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 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                                 string alias = Alias.ToString ();
 256                                 while ((curr_ns != null) && (resolved == null)) {
 257                                         resolved = curr_ns.Lookup (null, alias, false, Location);
 258
 259                                         if (resolved == null)
 260                                                 curr_ns = curr_ns.Parent;
 261                                 }
 262
 263                                 return resolved;
 264                         }
 265                 }
 266
 267                 public NamespaceEntry (NamespaceEntry parent, SourceFile file, string name, Location loc)
 268                         : this (parent, file, name, false, loc)
 269                 { }
 270
 271                 protected NamespaceEntry (NamespaceEntry parent, SourceFile file, string name, bool is_implicit, Location loc)
 272                 {
 273                         this.parent = parent;
 274                         this.file = file;
 275                         this.IsImplicit = is_implicit;
 276                         this.ID = ++next_id;
 277
 278                         if (!is_implicit && (parent != null))
 279                                 ns = parent.NS.GetNamespace (name, true);
 280                         else if (name != null)
 281                                 ns = Namespace.LookupNamespace (name, true);
 282                         else
 283                                 ns = Namespace.Root;
 284                         ns.AddNamespaceEntry (this);
 285
 286                         if ((parent != null) && (parent.NS != ns.Parent))
 287                                 implicit_parent = new NamespaceEntry (parent, file, ns.Parent.Name, true, loc);
 288                         else
 289                                 implicit_parent = parent;
 290
 291                         this.FullName = ns.Name;
 292                 }
 293
 294                 static int next_id = 0;
 295                 public readonly string FullName;
 296                 public readonly int ID;
 297                 public readonly bool IsImplicit;
 298
 299                 public Namespace NS {
 300                         get {
 301                                 return ns;
 302                         }
 303                 }
 304
 305                 public NamespaceEntry Parent {
 306                         get {
 307                                 return parent;
 308                         }
 309                 }
 310
 311                 public NamespaceEntry ImplicitParent {
 312                         get {
 313                                 return implicit_parent;
 314                         }
 315                 }
 316
 317                 public void DefineName (string name, object o)
 318                 {
 319                         ns.DefineName (name, o);
 320                 }
 321
 322                 /// <summary>
 323                 ///   Records a new namespace for resolving name references
 324                 /// </summary>
 325                 public void Using (string ns, Location loc)
 326                 {
 327                         if (DeclarationFound){
 328                                 Report.Error (1529, loc, "A using clause must precede all other namespace elements");
 329                                 return;
 330                         }
 331
 332                         if (ns == FullName)
 333                                 return;
 334
 335                         if (using_clauses == null)
 336                                 using_clauses = new ArrayList ();
 337
 338                         foreach (UsingEntry old_entry in using_clauses){
 339                                 if (old_entry.Name == ns){
 340                                         Report.Warning (105, loc, "The using directive for '" + ns +
 341                                                         "' appeared previously in this namespace");
 342                                         return;
 343                                 }
 344                         }
 345
 346                         UsingEntry ue = new UsingEntry (this, ns, loc);
 347                         using_clauses.Add (ue);
 348                 }
 349
 350                 public void UsingAlias (string alias, Expression namespace_or_type, Location loc)
 351                 {
 352                         if (aliases == null)
 353                                 aliases = new Hashtable ();
 354
 355                         if (aliases.Contains (alias)){
 356                                 Report.Error (1537, loc, "The using alias `" + alias +
 357                                               "' appeared previously in this namespace");
 358                                 return;
 359                         }
 360
 361                         aliases [alias] = new AliasEntry (this, alias, namespace_or_type, loc);
 362                 }
 363
 364                 protected AliasEntry GetAliasEntry (string alias)
 365                 {
 366                         AliasEntry entry = null;
 367
 368                         if (aliases != null)
 369                                 entry = (AliasEntry) aliases [alias];
 370                         if (entry == null && Parent != null)
 371                                 entry = Parent.GetAliasEntry (alias);
 372
 373                         return entry;
 374                 }
 375
 376                 public string LookupAlias (string alias)
 377                 {
 378                         AliasEntry entry = GetAliasEntry (alias);
 379
 380                         if (entry == null)
 381                                 return null;
 382
 383                         object resolved = entry.Resolve ();
 384                         if (resolved == null)
 385                                 return null;
 386                         else if (resolved is Namespace)
 387                                 return ((Namespace) resolved).Name;
 388                         else
 389                                 return ((Type) resolved).FullName;
 390                 }
 391
 392                 public object Lookup (DeclSpace ds, string name, bool silent, Location loc)
 393                 {
 394                         object o;
 395                         Namespace ns;
 396
 397                         //
 398                         // If name is of the form `N.I', first lookup `N', then search a member `I' in it.
 399                         //
 400                         int pos = name.IndexOf ('.');
 401                         if (pos >= 0) {
 402                                 string first = name.Substring (0, pos);
 403                                 string last = name.Substring (pos + 1);
 404
 405                                 o = Lookup (ds, first, silent, loc);
 406                                 if (o == null)
 407                                         return null;
 408
 409                                 ns = o as Namespace;
 410                                 if (ns != null)
 411                                         return ns.Lookup (ds, last);
 412
 413                                 Type nested = TypeManager.LookupType ((((Type) o).Name + "." + last));
 414                                 if ((nested == null) || ((ds != null) && !ds.CheckAccessLevel (nested)))
 415                                         return null;
 416
 417                                 return nested;
 418                         }
 419
 420                         //
 421                         // Check whether it's a namespace.
 422                         //
 423                         o = NS.Lookup (ds, name);
 424                         if (o != null)
 425                                 return o;
 426
 427                         //
 428                         // Check aliases.
 429                         //
 430                         AliasEntry entry = GetAliasEntry (name);
 431                         if (entry != null) {
 432                                 o = entry.Resolve ();
 433                                 if (o != null)
 434                                         return o;
 435                         }
 436
 437                         if (name.IndexOf ('.') > 0)
 438                                 return null;
 439
 440                         //
 441                         // Check using entries.
 442                         //
 443                         Type t = null, match = null;
 444                         foreach (Namespace using_ns in GetUsingTable ()) {
 445                                 match = using_ns.Lookup (ds, name) as Type;
 446                                 if (match != null){
 447                                         if (t != null) {
 448                                                 if (!silent)
 449                                                         DeclSpace.Error_AmbiguousTypeReference (loc, name, t, match);
 450                                                 return null;
 451                                         } else {
 452                                                 t = match;
 453                                         }
 454                                 }
 455                         }
 456
 457                         return t;
 458                 }
 459
 460                 // Our cached computation.
 461                 Namespace [] namespace_using_table;
 462                 public Namespace[] GetUsingTable ()
 463                 {
 464                         if (namespace_using_table != null)
 465                                 return namespace_using_table;
 466
 467                         if (using_clauses == null)
 468                                 return new Namespace [0];
 469
 470                         ArrayList list = new ArrayList (using_clauses.Count);
 471
 472                         foreach (UsingEntry ue in using_clauses) {
 473                                 Namespace using_ns = ue.Resolve ();
 474                                 if (using_ns == null)
 475                                         continue;
 476
 477                                 list.Add (using_ns);
 478                         }
 479
 480                         namespace_using_table = new Namespace [list.Count];
 481                         list.CopyTo (namespace_using_table, 0);
 482                         return namespace_using_table;
 483                 }
 484
 485                 public void DefineNamespace (SymbolWriter symwriter)
 486                 {
 487                         if (symfile_id != 0)
 488                                 return;
 489                         if (parent != null)
 490                                 parent.DefineNamespace (symwriter);
 491
 492                         string[] using_list;
 493                         if (using_clauses != null) {
 494                                 using_list = new string [using_clauses.Count];
 495                                 for (int i = 0; i < using_clauses.Count; i++)
 496                                         using_list [i] = ((UsingEntry) using_clauses [i]).Name;
 497                         } else {
 498                                 using_list = new string [0];
 499                         }
 500
 501                         int parent_id = parent != null ? parent.symfile_id : 0;
 502                         symfile_id = symwriter.DefineNamespace (ns.Name, file, using_list, parent_id);
 503                 }
 504
 505                 public int SymbolFileID {
 506                         get {
 507                                 return symfile_id;
 508                         }
 509                 }
 510
 511                 static void Msgtry (string s)
 512                 {
 513                         Console.WriteLine ("    Try using -r:" + s);
 514                 }
 515
 516                 protected void error246 (Location loc, string name)
 517                 {
 518                         if (TypeManager.LookupType (name) != null)
 519                                 Report.Error (138, loc, "The using keyword only lets you specify a namespace, " +
 520                                               "`" + name + "' is a class not a namespace.");
 521                         else {
 522                                 Report.Error (246, loc, "The namespace `" + name +
 523                                               "' can not be found (missing assembly reference?)");
 524
 525                                 switch (name){
 526                                 case "Gtk": case "GtkSharp":
 527                                         Msgtry ("gtk-sharp");
 528                                         break;
 529
 530                                 case "Gdk": case "GdkSharp":
 531                                         Msgtry ("gdk-sharp");
 532                                         break;
 533
 534                                 case "Glade": case "GladeSharp":
 535                                         Msgtry ("glade-sharp");
 536                                         break;
 537
 538                                 case "System.Drawing":
 539                                         Msgtry ("System.Drawing");
 540                                         break;
 541
 542                                 case "System.Web.Services":
 543                                         Msgtry ("System.Web.Services");
 544                                         break;
 545
 546                                 case "System.Web":
 547                                         Msgtry ("System.Web");
 548                                         break;
 549
 550                                 case "System.Data":
 551                                         Msgtry ("System.Data");
 552                                         break;
 553
 554                                 case "System.Windows.Forms":
 555                                         Msgtry ("System.Windows.Forms");
 556                                         break;
 557                                 }
 558                         }
 559                 }
 560
 561                 /// <summary>
 562                 ///   Used to validate that all the using clauses are correct
 563                 ///   after we are finished parsing all the files.
 564                 /// </summary>
 565                 public void VerifyUsing ()
 566                 {
 567                         if (using_clauses != null){
 568                                 foreach (UsingEntry ue in using_clauses){
 569                                         if (ue.Resolve () != null)
 570                                                 continue;
 571
 572                                         error246 (ue.Location, ue.Name);
 573                                 }
 574                         }
 575
 576                         if (aliases != null){
 577                                 foreach (DictionaryEntry de in aliases){
 578                                         AliasEntry alias = (AliasEntry) de.Value;
 579
 580                                         if (alias.Resolve () != null)
 581                                                 continue;
 582
 583                                         error246 (alias.Location, alias.Alias.ToString ());
 584                                 }
 585                         }
 586                 }
 587
 588                 public override string ToString ()
 589                 {
 590                         if (NS == Namespace.Root)
 591                                 return "NamespaceEntry (<root>)";
 592                         else
 593                                 return String.Format ("NamespaceEntry ({0},{1},{2})", FullName, IsImplicit, ID);
 594                 }
 595         }
 596 }