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