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 {
  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 Expression Alias;
 235                         public readonly NamespaceEntry NamespaceEntry;
 236                         public readonly Location Location;
 237
 238                         public AliasEntry (NamespaceEntry entry, string name, Expression 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                                 NamespaceEntry curr_ns = NamespaceEntry;
 254
 255                                 //
 256                                 // GENERICS: Cope with the expression and not with the string
 257                                 // this will fail with `using A = Stack<int>'
 258                                 //
 259
 260                                 string alias = Alias.ToString ();
 261                                 while ((curr_ns != null) && (resolved == null)) {
 262                                         resolved = curr_ns.Lookup (null, alias, 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                                         Report.Warning (105, loc, "The using directive for '" + ns +
 346                                                         "' appeared previously in this namespace");
 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 alias, Expression namespace_or_type, Location loc)
 356                 {
 357                         if (aliases == null)
 358                                 aliases = new Hashtable ();
 359
 360                         if (aliases.Contains (alias)){
 361                                 Report.Error (1537, loc, "The using alias `" + alias +
 362                                               "' appeared previously in this namespace");
 363                                 return;
 364                         }
 365
 366                         aliases [alias] = new AliasEntry (this, alias, namespace_or_type, loc);
 367                 }
 368
 369                 protected AliasEntry GetAliasEntry (string alias)
 370                 {
 371                         AliasEntry entry = null;
 372
 373                         if (aliases != null)
 374                                 entry = (AliasEntry) aliases [alias];
 375                         if (entry == null && Parent != null)
 376                                 entry = Parent.GetAliasEntry (alias);
 377
 378                         return entry;
 379                 }
 380
 381                 public string LookupAlias (string alias)
 382                 {
 383                         AliasEntry entry = GetAliasEntry (alias);
 384
 385                         if (entry == null)
 386                                 return null;
 387
 388                         object resolved = entry.Resolve ();
 389                         if (resolved == null)
 390                                 return null;
 391                         else if (resolved is Namespace)
 392                                 return ((Namespace) resolved).Name;
 393                         else
 394                                 return ((Type) resolved).FullName;
 395                 }
 396
 397                 public object Lookup (DeclSpace ds, string name, Location loc)
 398                 {
 399                         object o;
 400                         Namespace ns;
 401
 402                         //
 403                         // If name is of the form `N.I', first lookup `N', then search a member `I' in it.
 404                         //
 405                         int pos = name.IndexOf ('.');
 406                         if (pos >= 0) {
 407                                 string first = name.Substring (0, pos);
 408                                 string last = name.Substring (pos + 1);
 409
 410                                 o = Lookup (ds, first, loc);
 411                                 if (o == null)
 412                                         return null;
 413
 414                                 ns = o as Namespace;
 415                                 if (ns != null)
 416                                         return ns.Lookup (ds, last);
 417
 418                                 Type nested = TypeManager.LookupType ((((Type) o).Name + "." + last));
 419                                 if ((nested == null) || ((ds != null) && !ds.CheckAccessLevel (nested)))
 420                                         return null;
 421
 422                                 return nested;
 423                         }
 424
 425                         //
 426                         // Check whether it's a namespace.
 427                         //
 428                         o = NS.Lookup (ds, name);
 429                         if (o != null)
 430                                 return o;
 431
 432                         //
 433                         // Check aliases.
 434                         //
 435                         AliasEntry entry = GetAliasEntry (name);
 436                         if (entry != null) {
 437                                 o = entry.Resolve ();
 438                                 if (o != null)
 439                                         return o;
 440                         }
 441
 442                         //
 443                         // Check using entries.
 444                         //
 445                         Type t = null, match = null;
 446                         foreach (Namespace using_ns in GetUsingTable ()) {
 447                                 match = using_ns.Lookup (ds, name) as Type;
 448                                 if (match != null){
 449                                         if (t != null) {
 450                                                 DeclSpace.Error_AmbiguousTypeReference (loc, name, t, match);
 451                                                 return null;
 452                                         } else {
 453                                                 t = match;
 454                                         }
 455                                 }
 456                         }
 457
 458                         return t;
 459                 }
 460
 461                 // Our cached computation.
 462                 Namespace [] namespace_using_table;
 463                 public Namespace[] GetUsingTable ()
 464                 {
 465                         if (namespace_using_table != null)
 466                                 return namespace_using_table;
 467
 468                         if (using_clauses == null)
 469                                 return new Namespace [0];
 470
 471                         ArrayList list = new ArrayList (using_clauses.Count);
 472
 473                         foreach (UsingEntry ue in using_clauses) {
 474                                 Namespace using_ns = ue.Resolve ();
 475                                 if (using_ns == null)
 476                                         continue;
 477
 478                                 list.Add (using_ns);
 479                         }
 480
 481                         namespace_using_table = new Namespace [list.Count];
 482                         list.CopyTo (namespace_using_table, 0);
 483                         return namespace_using_table;
 484                 }
 485
 486                 public void DefineNamespace (SymbolWriter symwriter)
 487                 {
 488                         if (symfile_id != 0)
 489                                 return;
 490                         if (parent != null)
 491                                 parent.DefineNamespace (symwriter);
 492
 493                         string[] using_list;
 494                         if (using_clauses != null) {
 495                                 using_list = new string [using_clauses.Count];
 496                                 for (int i = 0; i < using_clauses.Count; i++)
 497                                         using_list [i] = ((UsingEntry) using_clauses [i]).Name;
 498                         } else {
 499                                 using_list = new string [0];
 500                         }
 501
 502                         int parent_id = parent != null ? parent.symfile_id : 0;
 503                         symfile_id = symwriter.DefineNamespace (ns.Name, file, using_list, parent_id);
 504                 }
 505
 506                 public int SymbolFileID {
 507                         get {
 508                                 return symfile_id;
 509                         }
 510                 }
 511
 512                 static void Msgtry (string s)
 513                 {
 514                         Console.WriteLine ("    Try using -r:" + s);
 515                 }
 516
 517                 protected void error246 (Location loc, string name)
 518                 {
 519                         if (TypeManager.LookupType (name) != null)
 520                                 Report.Error (138, loc, "The using keyword only lets you specify a namespace, " +
 521                                               "`" + name + "' is a class not a namespace.");
 522                         else {
 523                                 Report.Error (246, loc, "The namespace `" + name +
 524                                               "' can not be found (missing assembly reference?)");
 525
 526                                 switch (name){
 527                                 case "Gtk": case "GtkSharp":
 528                                         Msgtry ("gtk-sharp");
 529                                         break;
 530
 531                                 case "Gdk": case "GdkSharp":
 532                                         Msgtry ("gdk-sharp");
 533                                         break;
 534
 535                                 case "Glade": case "GladeSharp":
 536                                         Msgtry ("glade-sharp");
 537                                         break;
 538
 539                                 case "System.Drawing":
 540                                         Msgtry ("System.Drawing");
 541                                         break;
 542
 543                                 case "System.Web.Services":
 544                                         Msgtry ("System.Web.Services");
 545                                         break;
 546
 547                                 case "System.Web":
 548                                         Msgtry ("System.Web");
 549                                         break;
 550
 551                                 case "System.Data":
 552                                         Msgtry ("System.Data");
 553                                         break;
 554
 555                                 case "System.Windows.Forms":
 556                                         Msgtry ("System.Windows.Forms");
 557                                         break;
 558                                 }
 559                         }
 560                 }
 561
 562                 /// <summary>
 563                 ///   Used to validate that all the using clauses are correct
 564                 ///   after we are finished parsing all the files.
 565                 /// </summary>
 566                 public void VerifyUsing ()
 567                 {
 568                         if (using_clauses != null){
 569                                 foreach (UsingEntry ue in using_clauses){
 570                                         if (ue.Resolve () != null)
 571                                                 continue;
 572
 573                                         error246 (ue.Location, ue.Name);
 574                                 }
 575                         }
 576
 577                         if (aliases != null){
 578                                 foreach (DictionaryEntry de in aliases){
 579                                         AliasEntry alias = (AliasEntry) de.Value;
 580
 581                                         if (alias.Resolve () != null)
 582                                                 continue;
 583
 584                                         error246 (alias.Location, alias.Alias.ToString ());
 585                                 }
 586                         }
 587                 }
 588
 589                 public override string ToString ()
 590                 {
 591                         if (NS == Namespace.Root)
 592                                 return "NamespaceEntry (<root>)";
 593                         else
 594                                 return String.Format ("NamespaceEntry ({0},{1},{2})", FullName, IsImplicit, ID);
 595                 }
 596         }
 597 }