ();
  52                         namespaces = new Hashtable ();
  53                         defined_names = new Hashtable ();
  54
  55                         all_namespaces.Add (this);
  56                         if (namespaces_map.Contains (fullname))
  57                                 return;
  58                         namespaces_map [fullname] = true;
  59                 }
  60
  61                 public override Expression DoResolve (EmitContext ec)
  62                 {
  63                         return this;
  64                 }
  65
  66                 public override void Emit (EmitContext ec)
  67                 {
  68                         throw new InternalErrorException ("Expression tree referenced namespace " + fullname + " during Emit ()");
  69                 }
  70
  71                 public static bool IsNamespace (string name)
  72                 {
  73                         return namespaces_map [name] != null;
  74                 }
  75
  76                 public static Namespace Root = new Namespace (null, "");
  77
  78                 public Namespace GetNamespace (string name, bool create)
  79                 {
  80                         int pos = name.IndexOf ('.');
  81
  82                         Namespace ns;
  83                         string first;
  84                         if (pos >= 0)
  85                                 first = name.Substring (0, pos);
  86                         else
  87                                 first = name;
  88
  89                         ns = (Namespace) namespaces [first];
  90                         if (ns == null) {
  91                                 if (!create)
  92                                         return null;
  93
  94                                 ns = new Namespace (this, first);
  95                                 namespaces.Add (first, ns);
  96                         }
  97
  98                         if (pos >= 0)
  99                                 ns = ns.GetNamespace (name.Substring (pos + 1), create);
 100
 101                         return ns;
 102                 }
 103
 104                 public static Namespace LookupNamespace (string name, bool create)
 105                 {
 106                         return Root.GetNamespace (name, create);
 107                 }
 108
 109                 public FullNamedExpression Lookup (DeclSpace ds, string name, Location loc)
 110                 {
 111                         IAlias o = (IAlias) defined_names [name];
 112
 113                         Type t;
 114                         DeclSpace tdecl = o as DeclSpace;
 115                         if (tdecl != null) {
 116                                 t = tdecl.DefineType ();
 117                                 if (t == null)
 118                                         return null;
 119
 120                                 if ((ds == null) || ds.CheckAccessLevel (t))
 121                                         return new TypeExpression (t, Location.Null);
 122                         }
 123
 124                         Namespace ns = GetNamespace (name, false);
 125                         if (ns != null)
 126                                 return ns;
 127
 128                         t = TypeManager.LookupType (DeclSpace.MakeFQN (fullname, name));
 129                         if ((t == null) || ((ds != null) && !ds.CheckAccessLevel (t)))
 130                                 return null;
 131
 132                         return new TypeExpression (t, Location.Null);
 133                 }
 134
 135                 public void AddNamespaceEntry (NamespaceEntry entry)
 136                 {
 137                         entries.Add (entry);
 138                 }
 139
 140                 public void DefineName (string name, IAlias o)
 141                 {
 142                         defined_names.Add (name, o);
 143                 }
 144
 145                 static public ArrayList UserDefinedNamespaces {
 146                         get {
 147                                 return all_namespaces;
 148                         }
 149                 }
 150
 151                 /// <summary>
 152                 ///   The qualified name of the current namespace
 153                 /// </summary>
 154                 public string Name {
 155                         get {
 156                                 return fullname;
 157                         }
 158                 }
 159
 160                 public override string FullName {
 161                         get {
 162                                 return fullname;
 163                         }
 164                 }
 165
 166                 /// <summary>
 167                 ///   The parent of this namespace, used by the parser to "Pop"
 168                 ///   the current namespace declaration
 169                 /// </summary>
 170                 public Namespace Parent {
 171                         get {
 172                                 return parent;
 173                         }
 174                 }
 175
 176                 public static void DefineNamespaces (SymbolWriter symwriter)
 177                 {
 178                         foreach (Namespace ns in all_namespaces) {
 179                                 foreach (NamespaceEntry entry in ns.entries)
 180                                         entry.DefineNamespace (symwriter);
 181                         }
 182                 }
 183
 184                 /// <summary>
 185                 ///   Used to validate that all the using clauses are correct
 186                 ///   after we are finished parsing all the files.
 187                 /// </summary>
 188                 public static void VerifyUsing ()
 189                 {
 190                         foreach (Namespace ns in all_namespaces) {
 191                                 foreach (NamespaceEntry entry in ns.entries)
 192                                         entry.VerifyUsing ();
 193                         }
 194                 }
 195
 196                 public override string ToString ()
 197                 {
 198                         if (this == Root)
 199                                 return "Namespace (<root>)";
 200                         else
 201                                 return String.Format ("Namespace ({0})", Name);
 202                 }
 203
 204                 bool IAlias.IsType {
 205                         get { return false; }
 206                 }
 207
 208                 TypeExpr IAlias.ResolveAsType (EmitContext ec)
 209                 {
 210                         throw new InvalidOperationException ();
 211                 }
 212         }
 213
 214         public class NamespaceEntry
 215         {
 216                 Namespace ns;
 217                 NamespaceEntry parent, implicit_parent;
 218                 SourceFile file;
 219                 int symfile_id;
 220                 Hashtable aliases;
 221                 ArrayList using_clauses;
 222                 public bool DeclarationFound = false;
 223
 224                 //
 225                 // This class holds the location where a using definition is
 226                 // done, and whether it has been used by the program or not.
 227                 //
 228                 // We use this to flag using clauses for namespaces that do not
 229                 // exist.
 230                 //
 231                 public class UsingEntry {
 232                         public readonly string Name;
 233                         public readonly NamespaceEntry NamespaceEntry;
 234                         public readonly Location Location;
 235
 236                         public UsingEntry (NamespaceEntry entry, string name, Location loc)
 237                         {
 238                                 Name = name;
 239                                 NamespaceEntry = entry;
 240                                 Location = loc;
 241                         }
 242
 243                         Namespace resolved_ns;
 244
 245                         public Namespace Resolve ()
 246                         {
 247                                 if (resolved_ns != null)
 248                                         return resolved_ns;
 249
 250                                 FullNamedExpression resolved = NamespaceEntry.LookupForUsing (Name, Location);
 251                                 resolved_ns = resolved as Namespace;
 252                                 return resolved_ns;
 253                         }
 254                 }
 255
 256                 public class AliasEntry {
 257                         public readonly string Name;
 258                         public readonly MemberName Alias;
 259                         public readonly NamespaceEntry NamespaceEntry;
 260                         public readonly Location Location;
 261
 262                         public AliasEntry (NamespaceEntry entry, string name, MemberName alias, Location loc)
 263                         {
 264                                 Name = name;
 265                                 Alias = alias;
 266                                 NamespaceEntry = entry;
 267                                 Location = loc;
 268                         }
 269
 270                         FullNamedExpression resolved;
 271
 272                         public FullNamedExpression Resolve ()
 273                         {
 274                                 if (resolved != null)
 275                                         return resolved;
 276
 277                                 //
 278                                 // GENERICS: Cope with the expression and not with the string
 279                                 // this will fail with `using A = Stack<int>'
 280                                 //
 281
 282                                 string alias = Alias.GetTypeName ();
 283
 284                                 resolved = NamespaceEntry.LookupForUsing (alias, Location);
 285                                 if (resolved == null)
 286                                         return null;
 287
 288                                 if (Alias.TypeArguments == null)
 289                                         return resolved;
 290
 291                                 EmitContext ec = RootContext.Tree.Types.EmitContext;
 292                                 resolved = new TypeAliasExpression (resolved, Alias.TypeArguments, Location);
 293                                 resolved = resolved.ResolveAsTypeStep (ec);
 294
 295                                 return resolved;
 296                         }
 297                 }
 298
 299                 public NamespaceEntry (NamespaceEntry parent, SourceFile file, string name, Location loc)
 300                         : this (parent, file, name, false, loc)
 301                 { }
 302
 303                 protected NamespaceEntry (NamespaceEntry parent, SourceFile file, string name, bool is_implicit, Location loc)
 304                 {
 305                         this.parent = parent;
 306                         this.file = file;
 307                         this.IsImplicit = is_implicit;
 308                         this.ID = ++next_id;
 309
 310                         if (!is_implicit && (parent != null))
 311                                 ns = parent.NS.GetNamespace (name, true);
 312                         else if (name != null)
 313                                 ns = Namespace.LookupNamespace (name, true);
 314                         else
 315                                 ns = Namespace.Root;
 316                         ns.AddNamespaceEntry (this);
 317
 318                         if ((parent != null) && (parent.NS != ns.Parent))
 319                                 implicit_parent = new NamespaceEntry (parent, file, ns.Parent.Name, true, loc);
 320                         else
 321                                 implicit_parent = parent;
 322
 323                         this.FullName = ns.Name;
 324                 }
 325
 326                 static int next_id = 0;
 327                 public readonly string FullName;
 328                 public readonly int ID;
 329                 public readonly bool IsImplicit;
 330
 331                 public Namespace NS {
 332                         get {
 333                                 return ns;
 334                         }
 335                 }
 336
 337                 public NamespaceEntry Parent {
 338                         get {
 339                                 return parent;
 340                         }
 341                 }
 342
 343                 public NamespaceEntry ImplicitParent {
 344                         get {
 345                                 return implicit_parent;
 346                         }
 347                 }
 348
 349                 public void DefineName (string name, IAlias o)
 350                 {
 351                         ns.DefineName (name, o);
 352                 }
 353
 354                 /// <summary>
 355                 ///   Records a new namespace for resolving name references
 356                 /// </summary>
 357                 public void Using (string ns, Location loc)
 358                 {
 359                         if (DeclarationFound){
 360                                 Report.Error (1529, loc, "A using clause must precede all other namespace elements");
 361                                 return;
 362                         }
 363
 364                         if (ns == FullName)
 365                                 return;
 366
 367                         if (using_clauses == null)
 368                                 using_clauses = new ArrayList ();
 369
 370                         foreach (UsingEntry old_entry in using_clauses) {
 371                                 if (old_entry.Name == ns) {
 372                                         if (RootContext.WarningLevel >= 3)
 373                                                 Report.Warning (105, loc, "The using directive for '{0}' appeared previously in this namespace", ns);
 374                                                 return;
 375                                         }
 376                                 }
 377
 378                         UsingEntry ue = new UsingEntry (this, ns, loc);
 379                         using_clauses.Add (ue);
 380                 }
 381
 382                 public void UsingAlias (string name, MemberName alias, Location loc)
 383                 {
 384                         if (DeclarationFound){
 385                                 Report.Error (1529, loc, "A using clause must precede all other namespace elements");
 386                                 return;
 387                         }
 388
 389                         if (aliases == null)
 390                                 aliases = new Hashtable ();
 391
 392                         if (aliases.Contains (name)){
 393                                 Report.Error (1537, loc, "The using alias `" + name +
 394                                               "' appeared previously in this namespace");
 395                                 return;
 396                         }
 397
 398                         aliases [name] = new AliasEntry (this, name, alias, loc);
 399                 }
 400
 401                 public FullNamedExpression LookupAlias (string alias)
 402                 {
 403                         AliasEntry entry = null;
 404                         if (aliases != null)
 405                                 entry = (AliasEntry) aliases [alias];
 406
 407                         return entry == null ? null : entry.Resolve ();
 408                 }
 409
 410                 //
 411                 // According to section 16.3.1 (using-alias-directive), the namespace-or-type-name is
 412                 // resolved as if the immediately containing namespace body has no using-directives.
 413                 //
 414                 // Section 16.3.2 says that the same rule is applied when resolving the namespace-name
 415                 // in the using-namespace-directive.
 416                 //
 417                 public FullNamedExpression LookupForUsing (string dotted_name, Location loc)
 418                 {
 419                         int pos = dotted_name.IndexOf ('.');
 420                         string simple_name = dotted_name;
 421                         string rest = null;
 422                         if (pos >= 0) {
 423                                 simple_name = dotted_name.Substring (0, pos);
 424                                 rest = dotted_name.Substring (pos + 1);
 425                         }
 426
 427                         FullNamedExpression o = NS.Lookup (null, simple_name, loc);
 428                         if (o == null && ImplicitParent != null)
 429                                 o = ImplicitParent.LookupNamespaceOrType (null, simple_name, loc);
 430
 431                         if (o == null || rest == null)
 432                                 return o;
 433
 434                         Namespace ns = o as Namespace;
 435                         if (ns != null)
 436                                 return ns.Lookup (null, rest, loc);
 437
 438                         Type nested = TypeManager.LookupType (o.FullName + "." + rest);
 439                         if (nested == null)
 440                                 return null;
 441
 442                         return new TypeExpression (nested, Location.Null);
 443                 }
 444
 445                 public FullNamedExpression LookupNamespaceOrType (DeclSpace ds, string name, Location loc)
 446                 {
 447                         FullNamedExpression resolved = null;
 448                         for (NamespaceEntry curr_ns = this; curr_ns != null; curr_ns = curr_ns.ImplicitParent) {
 449                                 if ((resolved = curr_ns.Lookup (ds, name, loc)) != null)
 450                                         break;
 451                         }
 452                         return resolved;
 453                 }
 454
 455                 private FullNamedExpression Lookup (DeclSpace ds, string name, Location loc)
 456                 {
 457                         FullNamedExpression o;
 458                         Namespace ns;
 459
 460                         //
 461                         // If name is of the form `N.I', first lookup `N', then search a member `I' in it.
 462                         //
 463                         // FIXME: Remove this block.  Only simple names should come here.
 464                         //        The bug: The loop in LookupNamespaceOrType continues if
 465                         //        the lookup for N succeeds but the nested lookup for I fails.
 466                         //        This is one part of #52697.
 467                         //
 468                         int pos = name.IndexOf ('.');
 469                         if (pos >= 0) {
 470                                 string first = name.Substring (0, pos);
 471                                 string last = name.Substring (pos + 1);
 472
 473                                 o = Lookup (ds, first, loc);
 474                                 if (o == null)
 475                                         return null;
 476
 477                                 ns = o as Namespace;
 478                                 if (ns != null) {
 479                                         o = ns.Lookup (ds, last, loc);
 480                                         return o;
 481                                 }
 482
 483                                 Type nested = TypeManager.LookupType (o.FullName + "." + last);
 484                                 if ((nested == null) || ((ds != null) && !ds.CheckAccessLevel (nested)))
 485                                         return null;
 486
 487                                 return new TypeExpression (nested, Location.Null);
 488                         }
 489
 490                         //
 491                         // Check whether it's in the namespace.
 492                         //
 493                         o = NS.Lookup (ds, name, loc);
 494                         if (o != null)
 495                                 return o;
 496
 497                         //
 498                         // Check aliases.
 499                         //
 500                         o = LookupAlias (name);
 501                         if (o != null)
 502                                 return o;
 503
 504                         if (name.IndexOf ('.') > 0)
 505                                 return null;
 506
 507                         //
 508                         // Check using entries.
 509                         //
 510                         FullNamedExpression t = null, match = null;
 511                         foreach (Namespace using_ns in GetUsingTable ()) {
 512                                 match = using_ns.Lookup (ds, name, loc);
 513                                 if ((match != null) && (match is TypeExpr)) {
 514                                         if (t != null) {
 515                                                 DeclSpace.Error_AmbiguousTypeReference (loc, name, t.FullName, match.FullName);
 516                                                 return null;
 517                                         } else {
 518                                                 t = match;
 519                                         }
 520                                 }
 521                         }
 522
 523                         return t;
 524                 }
 525
 526                 // Our cached computation.
 527                 Namespace [] namespace_using_table;
 528                 public Namespace[] GetUsingTable ()
 529                 {
 530                         if (namespace_using_table != null)
 531                                 return namespace_using_table;
 532
 533                         if (using_clauses == null) {
 534                                 namespace_using_table = new Namespace [0];
 535                                 return namespace_using_table;
 536                         }
 537
 538                         ArrayList list = new ArrayList (using_clauses.Count);
 539
 540                         foreach (UsingEntry ue in using_clauses) {
 541                                 Namespace using_ns = ue.Resolve ();
 542                                 if (using_ns == null)
 543                                         continue;
 544
 545                                 list.Add (using_ns);
 546                         }
 547
 548                         namespace_using_table = new Namespace [list.Count];
 549                         list.CopyTo (namespace_using_table, 0);
 550                         return namespace_using_table;
 551                 }
 552
 553                 public void DefineNamespace (SymbolWriter symwriter)
 554                 {
 555                         if (symfile_id != 0)
 556                                 return;
 557                         if (parent != null)
 558                                 parent.DefineNamespace (symwriter);
 559
 560                         string[] using_list;
 561                         if (using_clauses != null) {
 562                                 using_list = new string [using_clauses.Count];
 563                                 for (int i = 0; i < using_clauses.Count; i++)
 564                                         using_list [i] = ((UsingEntry) using_clauses [i]).Name;
 565                         } else {
 566                                 using_list = new string [0];
 567                         }
 568
 569                         int parent_id = parent != null ? parent.symfile_id : 0;
 570                         if (file.SourceFileEntry == null)
 571                                 return;
 572
 573                         symfile_id = symwriter.DefineNamespace (
 574                                 ns.Name, file.SourceFileEntry, using_list, parent_id);
 575                 }
 576
 577                 public int SymbolFileID {
 578                         get {
 579                                 return symfile_id;
 580                         }
 581                 }
 582
 583                 static void MsgtryRef (string s)
 584                 {
 585                         Console.WriteLine ("    Try using -r:" + s);
 586                 }
 587
 588                 static void MsgtryPkg (string s)
 589                 {
 590                         Console.WriteLine ("    Try using -pkg:" + s);
 591                 }
 592
 593                 protected void error246 (Location loc, string name)
 594                 {
 595                         Report.Error (246, loc, "The namespace `" + name +
 596                                       "' can not be found (missing assembly reference?)");
 597
 598                         switch (name) {
 599                         case "Gtk": case "GtkSharp":
 600                                 MsgtryPkg ("gtk-sharp");
 601                                 break;
 602
 603                         case "Gdk": case "GdkSharp":
 604                                 MsgtryPkg ("gdk-sharp");
 605                                 break;
 606
 607                         case "Glade": case "GladeSharp":
 608                                 MsgtryPkg ("glade-sharp");
 609                                 break;
 610
 611                         case "System.Drawing":
 612                         case "System.Web.Services":
 613                         case "System.Web":
 614                         case "System.Data":
 615                         case "System.Windows.Forms":
 616                                 MsgtryRef (name);
 617                                 break;
 618                         }
 619                 }
 620
 621                 /// <summary>
 622                 ///   Used to validate that all the using clauses are correct
 623                 ///   after we are finished parsing all the files.
 624                 /// </summary>
 625                 public void VerifyUsing ()
 626                 {
 627                         if (using_clauses != null){
 628                                 foreach (UsingEntry ue in using_clauses){
 629                                         if (ue.Resolve () != null)
 630                                                 continue;
 631
 632                                         if (LookupForUsing (ue.Name, ue.Location) == null)
 633                                                 error246 (ue.Location, ue.Name);
 634                                         else
 635                                                 Report.Error (138, ue.Location, "The using keyword only lets you specify a namespace, " +
 636                                                               "`" + ue.Name + "' is a class not a namespace.");
 637
 638                                 }
 639                         }
 640
 641                         if (aliases != null){
 642                                 foreach (DictionaryEntry de in aliases){
 643                                         AliasEntry alias = (AliasEntry) de.Value;
 644
 645                                         if (alias.Resolve () != null)
 646                                                 continue;
 647
 648                                         error246 (alias.Location, alias.Alias.GetTypeName ());
 649                                 }
 650                         }
 651                 }
 652
 653                 public override string ToString ()
 654                 {
 655                         if (NS == Namespace.Root)
 656                                 return "NamespaceEntry (<root>)";
 657                         else
 658                                 return String.Format ("NamespaceEntry ({0},{1},{2})", FullName, IsImplicit, ID);
 659                 }
 660         }
 661 }