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                                 NamespaceEntry curr_ns = NamespaceEntry;
 264
 265                                 //
 266                                 // GENERICS: Cope with the expression and not with the string
 267                                 // this will fail with `using A = Stack<int>'
 268                                 //
 269
 270                                 string alias = Alias.GetTypeName ();
 271                                 while ((curr_ns != null) && (resolved == null)) {
 272                                         resolved = curr_ns.Lookup (
 273                                                 null, alias, Alias.CountTypeArguments,
 274                                                 false, Location);
 275
 276                                         if (resolved == null)
 277                                                 curr_ns = curr_ns.Parent;
 278                                 }
 279
 280                                 if (resolved == null)
 281                                         return null;
 282
 283                                 if (resolved.IsType)
 284                                         resolved = new TypeAliasExpression (
 285                                                 resolved.Type, Alias.TypeArguments, Location);
 286
 287                                 return resolved;
 288                         }
 289                 }
 290
 291                 public NamespaceEntry (NamespaceEntry parent, SourceFile file, string name, Location loc)
 292                         : this (parent, file, name, false, loc)
 293                 { }
 294
 295                 protected NamespaceEntry (NamespaceEntry parent, SourceFile file, string name, bool is_implicit, Location loc)
 296                 {
 297                         this.parent = parent;
 298                         this.file = file;
 299                         this.IsImplicit = is_implicit;
 300                         this.ID = ++next_id;
 301
 302                         if (!is_implicit && (parent != null))
 303                                 ns = parent.NS.GetNamespace (name, true);
 304                         else if (name != null)
 305                                 ns = Namespace.LookupNamespace (name, true);
 306                         else
 307                                 ns = Namespace.Root;
 308                         ns.AddNamespaceEntry (this);
 309
 310                         if ((parent != null) && (parent.NS != ns.Parent))
 311                                 implicit_parent = new NamespaceEntry (parent, file, ns.Parent.Name, true, loc);
 312                         else
 313                                 implicit_parent = parent;
 314
 315                         this.FullName = ns.Name;
 316                 }
 317
 318                 static int next_id = 0;
 319                 public readonly string FullName;
 320                 public readonly int ID;
 321                 public readonly bool IsImplicit;
 322
 323                 public Namespace NS {
 324                         get {
 325                                 return ns;
 326                         }
 327                 }
 328
 329                 public NamespaceEntry Parent {
 330                         get {
 331                                 return parent;
 332                         }
 333                 }
 334
 335                 public NamespaceEntry ImplicitParent {
 336                         get {
 337                                 return implicit_parent;
 338                         }
 339                 }
 340
 341                 public void DefineName (string name, IAlias o)
 342                 {
 343                         ns.DefineName (name, o);
 344                 }
 345
 346                 /// <summary>
 347                 ///   Records a new namespace for resolving name references
 348                 /// </summary>
 349                 public void Using (string ns, Location loc)
 350                 {
 351                         if (DeclarationFound){
 352                                 Report.Error (1529, loc, "A using clause must precede all other namespace elements");
 353                                 return;
 354                         }
 355
 356                         if (ns == FullName)
 357                                 return;
 358
 359                         if (using_clauses == null)
 360                                 using_clauses = new ArrayList ();
 361
 362                         foreach (UsingEntry old_entry in using_clauses){
 363                                 if (old_entry.Name == ns){
 364                                         Report.Warning (105, loc, "The using directive for '" + ns +
 365                                                         "' appeared previously in this namespace");
 366                                         return;
 367                                 }
 368                         }
 369
 370                         UsingEntry ue = new UsingEntry (this, ns, loc);
 371                         using_clauses.Add (ue);
 372                 }
 373
 374                 public void UsingAlias (string name, MemberName alias, Location loc)
 375                 {
 376                         if (DeclarationFound){
 377                                 Report.Error (1529, loc, "A using clause must precede all other namespace elements");
 378                                 return;
 379                         }
 380
 381                         if (aliases == null)
 382                                 aliases = new Hashtable ();
 383
 384                         if (aliases.Contains (name)){
 385                                 Report.Error (1537, loc, "The using alias `" + name +
 386                                               "' appeared previously in this namespace");
 387                                 return;
 388                         }
 389
 390                         aliases [name] = new AliasEntry (this, name, alias, loc);
 391                 }
 392
 393                 protected AliasEntry GetAliasEntry (string alias)
 394                 {
 395                         AliasEntry entry = null;
 396
 397                         if (aliases != null)
 398                                 entry = (AliasEntry) aliases [alias];
 399                         if (entry == null && Parent != null)
 400                                 entry = Parent.GetAliasEntry (alias);
 401
 402                         return entry;
 403                 }
 404
 405                 public IAlias LookupAlias (string alias)
 406                 {
 407                         AliasEntry entry = GetAliasEntry (alias);
 408
 409                         if (entry == null)
 410                                 return null;
 411
 412                         return entry.Resolve ();
 413                 }
 414
 415                 public IAlias Lookup (DeclSpace ds, string name, int num_type_params,
 416                                       bool silent, Location loc)
 417                 {
 418                         IAlias o;
 419                         Namespace ns;
 420
 421                         //
 422                         // If name is of the form `N.I', first lookup `N', then search a member `I' in it.
 423                         //
 424                         int pos = name.IndexOf ('.');
 425                         if (pos >= 0) {
 426                                 string first = name.Substring (0, pos);
 427                                 string last = name.Substring (pos + 1);
 428
 429                                 o = Lookup (ds, first, 0, silent, loc);
 430                                 if (o == null)
 431                                         return null;
 432
 433                                 ns = o as Namespace;
 434                                 if (ns != null) {
 435                                         o = ns.Lookup (ds, last, loc);
 436                                         return o;
 437                                 }
 438
 439                                 Type nested = TypeManager.LookupType (o.Name + "." + last);
 440                                 if ((nested == null) || ((ds != null) && !ds.CheckAccessLevel (nested)))
 441                                         return null;
 442
 443                                 return new TypeExpression (nested, loc);
 444                         }
 445
 446                         //
 447                         // Check whether it's a namespace.
 448                         //
 449                         o = NS.Lookup (ds, name, loc);
 450                         if (o != null)
 451                                 return o;
 452
 453                         //
 454                         // Check aliases.
 455                         //
 456                         AliasEntry entry = GetAliasEntry (name);
 457                         if (entry != null) {
 458                                 IAlias alias = entry.Resolve ();
 459                                 if (alias != null)
 460                                         return alias;
 461                         }
 462
 463                         if (name.IndexOf ('.') > 0)
 464                                 return null;
 465
 466                         //
 467                         // Check using entries.
 468                         //
 469                         IAlias t = null, match = null;
 470                         foreach (Namespace using_ns in GetUsingTable ()) {
 471                                 match = using_ns.Lookup (ds, name, loc);
 472                                 if ((match != null) && match.IsType){
 473                                         if (t != null) {
 474                                                 if (!silent)
 475                                                         DeclSpace.Error_AmbiguousTypeReference (loc, name, t.Name, match.Name);
 476                                                 return null;
 477                                         } else {
 478                                                 t = match;
 479                                         }
 480                                 }
 481                         }
 482
 483                         return t;
 484                 }
 485
 486                 // Our cached computation.
 487                 Namespace [] namespace_using_table;
 488                 public Namespace[] GetUsingTable ()
 489                 {
 490                         if (namespace_using_table != null)
 491                                 return namespace_using_table;
 492
 493                         if (using_clauses == null)
 494                                 return new Namespace [0];
 495
 496                         ArrayList list = new ArrayList (using_clauses.Count);
 497
 498                         foreach (UsingEntry ue in using_clauses) {
 499                                 Namespace using_ns = ue.Resolve ();
 500                                 if (using_ns == null)
 501                                         continue;
 502
 503                                 list.Add (using_ns);
 504                         }
 505
 506                         namespace_using_table = new Namespace [list.Count];
 507                         list.CopyTo (namespace_using_table, 0);
 508                         return namespace_using_table;
 509                 }
 510
 511                 public void DefineNamespace (SymbolWriter symwriter)
 512                 {
 513                         if (symfile_id != 0)
 514                                 return;
 515                         if (parent != null)
 516                                 parent.DefineNamespace (symwriter);
 517
 518                         string[] using_list;
 519                         if (using_clauses != null) {
 520                                 using_list = new string [using_clauses.Count];
 521                                 for (int i = 0; i < using_clauses.Count; i++)
 522                                         using_list [i] = ((UsingEntry) using_clauses [i]).Name;
 523                         } else {
 524                                 using_list = new string [0];
 525                         }
 526
 527                         int parent_id = parent != null ? parent.symfile_id : 0;
 528                         if (file.SourceFileEntry == null)
 529                                 return;
 530
 531                         symfile_id = symwriter.DefineNamespace (
 532                                 ns.Name, file.SourceFileEntry, using_list, parent_id);
 533                 }
 534
 535                 public int SymbolFileID {
 536                         get {
 537                                 return symfile_id;
 538                         }
 539                 }
 540
 541                 static void Msgtry (string s)
 542                 {
 543                         Console.WriteLine ("    Try using -r:" + s);
 544                 }
 545
 546                 protected void error246 (Location loc, string name)
 547                 {
 548                         if (TypeManager.LookupType (name) != null)
 549                                 Report.Error (138, loc, "The using keyword only lets you specify a namespace, " +
 550                                               "`" + name + "' is a class not a namespace.");
 551                         else {
 552                                 Report.Error (246, loc, "The namespace `" + name +
 553                                               "' can not be found (missing assembly reference?)");
 554
 555                                 switch (name){
 556                                 case "Gtk": case "GtkSharp":
 557                                         Msgtry ("gtk-sharp");
 558                                         break;
 559
 560                                 case "Gdk": case "GdkSharp":
 561                                         Msgtry ("gdk-sharp");
 562                                         break;
 563
 564                                 case "Glade": case "GladeSharp":
 565                                         Msgtry ("glade-sharp");
 566                                         break;
 567
 568                                 case "System.Drawing":
 569                                         Msgtry ("System.Drawing");
 570                                         break;
 571
 572                                 case "System.Web.Services":
 573                                         Msgtry ("System.Web.Services");
 574                                         break;
 575
 576                                 case "System.Web":
 577                                         Msgtry ("System.Web");
 578                                         break;
 579
 580                                 case "System.Data":
 581                                         Msgtry ("System.Data");
 582                                         break;
 583
 584                                 case "System.Windows.Forms":
 585                                         Msgtry ("System.Windows.Forms");
 586                                         break;
 587                                 }
 588                         }
 589                 }
 590
 591                 /// <summary>
 592                 ///   Used to validate that all the using clauses are correct
 593                 ///   after we are finished parsing all the files.
 594                 /// </summary>
 595                 public void VerifyUsing ()
 596                 {
 597                         TypeContainer dummy = new RootTypes ();
 598                         EmitContext ec = new EmitContext (
 599                                 dummy, Location.Null, null, null, 0, false);
 600
 601                         if (using_clauses != null){
 602                                 foreach (UsingEntry ue in using_clauses){
 603                                         if (ue.Resolve () != null)
 604                                                 continue;
 605
 606                                         error246 (ue.Location, ue.Name);
 607                                 }
 608                         }
 609
 610                         if (aliases != null){
 611                                 foreach (DictionaryEntry de in aliases){
 612                                         AliasEntry entry = (AliasEntry) de.Value;
 613
 614                                         IAlias alias = entry.Resolve ();
 615                                         if (alias != null) {
 616                                                 if (alias.IsType)
 617                                                         alias.Type.ResolveType (ec);
 618
 619                                                 continue;
 620                                         }
 621
 622                                         error246 (entry.Location, entry.Alias.ToString ());
 623                                 }
 624                         }
 625                 }
 626
 627                 public override string ToString ()
 628                 {
 629                         if (NS == Namespace.Root)
 630                                 return "NamespaceEntry (<root>)";
 631                         else
 632                                 return String.Format ("NamespaceEntry ({0},{1},{2})", FullName, IsImplicit, ID);
 633                 }
 634         }
 635 }