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 {
  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 object Lookup (DeclSpace ds, string name)
  92                 {
  93                         object 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 t;
 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 t;
 113                 }
 114
 115                 public void AddNamespaceEntry (NamespaceEntry entry)
 116                 {
 117                         entries.Add (entry);
 118                 }
 119
 120                 public void DefineName (string name, object o)
 121                 {
 122                         defined_names.Add (name, o);
 123                 }
 124
 125                 public object Lookup (string name)
 126                 {
 127                         return 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
 184         public class NamespaceEntry
 185         {
 186                 Namespace ns;
 187                 NamespaceEntry parent, implicit_parent;
 188                 SourceFile file;
 189                 int symfile_id;
 190                 Hashtable aliases;
 191                 ArrayList using_clauses;
 192                 public bool DeclarationFound = false;
 193
 194                 //
 195                 // This class holds the location where a using definition is
 196                 // done, and whether it has been used by the program or not.
 197                 //
 198                 // We use this to flag using clauses for namespaces that do not
 199                 // exist.
 200                 //
 201                 public class UsingEntry {
 202                         public readonly string Name;
 203                         public readonly NamespaceEntry NamespaceEntry;
 204                         public readonly Location Location;
 205
 206                         public UsingEntry (NamespaceEntry entry, string name, Location loc)
 207                         {
 208                                 Name = name;
 209                                 NamespaceEntry = entry;
 210                                 Location = loc;
 211                         }
 212
 213                         Namespace resolved_ns;
 214
 215                         public Namespace Resolve ()
 216                         {
 217                                 if (resolved_ns != null)
 218                                         return resolved_ns;
 219
 220                                 Namespace curr_ns = NamespaceEntry.NS;
 221                                 while ((curr_ns != null) && (resolved_ns == null)) {
 222                                         resolved_ns = curr_ns.GetNamespace (Name, false);
 223
 224                                         if (resolved_ns == null)
 225                                                 curr_ns = curr_ns.Parent;
 226                                 }
 227
 228                                 return resolved_ns;
 229                         }
 230                 }
 231
 232                 public class AliasEntry {
 233                         public readonly string Name;
 234                         public readonly MemberName Alias;
 235                         public readonly NamespaceEntry NamespaceEntry;
 236                         public readonly Location Location;
 237
 238                         public AliasEntry (NamespaceEntry entry, string name, MemberName alias, Location loc)
 239                         {
 240                                 Name = name;
 241                                 Alias = alias;
 242                                 NamespaceEntry = entry;
 243                                 Location = loc;
 244                         }
 245
 246                         object resolved;
 247
 248                         public object Resolve ()
 249                         {
 250                                 if (resolved != null)
 251                                         return resolved;
 252
 253                                 string alias = Alias.GetPartialName ();
 254
 255                                 // According to section 16.3.1, the namespace-or-type-name is resolved
 256                                 // as if the immediately containing namespace body has no using-directives.
 257                                 resolved = NamespaceEntry.Lookup (null, alias, true, Location);
 258
 259                                 NamespaceEntry curr_ns = NamespaceEntry.Parent;
 260
 261                                 while ((curr_ns != null) && (resolved == null)) {
 262                                         resolved = curr_ns.Lookup (null, alias, false, Location);
 263
 264                                         if (resolved == null)
 265                                                 curr_ns = curr_ns.Parent;
 266                                 }
 267
 268                                 return resolved;
 269                         }
 270                 }
 271
 272                 public NamespaceEntry (NamespaceEntry parent, SourceFile file, string name, Location loc)
 273                         : this (parent, file, name, false, loc)
 274                 { }
 275
 276                 protected NamespaceEntry (NamespaceEntry parent, SourceFile file, string name, bool is_implicit, Location loc)
 277                 {
 278                         this.parent = parent;
 279                         this.file = file;
 280                         this.IsImplicit = is_implicit;
 281                         this.ID = ++next_id;
 282
 283                         if (!is_implicit && (parent != null))
 284                                 ns = parent.NS.GetNamespace (name, true);
 285                         else if (name != null)
 286                                 ns = Namespace.LookupNamespace (name, true);
 287                         else
 288                                 ns = Namespace.Root;
 289                         ns.AddNamespaceEntry (this);
 290
 291                         if ((parent != null) && (parent.NS != ns.Parent))
 292                                 implicit_parent = new NamespaceEntry (parent, file, ns.Parent.Name, true, loc);
 293                         else
 294                                 implicit_parent = parent;
 295
 296                         this.FullName = ns.Name;
 297                 }
 298
 299                 static int next_id = 0;
 300                 public readonly string FullName;
 301                 public readonly int ID;
 302                 public readonly bool IsImplicit;
 303
 304                 public Namespace NS {
 305                         get {
 306                                 return ns;
 307                         }
 308                 }
 309
 310                 public NamespaceEntry Parent {
 311                         get {
 312                                 return parent;
 313                         }
 314                 }
 315
 316                 public NamespaceEntry ImplicitParent {
 317                         get {
 318                                 return implicit_parent;
 319                         }
 320                 }
 321
 322                 public void DefineName (string name, object o)
 323                 {
 324                         ns.DefineName (name, o);
 325                 }
 326
 327                 /// <summary>
 328                 ///   Records a new namespace for resolving name references
 329                 /// </summary>
 330                 public void Using (string ns, Location loc)
 331                 {
 332                         if (DeclarationFound){
 333                                 Report.Error (1529, loc, "A using clause must precede all other namespace elements");
 334                                 return;
 335                         }
 336
 337                         if (ns == FullName)
 338                                 return;
 339
 340                         if (using_clauses == null)
 341                                 using_clauses = new ArrayList ();
 342
 343                         foreach (UsingEntry old_entry in using_clauses) {
 344                                 if (old_entry.Name == ns) {
 345                                         if (RootContext.WarningLevel >= 3)
 346                                                 Report.Warning (105, loc, "The using directive for '{0}' appeared previously in this namespace", ns);
 347                                         return;
 348                                 }
 349                         }
 350
 351                         UsingEntry ue = new UsingEntry (this, ns, loc);
 352                         using_clauses.Add (ue);
 353                 }
 354
 355                 public void UsingAlias (string name, MemberName alias, 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 (aliases == null)
 363                                 aliases = new Hashtable ();
 364
 365                         if (aliases.Contains (name)){
 366                                 Report.Error (1537, loc, "The using alias `" + name +
 367                                               "' appeared previously in this namespace");
 368                                 return;
 369                         }
 370
 371                         aliases [name] = new AliasEntry (this, name, alias, loc);
 372                 }
 373
 374                 protected AliasEntry GetAliasEntry (string alias)
 375                 {
 376                         AliasEntry entry = null;
 377
 378                         if (aliases != null)
 379                                 entry = (AliasEntry) aliases [alias];
 380                         if (entry == null && Parent != null)
 381                                 entry = Parent.GetAliasEntry (alias);
 382
 383                         return entry;
 384                 }
 385
 386                 public string LookupAlias (string alias)
 387                 {
 388                         AliasEntry entry = GetAliasEntry (alias);
 389
 390                         if (entry == null)
 391                                 return null;
 392
 393                         object resolved = entry.Resolve ();
 394                         if (resolved == null)
 395                                 return null;
 396                         else if (resolved is Namespace)
 397                                 return ((Namespace) resolved).Name;
 398                         else
 399                                 return ((Type) resolved).FullName;
 400                 }
 401
 402                 public object Lookup (DeclSpace ds, string name, bool ignore_using, Location loc)
 403                 {
 404                         object o;
 405                         Namespace ns;
 406
 407                         //
 408                         // If name is of the form `N.I', first lookup `N', then search a member `I' in it.
 409                         //
 410                         int pos = name.IndexOf ('.');
 411                         if (pos >= 0) {
 412                                 string first = name.Substring (0, pos);
 413                                 string last = name.Substring (pos + 1);
 414
 415                                 o = Lookup (ds, first, ignore_using, loc);
 416                                 if (o == null)
 417                                         return null;
 418
 419                                 ns = o as Namespace;
 420                                 if (ns != null)
 421                                         return ns.Lookup (ds, last);
 422
 423                                 Type nested = TypeManager.LookupType ((((Type) o).Name + "." + last));
 424                                 if ((nested == null) || ((ds != null) && !ds.CheckAccessLevel (nested)))
 425                                         return null;
 426
 427                                 return nested;
 428                         }
 429
 430                         //
 431                         // Check whether it's a namespace.
 432                         //
 433                         o = NS.Lookup (ds, name);
 434                         if (o != null)
 435                                 return o;
 436
 437                         if (ignore_using)
 438                                 return null;
 439
 440                         //
 441                         // Check aliases.
 442                         //
 443                         AliasEntry entry = GetAliasEntry (name);
 444                         if (entry != null) {
 445                                 o = entry.Resolve ();
 446                                 if (o != null)
 447                                         return o;
 448                         }
 449
 450                         if (name.IndexOf ('.') > 0)
 451                                 return null;
 452
 453                         //
 454                         // Check using entries.
 455                         //
 456                         Type t = null, match = null;
 457                         foreach (Namespace using_ns in GetUsingTable ()) {
 458                                 match = using_ns.Lookup (ds, name) as Type;
 459                                 if (match != null){
 460                                         if (t != null) {
 461                                                 DeclSpace.Error_AmbiguousTypeReference (loc, name, t, match);
 462                                                 return null;
 463                                         } else {
 464                                                 t = match;
 465                                         }
 466                                 }
 467                         }
 468
 469                         return t;
 470                 }
 471
 472                 // Our cached computation.
 473                 Namespace [] namespace_using_table;
 474                 public Namespace[] GetUsingTable ()
 475                 {
 476                         if (namespace_using_table != null)
 477                                 return namespace_using_table;
 478
 479                         if (using_clauses == null)
 480                                 return new Namespace [0];
 481
 482                         ArrayList list = new ArrayList (using_clauses.Count);
 483
 484                         foreach (UsingEntry ue in using_clauses) {
 485                                 Namespace using_ns = ue.Resolve ();
 486                                 if (using_ns == null)
 487                                         continue;
 488
 489                                 list.Add (using_ns);
 490                         }
 491
 492                         namespace_using_table = new Namespace [list.Count];
 493                         list.CopyTo (namespace_using_table, 0);
 494                         return namespace_using_table;
 495                 }
 496
 497                 public void DefineNamespace (SymbolWriter symwriter)
 498                 {
 499                         if (symfile_id != 0)
 500                                 return;
 501                         if (parent != null)
 502                                 parent.DefineNamespace (symwriter);
 503
 504                         string[] using_list;
 505                         if (using_clauses != null) {
 506                                 using_list = new string [using_clauses.Count];
 507                                 for (int i = 0; i < using_clauses.Count; i++)
 508                                         using_list [i] = ((UsingEntry) using_clauses [i]).Name;
 509                         } else {
 510                                 using_list = new string [0];
 511                         }
 512
 513                         int parent_id = parent != null ? parent.symfile_id : 0;
 514                         if (file.SourceFileEntry == null)
 515                                 return;
 516
 517                         symfile_id = symwriter.DefineNamespace (
 518                                 ns.Name, file.SourceFileEntry, using_list, parent_id);
 519                 }
 520
 521                 public int SymbolFileID {
 522                         get {
 523                                 return symfile_id;
 524                         }
 525                 }
 526
 527                 static void MsgtryRef (string s)
 528                 {
 529                         Console.WriteLine ("    Try using -r:" + s);
 530                 }
 531
 532                 static void MsgtryPkg (string s)
 533                 {
 534                         Console.WriteLine ("    Try using -pkg:" + s);
 535                 }
 536
 537                 protected void error246 (Location loc, string name)
 538                 {
 539                         if (TypeManager.LookupType (name) != null)
 540                                 Report.Error (138, loc, "The using keyword only lets you specify a namespace, " +
 541                                               "`" + name + "' is a class not a namespace.");
 542                         else {
 543                                 Report.Error (246, loc, "The namespace `" + name +
 544                                               "' can not be found (missing assembly reference?)");
 545
 546                                 switch (name){
 547                                 case "Gtk": case "GtkSharp":
 548                                         MsgtryPkg ("gtk-sharp");
 549                                         break;
 550
 551                                 case "Gdk": case "GdkSharp":
 552                                         MsgtryPkg ("gdk-sharp");
 553                                         break;
 554
 555                                 case "Glade": case "GladeSharp":
 556                                         MsgtryPkg ("glade-sharp");
 557                                         break;
 558
 559                                 case "System.Drawing":
 560                                         MsgtryRef ("System.Drawing");
 561                                         break;
 562
 563                                 case "System.Web.Services":
 564                                         MsgtryRef ("System.Web.Services");
 565                                         break;
 566
 567                                 case "System.Web":
 568                                         MsgtryRef ("System.Web");
 569                                         break;
 570
 571                                 case "System.Data":
 572                                         MsgtryRef ("System.Data");
 573                                         break;
 574
 575                                 case "System.Windows.Forms":
 576                                         MsgtryRef ("System.Windows.Forms");
 577                                         break;
 578                                 }
 579                         }
 580                 }
 581
 582                 /// <summary>
 583                 ///   Used to validate that all the using clauses are correct
 584                 ///   after we are finished parsing all the files.
 585                 /// </summary>
 586                 public void VerifyUsing ()
 587                 {
 588                         if (using_clauses != null){
 589                                 foreach (UsingEntry ue in using_clauses){
 590                                         if (ue.Resolve () != null)
 591                                                 continue;
 592
 593                                         error246 (ue.Location, ue.Name);
 594                                 }
 595                         }
 596
 597                         if (aliases != null){
 598                                 foreach (DictionaryEntry de in aliases){
 599                                         AliasEntry alias = (AliasEntry) de.Value;
 600
 601                                         if (alias.Resolve () != null)
 602                                                 continue;
 603
 604                                         error246 (alias.Location, alias.Alias.GetPartialName ());
 605                                 }
 606                         }
 607                 }
 608
 609                 public override string ToString ()
 610                 {
 611                         if (NS == Namespace.Root)
 612                                 return "NamespaceEntry (<root>)";
 613                         else
 614                                 return String.Format ("NamespaceEntry ({0},{1},{2})", FullName, IsImplicit, ID);
 615                 }
 616         }
 617 }