bmcs/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         ///
  17         ///   This is an Expression to allow it to be referenced in the
  18         ///   compiler parse/intermediate tree during name resolution.
  19         /// </summary>
  20         public class Namespace : FullNamedExpression, IAlias {
  21                 static ArrayList all_namespaces = new ArrayList ();
  22                 static Hashtable namespaces_map = new Hashtable ();
  23
  24                 Namespace parent;
  25                 string fullname;
  26                 ArrayList entries;
  27                 Hashtable namespaces;
  28                 Hashtable defined_names;
  29
  30                 /// <summary>
  31                 ///   Constructor Takes the current namespace and the
  32                 ///   name.  This is bootstrapped with parent == null
  33                 ///   and name = ""
  34                 /// </summary>
  35                 public Namespace (Namespace parent, string name)
  36                 {
  37                         // Expression members.
  38                         this.eclass = ExprClass.Namespace;
  39                         this.Type = null;
  40                         this.loc = Location.Null;
  41
  42                         this.parent = parent;
  43
  44                         string pname = parent != null ? parent.Name : "";
  45
  46                         if (pname == "")
  47                                 fullname = name;
  48                         else
  49                                 fullname = parent.Name + "." + name;
  50
  51                         entries = new ArrayList ();
  52                         namespaces = new Hashtable ();
  53                         defined_names = new Hashtable ();
  54
  55                         all_namespaces.Add (this);
  56                         if (namespaces_map.Contains (fullname))
  57                                 return;
  58                         namespaces_map [fullname] = true;
  59                 }
  60
  61                 public override Expression DoResolve (EmitContext ec)
  62                 {
  63                         return this;
  64                 }
  65
  66                 public override void Emit (EmitContext ec)
  67                 {
  68                         throw new InternalErrorException ("Expression tree referenced namespace " + fullname + " during Emit ()");
  69                 }
  70
  71                 public static bool IsNamespace (string name)
  72                 {
  73                         return namespaces_map [name] != null;
  74                 }
  75
  76                 public static Namespace Root = new Namespace (null, "");
  77
  78                 public Namespace GetNamespace (string name, bool create)
  79                 {
  80                         int pos = name.IndexOf ('.');
  81
  82                         Namespace ns;
  83                         string first;
  84                         if (pos >= 0)
  85                                 first = name.Substring (0, pos);
  86                         else
  87                                 first = name;
  88
  89                         ns = (Namespace) namespaces [first];
  90                         if (ns == null) {
  91                                 if (!create)
  92                                         return null;
  93
  94                                 ns = new Namespace (this, first);
  95                                 namespaces.Add (first, ns);
  96                         }
  97
  98                         if (pos >= 0)
  99                                 ns = ns.GetNamespace (name.Substring (pos + 1), create);
 100
 101                         return ns;
 102                 }
 103
 104                 public static Namespace LookupNamespace (string name, bool create)
 105                 {
 106                         return Root.GetNamespace (name, create);
 107                 }
 108
 109                 public FullNamedExpression Lookup (DeclSpace ds, string name, Location loc)
 110                 {
 111                         IAlias o = (IAlias) defined_names [name];
 112
 113                         Type t;
 114                         DeclSpace tdecl = o as DeclSpace;
 115                         if (tdecl != null) {
 116                                 t = tdecl.DefineType ();
 117                                 if (t == null)
 118                                         return null;
 119
 120                                 if ((ds == null) || ds.CheckAccessLevel (t))
 121                                         return new TypeExpression (t, Location.Null);
 122                         }
 123
 124                         Namespace ns = GetNamespace (name, false);
 125                         if (ns != null)
 126                                 return ns;
 127
 128                         t = TypeManager.LookupType (DeclSpace.MakeFQN (fullname, name));
 129                         if ((t == null) || ((ds != null) && !ds.CheckAccessLevel (t)))
 130                                 return null;
 131
 132                         return new TypeExpression (t, Location.Null);
 133                 }
 134
 135                 public void AddNamespaceEntry (NamespaceEntry entry)
 136                 {
 137                         entries.Add (entry);
 138                 }
 139
 140                 public void DefineName (string name, IAlias o)
 141                 {
 142                         defined_names.Add (name, o);
 143                 }
 144
 145                 static public ArrayList UserDefinedNamespaces {
 146                         get {
 147                                 return all_namespaces;
 148                         }
 149                 }
 150
 151                 /// <summary>
 152                 ///   The qualified name of the current namespace
 153                 /// </summary>
 154                 public string Name {
 155                         get {
 156                                 return fullname;
 157                         }
 158                 }
 159
 160                 public override string FullName {
 161                         get {
 162                                 return fullname;
 163                         }
 164                 }
 165
 166                 /// <summary>
 167                 ///   The parent of this namespace, used by the parser to "Pop"
 168                 ///   the current namespace declaration
 169                 /// </summary>
 170                 public Namespace Parent {
 171                         get {
 172                                 return parent;
 173                         }
 174                 }
 175
 176                 public static void DefineNamespaces (SymbolWriter symwriter)
 177                 {
 178                         foreach (Namespace ns in all_namespaces) {
 179                                 foreach (NamespaceEntry entry in ns.entries)
 180                                         entry.DefineNamespace (symwriter);
 181                         }
 182                 }
 183
 184                 /// <summary>
 185                 ///   Used to validate that all the using clauses are correct
 186                 ///   after we are finished parsing all the files.
 187                 /// </summary>
 188                 public static void VerifyUsing ()
 189                 {
 190                         foreach (Namespace ns in all_namespaces) {
 191                                 foreach (NamespaceEntry entry in ns.entries)
 192                                         entry.VerifyUsing ();
 193                         }
 194                 }
 195
 196                 public override string ToString ()
 197                 {
 198                         if (this == Root)
 199                                 return "Namespace (<root>)";
 200                         else
 201                                 return String.Format ("Namespace ({0})", Name);
 202                 }
 203
 204                 bool IAlias.IsType {
 205                         get { return false; }
 206                 }
 207
 208                 TypeExpr IAlias.ResolveAsType (EmitContext ec)
 209                 {
 210                         throw new InvalidOperationException ();
 211                 }
 212         }
 213
 214         public class NamespaceEntry
 215         {
 216                 Namespace ns;
 217                 NamespaceEntry parent, implicit_parent;
 218                 SourceFile file;
 219                 int symfile_id;
 220                 Hashtable aliases;
 221                 ArrayList using_clauses;
 222                 public bool DeclarationFound = false;
 223
 224                 //
 225                 // This class holds the location where a using definition is
 226                 // done, and whether it has been used by the program or not.
 227                 //
 228                 // We use this to flag using clauses for namespaces that do not
 229                 // exist.
 230                 //
 231                 public class UsingEntry {
 232                         public Expression Name;
 233                         public readonly NamespaceEntry NamespaceEntry;
 234                         public readonly Location Location;
 235
 236                         public UsingEntry (NamespaceEntry entry, Expression name, Location loc)
 237                         {
 238                                 Name = name;
 239                                 NamespaceEntry = entry;
 240                                 Location = loc;
 241                         }
 242
 243                         internal FullNamedExpression resolved;
 244
 245                         public Namespace Resolve ()
 246                         {
 247                                 if (resolved != null)
 248                                         return resolved as Namespace;
 249
 250                                 DeclSpace root = RootContext.Tree.Types;
 251                                 root.NamespaceEntry = NamespaceEntry;
 252                                 resolved = Name.ResolveAsTypeStep (root.EmitContext);
 253                                 root.NamespaceEntry = null;
 254
 255                                 return resolved as Namespace;
 256                         }
 257                 }
 258
 259                 public class AliasEntry {
 260                         public readonly string Name;
 261                         public readonly Expression Alias;
 262                         public readonly NamespaceEntry NamespaceEntry;
 263                         public readonly Location Location;
 264
 265                         public AliasEntry (NamespaceEntry entry, string name, Expression alias, Location loc)
 266                         {
 267                                 Name = name;
 268                                 Alias = alias;
 269                                 NamespaceEntry = entry;
 270                                 Location = loc;
 271                         }
 272
 273                         FullNamedExpression resolved;
 274
 275                         public FullNamedExpression Resolve ()
 276                         {
 277                                 if (resolved != null)
 278                                         return resolved;
 279
 280                                 DeclSpace root = RootContext.Tree.Types;
 281                                 root.NamespaceEntry = NamespaceEntry;
 282                                 resolved = Alias.ResolveAsTypeStep (root.EmitContext);
 283                                 root.NamespaceEntry = null;
 284
 285                                 return resolved;
 286                         }
 287                 }
 288
 289                 public NamespaceEntry (NamespaceEntry parent, SourceFile file, string name, Location loc)
 290                 {
 291                         this.parent = parent;
 292                         this.file = file;
 293                         this.IsImplicit = false;
 294                         this.ID = ++next_id;
 295
 296                         if (parent != null)
 297                                 ns = parent.NS.GetNamespace (name, true);
 298                         else if (name != null)
 299                                 ns = Namespace.LookupNamespace (name, true);
 300                         else
 301                                 ns = Namespace.Root;
 302                         ns.AddNamespaceEntry (this);
 303                         this.FullName = ns.Name;
 304                 }
 305
 306
 307                 private NamespaceEntry (NamespaceEntry parent, SourceFile file, Namespace ns)
 308                 {
 309                         this.parent = parent;
 310                         this.file = file;
 311                         this.IsImplicit = true;
 312                         this.ID = ++next_id;
 313                         this.ns = ns;
 314                         this.FullName = ns.Name;
 315                 }
 316
 317                 //
 318                 // According to section 16.3.1 (using-alias-directive), the namespace-or-type-name is
 319                 // resolved as if the immediately containing namespace body has no using-directives.
 320                 //
 321                 // Section 16.3.2 says that the same rule is applied when resolving the namespace-name
 322                 // in the using-namespace-directive.
 323                 //
 324                 // To implement these rules, the expressions in the using directives are resolved using
 325                 // the "doppelganger" (ghostly bodiless duplicate).
 326                 //
 327                 NamespaceEntry doppelganger;
 328                 NamespaceEntry Doppelganger {
 329                         get {
 330                                 if (!IsImplicit && doppelganger == null)
 331                                         doppelganger = new NamespaceEntry (ImplicitParent, file, ns);
 332                                 return doppelganger;
 333                         }
 334                 }
 335
 336                 static int next_id = 0;
 337                 public readonly string FullName;
 338                 public readonly int ID;
 339                 public readonly bool IsImplicit;
 340
 341                 public Namespace NS {
 342                         get {
 343                                 return ns;
 344                         }
 345                 }
 346
 347                 public NamespaceEntry Parent {
 348                         get {
 349                                 return parent;
 350                         }
 351                 }
 352
 353                 public NamespaceEntry ImplicitParent {
 354                         get {
 355                                 if (parent == null)
 356                                         return null;
 357                                 if (implicit_parent == null) {
 358                                         implicit_parent = (parent.NS == ns.Parent)
 359                                                 ? parent
 360                                                 : new NamespaceEntry (parent, file, ns.Parent);
 361                                 }
 362                                 return implicit_parent;
 363                         }
 364                 }
 365
 366                 public void DefineName (string name, IAlias o)
 367                 {
 368                         ns.DefineName (name, o);
 369                 }
 370
 371                 /// <summary>
 372                 ///   Records a new namespace for resolving name references
 373                 /// </summary>
 374                 public void Using (Expression ns, Location loc)
 375                 {
 376                         string name = ns.ToString ();
 377                         if (DeclarationFound){
 378                                 Report.Error (1529, loc, "A using clause must precede all other namespace elements");
 379                                 return;
 380                         }
 381
 382                         if (name == FullName)
 383                                 return;
 384
 385                         if (using_clauses == null)
 386                                 using_clauses = new ArrayList ();
 387
 388                         foreach (UsingEntry old_entry in using_clauses) {
 389                                 if (old_entry.Name.ToString () == name) {
 390                                         if (RootContext.WarningLevel >= 3)
 391                                                 Report.Warning (105, loc, "The using directive for '{0}' appeared previously in this namespace", name);
 392                                                 return;
 393                                         }
 394                                 }
 395
 396
 397                         UsingEntry ue = new UsingEntry (Doppelganger, ns, loc);
 398                         using_clauses.Add (ue);
 399                 }
 400
 401                 public void UsingAlias (string name, Expression alias, Location loc)
 402                 {
 403                         if (DeclarationFound){
 404                                 Report.Error (1529, loc, "A using clause must precede all other namespace elements");
 405                                 return;
 406                         }
 407
 408                         if (aliases == null)
 409                                 aliases = new Hashtable ();
 410
 411                         if (aliases.Contains (name)){
 412                                 Report.Error (1537, loc, "The using alias `" + name +
 413                                               "' appeared previously in this namespace");
 414                                 return;
 415                         }
 416
 417                         aliases [name] = new AliasEntry (Doppelganger, name, alias, loc);
 418                 }
 419
 420                 public FullNamedExpression LookupAlias (string alias)
 421                 {
 422                         AliasEntry entry = null;
 423                         if (aliases != null)
 424                                 entry = (AliasEntry) aliases [alias];
 425
 426                         return entry == null ? null : entry.Resolve ();
 427                 }
 428
 429                 public FullNamedExpression LookupNamespaceOrType (DeclSpace ds, string name, Location loc)
 430                 {
 431                         FullNamedExpression resolved = null;
 432                         string rest = null;
 433
 434                         // If name is of the form `N.I', first lookup `N', then search a member `I' in it.
 435                         int pos = name.IndexOf ('.');
 436                         if (pos >= 0) {
 437                                 rest = name.Substring (pos + 1);
 438                                 name = name.Substring (0, pos);
 439                         }
 440
 441                         for (NamespaceEntry curr_ns = this; curr_ns != null; curr_ns = curr_ns.ImplicitParent) {
 442                                 if ((resolved = curr_ns.Lookup (ds, name, loc)) != null)
 443                                         break;
 444                         }
 445
 446                         if (resolved == null || rest == null)
 447                                 return resolved;
 448
 449                         Namespace ns = resolved as Namespace;
 450                         if (ns != null)
 451                                 return ns.Lookup (ds, rest, loc);
 452
 453                         Type nested = TypeManager.LookupType (resolved.FullName + "." + rest);
 454                         if ((nested == null) || ((ds != null) && !ds.CheckAccessLevel (nested)))
 455                                 return null;
 456
 457                         return new TypeExpression (nested, Location.Null);
 458                 }
 459
 460                 private FullNamedExpression Lookup (DeclSpace ds, string name, Location loc)
 461                 {
 462                         // Precondition: Only simple names (no dots) will be looked up with this function.
 463
 464                         //
 465                         // Check whether it's in the namespace.
 466                         //
 467                         FullNamedExpression o = NS.Lookup (ds, name, loc);
 468                         if (o != null)
 469                                 return o;
 470
 471                         if (IsImplicit)
 472                                 return null;
 473
 474                         //
 475                         // Check aliases.
 476                         //
 477                         o = LookupAlias (name);
 478                         if (o != null)
 479                                 return o;
 480
 481                         //
 482                         // Check using entries.
 483                         //
 484                         FullNamedExpression t = null, match = null;
 485                         foreach (Namespace using_ns in GetUsingTable ()) {
 486                                 match = using_ns.Lookup (ds, name, loc);
 487                                 if ((match != null) && (match is TypeExpr)) {
 488                                         if (t != null) {
 489                                                 DeclSpace.Error_AmbiguousTypeReference (loc, name, t.FullName, match.FullName);
 490                                                 return null;
 491                                         } else {
 492                                                 t = match;
 493                                         }
 494                                 }
 495                         }
 496
 497                         return t;
 498                 }
 499
 500                 // Our cached computation.
 501                 Namespace [] namespace_using_table;
 502                 public Namespace[] GetUsingTable ()
 503                 {
 504                         if (namespace_using_table != null)
 505                                 return namespace_using_table;
 506
 507                         if (using_clauses == null) {
 508                                 namespace_using_table = new Namespace [0];
 509                                 return namespace_using_table;
 510                         }
 511
 512                         ArrayList list = new ArrayList (using_clauses.Count);
 513
 514                         foreach (UsingEntry ue in using_clauses) {
 515                                 Namespace using_ns = ue.Resolve ();
 516                                 if (using_ns == null)
 517                                         continue;
 518
 519                                 list.Add (using_ns);
 520                         }
 521
 522                         namespace_using_table = new Namespace [list.Count];
 523                         list.CopyTo (namespace_using_table, 0);
 524                         return namespace_using_table;
 525                 }
 526
 527                 public void DefineNamespace (SymbolWriter symwriter)
 528                 {
 529                         if (symfile_id != 0)
 530                                 return;
 531                         if (parent != null)
 532                                 parent.DefineNamespace (symwriter);
 533
 534                         string[] using_list;
 535                         if (using_clauses != null) {
 536                                 using_list = new string [using_clauses.Count];
 537                                 for (int i = 0; i < using_clauses.Count; i++)
 538                                         using_list [i] = ((UsingEntry) using_clauses [i]).Name.ToString ();
 539                         } else {
 540                                 using_list = new string [0];
 541                         }
 542
 543                         int parent_id = parent != null ? parent.symfile_id : 0;
 544                         if (file.SourceFileEntry == null)
 545                                 return;
 546
 547                         symfile_id = symwriter.DefineNamespace (
 548                                 ns.Name, file.SourceFileEntry, using_list, parent_id);
 549                 }
 550
 551                 public int SymbolFileID {
 552                         get {
 553                                 return symfile_id;
 554                         }
 555                 }
 556
 557                 static void MsgtryRef (string s)
 558                 {
 559                         Console.WriteLine ("    Try using -r:" + s);
 560                 }
 561
 562                 static void MsgtryPkg (string s)
 563                 {
 564                         Console.WriteLine ("    Try using -pkg:" + s);
 565                 }
 566
 567                 protected void error246 (Location loc, string name)
 568                 {
 569                         Report.Error (246, loc, "The namespace `" + name +
 570                                       "' can not be found (missing assembly reference?)");
 571
 572                         switch (name) {
 573                         case "Gtk": case "GtkSharp":
 574                                 MsgtryPkg ("gtk-sharp");
 575                                 break;
 576
 577                         case "Gdk": case "GdkSharp":
 578                                 MsgtryPkg ("gdk-sharp");
 579                                 break;
 580
 581                         case "Glade": case "GladeSharp":
 582                                 MsgtryPkg ("glade-sharp");
 583                                 break;
 584
 585                         case "System.Drawing":
 586                         case "System.Web.Services":
 587                         case "System.Web":
 588                         case "System.Data":
 589                         case "System.Windows.Forms":
 590                                 MsgtryRef (name);
 591                                 break;
 592                         }
 593                 }
 594
 595                 /// <summary>
 596                 ///   Used to validate that all the using clauses are correct
 597                 ///   after we are finished parsing all the files.
 598                 /// </summary>
 599                 public void VerifyUsing ()
 600                 {
 601                         if (using_clauses != null){
 602                                 foreach (UsingEntry ue in using_clauses){
 603                                         if (ue.Resolve () != null)
 604                                                 continue;
 605
 606                                         if (ue.resolved == null)
 607                                                 error246 (ue.Location, ue.Name.ToString ());
 608                                         else
 609                                                 Report.Error (138, ue.Location, "The using keyword only lets you specify a namespace, " +
 610                                                               "`" + ue.Name + "' is a class not a namespace.");
 611
 612                                 }
 613                         }
 614
 615                         if (aliases != null){
 616                                 foreach (DictionaryEntry de in aliases){
 617                                         AliasEntry alias = (AliasEntry) de.Value;
 618
 619                                         if (alias.Resolve () != null)
 620                                                 continue;
 621
 622                                         error246 (alias.Location, alias.Alias.ToString ());
 623                                 }
 624                         }
 625                 }
 626
 627                 public override string ToString ()
 628                 {
 629                         if (NS == Namespace.Root)
 630                                 return "NamespaceEntry (<root>)";
 631                         else
 632                                 return String.Format ("NamespaceEntry ({0},{1},{2})", FullName, IsImplicit, ID);
 633                 }
 634         }
 635 }