mcs/delegate.cs

   1 //
   2 // delegate.cs: Delegate Handler
   3 //
   4 // Authors:
   5 //     Ravi Pratap (ravi@ximian.com)
   6 //     Miguel de Icaza (miguel@ximian.com)
   7 //     Marek Safar (marek.safar@gmail.com)
   8 //
   9 // Dual licensed under the terms of the MIT X11 or GNU GPL
  10 //
  11 // Copyright 2001 Ximian, Inc (http://www.ximian.com)
  12 // Copyright 2003-2008 Novell, Inc (http://www.ximian.com)
  13 //
  14
  15 using System;
  16 using System.Collections;
  17 using System.Reflection;
  18 using System.Reflection.Emit;
  19 using System.Text;
  20
  21 namespace Mono.CSharp {
  22
  23         /// <summary>
  24         ///   Holds Delegates
  25         /// </summary>
  26         public class Delegate : DeclSpace, IMemberContainer
  27         {
  28                 FullNamedExpression ReturnType;
  29                 public ParametersCompiled      Parameters;
  30
  31                 public ConstructorBuilder ConstructorBuilder;
  32                 public MethodBuilder      InvokeBuilder;
  33                 public MethodBuilder      BeginInvokeBuilder;
  34                 public MethodBuilder      EndInvokeBuilder;
  35
  36                 Type ret_type;
  37
  38                 static string[] attribute_targets = new string [] { "type", "return" };
  39
  40                 Expression instance_expr;
  41                 MethodBase delegate_method;
  42                 ReturnParameter return_attributes;
  43
  44                 MemberCache member_cache;
  45
  46                 const MethodAttributes mattr = MethodAttributes.Public | MethodAttributes.HideBySig |
  47                         MethodAttributes.Virtual | MethodAttributes.NewSlot;
  48
  49                 const int AllowedModifiers =
  50                         Modifiers.NEW |
  51                         Modifiers.PUBLIC |
  52                         Modifiers.PROTECTED |
  53                         Modifiers.INTERNAL |
  54                         Modifiers.UNSAFE |
  55                         Modifiers.PRIVATE;
  56
  57                 public Delegate (NamespaceEntry ns, DeclSpace parent, FullNamedExpression type,
  58                                  int mod_flags, MemberName name, ParametersCompiled param_list,
  59                                  Attributes attrs)
  60                         : base (ns, parent, name, attrs)
  61
  62                 {
  63                         this.ReturnType = type;
  64                         ModFlags        = Modifiers.Check (AllowedModifiers, mod_flags,
  65                                                            IsTopLevel ? Modifiers.INTERNAL :
  66                                                            Modifiers.PRIVATE, name.Location);
  67                         Parameters      = param_list;
  68                 }
  69
  70                 public override void ApplyAttributeBuilder (Attribute a, CustomAttributeBuilder cb, PredefinedAttributes pa)
  71                 {
  72                         if (a.Target == AttributeTargets.ReturnValue) {
  73                                 if (return_attributes == null)
  74                                         return_attributes = new ReturnParameter (InvokeBuilder, Location);
  75
  76                                 return_attributes.ApplyAttributeBuilder (a, cb, pa);
  77                                 return;
  78                         }
  79
  80                         base.ApplyAttributeBuilder (a, cb, pa);
  81                 }
  82
  83                 public override TypeBuilder DefineType ()
  84                 {
  85                         if (TypeBuilder != null)
  86                                 return TypeBuilder;
  87
  88                         if (IsTopLevel) {
  89                                 if (TypeManager.NamespaceClash (Name, Location))
  90                                         return null;
  91
  92                                 ModuleBuilder builder = CodeGen.Module.Builder;
  93
  94                                 TypeBuilder = builder.DefineType (
  95                                         Name, TypeAttr, TypeManager.multicast_delegate_type);
  96                         } else {
  97                                 TypeBuilder builder = Parent.TypeBuilder;
  98
  99                                 string name = Name.Substring (1 + Name.LastIndexOf ('.'));
 100                                 TypeBuilder = builder.DefineNestedType (
 101                                         name, TypeAttr, TypeManager.multicast_delegate_type);
 102                         }
 103
 104                         TypeManager.AddUserType (this);
 105
 106 #if GMCS_SOURCE
 107                         if (IsGeneric) {
 108                                 string[] param_names = new string [TypeParameters.Length];
 109                                 for (int i = 0; i < TypeParameters.Length; i++)
 110                                         param_names [i] = TypeParameters [i].Name;
 111
 112                                 GenericTypeParameterBuilder[] gen_params;
 113                                 gen_params = TypeBuilder.DefineGenericParameters (param_names);
 114
 115                                 int offset = CountTypeParameters - CurrentTypeParameters.Length;
 116                                 for (int i = offset; i < gen_params.Length; i++)
 117                                         CurrentTypeParameters [i - offset].Define (gen_params [i]);
 118
 119                                 foreach (TypeParameter type_param in CurrentTypeParameters) {
 120                                         if (!type_param.Resolve (this))
 121                                                 return null;
 122                                 }
 123
 124                                 Expression current = new SimpleName (
 125                                         MemberName.Basename, TypeParameters, Location);
 126                                 current = current.ResolveAsTypeTerminal (this, false);
 127                                 if (current == null)
 128                                         return null;
 129
 130                                 CurrentType = current.Type;
 131                         }
 132 #endif
 133
 134                         return TypeBuilder;
 135                 }
 136
 137                 public override bool Define ()
 138                 {
 139 #if GMCS_SOURCE
 140                         if (IsGeneric) {
 141                                 foreach (TypeParameter type_param in TypeParameters) {
 142                                         if (!type_param.Resolve (this))
 143                                                 return false;
 144                                 }
 145
 146                                 foreach (TypeParameter type_param in TypeParameters) {
 147                                         if (!type_param.DefineType (this))
 148                                                 return false;
 149                                 }
 150                         }
 151 #endif
 152                         member_cache = new MemberCache (TypeManager.multicast_delegate_type, this);
 153
 154                         // FIXME: POSSIBLY make this static, as it is always constant
 155                         //
 156                         Type [] const_arg_types = new Type [2];
 157                         const_arg_types [0] = TypeManager.object_type;
 158                         const_arg_types [1] = TypeManager.intptr_type;
 159
 160                         const MethodAttributes ctor_mattr = MethodAttributes.RTSpecialName | MethodAttributes.SpecialName |
 161                                 MethodAttributes.HideBySig | MethodAttributes.Public;
 162
 163                         ConstructorBuilder = TypeBuilder.DefineConstructor (ctor_mattr,
 164                                                                             CallingConventions.Standard,
 165                                                                             const_arg_types);
 166
 167                         ConstructorBuilder.DefineParameter (1, ParameterAttributes.None, "object");
 168                         ConstructorBuilder.DefineParameter (2, ParameterAttributes.None, "method");
 169                         //
 170                         // HACK because System.Reflection.Emit is lame
 171                         //
 172                         IParameterData [] fixed_pars = new IParameterData [] {
 173                                 new ParameterData ("object", Parameter.Modifier.NONE),
 174                                 new ParameterData ("method", Parameter.Modifier.NONE)
 175                         };
 176
 177                         AParametersCollection const_parameters = new ParametersImported (
 178                                 fixed_pars,
 179                                 new Type[] { TypeManager.object_type, TypeManager.intptr_type });
 180
 181                         TypeManager.RegisterMethod (ConstructorBuilder, const_parameters);
 182                         member_cache.AddMember (ConstructorBuilder, this);
 183
 184                         ConstructorBuilder.SetImplementationFlags (MethodImplAttributes.Runtime);
 185
 186                         //
 187                         // Here the various methods like Invoke, BeginInvoke etc are defined
 188                         //
 189                         // First, call the `out of band' special method for
 190                         // defining recursively any types we need:
 191
 192                         if (!Parameters.Resolve (this))
 193                                 return false;
 194
 195                         //
 196                         // Invoke method
 197                         //
 198
 199                         // Check accessibility
 200                         foreach (Type partype in Parameters.Types){
 201                                 if (!IsAccessibleAs (partype)) {
 202                                         Report.SymbolRelatedToPreviousError (partype);
 203                                         Report.Error (59, Location,
 204                                                       "Inconsistent accessibility: parameter type `{0}' is less accessible than delegate `{1}'",
 205                                                       TypeManager.CSharpName (partype),
 206                                                       GetSignatureForError ());
 207                                         return false;
 208                                 }
 209                         }
 210
 211                         ReturnType = ReturnType.ResolveAsTypeTerminal (this, false);
 212                         if (ReturnType == null)
 213                                 return false;
 214
 215                         ret_type = ReturnType.Type;
 216
 217                         if (!IsAccessibleAs (ret_type)) {
 218                                 Report.SymbolRelatedToPreviousError (ret_type);
 219                                 Report.Error (58, Location,
 220                                               "Inconsistent accessibility: return type `" +
 221                                               TypeManager.CSharpName (ret_type) + "' is less " +
 222                                               "accessible than delegate `" + GetSignatureForError () + "'");
 223                                 return false;
 224                         }
 225
 226                         CheckProtectedModifier ();
 227
 228                         if (RootContext.StdLib && TypeManager.IsSpecialType (ret_type)) {
 229                                 Method.Error1599 (Location, ret_type);
 230                                 return false;
 231                         }
 232
 233 #if GMCS_SOURCE
 234                         if (ret_type.IsGenericParameter && (ret_type.GenericParameterAttributes & GenericParameterAttributes.Contravariant) != 0) {
 235                                 Report.Error (-33, Location, "Contravariant type parameters can only be used in input positions");
 236                                 return false;
 237                         }
 238 #endif
 239
 240                         //
 241                         // We don't have to check any others because they are all
 242                         // guaranteed to be accessible - they are standard types.
 243                         //
 244
 245                         CallingConventions cc = Parameters.CallingConvention;
 246
 247                         InvokeBuilder = TypeBuilder.DefineMethod ("Invoke",
 248                                                                   mattr,
 249                                                                   cc,
 250                                                                   ret_type,
 251                                                                   Parameters.GetEmitTypes ());
 252
 253                         InvokeBuilder.SetImplementationFlags (MethodImplAttributes.Runtime);
 254
 255                         TypeManager.RegisterMethod (InvokeBuilder, Parameters);
 256                         member_cache.AddMember (InvokeBuilder, this);
 257
 258                         if (TypeManager.iasyncresult_type != null && TypeManager.asynccallback_type != null) {
 259                                 DefineAsyncMethods (cc);
 260                         }
 261
 262                         return true;
 263                 }
 264
 265                 void DefineAsyncMethods (CallingConventions cc)
 266                 {
 267                         //
 268                         // BeginInvoke
 269                         //
 270                         ParametersCompiled async_parameters = ParametersCompiled.MergeGenerated (Parameters, false,
 271                                 new Parameter [] {
 272                                         new Parameter (null, "callback", Parameter.Modifier.NONE, null, Location),
 273                                         new Parameter (null, "object", Parameter.Modifier.NONE, null, Location)
 274                                 },
 275                                 new Type [] {
 276                                         TypeManager.asynccallback_type,
 277                                         TypeManager.object_type
 278                                 }
 279                         );
 280
 281                         BeginInvokeBuilder = TypeBuilder.DefineMethod ("BeginInvoke",
 282                                 mattr, cc, TypeManager.iasyncresult_type, async_parameters.GetEmitTypes ());
 283
 284                         BeginInvokeBuilder.SetImplementationFlags (MethodImplAttributes.Runtime);
 285                         TypeManager.RegisterMethod (BeginInvokeBuilder, async_parameters);
 286                         member_cache.AddMember (BeginInvokeBuilder, this);
 287
 288                         //
 289                         // EndInvoke is a bit more interesting, all the parameters labeled as
 290                         // out or ref have to be duplicated here.
 291                         //
 292
 293                         //
 294                         // Define parameters, and count out/ref parameters
 295                         //
 296                         ParametersCompiled end_parameters;
 297                         int out_params = 0;
 298
 299                         foreach (Parameter p in Parameters.FixedParameters) {
 300                                 if ((p.ModFlags & Parameter.Modifier.ISBYREF) != 0)
 301                                         ++out_params;
 302                         }
 303
 304                         if (out_params > 0) {
 305                                 Type [] end_param_types = new Type [out_params];
 306                                 Parameter[] end_params = new Parameter [out_params];
 307
 308                                 int param = 0;
 309                                 for (int i = 0; i < Parameters.FixedParameters.Length; ++i) {
 310                                         Parameter p = Parameters [i];
 311                                         if ((p.ModFlags & Parameter.Modifier.ISBYREF) == 0)
 312                                                 continue;
 313
 314                                         end_param_types [param] = Parameters.Types [i];
 315                                         end_params [param] = p;
 316                                         ++param;
 317                                 }
 318                                 end_parameters = ParametersCompiled.CreateFullyResolved (end_params, end_param_types);
 319                         } else {
 320                                 end_parameters = ParametersCompiled.EmptyReadOnlyParameters;
 321                         }
 322
 323                         end_parameters = ParametersCompiled.MergeGenerated (end_parameters, false,
 324                                 new Parameter (null, "result", Parameter.Modifier.NONE, null, Location), TypeManager.iasyncresult_type);
 325
 326                         //
 327                         // Create method, define parameters, register parameters with type system
 328                         //
 329                         EndInvokeBuilder = TypeBuilder.DefineMethod ("EndInvoke", mattr, cc, ret_type, end_parameters.GetEmitTypes ());
 330                         EndInvokeBuilder.SetImplementationFlags (MethodImplAttributes.Runtime);
 331
 332                         end_parameters.ApplyAttributes (EndInvokeBuilder);
 333                         TypeManager.RegisterMethod (EndInvokeBuilder, end_parameters);
 334                         member_cache.AddMember (EndInvokeBuilder, this);
 335                 }
 336
 337                 public override void Emit ()
 338                 {
 339                         Parameters.ApplyAttributes (InvokeBuilder);
 340
 341                         if (BeginInvokeBuilder != null) {
 342                                 ParametersCompiled p = (ParametersCompiled) TypeManager.GetParameterData (BeginInvokeBuilder);
 343                                 p.ApplyAttributes (BeginInvokeBuilder);
 344                         }
 345
 346                         if (OptAttributes != null) {
 347                                 OptAttributes.Emit ();
 348                         }
 349
 350                         base.Emit ();
 351                 }
 352
 353                 protected override TypeAttributes TypeAttr {
 354                         get {
 355                                 return Modifiers.TypeAttr (ModFlags, IsTopLevel) |
 356                                         TypeAttributes.Class | TypeAttributes.Sealed |
 357                                         base.TypeAttr;
 358                         }
 359                 }
 360
 361                 public override string[] ValidAttributeTargets {
 362                         get {
 363                                 return attribute_targets;
 364                         }
 365                 }
 366
 367                 //TODO: duplicate
 368                 protected override bool VerifyClsCompliance ()
 369                 {
 370                         if (!base.VerifyClsCompliance ()) {
 371                                 return false;
 372                         }
 373
 374                         Parameters.VerifyClsCompliance ();
 375
 376                         if (!AttributeTester.IsClsCompliant (ReturnType.Type)) {
 377                                 Report.Warning (3002, 1, Location, "Return type of `{0}' is not CLS-compliant",
 378                                         GetSignatureForError ());
 379                         }
 380                         return true;
 381                 }
 382
 383
 384                 public static ConstructorInfo GetConstructor (Type container_type, Type delegate_type)
 385                 {
 386                         Type dt = delegate_type;
 387 #if GMCS_SOURCE
 388                         Type[] g_args = null;
 389                         if (delegate_type.IsGenericType) {
 390                                 g_args = delegate_type.GetGenericArguments ();
 391                                 delegate_type = delegate_type.GetGenericTypeDefinition ();
 392                         }
 393 #endif
 394
 395                         Delegate d = TypeManager.LookupDelegate (delegate_type);
 396                         if (d != null) {
 397 #if GMCS_SOURCE
 398                                 if (g_args != null)
 399                                         return TypeBuilder.GetConstructor (dt, d.ConstructorBuilder);
 400 #endif
 401                                 return d.ConstructorBuilder;
 402                         }
 403
 404                         Expression ml = Expression.MemberLookup (container_type,
 405                                 null, dt, ConstructorInfo.ConstructorName, MemberTypes.Constructor,
 406                                 BindingFlags.Public | BindingFlags.Instance | BindingFlags.DeclaredOnly, Location.Null);
 407
 408                         MethodGroupExpr mg = ml as MethodGroupExpr;
 409                         if (mg == null) {
 410                                 Report.Error (-100, Location.Null, "Internal error: could not find delegate constructor!");
 411                                 // FIXME: null will cause a crash later
 412                                 return null;
 413                         }
 414
 415                         return (ConstructorInfo) mg.Methods[0];
 416                 }
 417
 418                 //
 419                 // Returns the MethodBase for "Invoke" from a delegate type, this is used
 420                 // to extract the signature of a delegate.
 421                 //
 422                 public static MethodInfo GetInvokeMethod (Type container_type, Type delegate_type)
 423                 {
 424                         Type dt = delegate_type;
 425 #if GMCS_SOURCE
 426                         Type[] g_args = null;
 427                         if (delegate_type.IsGenericType) {
 428                                 g_args = delegate_type.GetGenericArguments ();
 429                                 delegate_type = delegate_type.GetGenericTypeDefinition ();
 430                         }
 431 #endif
 432                         Delegate d = TypeManager.LookupDelegate (delegate_type);
 433                         MethodInfo invoke;
 434                         if (d != null) {
 435 #if GMCS_SOURCE
 436                                 if (g_args != null) {
 437                                         invoke = TypeBuilder.GetMethod (dt, d.InvokeBuilder);
 438 #if MS_COMPATIBLE
 439                                         ParametersCompiled p = (ParametersCompiled) d.Parameters.InflateTypes (g_args, g_args);
 440                                         TypeManager.RegisterMethod (invoke, p);
 441 #endif
 442                                         return invoke;
 443                                 }
 444 #endif
 445                                 return d.InvokeBuilder;
 446                         }
 447
 448                         Expression ml = Expression.MemberLookup (container_type, null, dt,
 449                                 "Invoke", Location.Null);
 450
 451                         MethodGroupExpr mg = ml as MethodGroupExpr;
 452                         if (mg == null) {
 453                                 Report.Error (-100, Location.Null, "Internal error: could not find Invoke method!");
 454                                 // FIXME: null will cause a crash later
 455                                 return null;
 456                         }
 457
 458                         invoke = (MethodInfo) mg.Methods[0];
 459 #if MS_COMPATIBLE
 460                         if (g_args != null) {
 461                                 AParametersCollection p = TypeManager.GetParameterData (invoke);
 462                                 p = p.InflateTypes (g_args, g_args);
 463                                 TypeManager.RegisterMethod (invoke, p);
 464                                 return invoke;
 465                         }
 466 #endif
 467
 468                         return invoke;
 469                 }
 470
 471                 //
 472                 // 15.2 Delegate compatibility
 473                 //
 474                 public static bool IsTypeCovariant (Expression a, Type b)
 475                 {
 476                         //
 477                         // For each value parameter (a parameter with no ref or out modifier), an
 478                         // identity conversion or implicit reference conversion exists from the
 479                         // parameter type in D to the corresponding parameter type in M
 480                         //
 481                         if (a.Type == b)
 482                                 return true;
 483
 484                         if (RootContext.Version == LanguageVersion.ISO_1)
 485                                 return false;
 486
 487                         return Convert.ImplicitReferenceConversionExists (a, b);
 488                 }
 489
 490                 /// <summary>
 491                 ///  Verifies whether the method in question is compatible with the delegate
 492                 ///  Returns the method itself if okay and null if not.
 493                 /// </summary>
 494                 public static MethodBase VerifyMethod (Type container_type, Type delegate_type,
 495                                                        MethodGroupExpr old_mg, MethodBase mb)
 496                 {
 497                         bool is_method_definition = TypeManager.IsGenericMethodDefinition (mb);
 498
 499                         MethodInfo invoke_mb = GetInvokeMethod (container_type, delegate_type);
 500                         if (invoke_mb == null)
 501                                 return null;
 502
 503                         if (is_method_definition)
 504                                 invoke_mb = (MethodInfo) TypeManager.DropGenericMethodArguments (invoke_mb);
 505
 506                         AParametersCollection invoke_pd = TypeManager.GetParameterData (invoke_mb);
 507
 508 #if GMCS_SOURCE
 509                         if (!is_method_definition && old_mg.type_arguments == null &&
 510                             !TypeManager.InferTypeArguments (invoke_pd, ref mb))
 511                                 return null;
 512 #endif
 513                         AParametersCollection pd = TypeManager.GetParameterData (mb);
 514
 515                         if (invoke_pd.Count != pd.Count)
 516                                 return null;
 517
 518                         for (int i = pd.Count; i > 0; ) {
 519                                 i--;
 520
 521                                 Type invoke_pd_type = invoke_pd.Types [i];
 522                                 Type pd_type = pd.Types [i];
 523                                 Parameter.Modifier invoke_pd_type_mod = invoke_pd.FixedParameters [i].ModFlags;
 524                                 Parameter.Modifier pd_type_mod = pd.FixedParameters [i].ModFlags;
 525
 526                                 invoke_pd_type_mod &= ~Parameter.Modifier.PARAMS;
 527                                 pd_type_mod &= ~Parameter.Modifier.PARAMS;
 528
 529                                 if (invoke_pd_type_mod != pd_type_mod)
 530                                         return null;
 531
 532                                 if (TypeManager.IsEqual (invoke_pd_type, pd_type))
 533                                         continue;
 534
 535                                 if (IsTypeCovariant (new EmptyExpression (invoke_pd_type), pd_type))
 536                                         continue;
 537
 538                                 return null;
 539                         }
 540
 541                         Type invoke_mb_retval = ((MethodInfo) invoke_mb).ReturnType;
 542                         Type mb_retval = ((MethodInfo) mb).ReturnType;
 543                         if (TypeManager.TypeToCoreType (invoke_mb_retval) == TypeManager.TypeToCoreType (mb_retval))
 544                                 return mb;
 545
 546                         //if (!IsTypeCovariant (mb_retval, invoke_mb_retval))
 547                         //      return null;
 548
 549                         if (RootContext.Version == LanguageVersion.ISO_1)
 550                                 return null;
 551
 552                         return mb;
 553                 }
 554
 555                 // <summary>
 556                 //  Verifies whether the invocation arguments are compatible with the
 557                 //  delegate's target method
 558                 // </summary>
 559                 public static bool VerifyApplicability (EmitContext ec, Type delegate_type,
 560                                                         ArrayList args, Location loc)
 561                 {
 562                         int arg_count;
 563
 564                         if (args == null)
 565                                 arg_count = 0;
 566                         else
 567                                 arg_count = args.Count;
 568
 569                         MethodBase mb = GetInvokeMethod (ec.ContainerType, delegate_type);
 570                         MethodGroupExpr me = new MethodGroupExpr (new MemberInfo [] { mb }, delegate_type, loc);
 571
 572                         AParametersCollection pd = TypeManager.GetParameterData (mb);
 573
 574                         int pd_count = pd.Count;
 575
 576                         bool params_method = pd.HasParams;
 577                         bool is_params_applicable = false;
 578                         bool is_applicable = me.IsApplicable (ec, args, arg_count, ref mb, ref is_params_applicable) == 0;
 579
 580                         if (!is_applicable && !params_method && arg_count != pd_count) {
 581                                 Report.Error (1593, loc, "Delegate `{0}' does not take `{1}' arguments",
 582                                         TypeManager.CSharpName (delegate_type), arg_count.ToString ());
 583                                 return false;
 584                         }
 585
 586                         return me.VerifyArgumentsCompat (
 587                                         ec, ref args, arg_count, mb,
 588                                         is_params_applicable || (!is_applicable && params_method),
 589                                         false, loc);
 590                 }
 591
 592                 public static string FullDelegateDesc (MethodBase invoke_method)
 593                 {
 594                         return TypeManager.GetFullNameSignature (invoke_method).Replace (".Invoke", "");
 595                 }
 596
 597                 public override MemberCache MemberCache {
 598                         get {
 599                                 return member_cache;
 600                         }
 601                 }
 602
 603                 public Expression InstanceExpression {
 604                         get {
 605                                 return instance_expr;
 606                         }
 607                         set {
 608                                 instance_expr = value;
 609                         }
 610                 }
 611
 612                 public MethodBase TargetMethod {
 613                         get {
 614                                 return delegate_method;
 615                         }
 616                         set {
 617                                 delegate_method = value;
 618                         }
 619                 }
 620
 621                 public Type TargetReturnType {
 622                         get {
 623                                 return ret_type;
 624                         }
 625                 }
 626
 627                 public override AttributeTargets AttributeTargets {
 628                         get {
 629                                 return AttributeTargets.Delegate;
 630                         }
 631                 }
 632
 633                 //
 634                 //   Represents header string for documentation comment.
 635                 //
 636                 public override string DocCommentHeader {
 637                         get { return "T:"; }
 638                 }
 639
 640                 #region IMemberContainer Members
 641
 642                 string IMemberContainer.Name
 643                 {
 644                         get { throw new NotImplementedException (); }
 645                 }
 646
 647                 Type IMemberContainer.Type
 648                 {
 649                         get { throw new NotImplementedException (); }
 650                 }
 651
 652                 MemberCache IMemberContainer.BaseCache
 653                 {
 654                         get { throw new NotImplementedException (); }
 655                 }
 656
 657                 bool IMemberContainer.IsInterface {
 658                         get {
 659                                 return false;
 660                         }
 661                 }
 662
 663                 MemberList IMemberContainer.GetMembers (MemberTypes mt, BindingFlags bf)
 664                 {
 665                         throw new NotImplementedException ();
 666                 }
 667
 668                 #endregion
 669         }
 670
 671         //
 672         // Base class for `NewDelegate' and `ImplicitDelegateCreation'
 673         //
 674         public abstract class DelegateCreation : Expression, MethodGroupExpr.IErrorHandler
 675         {
 676                 protected ConstructorInfo constructor_method;
 677                 protected MethodInfo delegate_method;
 678                 // We keep this to handle IsBase only
 679                 protected MethodGroupExpr method_group;
 680                 protected Expression delegate_instance_expression;
 681
 682                 public static ArrayList CreateDelegateMethodArguments (MethodInfo invoke_method, Location loc)
 683                 {
 684                         AParametersCollection pd = TypeManager.GetParameterData (invoke_method);
 685                         ArrayList delegate_arguments = new ArrayList (pd.Count);
 686                         for (int i = 0; i < pd.Count; ++i) {
 687                                 Argument.AType atype_modifier;
 688                                 Type atype = pd.Types [i];
 689                                 switch (pd.FixedParameters [i].ModFlags) {
 690                                 case Parameter.Modifier.REF:
 691                                         atype_modifier = Argument.AType.Ref;
 692                                         //atype = atype.GetElementType ();
 693                                         break;
 694                                 case Parameter.Modifier.OUT:
 695                                         atype_modifier = Argument.AType.Out;
 696                                         //atype = atype.GetElementType ();
 697                                         break;
 698                                 case Parameter.Modifier.ARGLIST:
 699                                         // __arglist is not valid
 700                                         throw new InternalErrorException ("__arglist modifier");
 701                                 default:
 702                                         atype_modifier = Argument.AType.Expression;
 703                                         break;
 704                                 }
 705                                 delegate_arguments.Add (new Argument (new TypeExpression (atype, loc), atype_modifier));
 706                         }
 707                         return delegate_arguments;
 708                 }
 709
 710                 public override Expression CreateExpressionTree (EmitContext ec)
 711                 {
 712                         MemberAccess ma = new MemberAccess (new MemberAccess (new QualifiedAliasMember ("global", "System", loc), "Delegate", loc), "CreateDelegate", loc);
 713
 714                         ArrayList args = new ArrayList (3);
 715                         args.Add (new Argument (new TypeOf (new TypeExpression (type, loc), loc)));
 716                         args.Add (new Argument (new NullLiteral (loc)));
 717                         args.Add (new Argument (new TypeOfMethodInfo (delegate_method, loc)));
 718                         Expression e = new Invocation (ma, args).Resolve (ec);
 719                         if (e == null)
 720                                 return null;
 721
 722                         e = Convert.ExplicitConversion (ec, e, type, loc);
 723                         if (e == null)
 724                                 return null;
 725
 726                         return e.CreateExpressionTree (ec);
 727                 }
 728
 729                 public override Expression DoResolve (EmitContext ec)
 730                 {
 731                         constructor_method = Delegate.GetConstructor (ec.ContainerType, type);
 732
 733                         MethodInfo invoke_method = Delegate.GetInvokeMethod (ec.ContainerType, type);
 734                         method_group.DelegateType = type;
 735                         method_group.CustomErrorHandler = this;
 736
 737                         ArrayList arguments = CreateDelegateMethodArguments (invoke_method, loc);
 738                         method_group = method_group.OverloadResolve (ec, ref arguments, false, loc);
 739                         if (method_group == null)
 740                                 return null;
 741
 742                         delegate_method = (MethodInfo) method_group;
 743
 744                         if (TypeManager.IsNullableType (delegate_method.DeclaringType)) {
 745                                 Report.Error (1728, loc, "Cannot create delegate from method `{0}' because it is a member of System.Nullable<T> type",
 746                                         TypeManager.GetFullNameSignature (delegate_method));
 747                                 return null;
 748                         }
 749
 750                         Invocation.IsSpecialMethodInvocation (delegate_method, loc);
 751
 752                         ExtensionMethodGroupExpr emg = method_group as ExtensionMethodGroupExpr;
 753                         if (emg != null) {
 754                                 delegate_instance_expression = emg.ExtensionExpression;
 755                                 Type e_type = delegate_instance_expression.Type;
 756                                 if (TypeManager.IsValueType (e_type)) {
 757                                         Report.Error (1113, loc, "Extension method `{0}' of value type `{1}' cannot be used to create delegates",
 758                                                 TypeManager.CSharpSignature (delegate_method), TypeManager.CSharpName (e_type));
 759                                 }
 760                         }
 761
 762                         Type rt = TypeManager.TypeToCoreType (delegate_method.ReturnType);
 763                         Expression ret_expr = new TypeExpression (rt, loc);
 764                         if (!Delegate.IsTypeCovariant (ret_expr, (TypeManager.TypeToCoreType (invoke_method.ReturnType)))) {
 765                                 Error_ConversionFailed (ec, delegate_method, ret_expr);
 766                         }
 767
 768                         if (Invocation.IsMethodExcluded (delegate_method, loc)) {
 769                                 Report.SymbolRelatedToPreviousError (delegate_method);
 770                                 MethodOrOperator m = TypeManager.GetMethod (delegate_method) as MethodOrOperator;
 771                                 if (m != null && m.IsPartialDefinition) {
 772                                         Report.Error (762, loc, "Cannot create delegate from partial method declaration `{0}'",
 773                                                 TypeManager.CSharpSignature (delegate_method));
 774                                 } else {
 775                                         Report.Error (1618, loc, "Cannot create delegate with `{0}' because it has a Conditional attribute",
 776                                                 TypeManager.CSharpSignature (delegate_method));
 777                                 }
 778                         }
 779
 780                         DoResolveInstanceExpression (ec);
 781                         eclass = ExprClass.Value;
 782                         return this;
 783                 }
 784
 785                 void DoResolveInstanceExpression (EmitContext ec)
 786                 {
 787                         //
 788                         // Argument is another delegate
 789                         //
 790                         if (delegate_instance_expression != null)
 791                                 return;
 792
 793                         Expression instance = method_group.InstanceExpression;
 794                         if (instance != null && instance != EmptyExpression.Null) {
 795                                 delegate_instance_expression = instance;
 796                                 Type instance_type = delegate_instance_expression.Type;
 797                                 if (TypeManager.IsValueType (instance_type) || TypeManager.IsGenericParameter (instance_type)) {
 798                                         delegate_instance_expression = new BoxedCast (
 799                                                 delegate_instance_expression, TypeManager.object_type);
 800                                 }
 801                         } else if (!delegate_method.IsStatic && !ec.IsStatic) {
 802                                 delegate_instance_expression = ec.GetThis (loc);
 803                         }
 804                 }
 805
 806                 public override void Emit (EmitContext ec)
 807                 {
 808                         if (delegate_instance_expression == null)
 809                                 ec.ig.Emit (OpCodes.Ldnull);
 810                         else
 811                                 delegate_instance_expression.Emit (ec);
 812
 813                         if (!delegate_method.DeclaringType.IsSealed && delegate_method.IsVirtual && !method_group.IsBase) {
 814                                 ec.ig.Emit (OpCodes.Dup);
 815                                 ec.ig.Emit (OpCodes.Ldvirtftn, delegate_method);
 816                         } else {
 817                                 ec.ig.Emit (OpCodes.Ldftn, delegate_method);
 818                         }
 819
 820                         ec.ig.Emit (OpCodes.Newobj, constructor_method);
 821                 }
 822
 823                 void Error_ConversionFailed (EmitContext ec, MethodBase method, Expression return_type)
 824                 {
 825                         MethodInfo invoke_method = Delegate.GetInvokeMethod (ec.ContainerType, type);
 826                         string member_name = delegate_instance_expression != null ?
 827                                 Delegate.FullDelegateDesc (method) :
 828                                 TypeManager.GetFullNameSignature (method);
 829
 830                         Report.SymbolRelatedToPreviousError (type);
 831                         Report.SymbolRelatedToPreviousError (method);
 832                         if (RootContext.Version == LanguageVersion.ISO_1) {
 833                                 Report.Error (410, loc, "A method or delegate `{0} {1}' parameters and return type must be same as delegate `{2} {3}' parameters and return type",
 834                                         TypeManager.CSharpName (((MethodInfo) method).ReturnType), member_name,
 835                                         TypeManager.CSharpName (invoke_method.ReturnType), Delegate.FullDelegateDesc (invoke_method));
 836                                 return;
 837                         }
 838                         if (return_type == null) {
 839                                 Report.Error (123, loc, "A method or delegate `{0}' parameters do not match delegate `{1}' parameters",
 840                                         member_name, Delegate.FullDelegateDesc (invoke_method));
 841                                 return;
 842                         }
 843
 844                         Report.Error (407, loc, "A method or delegate `{0} {1}' return type does not match delegate `{2} {3}' return type",
 845                                 return_type.GetSignatureForError (), member_name,
 846                                 TypeManager.CSharpName (invoke_method.ReturnType), Delegate.FullDelegateDesc (invoke_method));
 847                 }
 848
 849                 public static MethodBase ImplicitStandardConversionExists (MethodGroupExpr mg, Type target_type)
 850                 {
 851                         if (target_type == TypeManager.delegate_type || target_type == TypeManager.multicast_delegate_type)
 852                                 return null;
 853
 854                         foreach (MethodInfo mi in mg.Methods){
 855                                 MethodBase mb = Delegate.VerifyMethod (mg.DeclaringType, target_type, mg, mi);
 856                                 if (mb != null)
 857                                         return mb;
 858                         }
 859                         return null;
 860                 }
 861
 862                 public override void MutateHoistedGenericType (AnonymousMethodStorey storey)
 863                 {
 864                         if (delegate_instance_expression != null)
 865                                 delegate_instance_expression.MutateHoistedGenericType (storey);
 866
 867                         delegate_method = storey.MutateGenericMethod (delegate_method);
 868                         constructor_method = storey.MutateConstructor (constructor_method);
 869                 }
 870
 871                 #region IErrorHandler Members
 872
 873                 public bool NoExactMatch (EmitContext ec, MethodBase method)
 874                 {
 875                         if (TypeManager.IsGenericMethod (method))
 876                                 return false;
 877
 878                         Error_ConversionFailed (ec, method, null);
 879                         return true;
 880                 }
 881
 882                 public bool AmbiguousCall (MethodBase ambiguous)
 883                 {
 884                         return false;
 885                 }
 886
 887                 #endregion
 888         }
 889
 890         //
 891         // Created from the conversion code
 892         //
 893         public class ImplicitDelegateCreation : DelegateCreation
 894         {
 895                 ImplicitDelegateCreation (Type t, MethodGroupExpr mg, Location l)
 896                 {
 897                         type = t;
 898                         this.method_group = mg;
 899                         loc = l;
 900                 }
 901
 902                 static public Expression Create (EmitContext ec, MethodGroupExpr mge,
 903                                                  Type target_type, Location loc)
 904                 {
 905                         ImplicitDelegateCreation d = new ImplicitDelegateCreation (target_type, mge, loc);
 906                         return d.DoResolve (ec);
 907                 }
 908         }
 909
 910         //
 911         // A delegate-creation-expression, invoked from the `New' class
 912         //
 913         public class NewDelegate : DelegateCreation
 914         {
 915                 public ArrayList Arguments;
 916
 917                 //
 918                 // This constructor is invoked from the `New' expression
 919                 //
 920                 public NewDelegate (Type type, ArrayList Arguments, Location loc)
 921                 {
 922                         this.type = type;
 923                         this.Arguments = Arguments;
 924                         this.loc  = loc;
 925                 }
 926
 927                 public override Expression DoResolve (EmitContext ec)
 928                 {
 929                         if (Arguments == null || Arguments.Count != 1) {
 930                                 Error_InvalidDelegateArgument ();
 931                                 return null;
 932                         }
 933
 934                         Argument a = (Argument) Arguments [0];
 935                         if (!a.ResolveMethodGroup (ec))
 936                                 return null;
 937
 938                         Expression e = a.Expr;
 939
 940                         AnonymousMethodExpression ame = e as AnonymousMethodExpression;
 941                         if (ame != null && RootContext.Version != LanguageVersion.ISO_1) {
 942                                 e = ame.Compatible (ec, type);
 943                                 if (e == null)
 944                                         return null;
 945
 946                                 return e.Resolve (ec);
 947                         }
 948
 949                         method_group = e as MethodGroupExpr;
 950                         if (method_group == null) {
 951                                 if (!TypeManager.IsDelegateType (e.Type)) {
 952                                         e.Error_UnexpectedKind (ResolveFlags.MethodGroup | ResolveFlags.Type, loc);
 953                                         return null;
 954                                 }
 955
 956                                 //
 957                                 // An argument is not a method but another delegate
 958                                 //
 959                                 delegate_instance_expression = e;
 960                                 method_group = new MethodGroupExpr (new MemberInfo [] {
 961                                         Delegate.GetInvokeMethod (ec.ContainerType, e.Type) }, e.Type, loc);
 962                         }
 963
 964                         return base.DoResolve (ec);
 965                 }
 966
 967                 void Error_InvalidDelegateArgument ()
 968                 {
 969                         Report.Error (149, loc, "Method name expected");
 970                 }
 971         }
 972
 973         public class DelegateInvocation : ExpressionStatement {
 974
 975                 readonly Expression InstanceExpr;
 976                 readonly ArrayList  Arguments;
 977
 978                 MethodInfo method;
 979
 980                 public DelegateInvocation (Expression instance_expr, ArrayList args, Location loc)
 981                 {
 982                         this.InstanceExpr = instance_expr;
 983                         this.Arguments = args;
 984                         this.loc = loc;
 985                 }
 986
 987                 public override Expression CreateExpressionTree (EmitContext ec)
 988                 {
 989                         ArrayList args;
 990                         if (Arguments == null)
 991                                 args = new ArrayList (1);
 992                         else
 993                                 args = new ArrayList (Arguments.Count + 1);
 994
 995                         args.Add (new Argument (InstanceExpr.CreateExpressionTree (ec)));
 996                         if (Arguments != null) {
 997                                 foreach (Argument a in Arguments)
 998                                         args.Add (new Argument (a.Expr.CreateExpressionTree (ec)));
 999                         }
1000
1001                         return CreateExpressionFactoryCall ("Invoke", args);
1002                 }
1003
1004                 public override Expression DoResolve (EmitContext ec)
1005                 {
1006                         if (InstanceExpr is EventExpr) {
1007                                 ((EventExpr) InstanceExpr).Error_CannotAssign ();
1008                                 return null;
1009                         }
1010
1011                         Type del_type = InstanceExpr.Type;
1012                         if (del_type == null)
1013                                 return null;
1014
1015                         if (Arguments != null){
1016                                 foreach (Argument a in Arguments){
1017                                         if (!a.Resolve (ec, loc))
1018                                                 return null;
1019                                 }
1020                         }
1021
1022                         if (!Delegate.VerifyApplicability (ec, del_type, Arguments, loc))
1023                                 return null;
1024
1025                         method = Delegate.GetInvokeMethod (ec.ContainerType, del_type);
1026                         type = TypeManager.TypeToCoreType (method.ReturnType);
1027                         eclass = ExprClass.Value;
1028
1029                         return this;
1030                 }
1031
1032                 public override void Emit (EmitContext ec)
1033                 {
1034                         //
1035                         // Invocation on delegates call the virtual Invoke member
1036                         // so we are always `instance' calls
1037                         //
1038                         Invocation.EmitCall (ec, false, InstanceExpr, method, Arguments, loc);
1039                 }
1040
1041                 public override void EmitStatement (EmitContext ec)
1042                 {
1043                         Emit (ec);
1044                         //
1045                         // Pop the return value if there is one
1046                         //
1047                         if (type != TypeManager.void_type)
1048                                 ec.ig.Emit (OpCodes.Pop);
1049                 }
1050
1051                 public override void MutateHoistedGenericType (AnonymousMethodStorey storey)
1052                 {
1053                         method = storey.MutateGenericMethod (method);
1054                         type = storey.MutateType (type);
1055
1056                         if (Arguments != null) {
1057                                 foreach (Argument a in Arguments) {
1058                                         a.Expr.MutateHoistedGenericType (storey);
1059                                 }
1060                         }
1061
1062                         InstanceExpr.MutateHoistedGenericType (storey);
1063                 }
1064         }
1065 }