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         ///
  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 {
  21                 static ArrayList all_namespaces;
  22                 static Hashtable namespaces_map;
  23
  24                 Namespace parent;
  25                 string fullname;
  26                 ArrayList entries;
  27                 Hashtable namespaces;
  28                 Hashtable declspaces;
  29                 Hashtable cached_types;
  30
  31                 public readonly MemberName MemberName;
  32
  33                 public static Namespace Root;
  34
  35                 static Namespace ()
  36                 {
  37                         Reset ();
  38                 }
  39
  40                 public static void Reset ()
  41                 {
  42                         all_namespaces = new ArrayList ();
  43                         namespaces_map = new Hashtable ();
  44
  45                         Root = new Namespace (null, "");
  46                 }
  47
  48                 /// <summary>
  49                 ///   Constructor Takes the current namespace and the
  50                 ///   name.  This is bootstrapped with parent == null
  51                 ///   and name = ""
  52                 /// </summary>
  53                 public Namespace (Namespace parent, string name)
  54                 {
  55                         // Expression members.
  56                         this.eclass = ExprClass.Namespace;
  57                         this.Type = null;
  58                         this.loc = Location.Null;
  59
  60                         this.parent = parent;
  61
  62                         string pname = parent != null ? parent.Name : "";
  63
  64                         if (pname == "")
  65                                 fullname = name;
  66                         else
  67                                 fullname = parent.Name + "." + name;
  68
  69                         if (parent != null && parent.MemberName != MemberName.Null)
  70                                 MemberName = new MemberName (parent.MemberName, name);
  71                         else if (name == "")
  72                                 MemberName = MemberName.Null;
  73                         else
  74                                 MemberName = new MemberName (name);
  75
  76                         entries = new ArrayList ();
  77                         namespaces = new Hashtable ();
  78                         declspaces = new Hashtable ();
  79                         cached_types = new Hashtable ();
  80
  81                         all_namespaces.Add (this);
  82                         if (namespaces_map.Contains (fullname))
  83                                 return;
  84                         namespaces_map [fullname] = true;
  85                 }
  86
  87                 public override Expression DoResolve (EmitContext ec)
  88                 {
  89                         return this;
  90                 }
  91
  92                 public override void Emit (EmitContext ec)
  93                 {
  94                         throw new InternalErrorException ("Expression tree referenced namespace " + fullname + " during Emit ()");
  95                 }
  96
  97                 public static bool IsNamespace (string name)
  98                 {
  99                         return namespaces_map [name] != null;
 100                 }
 101
 102                 public override string GetSignatureForError ()
 103                 {
 104                         return Name.Length == 0 ? "::global" : Name;
 105                 }
 106
 107                 public Namespace GetNamespace (string name, bool create)
 108                 {
 109                         int pos = name.IndexOf ('.');
 110
 111                         Namespace ns;
 112                         string first;
 113                         if (pos >= 0)
 114                                 first = name.Substring (0, pos);
 115                         else
 116                                 first = name;
 117
 118                         ns = (Namespace) namespaces [first];
 119                         if (ns == null) {
 120                                 if (!create)
 121                                         return null;
 122
 123                                 ns = new Namespace (this, first);
 124                                 namespaces.Add (first, ns);
 125                         }
 126
 127                         if (pos >= 0)
 128                                 ns = ns.GetNamespace (name.Substring (pos + 1), create);
 129
 130                         return ns;
 131                 }
 132
 133                 public static Namespace LookupNamespace (string name, bool create)
 134                 {
 135                         return Root.GetNamespace (name, create);
 136                 }
 137
 138                 public FullNamedExpression Lookup (DeclSpace ds, string name, Location loc)
 139                 {
 140                         Namespace ns = GetNamespace (name, false);
 141                         if (ns != null)
 142                                 return ns;
 143
 144                         TypeExpr te;
 145                         if (cached_types.Contains (name)) {
 146                                 te = (TypeExpr) cached_types [name];
 147                         } else {
 148                                 Type t;
 149                                 DeclSpace tdecl = declspaces [name] as DeclSpace;
 150                                 if (tdecl != null) {
 151                                         //
 152                                         // Note that this is not:
 153                                         //
 154                                         //   t = tdecl.DefineType ()
 155                                         //
 156                                         // This is to make it somewhat more useful when a DefineType
 157                                         // fails due to problems in nested types (more useful in the sense
 158                                         // of fewer misleading error messages)
 159                                         //
 160                                         tdecl.DefineType ();
 161                                         t = tdecl.TypeBuilder;
 162                                 } else {
 163                                         string lookup = this == Namespace.Root ? name : fullname + "." + name;
 164                                         t = TypeManager.LookupTypeReflection (lookup);
 165                                 }
 166                                 te = t == null ? null : new TypeExpression (t, Location.Null);
 167                                 cached_types [name] = te;
 168                         }
 169
 170                         if (te != null && ds != null && !ds.CheckAccessLevel (te.Type))
 171                                 return null;
 172
 173                         return te;
 174                 }
 175
 176                 public void AddNamespaceEntry (NamespaceEntry entry)
 177                 {
 178                         entries.Add (entry);
 179                 }
 180
 181                 public void AddDeclSpace (string name, DeclSpace ds)
 182                 {
 183                         declspaces.Add (name, ds);
 184                 }
 185
 186                 static public ArrayList UserDefinedNamespaces {
 187                         get { return all_namespaces; }
 188                 }
 189
 190                 /// <summary>
 191                 ///   The qualified name of the current namespace
 192                 /// </summary>
 193                 public string Name {
 194                         get { return fullname; }
 195                 }
 196
 197                 public override string FullName {
 198                         get { return fullname; }
 199                 }
 200
 201                 /// <summary>
 202                 ///   The parent of this namespace, used by the parser to "Pop"
 203                 ///   the current namespace declaration
 204                 /// </summary>
 205                 public Namespace Parent {
 206                         get { return parent; }
 207                 }
 208
 209                 public static void DefineNamespaces (SymbolWriter symwriter)
 210                 {
 211                         foreach (Namespace ns in all_namespaces) {
 212                                 foreach (NamespaceEntry entry in ns.entries)
 213                                         entry.DefineNamespace (symwriter);
 214                         }
 215                 }
 216
 217                 /// <summary>
 218                 ///   Used to validate that all the using clauses are correct
 219                 ///   after we are finished parsing all the files.
 220                 /// </summary>
 221                 public static void VerifyUsing ()
 222                 {
 223                         foreach (Namespace ns in all_namespaces) {
 224                                 foreach (NamespaceEntry entry in ns.entries)
 225                                         entry.VerifyUsing ();
 226                         }
 227                 }
 228
 229                 public override string ToString ()
 230                 {
 231                         if (this == Root)
 232                                 return "Namespace (<root>)";
 233                         else
 234                                 return String.Format ("Namespace ({0})", Name);
 235                 }
 236         }
 237
 238         public class NamespaceEntry
 239         {
 240                 Namespace ns;
 241                 NamespaceEntry parent, implicit_parent;
 242                 SourceFile file;
 243                 int symfile_id;
 244                 Hashtable aliases;
 245                 ArrayList using_clauses;
 246                 public bool DeclarationFound = false;
 247
 248                 //
 249                 // This class holds the location where a using definition is
 250                 // done, and whether it has been used by the program or not.
 251                 //
 252                 // We use this to flag using clauses for namespaces that do not
 253                 // exist.
 254                 //
 255                 public class UsingEntry {
 256                         public MemberName Name;
 257                         public Expression Expr;
 258                         public readonly NamespaceEntry NamespaceEntry;
 259                         public readonly Location Location;
 260
 261                         public UsingEntry (NamespaceEntry entry, MemberName name, Location loc)
 262                         {
 263                                 Name = name;
 264                                 Expr = name.GetTypeExpression (loc);
 265                                 NamespaceEntry = entry;
 266                                 Location = loc;
 267                         }
 268
 269                         internal FullNamedExpression resolved;
 270
 271                         public Namespace Resolve ()
 272                         {
 273                                 if (resolved != null)
 274                                         return resolved as Namespace;
 275
 276                                 DeclSpace root = RootContext.Tree.Types;
 277                                 root.NamespaceEntry = NamespaceEntry;
 278                                 resolved = Expr.ResolveAsTypeStep (root.EmitContext);
 279                                 root.NamespaceEntry = null;
 280
 281                                 return resolved as Namespace;
 282                         }
 283                 }
 284
 285                 public class AliasEntry {
 286                         public readonly string Name;
 287                         public readonly Expression Alias;
 288                         public readonly NamespaceEntry NamespaceEntry;
 289                         public readonly Location Location;
 290
 291                         public AliasEntry (NamespaceEntry entry, string name, MemberName alias, Location loc)
 292                         {
 293                                 Name = name;
 294                                 Alias = alias.GetTypeExpression (loc);
 295                                 NamespaceEntry = entry;
 296                                 Location = loc;
 297                         }
 298
 299                         FullNamedExpression resolved;
 300
 301                         public FullNamedExpression Resolve ()
 302                         {
 303                                 if (resolved != null)
 304                                         return resolved;
 305
 306                                 DeclSpace root = RootContext.Tree.Types;
 307                                 root.NamespaceEntry = NamespaceEntry;
 308                                 resolved = Alias.ResolveAsTypeStep (root.EmitContext);
 309                                 root.NamespaceEntry = null;
 310
 311                                 return resolved;
 312                         }
 313                 }
 314
 315                 public NamespaceEntry (NamespaceEntry parent, SourceFile file, string name, Location loc)
 316                 {
 317                         this.parent = parent;
 318                         this.file = file;
 319                         this.IsImplicit = false;
 320                         this.ID = ++next_id;
 321
 322                         if (parent != null)
 323                                 ns = parent.NS.GetNamespace (name, true);
 324                         else if (name != null)
 325                                 ns = Namespace.LookupNamespace (name, true);
 326                         else
 327                                 ns = Namespace.Root;
 328                         ns.AddNamespaceEntry (this);
 329                 }
 330
 331
 332                 private NamespaceEntry (NamespaceEntry parent, SourceFile file, Namespace ns)
 333                 {
 334                         this.parent = parent;
 335                         this.file = file;
 336                         this.IsImplicit = true;
 337                         this.ID = ++next_id;
 338                         this.ns = ns;
 339                 }
 340
 341                 //
 342                 // According to section 16.3.1 (using-alias-directive), the namespace-or-type-name is
 343                 // resolved as if the immediately containing namespace body has no using-directives.
 344                 //
 345                 // Section 16.3.2 says that the same rule is applied when resolving the namespace-name
 346                 // in the using-namespace-directive.
 347                 //
 348                 // To implement these rules, the expressions in the using directives are resolved using
 349                 // the "doppelganger" (ghostly bodiless duplicate).
 350                 //
 351                 NamespaceEntry doppelganger;
 352                 NamespaceEntry Doppelganger {
 353                         get {
 354                                 if (!IsImplicit && doppelganger == null)
 355                                         doppelganger = new NamespaceEntry (ImplicitParent, file, ns);
 356                                 return doppelganger;
 357                         }
 358                 }
 359
 360                 static int next_id = 0;
 361                 public readonly int ID;
 362                 public readonly bool IsImplicit;
 363
 364                 public Namespace NS {
 365                         get {
 366                                 return ns;
 367                         }
 368                 }
 369
 370                 public NamespaceEntry Parent {
 371                         get {
 372                                 return parent;
 373                         }
 374                 }
 375
 376                 public NamespaceEntry ImplicitParent {
 377                         get {
 378                                 if (parent == null)
 379                                         return null;
 380                                 if (implicit_parent == null) {
 381                                         implicit_parent = (parent.NS == ns.Parent)
 382                                                 ? parent
 383                                                 : new NamespaceEntry (parent, file, ns.Parent);
 384                                 }
 385                                 return implicit_parent;
 386                         }
 387                 }
 388
 389                 /// <summary>
 390                 ///   Records a new namespace for resolving name references
 391                 /// </summary>
 392                 public void Using (MemberName name, Location loc)
 393                 {
 394                         if (DeclarationFound){
 395                                 Report.Error (1529, loc, "A using clause must precede all other namespace elements except extern alias declarations");
 396                                 return;
 397                         }
 398
 399                         if (name.Equals (ns.MemberName))
 400                                 return;
 401
 402                         if (using_clauses == null)
 403                                 using_clauses = new ArrayList ();
 404
 405                         foreach (UsingEntry old_entry in using_clauses) {
 406                                 if (name.Equals (old_entry.Name)) {
 407                                         if (RootContext.WarningLevel >= 3)
 408                                                 Report.Warning (105, loc, "The using directive for `{0}' appeared previously in this namespace", name);
 409                                                 return;
 410                                         }
 411                                 }
 412
 413
 414                         UsingEntry ue = new UsingEntry (Doppelganger, name, loc);
 415                         using_clauses.Add (ue);
 416                 }
 417
 418                 public void UsingAlias (string name, MemberName alias, Location loc)
 419                 {
 420                         if (DeclarationFound){
 421                                 Report.Error (1529, loc, "A using clause must precede all other namespace elements except extern alias declarations");
 422                                 return;
 423                         }
 424
 425                         if (aliases == null)
 426                                 aliases = new Hashtable ();
 427
 428                         if (aliases.Contains (name)){
 429                                 AliasEntry ae = (AliasEntry)aliases [name];
 430                                 Report.SymbolRelatedToPreviousError (ae.Location, ae.Name);
 431                                 Report.Error (1537, loc, "The using alias `" + name +
 432                                               "' appeared previously in this namespace");
 433                                 return;
 434                         }
 435
 436                         aliases [name] = new AliasEntry (Doppelganger, name, alias, loc);
 437                 }
 438
 439                 public FullNamedExpression LookupAlias (string alias)
 440                 {
 441                         AliasEntry entry = null;
 442                         if (aliases != null)
 443                                 entry = (AliasEntry) aliases [alias];
 444
 445                         return entry == null ? null : entry.Resolve ();
 446                 }
 447
 448                 static readonly char [] dot_array = { '.' };
 449
 450                 public FullNamedExpression LookupNamespaceOrType (DeclSpace ds, string name, Location loc, bool ignore_cs0104)
 451                 {
 452                         FullNamedExpression resolved = null;
 453                         string rest = null;
 454
 455                         // If name is of the form `N.I', first lookup `N', then search a member `I' in it.
 456                         int pos = name.IndexOf ('.');
 457                         if (pos >= 0) {
 458                                 rest = name.Substring (pos + 1);
 459                                 name = name.Substring (0, pos);
 460                         }
 461
 462                         for (NamespaceEntry curr_ns = this; curr_ns != null; curr_ns = curr_ns.ImplicitParent) {
 463                                 if ((resolved = curr_ns.Lookup (ds, name, loc, ignore_cs0104)) != null)
 464                                         break;
 465                         }
 466
 467                         if (resolved == null || rest == null)
 468                                 return resolved;
 469
 470                         // Now handle the rest of the the name.
 471                         string [] elements = rest.Split (dot_array);
 472                         int count = elements.Length;
 473                         int i = 0;
 474                         while (i < count && resolved != null && resolved is Namespace) {
 475                                 Namespace ns = resolved as Namespace;
 476                                 resolved = ns.Lookup (ds, elements [i++], loc);
 477                         }
 478
 479                         if (resolved == null || resolved is Namespace)
 480                                 return resolved;
 481
 482                         Type t = ((TypeExpr) resolved).Type;
 483
 484                         while (t != null) {
 485                                 if (ds != null && !ds.CheckAccessLevel (t))
 486                                         break;
 487                                 if (i == count)
 488                                         return new TypeExpression (t, Location.Null);
 489                                 t = TypeManager.GetNestedType (t, elements [i++]);
 490                         }
 491
 492                         return null;
 493                 }
 494
 495                 private FullNamedExpression Lookup (DeclSpace ds, string name, Location loc, bool ignore_cs0104)
 496                 {
 497                         // Precondition: Only simple names (no dots) will be looked up with this function.
 498
 499                         //
 500                         // Check whether it's in the namespace.
 501                         //
 502                         FullNamedExpression o = NS.Lookup (ds, name, loc);
 503                         if (o != null)
 504                                 return o;
 505
 506                         if (IsImplicit)
 507                                 return null;
 508
 509                         //
 510                         // Check aliases.
 511                         //
 512                         o = LookupAlias (name);
 513                         if (o != null)
 514                                 return o;
 515
 516                         //
 517                         // Check using entries.
 518                         //
 519                         FullNamedExpression t = null, match = null;
 520                         foreach (Namespace using_ns in GetUsingTable ()) {
 521                                 match = using_ns.Lookup (ds, name, loc);
 522                                 if ((match != null) && (match is TypeExpr)) {
 523                                         if (t != null) {
 524                                                 if (!ignore_cs0104)
 525                                                         DeclSpace.Error_AmbiguousTypeReference (loc, name, t.FullName, match.FullName);
 526
 527                                                 return null;
 528                                         } else {
 529                                                 t = match;
 530                                         }
 531                                 }
 532                         }
 533
 534                         return t;
 535                 }
 536
 537                 // Our cached computation.
 538                 Namespace [] namespace_using_table;
 539                 public Namespace[] GetUsingTable ()
 540                 {
 541                         if (namespace_using_table != null)
 542                                 return namespace_using_table;
 543
 544                         if (using_clauses == null) {
 545                                 namespace_using_table = new Namespace [0];
 546                                 return namespace_using_table;
 547                         }
 548
 549                         ArrayList list = new ArrayList (using_clauses.Count);
 550
 551                         foreach (UsingEntry ue in using_clauses) {
 552                                 Namespace using_ns = ue.Resolve ();
 553                                 if (using_ns == null)
 554                                         continue;
 555
 556                                 list.Add (using_ns);
 557                         }
 558
 559                         namespace_using_table = new Namespace [list.Count];
 560                         list.CopyTo (namespace_using_table, 0);
 561                         return namespace_using_table;
 562                 }
 563
 564                 public void DefineNamespace (SymbolWriter symwriter)
 565                 {
 566                         if (symfile_id != 0)
 567                                 return;
 568                         if (parent != null)
 569                                 parent.DefineNamespace (symwriter);
 570
 571                         string[] using_list;
 572                         if (using_clauses != null) {
 573                                 using_list = new string [using_clauses.Count];
 574                                 for (int i = 0; i < using_clauses.Count; i++)
 575                                         using_list [i] = ((UsingEntry) using_clauses [i]).Name.ToString ();
 576                         } else {
 577                                 using_list = new string [0];
 578                         }
 579
 580                         int parent_id = parent != null ? parent.symfile_id : 0;
 581                         if (file.SourceFileEntry == null)
 582                                 return;
 583
 584                         symfile_id = symwriter.DefineNamespace (
 585                                 ns.Name, file.SourceFileEntry, using_list, parent_id);
 586                 }
 587
 588                 public int SymbolFileID {
 589                         get {
 590                                 return symfile_id;
 591                         }
 592                 }
 593
 594                 static void MsgtryRef (string s)
 595                 {
 596                         Console.WriteLine ("    Try using -r:" + s);
 597                 }
 598
 599                 static void MsgtryPkg (string s)
 600                 {
 601                         Console.WriteLine ("    Try using -pkg:" + s);
 602                 }
 603
 604                 public static void Error_NamespaceNotFound (Location loc, string name)
 605                 {
 606                         Report.Error (246, loc, "The type or namespace name `{0}' could not be found. Are you missing a using directive or an assembly reference?",
 607                                 name);
 608
 609                         switch (name) {
 610                         case "Gtk": case "GtkSharp":
 611                                 MsgtryPkg ("gtk-sharp");
 612                                 break;
 613
 614                         case "Gdk": case "GdkSharp":
 615                                 MsgtryPkg ("gdk-sharp");
 616                                 break;
 617
 618                         case "Glade": case "GladeSharp":
 619                                 MsgtryPkg ("glade-sharp");
 620                                 break;
 621
 622                         case "System.Drawing":
 623                         case "System.Web.Services":
 624                         case "System.Web":
 625                         case "System.Data":
 626                         case "System.Windows.Forms":
 627                                 MsgtryRef (name);
 628                                 break;
 629                         }
 630                 }
 631
 632                 /// <summary>
 633                 ///   Used to validate that all the using clauses are correct
 634                 ///   after we are finished parsing all the files.
 635                 /// </summary>
 636                 public void VerifyUsing ()
 637                 {
 638                         if (using_clauses != null){
 639                                 foreach (UsingEntry ue in using_clauses){
 640                                         if (ue.Resolve () != null)
 641                                                 continue;
 642
 643                                         if (ue.resolved == null)
 644                                                 Error_NamespaceNotFound (ue.Location, ue.Name.ToString ());
 645                                         else
 646                                                 Report.Error (138, ue.Location,
 647                                                         "`{0} is a type not a namespace. A using namespace directive can only be applied to namespaces", ue.Name);
 648
 649                                 }
 650                         }
 651
 652                         if (aliases != null){
 653                                 foreach (DictionaryEntry de in aliases){
 654                                         AliasEntry alias = (AliasEntry) de.Value;
 655
 656                                         if (alias.Resolve () != null)
 657                                                 continue;
 658
 659                                         Error_NamespaceNotFound (alias.Location, alias.Alias.ToString ());
 660                                 }
 661                         }
 662                 }
 663
 664                 public override string ToString ()
 665                 {
 666                         if (NS == Namespace.Root)
 667                                 return "NamespaceEntry (<root>)";
 668                         else
 669                                 return String.Format ("NamespaceEntry ({0},{1},{2})", ns.Name, IsImplicit, ID);
 670                 }
 671         }
 672 }