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