mcs/mcs/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.ResolveAsType (EmitContext ec)
 188                 {
 189                         throw new InvalidOperationException ();
 190                 }
 191         }
 192
 193         public class NamespaceEntry
 194         {
 195                 Namespace ns;
 196                 NamespaceEntry parent, implicit_parent;
 197                 SourceFile file;
 198                 int symfile_id;
 199                 Hashtable aliases;
 200                 ArrayList using_clauses;
 201                 public bool DeclarationFound = false;
 202
 203                 //
 204                 // This class holds the location where a using definition is
 205                 // done, and whether it has been used by the program or not.
 206                 //
 207                 // We use this to flag using clauses for namespaces that do not
 208                 // exist.
 209                 //
 210                 public class UsingEntry {
 211                         public readonly string Name;
 212                         public readonly NamespaceEntry NamespaceEntry;
 213                         public readonly Location Location;
 214
 215                         public UsingEntry (NamespaceEntry entry, string name, Location loc)
 216                         {
 217                                 Name = name;
 218                                 NamespaceEntry = entry;
 219                                 Location = loc;
 220                         }
 221
 222                         Namespace resolved_ns;
 223
 224                         public Namespace Resolve ()
 225                         {
 226                                 if (resolved_ns != null)
 227                                         return resolved_ns;
 228
 229                                 object resolved = NamespaceEntry.LookupForUsing (Name, Location);
 230                                 resolved_ns = resolved as Namespace;
 231                                 return resolved_ns;
 232                         }
 233                 }
 234
 235                 public class AliasEntry {
 236                         public readonly string Name;
 237                         public readonly MemberName Alias;
 238                         public readonly NamespaceEntry NamespaceEntry;
 239                         public readonly Location Location;
 240
 241                         public AliasEntry (NamespaceEntry entry, string name, MemberName alias, Location loc)
 242                         {
 243                                 Name = name;
 244                                 Alias = alias;
 245                                 NamespaceEntry = entry;
 246                                 Location = loc;
 247                         }
 248
 249                         IAlias resolved;
 250
 251                         public IAlias Resolve ()
 252                         {
 253                                 if (resolved != null)
 254                                         return resolved;
 255
 256                                 string alias = Alias.GetPartialName ();
 257
 258                                 resolved = NamespaceEntry.LookupForUsing (alias, Location);
 259                                 return resolved;
 260                         }
 261                 }
 262
 263                 public NamespaceEntry (NamespaceEntry parent, SourceFile file, string name, Location loc)
 264                         : this (parent, file, name, false, loc)
 265                 { }
 266
 267                 protected NamespaceEntry (NamespaceEntry parent, SourceFile file, string name, bool is_implicit, Location loc)
 268                 {
 269                         this.parent = parent;
 270                         this.file = file;
 271                         this.IsImplicit = is_implicit;
 272                         this.ID = ++next_id;
 273
 274                         if (!is_implicit && (parent != null))
 275                                 ns = parent.NS.GetNamespace (name, true);
 276                         else if (name != null)
 277                                 ns = Namespace.LookupNamespace (name, true);
 278                         else
 279                                 ns = Namespace.Root;
 280                         ns.AddNamespaceEntry (this);
 281
 282                         if ((parent != null) && (parent.NS != ns.Parent))
 283                                 implicit_parent = new NamespaceEntry (parent, file, ns.Parent.Name, true, loc);
 284                         else
 285                                 implicit_parent = parent;
 286
 287                         this.FullName = ns.Name;
 288                 }
 289
 290                 static int next_id = 0;
 291                 public readonly string FullName;
 292                 public readonly int ID;
 293                 public readonly bool IsImplicit;
 294
 295                 public Namespace NS {
 296                         get {
 297                                 return ns;
 298                         }
 299                 }
 300
 301                 public NamespaceEntry Parent {
 302                         get {
 303                                 return parent;
 304                         }
 305                 }
 306
 307                 public NamespaceEntry ImplicitParent {
 308                         get {
 309                                 return implicit_parent;
 310                         }
 311                 }
 312
 313                 public void DefineName (string name, IAlias o)
 314                 {
 315                         ns.DefineName (name, o);
 316                 }
 317
 318                 /// <summary>
 319                 ///   Records a new namespace for resolving name references
 320                 /// </summary>
 321                 public void Using (string ns, Location loc)
 322                 {
 323                         if (DeclarationFound){
 324                                 Report.Error (1529, loc, "A using clause must precede all other namespace elements");
 325                                 return;
 326                         }
 327
 328                         if (ns == FullName)
 329                                 return;
 330
 331                         if (using_clauses == null)
 332                                 using_clauses = new ArrayList ();
 333
 334                         foreach (UsingEntry old_entry in using_clauses) {
 335                                 if (old_entry.Name == ns) {
 336                                         if (RootContext.WarningLevel >= 3)
 337                                                 Report.Warning (105, loc, "The using directive for '{0}' appeared previously in this namespace", ns);
 338                                         return;
 339                                 }
 340                         }
 341
 342                         UsingEntry ue = new UsingEntry (this, ns, loc);
 343                         using_clauses.Add (ue);
 344                 }
 345
 346                 public void UsingAlias (string name, MemberName alias, Location loc)
 347                 {
 348                         if (DeclarationFound){
 349                                 Report.Error (1529, loc, "A using clause must precede all other namespace elements");
 350                                 return;
 351                         }
 352
 353                         if (aliases == null)
 354                                 aliases = new Hashtable ();
 355
 356                         if (aliases.Contains (name)){
 357                                 Report.Error (1537, loc, "The using alias `" + name +
 358                                               "' appeared previously in this namespace");
 359                                 return;
 360                         }
 361
 362                         aliases [name] = new AliasEntry (this, name, alias, loc);
 363                 }
 364
 365                 protected AliasEntry GetAliasEntry (string alias)
 366                 {
 367                         AliasEntry entry = null;
 368
 369                         if (aliases != null)
 370                                 entry = (AliasEntry) aliases [alias];
 371                         if (entry == null && Parent != null)
 372                                 entry = Parent.GetAliasEntry (alias);
 373
 374                         return entry;
 375                 }
 376
 377                 public IAlias LookupAlias (string alias)
 378                 {
 379                         AliasEntry entry = GetAliasEntry (alias);
 380
 381                         if (entry == null)
 382                                 return null;
 383
 384                         return entry.Resolve ();
 385                 }
 386
 387                 //
 388                 // According to section 16.3.1 (using-alias-directive), the namespace-or-type-name is
 389                 // resolved as if the immediately containing namespace body has no using-directives.
 390                 //
 391                 // Section 16.3.2 says that the same rule is applied when resolving the namespace-name
 392                 // in the using-namespace-directive.
 393                 //
 394                 public IAlias LookupForUsing (string dotted_name, Location loc)
 395                 {
 396                         int pos = dotted_name.IndexOf ('.');
 397                         string simple_name = dotted_name;
 398                         string rest = null;
 399                         if (pos >= 0) {
 400                                 simple_name = dotted_name.Substring (0, pos);
 401                                 rest = dotted_name.Substring (pos + 1);
 402                         }
 403
 404                         IAlias o = NS.Lookup (null, simple_name, loc);
 405                         if (o == null && ImplicitParent != null)
 406                                 o = ImplicitParent.LookupNamespaceOrType (null, simple_name, loc);
 407
 408                         if (o == null || rest == null)
 409                                 return o;
 410
 411                         Namespace ns = o as Namespace;
 412                         if (ns != null)
 413                                 return ns.Lookup (null, rest, loc);
 414
 415                         Type nested = TypeManager.LookupType (o.Name + "." + rest);
 416                         if (nested == null)
 417                                 return null;
 418
 419                         return new TypeExpression (nested, loc);
 420                 }
 421
 422                 public IAlias LookupNamespaceOrType (DeclSpace ds, string name, Location loc)
 423                 {
 424                         IAlias resolved = null;
 425                         for (NamespaceEntry curr_ns = this; curr_ns != null; curr_ns = curr_ns.ImplicitParent) {
 426                                 if ((resolved = curr_ns.Lookup (ds, name, loc)) != null)
 427                                         break;
 428                         }
 429                         return resolved;
 430                 }
 431
 432                 private IAlias Lookup (DeclSpace ds, string name, Location loc)
 433                 {
 434                         IAlias o;
 435                         Namespace ns;
 436
 437                         //
 438                         // If name is of the form `N.I', first lookup `N', then search a member `I' in it.
 439                         //
 440                         // FIXME: Remove this block.  Only simple names should come here.
 441                         //        The bug: The loop in LookupNamespaceOrType continues if
 442                         //        the lookup for N succeeds but the nested lookup for I fails.
 443                         //        This is one part of #52697.
 444                         //
 445                         int pos = name.IndexOf ('.');
 446                         if (pos >= 0) {
 447                                 string first = name.Substring (0, pos);
 448                                 string last = name.Substring (pos + 1);
 449
 450                                 o = Lookup (ds, first, loc);
 451                                 if (o == null)
 452                                         return null;
 453
 454                                 ns = o as Namespace;
 455                                 if (ns != null)
 456                                         return ns.Lookup (ds, last, loc);
 457
 458                                 Type nested = TypeManager.LookupType (o.Name + "." + last);
 459                                 if ((nested == null) || ((ds != null) && !ds.CheckAccessLevel (nested)))
 460                                         return null;
 461
 462                                 return new TypeExpression (nested, loc);
 463                         }
 464
 465                         //
 466                         // Check whether it's in the namespace.
 467                         //
 468                         o = NS.Lookup (ds, name, loc);
 469                         if (o != null)
 470                                 return o;
 471
 472                         //
 473                         // Check aliases.
 474                         //
 475                         AliasEntry entry = GetAliasEntry (name);
 476                         if (entry != null) {
 477                                 o = entry.Resolve ();
 478                                 if (o != null)
 479                                         return o;
 480                         }
 481
 482                         if (name.IndexOf ('.') > 0)
 483                                 return null;
 484
 485                         //
 486                         // Check using entries.
 487                         //
 488                         IAlias t = null, match = null;
 489                         foreach (Namespace using_ns in GetUsingTable ()) {
 490                                 match = using_ns.Lookup (ds, name, loc);
 491                                 if ((match != null) && match.IsType){
 492                                         if (t != null) {
 493                                                 DeclSpace.Error_AmbiguousTypeReference (loc, name, t.Name, match.Name);
 494                                                 return null;
 495                                         } else {
 496                                                 t = match;
 497                                         }
 498                                 }
 499                         }
 500
 501                         return t;
 502                 }
 503
 504                 // Our cached computation.
 505                 Namespace [] namespace_using_table;
 506                 public Namespace[] GetUsingTable ()
 507                 {
 508                         if (namespace_using_table != null)
 509                                 return namespace_using_table;
 510
 511                         if (using_clauses == null)
 512                                 return new Namespace [0];
 513
 514                         ArrayList list = new ArrayList (using_clauses.Count);
 515
 516                         foreach (UsingEntry ue in using_clauses) {
 517                                 Namespace using_ns = ue.Resolve ();
 518                                 if (using_ns == null)
 519                                         continue;
 520
 521                                 list.Add (using_ns);
 522                         }
 523
 524                         namespace_using_table = new Namespace [list.Count];
 525                         list.CopyTo (namespace_using_table, 0);
 526                         return namespace_using_table;
 527                 }
 528
 529                 public void DefineNamespace (SymbolWriter symwriter)
 530                 {
 531                         if (symfile_id != 0)
 532                                 return;
 533                         if (parent != null)
 534                                 parent.DefineNamespace (symwriter);
 535
 536                         string[] using_list;
 537                         if (using_clauses != null) {
 538                                 using_list = new string [using_clauses.Count];
 539                                 for (int i = 0; i < using_clauses.Count; i++)
 540                                         using_list [i] = ((UsingEntry) using_clauses [i]).Name;
 541                         } else {
 542                                 using_list = new string [0];
 543                         }
 544
 545                         int parent_id = parent != null ? parent.symfile_id : 0;
 546                         if (file.SourceFileEntry == null)
 547                                 return;
 548
 549                         symfile_id = symwriter.DefineNamespace (
 550                                 ns.Name, file.SourceFileEntry, using_list, parent_id);
 551                 }
 552
 553                 public int SymbolFileID {
 554                         get {
 555                                 return symfile_id;
 556                         }
 557                 }
 558
 559                 static void MsgtryRef (string s)
 560                 {
 561                         Console.WriteLine ("    Try using -r:" + s);
 562                 }
 563
 564                 static void MsgtryPkg (string s)
 565                 {
 566                         Console.WriteLine ("    Try using -pkg:" + s);
 567                 }
 568
 569                 protected void error246 (Location loc, string name)
 570                 {
 571                         Report.Error (246, loc, "The namespace `" + name +
 572                                       "' can not be found (missing assembly reference?)");
 573
 574                         switch (name) {
 575                         case "Gtk": case "GtkSharp":
 576                                 MsgtryPkg ("gtk-sharp");
 577                                 break;
 578
 579                         case "Gdk": case "GdkSharp":
 580                                 MsgtryPkg ("gdk-sharp");
 581                                 break;
 582
 583                         case "Glade": case "GladeSharp":
 584                                 MsgtryPkg ("glade-sharp");
 585                                 break;
 586
 587                         case "System.Drawing":
 588                         case "System.Web.Services":
 589                         case "System.Web":
 590                         case "System.Data":
 591                         case "System.Windows.Forms":
 592                                 MsgtryRef (name);
 593                                 break;
 594                         }
 595                 }
 596
 597                 /// <summary>
 598                 ///   Used to validate that all the using clauses are correct
 599                 ///   after we are finished parsing all the files.
 600                 /// </summary>
 601                 public void VerifyUsing ()
 602                 {
 603                         if (using_clauses != null){
 604                                 foreach (UsingEntry ue in using_clauses){
 605                                         if (ue.Resolve () != null)
 606                                                 continue;
 607
 608                                         if (LookupForUsing (ue.Name, ue.Location) == null)
 609                                                 error246 (ue.Location, ue.Name);
 610                                         else
 611                                                 Report.Error (138, ue.Location, "The using keyword only lets you specify a namespace, " +
 612                                                               "`" + ue.Name + "' is a class not a namespace.");
 613
 614                                 }
 615                         }
 616
 617                         if (aliases != null){
 618                                 foreach (DictionaryEntry de in aliases){
 619                                         AliasEntry alias = (AliasEntry) de.Value;
 620
 621                                         if (alias.Resolve () != null)
 622                                                 continue;
 623
 624                                         error246 (alias.Location, alias.Alias.GetPartialName ());
 625                                 }
 626                         }
 627                 }
 628
 629                 public override string ToString ()
 630                 {
 631                         if (NS == Namespace.Root)
 632                                 return "NamespaceEntry (<root>)";
 633                         else
 634                                 return String.Format ("NamespaceEntry ({0},{1},{2})", FullName, IsImplicit, ID);
 635                 }
 636         }
 637 }