mcs/mcs/anonymous.cs

   1 //
   2 // anonymous.cs: Support for anonymous methods
   3 //
   4 // Author:
   5 //   Miguel de Icaza (miguel@ximain.com)
   6 //   Marek Safar (marek.safar@gmail.com)
   7 //
   8 // (C) 2003, 2004 Novell, Inc.
   9 //
  10 // TODO: Ideally, we should have the helper classes emited as a hierarchy to map
  11 // their nesting, and have the visibility set to private, instead of NestedAssembly
  12 //
  13 //
  14 //
  15
  16 using System;
  17 using System.Text;
  18 using System.Collections;
  19 using System.Reflection;
  20 using System.Reflection.Emit;
  21
  22 namespace Mono.CSharp {
  23
  24         public abstract class CompilerGeneratedClass : Class
  25         {
  26                 GenericMethod generic_method;
  27                 static int next_index = 0;
  28
  29                 private static MemberName MakeProxyName (GenericMethod generic, Location loc)
  30                 {
  31                         string name = MakeName (null, "CompilerGenerated");
  32                         if (generic != null) {
  33                                 TypeArguments args = new TypeArguments (loc);
  34                                 foreach (TypeParameter tparam in generic.CurrentTypeParameters)
  35                                         args.Add (new SimpleName (tparam.Name, loc));
  36                                 return new MemberName (name, args, loc);
  37                         } else
  38                                 return new MemberName (name, loc);
  39                 }
  40
  41                 public static string MakeName (string host, string prefix)
  42                 {
  43                         return "<" + host + ">c__" + prefix + next_index++;
  44                 }
  45
  46                 protected CompilerGeneratedClass (DeclSpace parent,
  47                                         MemberName name, int mod, Location loc) :
  48                         base (parent.NamespaceEntry, parent, name, mod | Modifiers.COMPILER_GENERATED, null)
  49                 {
  50                         parent.PartialContainer.AddCompilerGeneratedClass (this);
  51                 }
  52
  53                 protected CompilerGeneratedClass (DeclSpace parent, GenericMethod generic,
  54                                                   int mod, Location loc)
  55                         : this (parent, MakeProxyName (generic, loc), mod, loc)
  56                 {
  57                         this.generic_method = generic;
  58
  59                         if (generic != null) {
  60                                 ArrayList list = new ArrayList ();
  61                                 foreach (TypeParameter tparam in generic.TypeParameters) {
  62                                         if (tparam.Constraints != null)
  63                                                 list.Add (tparam.Constraints.Clone ());
  64                                 }
  65                                 SetParameterInfo (list);
  66                         }
  67
  68                 }
  69
  70                 protected override bool DefineNestedTypes ()
  71                 {
  72                         RootContext.RegisterCompilerGeneratedType (TypeBuilder);
  73                         return base.DefineNestedTypes ();
  74                 }
  75
  76                 protected override bool DoDefineMembers ()
  77                 {
  78                         members_defined = true;
  79
  80                         if (!base.DoDefineMembers ())
  81                                 return false;
  82
  83                         if (CompilerGenerated != null) {
  84                                 foreach (CompilerGeneratedClass c in CompilerGenerated) {
  85                                         if (!c.DefineMembers ())
  86                                                 throw new InternalErrorException ();
  87                                 }
  88                         }
  89
  90                         return true;
  91                 }
  92
  93                 protected override bool DoResolveMembers ()
  94                 {
  95                         if (CompilerGenerated != null) {
  96                                 foreach (CompilerGeneratedClass c in CompilerGenerated) {
  97                                         if (!c.ResolveMembers ())
  98                                                 return false;
  99                                 }
 100                         }
 101
 102                         return base.DoResolveMembers ();
 103                 }
 104
 105                 public GenericMethod GenericMethod {
 106                         get { return generic_method; }
 107                 }
 108
 109                 public Parameters InflateParameters (Parameters ps)
 110                 {
 111                         if (generic_method == null)
 112                                 return ps;
 113
 114                         int n = ps.Count;
 115                         if (n == 0)
 116                                 return ps;
 117
 118                         Parameter[] inflated_params = new Parameter [n];
 119                         Type[] inflated_types = new Type [n];
 120
 121                         for (int i = 0; i < n; ++i) {
 122                                 Parameter p = ps [i];
 123                                 Type it = InflateType (p.ExternalType ()).ResolveAsTypeTerminal (this, false).Type;
 124                                 inflated_types [i] = it;
 125                                 inflated_params [i] = new Parameter (it, p.Name, p.ModFlags, p.OptAttributes, p.Location);
 126                         }
 127                         return Parameters.CreateFullyResolved (inflated_params, inflated_types);
 128                 }
 129
 130                 public TypeExpr InflateType (Type it)
 131                 {
 132 #if GMCS_SOURCE
 133                         if (generic_method == null)
 134                                 return new TypeExpression (it, Location);
 135
 136                         if (it.IsGenericParameter && (it.DeclaringMethod != null)) {
 137                                 int pos = it.GenericParameterPosition;
 138                                 it = CurrentTypeParameters [pos].Type;
 139                         } else if (it.IsGenericType) {
 140                                 Type[] args = it.GetGenericArguments ();
 141
 142                                 TypeArguments inflated = new TypeArguments (Location);
 143                                 foreach (Type t in args)
 144                                         inflated.Add (InflateType (t));
 145
 146                                 return new ConstructedType (it, inflated, Location);
 147                         } else if (it.IsArray) {
 148                                 TypeExpr et_expr = InflateType (it.GetElementType ());
 149                                 int rank = it.GetArrayRank ();
 150
 151                                 Type et = et_expr.ResolveAsTypeTerminal (this, false).Type;
 152                                 it = et.MakeArrayType (rank);
 153                         }
 154 #endif
 155
 156                         return new TypeExpression (it, Location);
 157                 }
 158
 159                 public Field CaptureVariable (string name, TypeExpr type)
 160                 {
 161                         if (members_defined)
 162                                 throw new InternalErrorException ("Helper class already defined!");
 163                         if (type == null)
 164                                 throw new ArgumentNullException ();
 165
 166                         return new CapturedVariableField (this, name, type);
 167                 }
 168
 169                 bool members_defined;
 170
 171                 internal void CheckMembersDefined ()
 172                 {
 173                         if (members_defined)
 174                                 throw new InternalErrorException ("Helper class already defined!");
 175                 }
 176
 177                 protected class CapturedVariableField : Field
 178                 {
 179                         public CapturedVariableField (CompilerGeneratedClass helper, string name,
 180                                                       TypeExpr type)
 181                                 : base (helper, type, Modifiers.INTERNAL, name, null, helper.Location)
 182                         {
 183                                 helper.AddField (this);
 184                         }
 185                 }
 186         }
 187
 188         public class ScopeInfo : CompilerGeneratedClass
 189         {
 190                 protected readonly RootScopeInfo RootScope;
 191                 new public readonly DeclSpace Parent;
 192                 public readonly int ID = ++next_id;
 193                 public readonly Block ScopeBlock;
 194                 protected ScopeInitializer scope_initializer;
 195
 196                 readonly Hashtable locals = new Hashtable ();
 197                 readonly Hashtable captured_scopes = new Hashtable ();
 198                 Hashtable captured_params;
 199
 200                 static int next_id;
 201
 202                 public static ScopeInfo CreateScope (Block block)
 203                 {
 204                         ToplevelBlock toplevel = block.Toplevel;
 205                         AnonymousContainer ac = toplevel.AnonymousContainer;
 206
 207                         Report.Debug (128, "CREATE SCOPE", block, block.ScopeInfo, toplevel, ac);
 208
 209                         if (ac == null)
 210                                 return new ScopeInfo (block, toplevel.RootScope.Parent,
 211                                                       toplevel.RootScope.GenericMethod);
 212
 213                         Report.Debug (128, "CREATE SCOPE #1", ac, ac.Host, ac.Scope, ac.Block,
 214                                       ac.Container,
 215                                       ac.Location);
 216
 217                         Block b;
 218                         ScopeInfo parent = null;
 219
 220                         for (b = ac.Block; b != null; b = b.Parent) {
 221                                 if (b.ScopeInfo != null) {
 222                                         parent = b.ScopeInfo;
 223                                         break;
 224                                 }
 225                         }
 226
 227                         Report.Debug (128, "CREATE SCOPE #2", parent);
 228
 229                         ScopeInfo new_scope = new ScopeInfo (block, parent, null);
 230
 231                         Report.Debug (128, "CREATE SCOPE #3", new_scope);
 232
 233                         return new_scope;
 234                 }
 235
 236                 private static int default_modflags (DeclSpace parent)
 237                 {
 238                         return parent is CompilerGeneratedClass ? Modifiers.PUBLIC : Modifiers.PRIVATE;
 239                 }
 240
 241                 protected ScopeInfo (Block block, DeclSpace parent, GenericMethod generic)
 242                         : base (parent, generic, default_modflags (parent), block.StartLocation)
 243                 {
 244                         Parent = parent;
 245                         RootScope = block.Toplevel.RootScope;
 246                         ScopeBlock = block;
 247
 248                         Report.Debug (128, "NEW SCOPE", this, block,
 249                                       block.Parent, block.Toplevel);
 250
 251                         RootScope.AddScope (this);
 252                 }
 253
 254                 protected ScopeInfo (ToplevelBlock toplevel, DeclSpace parent,
 255                                      GenericMethod generic, Location loc)
 256                         : base (parent, generic, default_modflags (parent), loc)
 257                 {
 258                         Parent = parent;
 259                         RootScope = (RootScopeInfo) this;
 260                         ScopeBlock = toplevel;
 261
 262                         Report.Debug (128, "NEW ROOT SCOPE", this, toplevel, loc);
 263                 }
 264
 265                 protected CapturedScope[] CapturedScopes {
 266                         get {
 267                                 CapturedScope[] list = new CapturedScope [captured_scopes.Count];
 268                                 captured_scopes.Values.CopyTo (list, 0);
 269                                 return list;
 270                         }
 271                 }
 272
 273                 protected CapturedVariable GetCapturedScope (ScopeInfo scope)
 274                 {
 275                         return (CapturedVariable) captured_scopes [scope];
 276                 }
 277
 278                 protected void EmitScopeInstance (EmitContext ec)
 279                 {
 280                         if (scope_initializer == null) {
 281                                 //
 282                                 // This is needed if someone overwrites the Emit method
 283                                 // of Statement and manually calls Block.Emit without
 284                                 // this snippet first:
 285                                 //
 286                                 //   ec.EmitScopeInitFromBlock (The_Block);
 287                                 //   The_Block.Emit (ec);
 288                                 //
 289                                 throw new InternalErrorException ();
 290                         }
 291
 292                         scope_initializer.Emit (ec);
 293                 }
 294
 295                 public ExpressionStatement GetScopeInitializer (EmitContext ec)
 296                 {
 297                         Report.Debug (128, "GET SCOPE INITIALIZER",
 298                                       this, GetType (), scope_initializer, ScopeBlock);
 299
 300                         if (scope_initializer == null) {
 301                                 scope_initializer = CreateScopeInitializer ();
 302                                 if (scope_initializer.Resolve (ec) == null)
 303                                         throw new InternalErrorException ();
 304                         }
 305
 306                         return scope_initializer;
 307                 }
 308
 309                 public Type GetScopeType (EmitContext ec)
 310                 {
 311                         if (!IsGeneric)
 312                                 return TypeBuilder;
 313
 314                         TypeArguments targs = new TypeArguments (Location);
 315
 316                         if (ec.DeclContainer.Parent.IsGeneric)
 317                                 foreach (TypeParameter t in ec.DeclContainer.Parent.TypeParameters)
 318                                         targs.Add (new TypeParameterExpr (t, Location));
 319                         if (ec.DeclContainer.IsGeneric)
 320                                 foreach (TypeParameter t in ec.DeclContainer.CurrentTypeParameters)
 321                                         targs.Add (new TypeParameterExpr (t, Location));
 322
 323                         Report.Debug (128, "GET SCOPE TYPE", this, TypeBuilder, targs,
 324                                       ec.DeclContainer, ec.DeclContainer.GetType (),
 325                                       ec.DeclContainer.Parent.Name);
 326
 327                         TypeExpr te = new ConstructedType (TypeBuilder, targs, Location);
 328                         te = te.ResolveAsTypeTerminal (ec, false);
 329                         if ((te == null) || (te.Type == null))
 330                                 return null;
 331                         return te.Type;
 332                 }
 333
 334                 protected override bool DoDefineMembers ()
 335                 {
 336                         Report.Debug (64, "SCOPE INFO DEFINE MEMBERS", this, GetType (), IsGeneric,
 337                                       Parent.IsGeneric, GenericMethod);
 338
 339                         foreach (CapturedScope child in CapturedScopes) {
 340                                 if (!child.DefineMembers ())
 341                                         return false;
 342                         }
 343
 344                         return base.DoDefineMembers ();
 345                 }
 346
 347                 protected override bool DoResolveMembers ()
 348                 {
 349                         Report.Debug (64, "SCOPE INFO RESOLVE MEMBERS", this, GetType (), IsGeneric,
 350                                       Parent.IsGeneric, GenericMethod);
 351
 352                         return base.DoResolveMembers ();
 353                 }
 354
 355                 public Variable CaptureScope (ScopeInfo child)
 356                 {
 357                         CheckMembersDefined ();
 358                         Report.Debug (128, "CAPTURE SCOPE", this, GetType (), child, child.GetType ());
 359                         if (child == this)
 360                                 throw new InternalErrorException ();
 361                         CapturedScope captured = (CapturedScope) captured_scopes [child];
 362                         if (captured == null) {
 363                                 captured = new CapturedScope (this, child);
 364                                 captured_scopes.Add (child, captured);
 365                         }
 366                         return captured;
 367                 }
 368
 369                 public Variable AddLocal (LocalInfo local)
 370                 {
 371                         Report.Debug (128, "CAPTURE LOCAL", this, local);
 372                         Variable var = (Variable) locals [local];
 373                         if (var == null) {
 374                                 var = new CapturedLocal (this, local);
 375                                 locals.Add (local, var);
 376                                 local.IsCaptured = true;
 377                         }
 378                         return var;
 379                 }
 380
 381                 public Variable GetCapturedVariable (LocalInfo local)
 382                 {
 383                         return (Variable) locals [local];
 384                 }
 385
 386                 public bool HostsParameters {
 387                         get { return captured_params != null; }
 388                 }
 389
 390                 public Variable GetCapturedParameter (Parameter par)
 391                 {
 392                         if (captured_params != null)
 393                                 return (Variable) captured_params [par];
 394                         else
 395                                 return null;
 396                 }
 397
 398                 public Variable AddParameter (Parameter par, int idx)
 399                 {
 400                         if (captured_params == null)
 401                                 captured_params = new Hashtable ();
 402
 403                         Variable var = (Variable) captured_params [par];
 404                         if (var == null) {
 405                                 var = new CapturedParameter (this, par, idx);
 406                                 captured_params.Add (par, var);
 407                                 par.IsCaptured = true;
 408                         }
 409
 410                         return var;
 411                 }
 412
 413                 protected string MakeFieldName (string local_name)
 414                 {
 415                         return "<" + ID + ":" + local_name + ">";
 416                 }
 417
 418                 protected virtual ScopeInitializer CreateScopeInitializer ()
 419                 {
 420                         return new ScopeInitializer (this);
 421                 }
 422
 423                 protected abstract class CapturedVariable : Variable
 424                 {
 425                         public readonly ScopeInfo Scope;
 426                         public readonly string Name;
 427
 428                         public FieldExpr FieldInstance;
 429                         protected Field field;
 430
 431                         protected CapturedVariable (ScopeInfo scope, string name)
 432                         {
 433                                 this.Scope = scope;
 434                                 this.Name = name;
 435                         }
 436
 437                         protected CapturedVariable (ScopeInfo scope, string name, Type type)
 438                                 : this (scope, name)
 439                         {
 440                                 this.field = scope.CaptureVariable (
 441                                         scope.MakeFieldName (name), scope.RootScope.InflateType (type));
 442                         }
 443
 444                         public Field Field {
 445                                 get { return field; }
 446                         }
 447
 448                         public override Type Type {
 449                                 get { return Field.MemberType; }
 450                         }
 451
 452                         public override bool HasInstance {
 453                                 get { return true; }
 454                         }
 455
 456                         public override bool NeedsTemporary {
 457                                 get { return true; }
 458                         }
 459
 460                         protected FieldInfo GetField (EmitContext ec)
 461                         {
 462                                 if ((ec.CurrentBlock != null) &&
 463                                     (ec.CurrentBlock.Toplevel != Scope.ScopeBlock.Toplevel))
 464                                         return Field.FieldBuilder;
 465                                 else
 466                                         return FieldInstance.FieldInfo;
 467                         }
 468
 469                         public override void EmitInstance (EmitContext ec)
 470                         {
 471                                 if ((ec.CurrentAnonymousMethod != null) &&
 472                                     (ec.CurrentAnonymousMethod.Scope == Scope)) {
 473                                         ec.ig.Emit (OpCodes.Ldarg_0);
 474                                         return;
 475                                 }
 476
 477                                 Scope.EmitScopeInstance (ec);
 478                         }
 479
 480                         public override void Emit (EmitContext ec)
 481                         {
 482                                 ec.ig.Emit (OpCodes.Ldfld, GetField (ec));
 483                         }
 484
 485                         public override void EmitAssign (EmitContext ec)
 486                         {
 487                                 ec.ig.Emit (OpCodes.Stfld, GetField (ec));
 488                         }
 489
 490                         public override void EmitAddressOf (EmitContext ec)
 491                         {
 492                                 ec.ig.Emit (OpCodes.Ldflda, GetField (ec));
 493                         }
 494                 }
 495
 496                 protected class CapturedParameter : CapturedVariable {
 497                         public readonly Parameter Parameter;
 498                         public readonly int Idx;
 499
 500                         public CapturedParameter (ScopeInfo scope, Parameter par, int idx)
 501                                 : base (scope, par.Name, par.ParameterType)
 502                         {
 503                                 this.Parameter = par;
 504                                 this.Idx = idx;
 505                         }
 506
 507                         public override string ToString ()
 508                         {
 509                                 return String.Format ("{0} ({1}:{2}:{3})", GetType (), Field,
 510                                                       Parameter.Name, Idx);
 511                         }
 512                 }
 513
 514                 protected class CapturedLocal : CapturedVariable {
 515                         public readonly LocalInfo Local;
 516
 517                         public CapturedLocal (ScopeInfo scope, LocalInfo local)
 518                                 : base (scope, local.Name, local.VariableType)
 519                         {
 520                                 this.Local = local;
 521                         }
 522
 523                         public override string ToString ()
 524                         {
 525                                 return String.Format ("{0} ({1}:{2})", GetType (), Field,
 526                                                       Local.Name);
 527                         }
 528                 }
 529
 530                 protected class CapturedThis : CapturedVariable {
 531                         public CapturedThis (RootScopeInfo host)
 532                                 : base (host, "<>THIS", host.ParentType)
 533                         { }
 534                 }
 535
 536                 protected class CapturedScope : CapturedVariable {
 537                         public readonly ScopeInfo ChildScope;
 538
 539                         public CapturedScope (ScopeInfo root, ScopeInfo child)
 540                                 : base (root, "scope" + child.ID)
 541                         {
 542                                 this.ChildScope = child;
 543                         }
 544
 545                         public bool DefineMembers ()
 546                         {
 547                                 Type type = ChildScope.IsGeneric ?
 548                                         ChildScope.CurrentType : ChildScope.TypeBuilder;
 549                                 Report.Debug (128, "CAPTURED SCOPE DEFINE MEMBERS", this, Scope,
 550                                               ChildScope, Name, type);
 551                                 if (type == null)
 552                                         throw new InternalErrorException ();
 553                                 field = Scope.CaptureVariable (
 554                                         Scope.MakeFieldName (Name), Scope.InflateType (type));
 555                                 return true;
 556                         }
 557
 558                         public override string ToString ()
 559                         {
 560                                 return String.Format ("CapturedScope ({1} captured in {0})",
 561                                                       Scope, ChildScope);
 562                         }
 563                 }
 564
 565                 static void DoPath (StringBuilder sb, ScopeInfo start)
 566                 {
 567                         sb.Append ((start.ID).ToString ());
 568                 }
 569
 570                 public override string ToString ()
 571                 {
 572                         StringBuilder sb = new StringBuilder ();
 573
 574                         sb.Append ("{");
 575                         DoPath (sb, this);
 576                         sb.Append ("}");
 577
 578                         return sb.ToString ();
 579                 }
 580
 581                 protected class ScopeInitializer : ExpressionStatement
 582                 {
 583                         ScopeInfo scope;
 584                         CapturedVariable captured_scope;
 585                         LocalBuilder scope_instance;
 586                         ConstructorInfo scope_ctor;
 587
 588                         bool initialized;
 589
 590                         public ScopeInitializer (ScopeInfo scope)
 591                         {
 592                                 this.scope = scope;
 593                                 this.loc = scope.Location;
 594                                 eclass = ExprClass.Value;
 595                         }
 596
 597                         public ScopeInfo Scope {
 598                                 get { return scope; }
 599                         }
 600
 601                         public override Expression DoResolve (EmitContext ec)
 602                         {
 603                                 if (scope_ctor != null)
 604                                         return this;
 605
 606                                 Report.Debug (64, "RESOLVE SCOPE INITIALIZER BASE", this, Scope,
 607                                               ec, ec.CurrentBlock);
 608
 609                                 type = Scope.GetScopeType (ec);
 610                                 if (type == null)
 611                                         throw new InternalErrorException ();
 612
 613                                 if (!DoResolveInternal (ec))
 614                                         throw new InternalErrorException ();
 615
 616                                 return this;
 617                         }
 618
 619                         protected virtual bool DoResolveInternal (EmitContext ec)
 620                         {
 621                                 MethodGroupExpr mg = (MethodGroupExpr) MemberLookupFinal (
 622                                         ec, ec.ContainerType, type, ".ctor", MemberTypes.Constructor,
 623                                         AllBindingFlags | BindingFlags.DeclaredOnly, loc);
 624                                 if (mg == null)
 625                                         throw new InternalErrorException ();
 626
 627                                 scope_ctor = (ConstructorInfo) mg.Methods [0];
 628
 629                                 Report.Debug (128, "RESOLVE THE INIT", this, Scope, Scope.RootScope,
 630                                               Scope.RootScope.GetType ());
 631
 632                                 ScopeInfo host = Scope.RootScope;
 633                                 if ((Scope != host) && (Scope.RootScope is IteratorHost)) {
 634                                         captured_scope = host.GetCapturedScope (Scope);
 635                                         Type root = host.GetScopeType (ec);
 636                                         FieldExpr fe = (FieldExpr) Expression.MemberLookup (
 637                                                 type, root, captured_scope.Field.Name, loc);
 638                                         if (fe == null)
 639                                                 throw new InternalErrorException ();
 640
 641                                         fe.InstanceExpression = this;
 642                                         captured_scope.FieldInstance = fe;
 643
 644                                         Report.Debug (128, "RESOLVE THE INIT #1", this,
 645                                                       captured_scope, fe);
 646                                 } else
 647                                         scope_instance = ec.ig.DeclareLocal (type);
 648
 649                                 foreach (CapturedLocal local in Scope.locals.Values) {
 650                                         FieldExpr fe = (FieldExpr) Expression.MemberLookup (
 651                                                 ec.ContainerType, type, local.Field.Name, loc);
 652                                         Report.Debug (64, "RESOLVE SCOPE INITIALIZER #2", this, Scope,
 653                                                       Scope, ec, ec.ContainerType, type,
 654                                                       local.Field, local.Field.Name, loc, fe);
 655                                         if (fe == null)
 656                                                 throw new InternalErrorException ();
 657
 658                                         fe.InstanceExpression = this;
 659                                         local.FieldInstance = fe;
 660                                 }
 661
 662                                 if (Scope.HostsParameters) {
 663                                         foreach (CapturedParameter cp in Scope.captured_params.Values) {
 664                                                 FieldExpr fe = (FieldExpr) Expression.MemberLookup (
 665                                                         ec.ContainerType, type, cp.Field.Name, loc);
 666                                                 if (fe == null)
 667                                                         throw new InternalErrorException ();
 668
 669                                                 fe.InstanceExpression = this;
 670                                                 cp.FieldInstance = fe;
 671                                         }
 672                                 }
 673
 674                                 foreach (CapturedScope scope in Scope.CapturedScopes) {
 675                                         FieldExpr fe = (FieldExpr) Expression.MemberLookup (
 676                                                 ec.ContainerType, type, scope.Field.Name, loc);
 677                                         Report.Debug (64, "RESOLVE SCOPE INITIALIZER #3", this, Scope,
 678                                                       scope, ec, ec.ContainerType, type,
 679                                                       scope.Field, scope.Field.Name, loc, fe);
 680                                         if (fe == null)
 681                                                 throw new InternalErrorException ();
 682
 683                                         fe.InstanceExpression = this;
 684                                         scope.FieldInstance = fe;
 685                                 }
 686
 687                                 return true;
 688                         }
 689
 690                         protected virtual void EmitParameterReference (EmitContext ec,
 691                                                                        CapturedParameter cp)
 692                         {
 693                                 int extra = ec.MethodIsStatic ? 0 : 1;
 694                                 ParameterReference.EmitLdArg (ec.ig, cp.Idx + extra);
 695                         }
 696
 697                         static int next_id;
 698                         int id = ++next_id;
 699
 700                         protected virtual void DoEmit (EmitContext ec)
 701                         {
 702                                 if ((ec.CurrentBlock != null) &&
 703                                     (ec.CurrentBlock.Toplevel != Scope.ScopeBlock.Toplevel)) {
 704                                         ec.ig.Emit (OpCodes.Ldarg_0);
 705
 706                                         if (ec.CurrentAnonymousMethod != null) {
 707                                                 ScopeInfo host = ec.CurrentAnonymousMethod.Scope;
 708                                                 Variable captured = host.GetCapturedScope (scope);
 709                                                 Report.Debug (128, "EMIT SCOPE INSTANCE #2",
 710                                                               ec.CurrentAnonymousMethod, host,
 711                                                               scope, captured);
 712                                                 if (captured != null)
 713                                                         captured.Emit (ec);
 714                                         }
 715                                 } else if (scope_instance != null)
 716                                         ec.ig.Emit (OpCodes.Ldloc, scope_instance);
 717                                 else {
 718                                         Report.Debug (128, "DO EMIT", this, Scope, ec,
 719                                                       scope_instance, captured_scope);
 720                                         captured_scope.EmitInstance (ec);
 721                                         captured_scope.Emit (ec);
 722                                 }
 723                         }
 724
 725                         protected void DoEmitInstance (EmitContext ec)
 726                         {
 727                                 Report.Debug (128, "DO EMIT INSTANCE", this, Scope, ec,
 728                                               scope_instance, captured_scope);
 729
 730                                 if (scope_instance != null)
 731                                         ec.ig.Emit (OpCodes.Ldloc, scope_instance);
 732                                 else
 733                                         captured_scope.EmitInstance (ec);
 734                         }
 735
 736                         protected virtual void EmitScopeConstructor (EmitContext ec)
 737                         {
 738                                 ec.ig.Emit (OpCodes.Newobj, scope_ctor);
 739                         }
 740
 741                         public override void Emit (EmitContext ec)
 742                         {
 743                                 if (!initialized)
 744                                         throw new InternalErrorException (
 745                                                 "Scope {0} not initialized yet", scope);
 746
 747                                 DoEmit (ec);
 748                         }
 749
 750                         public override void EmitStatement (EmitContext ec)
 751                         {
 752                                 if (initialized)
 753                                         return;
 754
 755                                 DoEmitStatement (ec);
 756                                 initialized = true;
 757                         }
 758
 759                         protected virtual void DoEmitStatement (EmitContext ec)
 760                         {
 761                                 Report.Debug (128, "EMIT SCOPE INITIALIZER STATEMENT", this, id,
 762                                               Scope, scope_instance, ec);
 763
 764                                 ec.ig.Emit (OpCodes.Nop);
 765                                 ec.ig.Emit (OpCodes.Ldc_I4, id);
 766                                 ec.ig.Emit (OpCodes.Pop);
 767                                 ec.ig.Emit (OpCodes.Nop);
 768
 769                                 if (scope_instance == null)
 770                                         ec.ig.Emit (OpCodes.Ldarg_0);
 771                                 EmitScopeConstructor (ec);
 772                                 if (scope_instance != null)
 773                                         ec.ig.Emit (OpCodes.Stloc, scope_instance);
 774                                 else
 775                                         captured_scope.EmitAssign (ec);
 776
 777                                 if (Scope.HostsParameters) {
 778                                         foreach (CapturedParameter cp in Scope.captured_params.Values) {
 779                                                 Report.Debug (128, "EMIT SCOPE INIT #6", this,
 780                                                               ec, ec.IsStatic, Scope, cp, cp.Field.Name);
 781                                                 DoEmitInstance (ec);
 782                                                 EmitParameterReference (ec, cp);
 783                                                 ec.ig.Emit (OpCodes.Stfld, cp.FieldInstance.FieldInfo);
 784                                         }
 785                                 }
 786
 787                                 if (Scope is IteratorHost)
 788                                         return;
 789
 790                                 foreach (CapturedScope scope in Scope.CapturedScopes) {
 791                                         ScopeInfo child = scope.ChildScope;
 792
 793                                         Report.Debug (128, "EMIT SCOPE INIT #5", this, Scope,
 794                                                       scope.Scope, scope.ChildScope);
 795
 796                                         ExpressionStatement init = child.GetScopeInitializer (ec);
 797                                         init.EmitStatement (ec);
 798
 799                                         DoEmit (ec);
 800                                         scope.ChildScope.EmitScopeInstance (ec);
 801                                         scope.EmitAssign (ec);
 802                                 }
 803                         }
 804                 }
 805         }
 806
 807         public class RootScopeInfo : ScopeInfo
 808         {
 809                 public RootScopeInfo (ToplevelBlock toplevel, DeclSpace parent,
 810                                       GenericMethod generic, Location loc)
 811                         : base (toplevel, parent, generic, loc)
 812                 {
 813                         scopes = new ArrayList ();
 814                 }
 815
 816                 TypeExpr parent_type;
 817                 CapturedVariableField parent_link;
 818                 CapturedThis this_variable;
 819                 protected ArrayList scopes;
 820
 821                 public virtual bool IsIterator {
 822                         get { return false; }
 823                 }
 824
 825                 public RootScopeInfo ParentHost {
 826                         get { return Parent.PartialContainer as RootScopeInfo; }
 827                 }
 828
 829                 public Type ParentType {
 830                         get { return parent_type.Type; }
 831                 }
 832
 833                 public Field ParentLink {
 834                         get { return parent_link; }
 835                 }
 836
 837                 protected CapturedThis THIS {
 838                         get { return this_variable; }
 839                 }
 840
 841                 public Variable CaptureThis ()
 842                 {
 843                         if (ParentHost != null)
 844                                 return ParentHost.CaptureThis ();
 845
 846                         CheckMembersDefined ();
 847                         if (this_variable == null)
 848                                 this_variable = new CapturedThis (this);
 849                         return this_variable;
 850                 }
 851
 852                 public void AddScope (ScopeInfo scope)
 853                 {
 854                         scopes.Add (scope);
 855                 }
 856
 857                 bool linked;
 858                 public void LinkScopes ()
 859                 {
 860                         Report.Debug (128, "LINK SCOPES", this, linked, scopes);
 861
 862                         if (linked)
 863                                 return;
 864
 865                         linked = true;
 866                         if (ParentHost != null)
 867                                 ParentHost.LinkScopes ();
 868
 869                         foreach (ScopeInfo si in scopes) {
 870                                 if (!si.Define ())
 871                                         throw new InternalErrorException ();
 872                                 if (si.DefineType () == null)
 873                                         throw new InternalErrorException ();
 874                                 if (!si.ResolveType ())
 875                                         throw new InternalErrorException ();
 876                         }
 877
 878                         foreach (ScopeInfo si in scopes) {
 879                                 if (!si.ResolveMembers ())
 880                                         throw new InternalErrorException ();
 881                                 if (!si.DefineMembers ())
 882                                         throw new InternalErrorException ();
 883                         }
 884                 }
 885
 886                 protected override ScopeInitializer CreateScopeInitializer ()
 887                 {
 888                         return new RootScopeInitializer (this);
 889                 }
 890
 891                 protected override bool DefineNestedTypes ()
 892                 {
 893                         if (Parent.IsGeneric) {
 894                                 parent_type = new ConstructedType (
 895                                         Parent.TypeBuilder, Parent.TypeParameters, Location);
 896                                 parent_type = parent_type.ResolveAsTypeTerminal (this, false);
 897                                 if ((parent_type == null) || (parent_type.Type == null))
 898                                         return false;
 899                         } else {
 900                                 parent_type = new TypeExpression (Parent.TypeBuilder, Location);
 901                         }
 902
 903                         CompilerGeneratedClass parent = Parent.PartialContainer as CompilerGeneratedClass;
 904                         if (parent != null)
 905                                 parent_link = new CapturedVariableField (this, "<>parent", parent_type);
 906
 907                         return base.DefineNestedTypes ();
 908                 }
 909
 910                 protected override bool DoDefineMembers ()
 911                 {
 912                         ArrayList args = new ArrayList ();
 913                         if (this is IteratorHost)
 914                                 args.Add (new Parameter (
 915                                         TypeManager.int32_type, "$PC", Parameter.Modifier.NONE,
 916                                         null, Location));
 917
 918                         Field pfield;
 919                         if (Parent is CompilerGeneratedClass)
 920                                 pfield = parent_link;
 921                         else
 922                                 pfield = this_variable !=  null ? this_variable.Field : null;
 923                         if (pfield != null)
 924                                 args.Add (new Parameter (
 925                                         pfield.MemberType, "parent", Parameter.Modifier.NONE,
 926                                         null, Location));
 927
 928                         Parameter[] ctor_params = new Parameter [args.Count];
 929                         args.CopyTo (ctor_params, 0);
 930                         Constructor ctor = new Constructor (
 931                                 this, MemberName.Name, Modifiers.PUBLIC,
 932                                 new Parameters (ctor_params),
 933                                 new GeneratedBaseInitializer (Location),
 934                                 Location);
 935                         AddConstructor (ctor);
 936
 937                         ctor.Block = new ToplevelBlock (null, Location);
 938                         ctor.Block.AddStatement (new TheCtor (this));
 939
 940                         return base.DoDefineMembers ();
 941                 }
 942
 943                 protected virtual void EmitScopeConstructor (EmitContext ec)
 944                 {
 945                         int pos = (this is IteratorHost) ? 2 : 1;
 946
 947                         Field pfield;
 948                         if (Parent is CompilerGeneratedClass)
 949                                 pfield = parent_link;
 950                         else
 951                                 pfield = this_variable !=  null ? this_variable.Field : null;
 952
 953                         if (pfield != null) {
 954                                 ec.ig.Emit (OpCodes.Ldarg_0);
 955                                 ec.ig.Emit (OpCodes.Ldarg, pos);
 956                                 ec.ig.Emit (OpCodes.Stfld, pfield.FieldBuilder);
 957                                 pos++;
 958                         }
 959                 }
 960
 961                 protected class TheCtor : Statement
 962                 {
 963                         RootScopeInfo host;
 964
 965                         public TheCtor (RootScopeInfo host)
 966                         {
 967                                 this.host = host;
 968                         }
 969
 970                         public override bool Resolve (EmitContext ec)
 971                         {
 972                                 return true;
 973                         }
 974
 975                         protected override void DoEmit (EmitContext ec)
 976                         {
 977                                 host.EmitScopeConstructor (ec);
 978                         }
 979                 }
 980
 981                 protected class RootScopeInitializer : ScopeInitializer
 982                 {
 983                         RootScopeInfo host;
 984
 985                         public RootScopeInitializer (RootScopeInfo host)
 986                                 : base (host)
 987                         {
 988                                 this.host = host;
 989                         }
 990
 991                         public RootScopeInfo Host {
 992                                 get { return host; }
 993                         }
 994
 995                         protected override bool DoResolveInternal (EmitContext ec)
 996                         {
 997                                 Report.Debug (64, "RESOLVE ANONYMOUS METHOD HOST INITIALIZER",
 998                                               this, Host, Host.ParentType, loc);
 999
1000                                 if (Host.THIS != null) {
1001                                         FieldExpr fe = (FieldExpr) Expression.MemberLookup (
1002                                                 ec.ContainerType, type, Host.THIS.Field.Name, loc);
1003                                         if (fe == null)
1004                                                 throw new InternalErrorException ();
1005
1006                                         fe.InstanceExpression = this;
1007                                         Host.THIS.FieldInstance = fe;
1008                                 }
1009
1010                                 return base.DoResolveInternal (ec);
1011                         }
1012
1013                         protected virtual bool IsGetEnumerator {
1014                                 get { return false; }
1015                         }
1016
1017                         protected override void EmitScopeConstructor (EmitContext ec)
1018                         {
1019                                 if (host.THIS != null) {
1020                                         ec.ig.Emit (OpCodes.Ldarg_0);
1021                                         if (IsGetEnumerator)
1022                                                 ec.ig.Emit (OpCodes.Ldfld, host.THIS.Field.FieldBuilder);
1023                                         else if (host.THIS.Type.IsValueType)
1024                                                 Expression.LoadFromPtr (ec.ig, host.THIS.Type);
1025                                 } else if (host.ParentLink != null)
1026                                         ec.ig.Emit (OpCodes.Ldarg_0);
1027
1028                                 base.EmitScopeConstructor (ec);
1029                         }
1030                 }
1031
1032         }
1033
1034         public interface IAnonymousContainer
1035         {
1036                 Block Container {
1037                         get;
1038                 }
1039
1040                 GenericMethod GenericMethod {
1041                         get;
1042                 }
1043
1044                 RootScopeInfo RootScope {
1045                         get;
1046                 }
1047
1048                 bool IsIterator {
1049                         get;
1050                 }
1051         }
1052
1053         public interface IAnonymousHost
1054         {
1055                 //
1056                 // Invoked if a yield statement is found in the body
1057                 //
1058                 void SetYields ();
1059
1060                 //
1061                 // Invoked if an anonymous method is found in the body
1062                 //
1063                 void AddAnonymousMethod (AnonymousMethodExpression anonymous);
1064         }
1065
1066         public class AnonymousMethodExpression : Expression, IAnonymousContainer, IAnonymousHost
1067         {
1068                 public readonly AnonymousMethodExpression Parent;
1069                 public readonly TypeContainer Host;
1070                 public readonly Parameters Parameters;
1071
1072                 public ToplevelBlock Block;
1073
1074                 protected Block container;
1075                 protected readonly GenericMethod generic;
1076
1077                 public Block Container {
1078                         get { return container; }
1079                 }
1080
1081                 public GenericMethod GenericMethod {
1082                         get { return generic; }
1083                 }
1084
1085                 public RootScopeInfo RootScope {
1086                         get { return root_scope; }
1087                 }
1088
1089                 public AnonymousMethodExpression (AnonymousMethodExpression parent,
1090                                                   GenericMethod generic, TypeContainer host,
1091                                                   Parameters parameters, Block container,
1092                                                   Location loc)
1093                 {
1094                         this.Parent = parent;
1095                         this.generic = parent != null ? null : generic;
1096                         this.Host = host;
1097                         this.Parameters = parameters;
1098                         this.container = container;
1099                         this.loc = loc;
1100
1101                         Report.Debug (64, "NEW ANONYMOUS METHOD EXPRESSION", this, parent, host,
1102                                       container, loc);
1103
1104                         if (parent != null)
1105                                 parent.AddAnonymousMethod (this);
1106                 }
1107
1108                 ArrayList children;
1109                 RootScopeInfo root_scope;
1110
1111                 static int next_index;
1112
1113                 void IAnonymousHost.SetYields ()
1114                 {
1115                         throw new InvalidOperationException ();
1116                 }
1117
1118                 public void AddAnonymousMethod (AnonymousMethodExpression anonymous)
1119                 {
1120                         if (children == null)
1121                                 children = new ArrayList ();
1122                         children.Add (anonymous);
1123                 }
1124
1125                 public bool CreateAnonymousHelpers ()
1126                 {
1127                         // FIXME: this polutes expression trees implementation
1128
1129                         Report.Debug (64, "ANONYMOUS METHOD EXPRESSION CREATE ROOT SCOPE",
1130                                       this, Host, container, loc);
1131
1132                         if (container != null)
1133                                 root_scope = container.Toplevel.CreateRootScope (Host);
1134
1135                         if (children != null) {
1136                                 foreach (AnonymousMethodExpression child in children) {
1137                                         if (!child.CreateAnonymousHelpers ())
1138                                                 return false;
1139                                 }
1140                         }
1141
1142                         return true;
1143                 }
1144
1145                 public override string ExprClassName {
1146                         get {
1147                                 return "anonymous method";
1148                         }
1149                 }
1150
1151                 public virtual bool HasExplicitParameters {
1152                         get {
1153                                 return true;
1154                         }
1155                 }
1156
1157                 //
1158                 // Returns true if the body of lambda expression can be implicitly
1159                 // converted to the delegate of type `delegate_type'
1160                 //
1161                 public bool ImplicitStandardConversionExists (Type delegate_type)
1162                 {
1163                         EmitContext ec = EmitContext.TempEc;
1164                         using (ec.Set (EmitContext.Flags.ProbingMode)) {
1165                                 return Compatible (ec, delegate_type) != null;
1166                         }
1167                 }
1168
1169                 protected Type CompatibleChecks (EmitContext ec, Type delegate_type)
1170                 {
1171                         if (!ec.IsAnonymousMethodAllowed) {
1172                                 Report.Error (1706, loc, "Anonymous methods and lambda expressions cannot be used in the current context");
1173                                 return null;
1174                         }
1175
1176                         if (TypeManager.IsDelegateType (delegate_type))
1177                                 return delegate_type;
1178
1179 #if GMCS_SOURCE
1180                         if (TypeManager.DropGenericTypeArguments (delegate_type) == TypeManager.expression_type) {
1181                                 delegate_type = TypeManager.GetTypeArguments (delegate_type) [0];
1182                                 if (TypeManager.IsDelegateType (delegate_type))
1183                                         return delegate_type;
1184
1185                                 Report.Error (835, loc, "Cannot convert `{0}' to an expression tree of non-delegate type `{1}'",
1186                                         GetSignatureForError (), TypeManager.CSharpName (delegate_type));
1187                                 return null;
1188                         }
1189 #endif
1190
1191                         Report.Error (1660, loc, "Cannot convert `{0}' to non-delegate type `{1}'",
1192                                       GetSignatureForError (), TypeManager.CSharpName (delegate_type));
1193                         return null;
1194                 }
1195
1196                 protected bool VerifyExplicitParameters (Type delegate_type, ParameterData parameters, bool ignore_error)
1197                 {
1198                         if (VerifyParameterCompatibility (delegate_type, parameters, ignore_error))
1199                                 return true;
1200
1201                         if (!ignore_error)
1202                                 Report.Error (1661, loc,
1203                                         "Cannot convert `{0}' to delegate type `{1}' since there is a parameter mismatch",
1204                                         GetSignatureForError (), TypeManager.CSharpName (delegate_type));
1205
1206                         return false;
1207                 }
1208
1209                 protected bool VerifyParameterCompatibility (Type delegate_type, ParameterData invoke_pd, bool ignore_errors)
1210                 {
1211                         if (Parameters.Count != invoke_pd.Count) {
1212                                 if (ignore_errors)
1213                                         return false;
1214
1215                                 Report.Error (1593, loc, "Delegate `{0}' does not take `{1}' arguments",
1216                                               TypeManager.CSharpName (delegate_type), Parameters.Count.ToString ());
1217                                 return false;
1218                         }
1219
1220                         if (!HasExplicitParameters)
1221                                 return true;
1222
1223                         bool error = false;
1224                         for (int i = 0; i < Parameters.Count; ++i) {
1225                                 Parameter.Modifier p_mod = invoke_pd.ParameterModifier (i);
1226                                 if (Parameters.ParameterModifier (i) != p_mod && p_mod != Parameter.Modifier.PARAMS) {
1227                                         if (ignore_errors)
1228                                                 return false;
1229
1230                                         if (p_mod == Parameter.Modifier.NONE)
1231                                                 Report.Error (1677, loc, "Parameter `{0}' should not be declared with the `{1}' keyword",
1232                                                               (i + 1).ToString (), Parameter.GetModifierSignature (Parameters.ParameterModifier (i)));
1233                                         else
1234                                                 Report.Error (1676, loc, "Parameter `{0}' must be declared with the `{1}' keyword",
1235                                                               (i+1).ToString (), Parameter.GetModifierSignature (p_mod));
1236                                         error = true;
1237                                         continue;
1238                                 }
1239
1240                                 Type type = invoke_pd.Types [i];
1241
1242                                 // We assume that generic parameters are always inflated
1243                                 if (TypeManager.IsGenericParameter (type))
1244                                         continue;
1245
1246                                 if (TypeManager.HasElementType (type) && TypeManager.IsGenericParameter (TypeManager.GetElementType (type)))
1247                                         continue;
1248
1249                                 if (invoke_pd.ParameterType (i) != Parameters.ParameterType (i)) {
1250                                         if (ignore_errors)
1251                                                 return false;
1252
1253                                         Report.Error (1678, loc, "Parameter `{0}' is declared as type `{1}' but should be `{2}'",
1254                                                       (i+1).ToString (),
1255                                                       TypeManager.CSharpName (Parameters.ParameterType (i)),
1256                                                       TypeManager.CSharpName (invoke_pd.ParameterType (i)));
1257                                         error = true;
1258                                 }
1259                         }
1260
1261                         return !error;
1262                 }
1263
1264                 //
1265                 // Infers type arguments based on explicit arguments
1266                 //
1267                 public bool ExplicitTypeInference (TypeInferenceContext type_inference, Type delegate_type)
1268                 {
1269                         if (!HasExplicitParameters)
1270                                 return false;
1271
1272                         if (!TypeManager.IsDelegateType (delegate_type))
1273                                 return false;
1274
1275                         ParameterData d_params = TypeManager.GetDelegateParameters (delegate_type);
1276                         if (d_params.Count != Parameters.Count)
1277                                 return false;
1278
1279                         for (int i = 0; i < Parameters.Count; ++i) {
1280                                 Type itype = d_params.Types [i];
1281                                 if (!TypeManager.IsGenericParameter (itype)) {
1282                                         if (!itype.HasElementType)
1283                                                 continue;
1284
1285                                         if (!TypeManager.IsGenericParameter (itype.GetElementType ()))
1286                                             continue;
1287                                 }
1288                                 type_inference.ExactInference (Parameters.FixedParameters[i].ParameterType, itype);
1289                         }
1290                         return true;
1291                 }
1292
1293                 public Type InferReturnType (EmitContext ec, TypeInferenceContext tic, Type delegate_type)
1294                 {
1295                         AnonymousMethod am;
1296                         using (ec.Set (EmitContext.Flags.ProbingMode | EmitContext.Flags.InferReturnType)) {
1297                                 am = CompatibleMethod (ec, tic, GetType (), delegate_type);
1298                         }
1299
1300                         if (am == null)
1301                                 return null;
1302
1303                         if (am.ReturnType == TypeManager.null_type)
1304                                 am.ReturnType = null;
1305
1306                         return am.ReturnType;
1307                 }
1308
1309                 //
1310                 // Returns AnonymousMethod container if this anonymous method
1311                 // expression can be implicitly converted to the delegate type `delegate_type'
1312                 //
1313                 public Expression Compatible (EmitContext ec, Type type)
1314                 {
1315                         Type delegate_type = CompatibleChecks (ec, type);
1316                         if (delegate_type == null)
1317                                 return null;
1318
1319                         //
1320                         // At this point its the first time we know the return type that is
1321                         // needed for the anonymous method.  We create the method here.
1322                         //
1323
1324                         MethodInfo invoke_mb = Delegate.GetInvokeMethod (
1325                                 ec.ContainerType, delegate_type);
1326                         Type return_type = invoke_mb.ReturnType;
1327
1328 #if MS_COMPATIBLE
1329                         Type[] g_args = delegate_type.GetGenericArguments ();
1330                         if (return_type.IsGenericParameter)
1331                                 return_type = g_args [return_type.GenericParameterPosition];
1332 #endif
1333
1334                         //
1335                         // Second: the return type of the delegate must be compatible with
1336                         // the anonymous type.   Instead of doing a pass to examine the block
1337                         // we satisfy the rule by setting the return type on the EmitContext
1338                         // to be the delegate type return type.
1339                         //
1340
1341                         Report.Debug (64, "COMPATIBLE", this, Parent, GenericMethod, Host,
1342                                       Container, Block, return_type, delegate_type,
1343                                       TypeManager.IsGenericType (delegate_type), loc);
1344
1345                         try {
1346                                 AnonymousMethod am = CompatibleMethod (ec, null, return_type, delegate_type);
1347                                 if (am != null && delegate_type != type)
1348                                         return CreateExpressionTree (ec, delegate_type);
1349
1350                                 return am;
1351                         } catch (Exception e) {
1352                                 throw new InternalErrorException (e, loc);
1353                         }
1354                 }
1355
1356                 protected virtual Expression CreateExpressionTree (EmitContext ec, Type delegate_type)
1357                 {
1358                         Report.Error (1946, loc, "An anonymous method cannot be converted to an expression tree");
1359                         return null;
1360                 }
1361
1362                 protected virtual Parameters ResolveParameters (EmitContext ec, TypeInferenceContext tic, Type delegate_type)
1363                 {
1364                         ParameterData delegate_parameters = TypeManager.GetDelegateParameters (delegate_type);
1365
1366                         if (Parameters == null) {
1367                                 //
1368                                 // We provide a set of inaccessible parameters
1369                                 //
1370                                 Parameter[] fixedpars = new Parameter[delegate_parameters.Count];
1371
1372                                 for (int i = 0; i < delegate_parameters.Count; i++) {
1373                                         Parameter.Modifier i_mod = delegate_parameters.ParameterModifier (i);
1374                                         if ((i_mod & Parameter.Modifier.OUTMASK) != 0) {
1375                                                 Report.Error (1688, loc, "Cannot convert anonymous " +
1376                                                                   "method block without a parameter list " +
1377                                                                   "to delegate type `{0}' because it has " +
1378                                                                   "one or more `out' parameters.",
1379                                                                   TypeManager.CSharpName (delegate_type));
1380                                                 return null;
1381                                         }
1382                                         fixedpars[i] = new Parameter (
1383                                                 delegate_parameters.ParameterType (i), "+" + (++next_index),
1384                                                 delegate_parameters.ParameterModifier (i), null, loc);
1385                                 }
1386
1387                                 return Parameters.CreateFullyResolved (fixedpars, delegate_parameters.Types);
1388                         }
1389
1390                         if (!VerifyExplicitParameters (delegate_type, delegate_parameters, ec.IsInProbingMode)) {
1391                                 return null;
1392                         }
1393
1394                         return Parameters;
1395                 }
1396
1397                 public override Expression DoResolve (EmitContext ec)
1398                 {
1399                         //
1400                         // Set class type, set type
1401                         //
1402
1403                         eclass = ExprClass.Value;
1404
1405                         //
1406                         // This hack means `The type is not accessible
1407                         // anywhere', we depend on special conversion
1408                         // rules.
1409                         //
1410                         type = TypeManager.anonymous_method_type;
1411
1412                         if ((Parameters != null) && !Parameters.Resolve (ec))
1413                                 return null;
1414
1415                         return this;
1416                 }
1417
1418                 public override void Emit (EmitContext ec)
1419                 {
1420                         // nothing, as we only exist to not do anything.
1421                 }
1422
1423                 public override string GetSignatureForError ()
1424                 {
1425                         return ExprClassName;
1426                 }
1427
1428                 public bool IsIterator {
1429                         get { return false; }
1430                 }
1431
1432                 protected AnonymousMethod CompatibleMethod (EmitContext ec, TypeInferenceContext tic, Type return_type, Type delegate_type)
1433                 {
1434                         Parameters p = ResolveParameters (ec, tic, delegate_type);
1435                         if (p == null)
1436                                 return null;
1437
1438                         ToplevelBlock b = ec.IsInProbingMode ? (ToplevelBlock) Block.PerformClone () : Block;
1439
1440                         AnonymousMethod anonymous = CompatibleMethodFactory (return_type, delegate_type, p, b);
1441                         if (!anonymous.Compatible (ec))
1442                                 return null;
1443
1444                         return anonymous;
1445                 }
1446
1447                 protected virtual AnonymousMethod CompatibleMethodFactory (Type return_type, Type delegate_type, Parameters p, ToplevelBlock b)
1448                 {
1449                         return new AnonymousMethod (RootScope, Host,
1450                                 GenericMethod, p, Container, b, return_type,
1451                                 delegate_type, loc);
1452                 }
1453
1454                 protected override void CloneTo (CloneContext clonectx, Expression t)
1455                 {
1456                         AnonymousMethodExpression target = (AnonymousMethodExpression) t;
1457
1458                         target.Block = (ToplevelBlock) clonectx.LookupBlock (Block);
1459                         target.container = clonectx.LookupBlock (Block);
1460                 }
1461         }
1462
1463         public abstract class AnonymousContainer : Expression, IAnonymousContainer
1464         {
1465                 public Parameters Parameters;
1466
1467                 //
1468                 // The block that makes up the body for the anonymous mehtod
1469                 //
1470                 public readonly ToplevelBlock Block;
1471
1472                 public readonly int ModFlags;
1473                 public Type ReturnType;
1474                 public readonly DeclSpace Host;
1475
1476                 //
1477                 // The implicit method we create
1478                 //
1479                 protected Method method;
1480                 protected EmitContext aec;
1481
1482                 // The emit context for the anonymous method
1483                 protected bool unreachable;
1484                 protected readonly Block container;
1485                 protected readonly GenericMethod generic;
1486
1487                 protected AnonymousContainer (DeclSpace host,
1488                                               GenericMethod generic, Parameters parameters,
1489                                               Block container, ToplevelBlock block,
1490                                               Type return_type, int mod, Location loc)
1491                 {
1492                         this.ReturnType = return_type;
1493                         this.ModFlags = mod | Modifiers.COMPILER_GENERATED;
1494                         this.Host = host;
1495
1496                         this.container = container;
1497                         this.generic = generic;
1498                         this.Parameters = parameters;
1499                         this.Block = block;
1500                         this.loc = loc;
1501
1502                         block.AnonymousContainer = this;
1503                 }
1504
1505                 public Method Method {
1506                         get { return method; }
1507                 }
1508
1509                 public abstract string ContainerType {
1510                         get;
1511                 }
1512
1513                 public abstract RootScopeInfo RootScope {
1514                         get;
1515                 }
1516
1517                 public abstract ScopeInfo Scope {
1518                         get;
1519                 }
1520
1521                 public bool Compatible (EmitContext ec)
1522                 {
1523                         // REFACTOR: The method should be refactor, many of the
1524                         // hacks can be handled in better way
1525
1526                         Report.Debug (64, "RESOLVE ANONYMOUS METHOD", this, Location, ec,
1527                                       RootScope, Parameters, ec.IsStatic);
1528
1529                         if (ReturnType != null) {
1530                                 TypeExpr return_type_expr;
1531                                 if (RootScope != null)
1532                                         return_type_expr = RootScope.InflateType (ReturnType);
1533                                 else
1534                                         return_type_expr = new TypeExpression (ReturnType, Location);
1535                                 return_type_expr = return_type_expr.ResolveAsTypeTerminal (ec, false);
1536                                 if ((return_type_expr == null) || (return_type_expr.Type == null))
1537                                         return false;
1538                                 ReturnType = return_type_expr.Type;
1539                         }
1540
1541                         // Linq type inference is done differently
1542                         if (RootScope != null && RootContext.Version != LanguageVersion.LINQ)
1543                                 Parameters = RootScope.InflateParameters (Parameters);
1544
1545                         aec = new EmitContext (
1546                                 ec.ResolveContext, ec.TypeContainer,
1547                                 RootScope != null ? RootScope : Host, Location, null, ReturnType,
1548                                 /* REVIEW */ (ec.InIterator ? Modifiers.METHOD_YIELDS : 0) |
1549                                 (ec.InUnsafe ? Modifiers.UNSAFE : 0), /* No constructor */ false);
1550
1551                         aec.CurrentAnonymousMethod = this;
1552                         aec.IsStatic = ec.IsStatic;
1553
1554                         //
1555                         // HACK: Overwrite parent declaration container to currently resolved.
1556                         // It's required for an anonymous container inside partial class.
1557                         //
1558                         if (RootScope != null)
1559                                 aec.DeclContainer.Parent = ec.TypeContainer;
1560
1561                         IDisposable aec_dispose = null;
1562                         EmitContext.Flags flags = 0;
1563                         if (ec.InferReturnType)
1564                                 flags |= EmitContext.Flags.InferReturnType;
1565
1566                         if (ec.IsInProbingMode)
1567                                 flags |= EmitContext.Flags.ProbingMode;
1568
1569                         if (ec.IsInFieldInitializer)
1570                                 flags |= EmitContext.Flags.InFieldInitializer;
1571
1572                         // HACK: Flag with 0 cannot be set
1573                         if (flags != 0)
1574                                 aec_dispose = aec.Set (flags);
1575
1576                         Report.Debug (64, "RESOLVE ANONYMOUS METHOD #1", this, Location, ec, aec,
1577                                       RootScope, Parameters, Block);
1578
1579                         bool unreachable;
1580                         bool res = aec.ResolveTopBlock (ec, Block, Parameters, null, out unreachable);
1581
1582                         if (ec.InferReturnType)
1583                                 ReturnType = aec.ReturnType;
1584
1585                         if (aec_dispose != null) {
1586                                 aec_dispose.Dispose ();
1587                         }
1588
1589                         return res;
1590                 }
1591
1592                 public virtual bool Define (EmitContext ec)
1593                 {
1594                         Report.Debug (64, "DEFINE ANONYMOUS METHOD #3", this, ec, aec, Block);
1595
1596                         if (aec == null && !Compatible (ec))
1597                                 return false;
1598
1599                         // Don't define anything when we are in probing scope (nested anonymous methods)
1600                         if (ec.IsInProbingMode)
1601                                 return true;
1602
1603                         method = DoCreateMethodHost (ec);
1604
1605                         if (Scope != null)
1606                                 return true;
1607
1608                         if (!method.ResolveMembers ())
1609                                 return false;
1610                         return method.Define ();
1611                 }
1612
1613                 protected abstract Method DoCreateMethodHost (EmitContext ec);
1614
1615                 public override void Emit (EmitContext ec)
1616                 {
1617                         throw new NotSupportedException ();
1618                 }
1619
1620                 public Block Container {
1621                         get { return container; }
1622                 }
1623
1624                 public GenericMethod GenericMethod {
1625                         get { return generic; }
1626                 }
1627
1628                 public abstract bool IsIterator {
1629                         get;
1630                 }
1631
1632                 protected class AnonymousMethodMethod : Method
1633                 {
1634                         public readonly AnonymousContainer AnonymousMethod;
1635                         public readonly ScopeInfo Scope;
1636
1637                         public AnonymousMethodMethod (AnonymousContainer am, ScopeInfo scope,
1638                                                       GenericMethod generic, TypeExpr return_type,
1639                                                       int mod, MemberName name, Parameters parameters)
1640                                 : base (scope != null ? scope : am.Host,
1641                                         generic, return_type, mod | Modifiers.COMPILER_GENERATED, false, name, parameters, null)
1642                         {
1643                                 this.AnonymousMethod = am;
1644                                 this.Scope = scope;
1645
1646                                 if (scope != null) {
1647                                         scope.CheckMembersDefined ();
1648                                         scope.AddMethod (this);
1649                                 } else {
1650                                         ModFlags |= Modifiers.STATIC;
1651                                         am.Host.PartialContainer.AddMethod (this);
1652                                 }
1653                                 Block = am.Block;
1654                         }
1655
1656                         public override EmitContext CreateEmitContext (DeclSpace tc, ILGenerator ig)
1657                         {
1658                                 EmitContext aec = AnonymousMethod.aec;
1659                                 aec.ig = ig;
1660                                 aec.MethodIsStatic = Scope == null;
1661                                 return aec;
1662                         }
1663                 }
1664         }
1665
1666         public class AnonymousMethod : AnonymousContainer
1667         {
1668                 Type DelegateType;
1669
1670                 //
1671                 // The value return by the Compatible call, this ensure that
1672                 // the code works even if invoked more than once (Resolve called
1673                 // more than once, due to the way Convert.ImplicitConversion works
1674                 //
1675                 RootScopeInfo root_scope;
1676                 ScopeInfo scope;
1677
1678                 public AnonymousMethod (RootScopeInfo root_scope,
1679                                         DeclSpace host, GenericMethod generic,
1680                                         Parameters parameters, Block container,
1681                                         ToplevelBlock block, Type return_type, Type delegate_type,
1682                                         Location loc)
1683                         : base (host, generic, parameters, container, block,
1684                                 return_type, 0, loc)
1685                 {
1686                         this.DelegateType = delegate_type;
1687                         this.root_scope = root_scope;
1688                 }
1689
1690                 public override string ContainerType {
1691                         get { return "anonymous method"; }
1692                 }
1693
1694                 public override RootScopeInfo RootScope {
1695                         get { return root_scope; }
1696                 }
1697
1698                 public override ScopeInfo Scope {
1699                         get { return scope; }
1700                 }
1701
1702                 public override bool IsIterator {
1703                         get { return false; }
1704                 }
1705
1706                 public override string GetSignatureForError ()
1707                 {
1708                         return TypeManager.CSharpName (DelegateType);
1709                 }
1710
1711                 //
1712                 // Creates the host for the anonymous method
1713                 //
1714                 protected override Method DoCreateMethodHost (EmitContext ec)
1715                 {
1716                         MemberCore mc = ec.ResolveContext as MemberCore;
1717                         string name = CompilerGeneratedClass.MakeName (mc.Name, null);
1718                         MemberName member_name;
1719
1720                         Report.Debug (128, "CREATE METHOD HOST #0", RootScope);
1721
1722                         Block b;
1723                         scope = RootScope;
1724
1725                         Report.Debug (128, "CREATE METHOD HOST #1", this, Block, Block.ScopeInfo,
1726                                       RootScope, Location);
1727
1728                         for (b = Block.Parent; b != null; b = b.Parent) {
1729                                 Report.Debug (128, "CREATE METHOD HOST #2", this, Block,
1730                                               b, b.ScopeInfo);
1731                                 if (b.ScopeInfo != null) {
1732                                         scope = b.ScopeInfo;
1733                                         break;
1734                                 }
1735                         }
1736
1737                         if (scope != null)
1738                                 scope.CheckMembersDefined ();
1739
1740                         ArrayList scopes = new ArrayList ();
1741                         if (b != null) {
1742                                 for (b = b.Parent; b != null; b = b.Parent) {
1743                                         if (b.ScopeInfo != null)
1744                                                 scopes.Add (b.ScopeInfo);
1745                                 }
1746                         }
1747
1748                         Report.Debug (128, "CREATE METHOD HOST #1", this, scope, scopes);
1749
1750                         foreach (ScopeInfo si in scopes)
1751                                 scope.CaptureScope (si);
1752
1753                         Report.Debug (128, "CREATE METHOD HOST", this, Block, container,
1754                                       RootScope, scope, scopes, Location);
1755
1756                         GenericMethod generic_method = null;
1757 #if GMCS_SOURCE
1758                         if (TypeManager.IsGenericType (DelegateType)) {
1759                                 TypeArguments args = new TypeArguments (Location);
1760
1761                                 Type dt = DelegateType.GetGenericTypeDefinition ();
1762
1763                                 Type[] tparam = TypeManager.GetTypeArguments (dt);
1764                                 for (int i = 0; i < tparam.Length; i++)
1765                                         args.Add (new SimpleName (tparam [i].Name, Location));
1766
1767                                 member_name = new MemberName (name, args, Location);
1768
1769                                 Report.Debug (128, "CREATE METHOD HOST #5", this, DelegateType,
1770                                               TypeManager.GetTypeArguments (DelegateType),
1771                                               dt, tparam, args);
1772
1773                                 generic_method = new GenericMethod (
1774                                         Host.NamespaceEntry, scope, member_name,
1775                                         new TypeExpression (ReturnType, Location), Parameters);
1776
1777                                 generic_method.SetParameterInfo (null);
1778                         } else
1779 #endif
1780                                 member_name = new MemberName (name, Location);
1781
1782                         return new AnonymousMethodMethod (
1783                                 this, scope, generic_method, new TypeExpression (ReturnType, Location),
1784                                 scope == null ? Modifiers.PRIVATE : Modifiers.INTERNAL, member_name, Parameters);
1785                 }
1786
1787                 public override Expression DoResolve (EmitContext ec)
1788                 {
1789                         if (!Define (ec))
1790                                 return null;
1791
1792                         return new AnonymousDelegate (this, DelegateType, Location).Resolve (ec);
1793                 }
1794
1795                 public MethodInfo GetMethodBuilder (EmitContext ec)
1796                 {
1797                         MethodInfo builder = method.MethodBuilder;
1798                         if ((Scope != null) && Scope.IsGeneric) {
1799                                 Type scope_type = Scope.GetScopeType (ec);
1800                                 if (scope_type == null)
1801                                         throw new InternalErrorException ();
1802
1803                                 MethodGroupExpr mg = (MethodGroupExpr) Expression.MemberLookup (
1804                                         ec.ContainerType, scope_type, builder.Name,
1805                                         MemberTypes.Method, Expression.AllBindingFlags | BindingFlags.NonPublic, Location);
1806
1807                                 if (mg == null)
1808                                         throw new InternalErrorException ();
1809                                 builder = (MethodInfo) mg.Methods [0];
1810                         }
1811
1812 #if GMCS_SOURCE
1813                         if (!DelegateType.IsGenericType)
1814                                 return builder;
1815
1816                         Type[] targs = TypeManager.GetTypeArguments (DelegateType);
1817                         return builder.MakeGenericMethod (targs);
1818 #else
1819                         return builder;
1820 #endif
1821                 }
1822
1823                 public static void Error_AddressOfCapturedVar (string name, Location loc)
1824                 {
1825                         Report.Error (1686, loc,
1826                                       "Local variable `{0}' or its members cannot have their " +
1827                                       "address taken and be used inside an anonymous method block",
1828                                       name);
1829                 }
1830         }
1831
1832         //
1833         // This will emit the code for the delegate, as well delegate creation on the host
1834         //
1835         public class AnonymousDelegate : DelegateCreation {
1836                 readonly AnonymousMethod am;
1837
1838                 //
1839                 // if target_type is null, this means that we do not know the type
1840                 // for this delegate, and we want to infer it from the various
1841                 // returns (implicit and explicit) from the body of this anonymous
1842                 // method.
1843                 //
1844                 // for example, the lambda: x => 1
1845                 //
1846                 public AnonymousDelegate (AnonymousMethod am, Type target_type, Location l)
1847                 {
1848                         type = target_type;
1849                         loc = l;
1850                         this.am = am;
1851                 }
1852
1853                 public override Expression DoResolve (EmitContext ec)
1854                 {
1855                         eclass = ExprClass.Value;
1856                         return this;
1857                 }
1858
1859                 public override void Emit (EmitContext ec)
1860                 {
1861                         //ec.ig.Emit (OpCodes.Ldstr, "EMIT ANONYMOUS DELEGATE");
1862                         //ec.ig.Emit (OpCodes.Pop);
1863
1864                         //
1865                         // Now emit the delegate creation.
1866                         //
1867                         if ((am.Method.ModFlags & Modifiers.STATIC) == 0) {
1868                                 Report.Debug (128, "EMIT ANONYMOUS DELEGATE", this, am, am.Scope, loc);
1869                                 delegate_instance_expression = am.Scope.GetScopeInitializer (ec);
1870
1871                                 if (delegate_instance_expression == null)
1872                                         throw new InternalErrorException ();
1873                         }
1874
1875                         constructor_method = Delegate.GetConstructor (ec.ContainerType, type);
1876 #if MS_COMPATIBLE
1877                         if (type.IsGenericType && type is TypeBuilder)
1878                                 constructor_method = TypeBuilder.GetConstructor (type, (ConstructorInfo)constructor_method);
1879 #endif
1880
1881                         delegate_method = am.GetMethodBuilder (ec);
1882                         base.Emit (ec);
1883
1884                         //ec.ig.Emit (OpCodes.Ldstr, "EMIT ANONYMOUS DELEGATE DONE");
1885                         //ec.ig.Emit (OpCodes.Pop);
1886
1887                         Report.Debug (128, "EMIT ANONYMOUS DELEGATE DONE", this, am, am.Scope, loc);
1888                 }
1889         }
1890
1891         //
1892         // Anonymous type container
1893         //
1894         public class AnonymousTypeClass : CompilerGeneratedClass
1895         {
1896                 static int types_counter;
1897                 public const string ClassNamePrefix = "<>__AnonType";
1898                 public const string SignatureForError = "anonymous type";
1899
1900                 static readonly IntConstant FNV_prime = new IntConstant (16777619, Location.Null);
1901
1902                 readonly ArrayList parameters;
1903
1904                 private AnonymousTypeClass (DeclSpace parent, MemberName name, ArrayList parameters, Location loc)
1905                         : base (parent, name, Modifiers.SEALED, loc)
1906                 {
1907                         this.parameters = parameters;
1908                 }
1909
1910                 public static AnonymousTypeClass Create (TypeContainer parent, ArrayList parameters, Location loc)
1911                 {
1912                         if (RootContext.Version <= LanguageVersion.ISO_2)
1913                                 Report.FeatureIsNotAvailable (loc, "anonymous types");
1914
1915                         string name = ClassNamePrefix + types_counter++;
1916
1917                         SimpleName [] t_args = new SimpleName [parameters.Count];
1918                         Parameter [] ctor_params = new Parameter [parameters.Count];
1919                         for (int i = 0; i < parameters.Count; ++i) {
1920                                 AnonymousTypeParameter p = (AnonymousTypeParameter) parameters [i];
1921
1922                                 t_args [i] = new SimpleName ("<" + p.Name + ">__T", p.Location);
1923                                 ctor_params [i] = new Parameter (t_args [i], p.Name, 0, null, p.Location);
1924                         }
1925
1926                         //
1927                         // Create generic anonymous type host with generic arguments
1928                         // named upon properties names
1929                         //
1930                         AnonymousTypeClass a_type = new AnonymousTypeClass (parent.NamespaceEntry.SlaveDeclSpace,
1931                                 new MemberName (name, new TypeArguments (loc, t_args), loc), parameters, loc);
1932
1933                         if (parameters.Count > 0)
1934                                 a_type.SetParameterInfo (null);
1935
1936                         Constructor c = new Constructor (a_type, name, Modifiers.PUBLIC,
1937                                 new Parameters (ctor_params), null, loc);
1938                         c.OptAttributes = a_type.GetDebuggerHiddenAttribute ();
1939                         c.Block = new ToplevelBlock (c.Parameters, loc);
1940
1941                         //
1942                         // Create fields and contructor body with field initialization
1943                         //
1944                         bool error = false;
1945                         for (int i = 0; i < parameters.Count; ++i) {
1946                                 AnonymousTypeParameter p = (AnonymousTypeParameter) parameters [i];
1947
1948                                 Field f = new Field (a_type, t_args [i], Modifiers.PRIVATE | Modifiers.READONLY,
1949                                         "<" + p.Name + ">", null, p.Location);
1950
1951                                 if (!a_type.AddField (f)) {
1952                                         error = true;
1953                                         Report.Error (833, p.Location, "`{0}': An anonymous type cannot have multiple properties with the same name",
1954                                                 p.Name);
1955                                         continue;
1956                                 }
1957
1958                                 c.Block.AddStatement (new StatementExpression (
1959                                         new Assign (new MemberAccess (new This (p.Location), f.Name),
1960                                                 c.Block.GetParameterReference (p.Name, p.Location))));
1961
1962                                 ToplevelBlock get_block = new ToplevelBlock (p.Location);
1963                                 get_block.AddStatement (new Return (
1964                                         new MemberAccess (new This (p.Location), f.Name), p.Location));
1965                                 Accessor get_accessor = new Accessor (get_block, 0, null, p.Location);
1966                                 Property prop = new Property (a_type, t_args [i], Modifiers.PUBLIC, false,
1967                                         new MemberName (p.Name, p.Location), null, get_accessor, null, false);
1968                                 a_type.AddProperty (prop);
1969                         }
1970
1971                         if (error)
1972                                 return null;
1973
1974                         a_type.AddConstructor (c);
1975                         return a_type;
1976                 }
1977
1978                 protected override bool AddToContainer (MemberCore symbol, string name)
1979                 {
1980                         MemberCore mc = (MemberCore) defined_names [name];
1981
1982                         if (mc == null) {
1983                                 defined_names.Add (name, symbol);
1984                                 return true;
1985                         }
1986
1987                         Report.SymbolRelatedToPreviousError (mc);
1988                         return false;
1989                 }
1990
1991                 void DefineOverrides ()
1992                 {
1993                         Location loc = Location;
1994
1995                         Method equals = new Method (this, null, TypeManager.system_boolean_expr,
1996                                 Modifiers.PUBLIC | Modifiers.OVERRIDE, false, new MemberName ("Equals", loc),
1997                                 new Parameters (new Parameter (TypeManager.system_object_expr, "obj", 0, null, loc)),
1998                                 GetDebuggerHiddenAttribute ());
1999
2000                         Method tostring = new Method (this, null, TypeManager.system_string_expr,
2001                                 Modifiers.PUBLIC | Modifiers.OVERRIDE, false, new MemberName ("ToString", loc),
2002                                 Mono.CSharp.Parameters.EmptyReadOnlyParameters, GetDebuggerHiddenAttribute ());
2003
2004                         ToplevelBlock equals_block = new ToplevelBlock (equals.Parameters, loc);
2005                         TypeExpr current_type;
2006                         if (IsGeneric)
2007                                 current_type = new ConstructedType (TypeBuilder, TypeParameters, loc);
2008                         else
2009                                 current_type = new TypeExpression (TypeBuilder, loc);
2010
2011                         equals_block.AddVariable (current_type, "other", loc);
2012                         LocalVariableReference other_variable = new LocalVariableReference (equals_block, "other", loc);
2013
2014                         MemberAccess system_collections_generic = new MemberAccess (new MemberAccess (
2015                                 new SimpleName ("System", loc), "Collections", loc), "Generic", loc);
2016
2017                         Expression rs_equals = null;
2018                         Expression string_concat = new StringConstant ("<empty type>", loc);
2019                         Expression rs_hashcode = new IntConstant (-2128831035, loc);
2020                         for (int i = 0; i < parameters.Count; ++i) {
2021                                 AnonymousTypeParameter p = (AnonymousTypeParameter) parameters [i];
2022                                 Field f = (Field) Fields [i];
2023
2024                                 MemberAccess equality_comparer = new MemberAccess (new MemberAccess (
2025                                         system_collections_generic, "EqualityComparer",
2026                                                 new TypeArguments (loc, new SimpleName (TypeParameters [i].Name, loc)), loc),
2027                                                 "Default", loc);
2028
2029                                 ArrayList arguments_equal = new ArrayList (2);
2030                                 arguments_equal.Add (new Argument (new MemberAccess (new This (f.Location), f.Name)));
2031                                 arguments_equal.Add (new Argument (new MemberAccess (other_variable, f.Name)));
2032
2033                                 Expression field_equal = new Invocation (new MemberAccess (equality_comparer,
2034                                         "Equals", loc), arguments_equal);
2035
2036                                 ArrayList arguments_hashcode = new ArrayList (1);
2037                                 arguments_hashcode.Add (new Argument (new MemberAccess (new This (f.Location), f.Name)));
2038                                 Expression field_hashcode = new Invocation (new MemberAccess (equality_comparer,
2039                                         "GetHashCode", loc), arguments_hashcode);
2040
2041                                 rs_hashcode = new Binary (Binary.Operator.Multiply,
2042                                         new Binary (Binary.Operator.ExclusiveOr, rs_hashcode, field_hashcode),
2043                                         FNV_prime);
2044
2045                                 Expression field_to_string = new Conditional (new Binary (Binary.Operator.Inequality,
2046                                         new MemberAccess (new This (f.Location), f.Name), new NullConstant (loc)),
2047                                         new Invocation (new MemberAccess (
2048                                                 new MemberAccess (new This (f.Location), f.Name), "ToString"), null),
2049                                         new StringConstant ("<null>", loc));
2050
2051                                 if (rs_equals == null) {
2052                                         rs_equals = field_equal;
2053                                         string_concat = new Binary (Binary.Operator.Addition,
2054                                                 new StringConstant (p.Name + " = ", loc),
2055                                                 field_to_string);
2056                                         continue;
2057                                 }
2058
2059                                 //
2060                                 // Implementation of ToString () body using string concatenation
2061                                 //
2062                                 string_concat = new Binary (Binary.Operator.Addition,
2063                                         new Binary (Binary.Operator.Addition,
2064                                                 string_concat,
2065                                                 new StringConstant (", " + p.Name + " = ", loc)),
2066                                         field_to_string);
2067
2068                                 rs_equals = new Binary (Binary.Operator.LogicalAnd, rs_equals, field_equal);
2069                         }
2070
2071                         //
2072                         // Equals (object obj) override
2073                         //
2074                         equals_block.AddStatement (new StatementExpression (
2075                                 new Assign (other_variable,
2076                                         new As (equals_block.GetParameterReference ("obj", loc),
2077                                                 current_type, loc), loc)));
2078
2079                         Expression equals_test = new Binary (Binary.Operator.Inequality, other_variable, new NullLiteral (loc));
2080                         if (rs_equals != null)
2081                                 equals_test = new Binary (Binary.Operator.LogicalAnd, equals_test, rs_equals);
2082                         equals_block.AddStatement (new Return (equals_test, loc));
2083
2084                         equals.Block = equals_block;
2085                         equals.ResolveMembers ();
2086                         AddMethod (equals);
2087
2088                         //
2089                         // GetHashCode () override
2090                         //
2091                         Method hashcode = new Method (this, null, TypeManager.system_int32_expr,
2092                                 Modifiers.PUBLIC | Modifiers.OVERRIDE, false, new MemberName ("GetHashCode", loc),
2093                                 Mono.CSharp.Parameters.EmptyReadOnlyParameters, GetDebuggerHiddenAttribute ());
2094
2095                         //
2096                         // Modified FNV with good avalanche behavior and uniform
2097                         // distribution with larger hash sizes.
2098                         //
2099                         // const int FNV_prime = 16777619;
2100                         // int hash = (int) 2166136261;
2101                         // foreach (int d in data)
2102                         //     hash = (hash ^ d) * FNV_prime;
2103                         // hash += hash << 13;
2104                         // hash ^= hash >> 7;
2105                         // hash += hash << 3;
2106                         // hash ^= hash >> 17;
2107                         // hash += hash << 5;
2108
2109                         ToplevelBlock hashcode_block = new ToplevelBlock (loc);
2110                         hashcode_block.AddVariable (TypeManager.system_int32_expr, "hash", loc);
2111                         LocalVariableReference hash_variable = new LocalVariableReference (hashcode_block, "hash", loc);
2112                         hashcode_block.AddStatement (new StatementExpression (
2113                                 new Assign (hash_variable, rs_hashcode)));
2114
2115                         hashcode_block.AddStatement (new StatementExpression (
2116                                 new CompoundAssign (Binary.Operator.Addition, hash_variable,
2117                                         new Binary (Binary.Operator.LeftShift, hash_variable, new IntConstant (13, loc)))));
2118                         hashcode_block.AddStatement (new StatementExpression (
2119                                 new CompoundAssign (Binary.Operator.ExclusiveOr, hash_variable,
2120                                         new Binary (Binary.Operator.RightShift, hash_variable, new IntConstant (7, loc)))));
2121                         hashcode_block.AddStatement (new StatementExpression (
2122                                 new CompoundAssign (Binary.Operator.Addition, hash_variable,
2123                                         new Binary (Binary.Operator.LeftShift, hash_variable, new IntConstant (3, loc)))));
2124                         hashcode_block.AddStatement (new StatementExpression (
2125                                 new CompoundAssign (Binary.Operator.ExclusiveOr, hash_variable,
2126                                         new Binary (Binary.Operator.RightShift, hash_variable, new IntConstant (17, loc)))));
2127                         hashcode_block.AddStatement (new StatementExpression (
2128                                 new CompoundAssign (Binary.Operator.Addition, hash_variable,
2129                                         new Binary (Binary.Operator.LeftShift, hash_variable, new IntConstant (5, loc)))));
2130
2131                         hashcode_block.AddStatement (new Return (hash_variable, loc));
2132                         hashcode.Block = hashcode_block;
2133                         hashcode.ResolveMembers ();
2134                         AddMethod (hashcode);
2135
2136                         //
2137                         // ToString () override
2138                         //
2139
2140                         ToplevelBlock tostring_block = new ToplevelBlock (loc);
2141                         tostring_block.AddStatement (new Return (string_concat, loc));
2142                         tostring.Block = tostring_block;
2143                         tostring.ResolveMembers ();
2144                         AddMethod (tostring);
2145                 }
2146
2147                 public override bool DefineMembers ()
2148                 {
2149                         DefineOverrides ();
2150
2151                         return base.DefineMembers ();
2152                 }
2153
2154                 Attributes GetDebuggerHiddenAttribute ()
2155                 {
2156                         return new Attributes (new Attribute (null, null,
2157                                 "System.Diagnostics.DebuggerHiddenAttribute", null, Location, false));
2158                 }
2159
2160                 public override string GetSignatureForError ()
2161                 {
2162                         return SignatureForError;
2163                 }
2164
2165                 public ArrayList Parameters {
2166                         get {
2167                                 return parameters;
2168                         }
2169                 }
2170         }
2171 }