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 using System.Collections.Specialized;
  12
  13 namespace Mono.CSharp {
  14
  15         /// <summary>
  16         ///   Keeps track of the namespaces defined in the C# code.
  17         ///
  18         ///   This is an Expression to allow it to be referenced in the
  19         ///   compiler parse/intermediate tree during name resolution.
  20         /// </summary>
  21         public class Namespace : FullNamedExpression {
  22                 static ArrayList all_namespaces;
  23                 static Hashtable namespaces_map;
  24
  25                 Namespace parent;
  26                 string fullname;
  27                 ArrayList entries;
  28                 Hashtable namespaces;
  29                 IDictionary declspaces;
  30                 Hashtable cached_types;
  31
  32                 public readonly MemberName MemberName;
  33
  34                 public static Namespace Root;
  35
  36                 static Namespace ()
  37                 {
  38                         Reset ();
  39                 }
  40
  41                 public static void Reset ()
  42                 {
  43                         all_namespaces = new ArrayList ();
  44                         namespaces_map = new Hashtable ();
  45
  46                         Root = new Namespace (null, "");
  47                 }
  48
  49                 /// <summary>
  50                 ///   Constructor Takes the current namespace and the
  51                 ///   name.  This is bootstrapped with parent == null
  52                 ///   and name = ""
  53                 /// </summary>
  54                 public Namespace (Namespace parent, string name)
  55                 {
  56                         // Expression members.
  57                         this.eclass = ExprClass.Namespace;
  58                         this.Type = null;
  59                         this.loc = Location.Null;
  60
  61                         this.parent = parent;
  62
  63                         string pname = parent != null ? parent.Name : "";
  64
  65                         if (pname == "")
  66                                 fullname = name;
  67                         else
  68                                 fullname = parent.Name + "." + name;
  69
  70                         if (fullname == null)
  71                                 throw new InternalErrorException ("Namespace has a null fullname");
  72
  73                         if (parent != null && parent.MemberName != MemberName.Null)
  74                                 MemberName = new MemberName (
  75                                         parent.MemberName, name, parent.MemberName.Location);
  76                         else if (name == "")
  77                                 MemberName = MemberName.Null;
  78                         else
  79                                 MemberName = new MemberName (name, Location.Null);
  80
  81                         entries = new ArrayList ();
  82                         namespaces = new Hashtable ();
  83                         cached_types = new Hashtable ();
  84
  85                         all_namespaces.Add (this);
  86                         if (namespaces_map.Contains (fullname))
  87                                 return;
  88                         namespaces_map [fullname] = true;
  89                 }
  90
  91                 public override Expression DoResolve (EmitContext ec)
  92                 {
  93                         return this;
  94                 }
  95
  96                 public override void Emit (EmitContext ec)
  97                 {
  98                         throw new InternalErrorException ("Expression tree referenced namespace " + fullname + " during Emit ()");
  99                 }
 100
 101                 public static bool IsNamespace (string name)
 102                 {
 103                         return namespaces_map [name] != null;
 104                 }
 105
 106                 public override string GetSignatureForError ()
 107                 {
 108                         return Name.Length == 0 ? "::global" : Name;
 109                 }
 110
 111                 public Namespace GetNamespace (string name, bool create)
 112                 {
 113                         int pos = name.IndexOf ('.');
 114
 115                         Namespace ns;
 116                         string first;
 117                         if (pos >= 0)
 118                                 first = name.Substring (0, pos);
 119                         else
 120                                 first = name;
 121
 122                         ns = (Namespace) namespaces [first];
 123                         if (ns == null) {
 124                                 if (!create)
 125                                         return null;
 126
 127                                 ns = new Namespace (this, first);
 128                                 namespaces.Add (first, ns);
 129                         }
 130
 131                         if (pos >= 0)
 132                                 ns = ns.GetNamespace (name.Substring (pos + 1), create);
 133
 134                         return ns;
 135                 }
 136
 137                 public static Namespace LookupNamespace (string name, bool create)
 138                 {
 139                         return Root.GetNamespace (name, create);
 140                 }
 141
 142                 TypeExpr LookupType (string name, Location loc)
 143                 {
 144                         if (cached_types.Contains (name))
 145                                 return cached_types [name] as TypeExpr;
 146
 147                         Type t = null;
 148                         if (declspaces != null) {
 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                                 }
 163                         }
 164                         string lookup = t != null ? t.FullName : (fullname == "" ? name : fullname + "." + name);
 165                         Type rt = TypeManager.LookupTypeReflection (lookup, loc);
 166                         if (t == null)
 167                                 t = rt;
 168
 169                         TypeExpr te = t == null ? null : new TypeExpression (t, Location.Null);
 170                         cached_types [name] = te;
 171                         return te;
 172                 }
 173
 174                 public FullNamedExpression Lookup (DeclSpace ds, string name, Location loc)
 175                 {
 176                         Namespace ns = GetNamespace (name, false);
 177                         if (ns != null)
 178                                 return ns;
 179
 180                         TypeExpr te = LookupType (name, loc);
 181                         if (te == null || !ds.CheckAccessLevel (te.Type))
 182                                 return null;
 183
 184                         return te;
 185                 }
 186
 187                 public void AddNamespaceEntry (NamespaceEntry entry)
 188                 {
 189                         entries.Add (entry);
 190                 }
 191
 192                 public void AddDeclSpace (string name, DeclSpace ds)
 193                 {
 194                         if (declspaces == null)
 195                                 declspaces = new HybridDictionary ();
 196                         declspaces.Add (name, ds);
 197                 }
 198
 199                 static public ArrayList UserDefinedNamespaces {
 200                         get { return all_namespaces; }
 201                 }
 202
 203                 /// <summary>
 204                 ///   The qualified name of the current namespace
 205                 /// </summary>
 206                 public string Name {
 207                         get { return fullname; }
 208                 }
 209
 210                 public override string FullName {
 211                         get { return fullname; }
 212                 }
 213
 214                 /// <summary>
 215                 ///   The parent of this namespace, used by the parser to "Pop"
 216                 ///   the current namespace declaration
 217                 /// </summary>
 218                 public Namespace Parent {
 219                         get { return parent; }
 220                 }
 221
 222                 public static void DefineNamespaces (SymbolWriter symwriter)
 223                 {
 224                         foreach (Namespace ns in all_namespaces) {
 225                                 foreach (NamespaceEntry entry in ns.entries)
 226                                         entry.DefineNamespace (symwriter);
 227                         }
 228                 }
 229
 230                 /// <summary>
 231                 ///   Used to validate that all the using clauses are correct
 232                 ///   after we are finished parsing all the files.
 233                 /// </summary>
 234                 public static void VerifyUsing ()
 235                 {
 236                         foreach (Namespace ns in all_namespaces) {
 237                                 foreach (NamespaceEntry entry in ns.entries)
 238                                         entry.VerifyUsing ();
 239                         }
 240                 }
 241
 242                 public override string ToString ()
 243                 {
 244                         if (this == Root)
 245                                 return "Namespace (<root>)";
 246                         else
 247                                 return String.Format ("Namespace ({0})", Name);
 248                 }
 249         }
 250
 251         public class NamespaceEntry
 252         {
 253                 Namespace ns;
 254                 NamespaceEntry parent, implicit_parent;
 255                 SourceFile file;
 256                 int symfile_id;
 257                 Hashtable aliases;
 258                 ArrayList using_clauses;
 259                 public bool DeclarationFound = false;
 260
 261                 //
 262                 // This class holds the location where a using definition is
 263                 // done, and whether it has been used by the program or not.
 264                 //
 265                 // We use this to flag using clauses for namespaces that do not
 266                 // exist.
 267                 //
 268                 public class UsingEntry {
 269                         public readonly MemberName Name;
 270                         readonly Expression Expr;
 271                         readonly NamespaceEntry NamespaceEntry;
 272                         readonly Location Location;
 273
 274                         public UsingEntry (NamespaceEntry entry, MemberName name, Location loc)
 275                         {
 276                                 Name = name;
 277                                 Expr = name.GetTypeExpression ();
 278                                 NamespaceEntry = entry;
 279                                 Location = loc;
 280                         }
 281
 282                         internal Namespace resolved;
 283
 284                         public Namespace Resolve ()
 285                         {
 286                                 if (resolved != null)
 287                                         return resolved;
 288
 289                                 DeclSpace root = RootContext.Tree.Types;
 290                                 root.NamespaceEntry = NamespaceEntry;
 291                                 FullNamedExpression fne = Expr.ResolveAsTypeStep (root.EmitContext, false);
 292                                 root.NamespaceEntry = null;
 293
 294                                 if (fne == null) {
 295                                         Error_NamespaceNotFound (Location, Name.ToString ());
 296                                         return null;
 297                                 }
 298
 299                                 resolved = fne as Namespace;
 300                                 if (resolved == null) {
 301                                         Report.Error (138, Location,
 302                                                 "`{0} is a type not a namespace. A using namespace directive can only be applied to namespaces", Name.ToString ());
 303                                 }
 304                                 return resolved;
 305                         }
 306                 }
 307
 308                 public class AliasEntry {
 309                         public readonly string Name;
 310                         public readonly Expression Alias;
 311                         public readonly NamespaceEntry NamespaceEntry;
 312                         public readonly Location Location;
 313
 314                         public AliasEntry (NamespaceEntry entry, string name, MemberName alias, Location loc)
 315                         {
 316                                 Name = name;
 317                                 Alias = alias.GetTypeExpression ();
 318                                 NamespaceEntry = entry;
 319                                 Location = loc;
 320                         }
 321
 322                         FullNamedExpression resolved;
 323
 324                         public FullNamedExpression Resolve ()
 325                         {
 326                                 if (resolved != null)
 327                                         return resolved;
 328
 329                                 DeclSpace root = RootContext.Tree.Types;
 330                                 root.NamespaceEntry = NamespaceEntry;
 331                                 resolved = Alias.ResolveAsTypeStep (root.EmitContext, false);
 332                                 root.NamespaceEntry = null;
 333
 334                                 return resolved;
 335                         }
 336                 }
 337
 338                 public NamespaceEntry (NamespaceEntry parent, SourceFile file, string name, Location loc)
 339                 {
 340                         this.parent = parent;
 341                         this.file = file;
 342                         this.IsImplicit = false;
 343                         this.ID = ++next_id;
 344
 345                         if (parent != null)
 346                                 ns = parent.NS.GetNamespace (name, true);
 347                         else if (name != null)
 348                                 ns = Namespace.LookupNamespace (name, true);
 349                         else
 350                                 ns = Namespace.Root;
 351                         ns.AddNamespaceEntry (this);
 352                 }
 353
 354
 355                 private NamespaceEntry (NamespaceEntry parent, SourceFile file, Namespace ns)
 356                 {
 357                         this.parent = parent;
 358                         this.file = file;
 359                         this.IsImplicit = true;
 360                         this.ID = ++next_id;
 361                         this.ns = ns;
 362                 }
 363
 364                 //
 365                 // According to section 16.3.1 (using-alias-directive), the namespace-or-type-name is
 366                 // resolved as if the immediately containing namespace body has no using-directives.
 367                 //
 368                 // Section 16.3.2 says that the same rule is applied when resolving the namespace-name
 369                 // in the using-namespace-directive.
 370                 //
 371                 // To implement these rules, the expressions in the using directives are resolved using
 372                 // the "doppelganger" (ghostly bodiless duplicate).
 373                 //
 374                 NamespaceEntry doppelganger;
 375                 NamespaceEntry Doppelganger {
 376                         get {
 377                                 if (!IsImplicit && doppelganger == null)
 378                                         doppelganger = new NamespaceEntry (ImplicitParent, file, ns);
 379                                 return doppelganger;
 380                         }
 381                 }
 382
 383                 static int next_id = 0;
 384                 public readonly int ID;
 385                 public readonly bool IsImplicit;
 386
 387                 public Namespace NS {
 388                         get { return ns; }
 389                 }
 390
 391                 public NamespaceEntry Parent {
 392                         get { return parent; }
 393                 }
 394
 395                 public NamespaceEntry ImplicitParent {
 396                         get {
 397                                 if (parent == null)
 398                                         return null;
 399                                 if (implicit_parent == null) {
 400                                         implicit_parent = (parent.NS == ns.Parent)
 401                                                 ? parent
 402                                                 : new NamespaceEntry (parent, file, ns.Parent);
 403                                 }
 404                                 return implicit_parent;
 405                         }
 406                 }
 407
 408                 /// <summary>
 409                 ///   Records a new namespace for resolving name references
 410                 /// </summary>
 411                 public void Using (MemberName name, Location loc)
 412                 {
 413                         if (DeclarationFound){
 414                                 Report.Error (1529, loc, "A using clause must precede all other namespace elements except extern alias declarations");
 415                                 return;
 416                         }
 417
 418                         if (name.Equals (ns.MemberName))
 419                                 return;
 420
 421                         if (using_clauses == null)
 422                                 using_clauses = new ArrayList ();
 423
 424                         foreach (UsingEntry old_entry in using_clauses) {
 425                                 if (name.Equals (old_entry.Name)) {
 426                                         if (RootContext.WarningLevel >= 3)
 427                                                 Report.Warning (105, loc, "The using directive for `{0}' appeared previously in this namespace", name);
 428                                                 return;
 429                                         }
 430                                 }
 431
 432
 433                         UsingEntry ue = new UsingEntry (Doppelganger, name, loc);
 434                         using_clauses.Add (ue);
 435                 }
 436
 437                 public void UsingAlias (string name, MemberName alias, Location loc)
 438                 {
 439                         if (DeclarationFound){
 440                                 Report.Error (1529, loc, "A using clause must precede all other namespace elements except extern alias declarations");
 441                                 return;
 442                         }
 443
 444                         if (aliases == null)
 445                                 aliases = new Hashtable ();
 446
 447                         if (aliases.Contains (name)) {
 448                                 AliasEntry ae = (AliasEntry)aliases [name];
 449                                 Report.SymbolRelatedToPreviousError (ae.Location, ae.Name);
 450                                 Report.Error (1537, loc, "The using alias `" + name +
 451                                               "' appeared previously in this namespace");
 452                                 return;
 453                         }
 454
 455                         if (RootContext.Version == LanguageVersion.Default &&
 456                             name == "global" && RootContext.WarningLevel >= 2)
 457                                 Report.Warning (440, loc, "An alias named `global' will not be used when resolving 'global::';" +
 458                                         " the global namespace will be used instead");
 459
 460                         aliases [name] = new AliasEntry (Doppelganger, name, alias, loc);
 461                 }
 462
 463                 public FullNamedExpression LookupNamespaceOrType (DeclSpace ds, string name, Location loc, bool ignore_cs0104)
 464                 {
 465                         // Precondition: Only simple names (no dots) will be looked up with this function.
 466                         FullNamedExpression resolved = null;
 467                         for (NamespaceEntry curr_ns = this; curr_ns != null; curr_ns = curr_ns.ImplicitParent) {
 468                                 if ((resolved = curr_ns.Lookup (ds, name, loc, ignore_cs0104)) != null)
 469                                         break;
 470                         }
 471                         return resolved;
 472                 }
 473
 474                 static void Error_AmbiguousTypeReference (Location loc, string name, FullNamedExpression t1, FullNamedExpression t2)
 475                 {
 476                         Report.Error (104, loc, "`{0}' is an ambiguous reference between `{1}' and `{2}'",
 477                                 name, t1.FullName, t2.FullName);
 478                 }
 479
 480                 // Looks-up a alias named @name in this and surrounding namespace declarations
 481                 public FullNamedExpression LookupAlias (string name)
 482                 {
 483                         AliasEntry entry = null;
 484                         // We use Parent rather than ImplicitParent since we know implicit namespace declarations
 485                         // cannot have using entries.
 486                         for (NamespaceEntry n = this; n != null; n = n.Parent) {
 487                                 if (n.aliases == null)
 488                                         continue;
 489                                 entry = n.aliases [name] as AliasEntry;
 490                                 if (entry != null)
 491                                         return entry.Resolve ();
 492                         }
 493                         return null;
 494                 }
 495
 496                 private FullNamedExpression Lookup (DeclSpace ds, string name, Location loc, bool ignore_cs0104)
 497                 {
 498                         //
 499                         // Check whether it's in the namespace.
 500                         //
 501                         FullNamedExpression fne = NS.Lookup (ds, name, loc);
 502                         if (fne != null)
 503                                 return fne;
 504
 505                         if (IsImplicit)
 506                                 return null;
 507
 508                         //
 509                         // Check aliases.
 510                         //
 511                         if (aliases != null) {
 512                                 AliasEntry entry = aliases [name] as AliasEntry;
 513                                 if (entry != null)
 514                                         return entry.Resolve ();
 515                         }
 516
 517                         //
 518                         // Check using entries.
 519                         //
 520                         FullNamedExpression match = null;
 521                         foreach (Namespace using_ns in GetUsingTable ()) {
 522                                 match = using_ns.Lookup (ds, name, loc);
 523                                 if (match == null || !(match is TypeExpr))
 524                                         continue;
 525                                 if (fne != null) {
 526                                         if (!ignore_cs0104)
 527                                                 Error_AmbiguousTypeReference (loc, name, fne, match);
 528                                         return null;
 529                                 }
 530                                 fne = match;
 531                         }
 532
 533                         return fne;
 534                 }
 535
 536                 // Our cached computation.
 537                 readonly Namespace [] empty_namespaces = new Namespace [0];
 538                 Namespace [] namespace_using_table;
 539                 Namespace [] GetUsingTable ()
 540                 {
 541                         if (namespace_using_table != null)
 542                                 return namespace_using_table;
 543
 544                         if (using_clauses == null) {
 545                                 namespace_using_table = empty_namespaces;
 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                 readonly string [] empty_using_list = new string [0];
 565
 566                 public void DefineNamespace (SymbolWriter symwriter)
 567                 {
 568                         if (symfile_id != 0)
 569                                 return;
 570                         if (parent != null)
 571                                 parent.DefineNamespace (symwriter);
 572
 573                         string [] using_list = empty_using_list;
 574                         if (using_clauses != null) {
 575                                 using_list = new string [using_clauses.Count];
 576                                 for (int i = 0; i < using_clauses.Count; i++)
 577                                         using_list [i] = ((UsingEntry) using_clauses [i]).Name.ToString ();
 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 { return symfile_id; }
 590                 }
 591
 592                 static void MsgtryRef (string s)
 593                 {
 594                         Console.WriteLine ("    Try using -r:" + s);
 595                 }
 596
 597                 static void MsgtryPkg (string s)
 598                 {
 599                         Console.WriteLine ("    Try using -pkg:" + s);
 600                 }
 601
 602                 public static void Error_NamespaceNotFound (Location loc, string name)
 603                 {
 604                         Report.Error (246, loc, "The type or namespace name `{0}' could not be found. Are you missing a using directive or an assembly reference?",
 605                                 name);
 606
 607                         switch (name) {
 608                         case "Gtk": case "GtkSharp":
 609                                 MsgtryPkg ("gtk-sharp");
 610                                 break;
 611
 612                         case "Gdk": case "GdkSharp":
 613                                 MsgtryPkg ("gdk-sharp");
 614                                 break;
 615
 616                         case "Glade": case "GladeSharp":
 617                                 MsgtryPkg ("glade-sharp");
 618                                 break;
 619
 620                         case "System.Drawing":
 621                         case "System.Web.Services":
 622                         case "System.Web":
 623                         case "System.Data":
 624                         case "System.Windows.Forms":
 625                                 MsgtryRef (name);
 626                                 break;
 627                         }
 628                 }
 629
 630                 /// <summary>
 631                 ///   Used to validate that all the using clauses are correct
 632                 ///   after we are finished parsing all the files.
 633                 /// </summary>
 634                 public void VerifyUsing ()
 635                 {
 636                         if (using_clauses != null) {
 637                                 foreach (UsingEntry ue in using_clauses)
 638                                         ue.Resolve ();
 639                         }
 640
 641                         if (aliases != null) {
 642                                 foreach (DictionaryEntry de in aliases) {
 643                                         AliasEntry alias = (AliasEntry) de.Value;
 644                                         if (alias.Resolve () == null)
 645                                                 Error_NamespaceNotFound (alias.Location, alias.Alias.ToString ());
 646                                 }
 647                         }
 648                 }
 649
 650                 public string GetSignatureForError ()
 651                 {
 652                         if (NS == Namespace.Root)
 653                                 return "::global";
 654                         else
 655                                 return ns.Name;
 656                 }
 657
 658                 public override string ToString ()
 659                 {
 660                         if (NS == Namespace.Root)
 661                                 return "NamespaceEntry (<root>)";
 662                         else
 663                                 return String.Format ("NamespaceEntry ({0},{1},{2})", ns.Name, IsImplicit, ID);
 664                 }
 665         }
 666 }