mcs/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 // Licensed under the terms of the GNU GPL
  10 //
  11 // (C) 2001 Ximian, Inc (http://www.ximian.com)
  12 //
  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 {
  27                 public Expression ReturnType;
  28                 public Parameters      Parameters;
  29
  30                 public ConstructorBuilder ConstructorBuilder;
  31                 public MethodBuilder      InvokeBuilder;
  32                 public MethodBuilder      BeginInvokeBuilder;
  33                 public MethodBuilder      EndInvokeBuilder;
  34
  35                 Type ret_type;
  36
  37                 static string[] attribute_targets = new string [] { "type", "return" };
  38
  39                 Expression instance_expr;
  40                 MethodBase delegate_method;
  41                 ReturnParameter return_attributes;
  42
  43                 const int AllowedModifiers =
  44                         Modifiers.NEW |
  45                         Modifiers.PUBLIC |
  46                         Modifiers.PROTECTED |
  47                         Modifiers.INTERNAL |
  48                         Modifiers.UNSAFE |
  49                         Modifiers.PRIVATE;
  50
  51                 public Delegate (NamespaceEntry ns, DeclSpace parent, Expression type,
  52                                  int mod_flags, MemberName name, Parameters param_list,
  53                                  Attributes attrs)
  54                         : base (ns, parent, name, attrs)
  55
  56                 {
  57                         this.ReturnType = type;
  58                         ModFlags        = Modifiers.Check (AllowedModifiers, mod_flags,
  59                                                            IsTopLevel ? Modifiers.INTERNAL :
  60                                                            Modifiers.PRIVATE, name.Location);
  61                         Parameters      = param_list;
  62                 }
  63
  64                 public override void ApplyAttributeBuilder(Attribute a, CustomAttributeBuilder cb)
  65                 {
  66                         if (a.Target == AttributeTargets.ReturnValue) {
  67                                 if (return_attributes == null)
  68                                         return_attributes = new ReturnParameter (InvokeBuilder, Location);
  69
  70                                 return_attributes.ApplyAttributeBuilder (a, cb);
  71                                 return;
  72                         }
  73
  74                         base.ApplyAttributeBuilder (a, cb);
  75                 }
  76
  77                 public override TypeBuilder DefineType ()
  78                 {
  79                         if (TypeBuilder != null)
  80                                 return TypeBuilder;
  81
  82                         if (TypeManager.multicast_delegate_type == null && !RootContext.StdLib) {
  83                                 Namespace system = RootNamespace.Global.GetNamespace ("System", true);
  84                                 TypeExpr expr = system.Lookup (this, "MulticastDelegate", Location) as TypeExpr;
  85                                 TypeManager.multicast_delegate_type = expr.Type;
  86                         }
  87
  88                         if (TypeManager.multicast_delegate_type == null)
  89                                 Report.Error (-100, Location, "Internal error: delegate used before " +
  90                                               "System.MulticastDelegate is resolved.  This can only " +
  91                                               "happen during corlib compilation, when using a delegate " +
  92                                               "in any of the `core' classes.  See bug #72015 for details.");
  93
  94                         if (IsTopLevel) {
  95                                 if (TypeManager.NamespaceClash (Name, Location))
  96                                         return null;
  97
  98                                 ModuleBuilder builder = CodeGen.Module.Builder;
  99
 100                                 TypeBuilder = builder.DefineType (
 101                                         Name, TypeAttr, TypeManager.multicast_delegate_type);
 102                         } else {
 103                                 TypeBuilder builder = Parent.TypeBuilder;
 104
 105                                 string name = Name.Substring (1 + Name.LastIndexOf ('.'));
 106                                 TypeBuilder = builder.DefineNestedType (
 107                                         name, TypeAttr, TypeManager.multicast_delegate_type);
 108                         }
 109
 110                         TypeManager.AddUserType (this);
 111
 112 #if GMCS_SOURCE
 113                         if (IsGeneric) {
 114                                 string[] param_names = new string [TypeParameters.Length];
 115                                 for (int i = 0; i < TypeParameters.Length; i++)
 116                                         param_names [i] = TypeParameters [i].Name;
 117
 118                                 GenericTypeParameterBuilder[] gen_params;
 119                                 gen_params = TypeBuilder.DefineGenericParameters (param_names);
 120
 121                                 int offset = CountTypeParameters - CurrentTypeParameters.Length;
 122                                 for (int i = offset; i < gen_params.Length; i++)
 123                                         CurrentTypeParameters [i - offset].Define (gen_params [i]);
 124
 125                                 foreach (TypeParameter type_param in CurrentTypeParameters) {
 126                                         if (!type_param.Resolve (this))
 127                                                 return null;
 128                                 }
 129
 130                                 Expression current = new SimpleName (
 131                                         MemberName.Basename, TypeParameters, Location);
 132                                 current = current.ResolveAsTypeTerminal (this, false);
 133                                 if (current == null)
 134                                         return null;
 135
 136                                 CurrentType = current.Type;
 137                         }
 138 #endif
 139
 140                         return TypeBuilder;
 141                 }
 142
 143                 public override bool Define ()
 144                 {
 145 #if GMCS_SOURCE
 146                         if (IsGeneric) {
 147                                 foreach (TypeParameter type_param in TypeParameters) {
 148                                         if (!type_param.Resolve (this))
 149                                                 return false;
 150                                 }
 151
 152                                 foreach (TypeParameter type_param in TypeParameters) {
 153                                         if (!type_param.DefineType (this))
 154                                                 return false;
 155                                 }
 156
 157                                 foreach (TypeParameter type_param in TypeParameters) {
 158                                         if (!type_param.CheckDependencies ())
 159                                                 return false;
 160                                 }
 161                         }
 162 #endif
 163
 164                         // FIXME: POSSIBLY make this static, as it is always constant
 165                         //
 166                         Type [] const_arg_types = new Type [2];
 167                         const_arg_types [0] = TypeManager.object_type;
 168                         const_arg_types [1] = TypeManager.intptr_type;
 169
 170                         const MethodAttributes ctor_mattr = MethodAttributes.RTSpecialName | MethodAttributes.SpecialName |
 171                                 MethodAttributes.HideBySig | MethodAttributes.Public;
 172
 173                         ConstructorBuilder = TypeBuilder.DefineConstructor (ctor_mattr,
 174                                                                             CallingConventions.Standard,
 175                                                                             const_arg_types);
 176
 177                         ConstructorBuilder.DefineParameter (1, ParameterAttributes.None, "object");
 178                         ConstructorBuilder.DefineParameter (2, ParameterAttributes.None, "method");
 179                         //
 180                         // HACK because System.Reflection.Emit is lame
 181                         //
 182                         Parameter [] fixed_pars = new Parameter [2];
 183                         fixed_pars [0] = new Parameter (TypeManager.object_type, "object",
 184                                                         Parameter.Modifier.NONE, null, Location);
 185                         fixed_pars [1] = new Parameter (TypeManager.intptr_type, "method",
 186                                                         Parameter.Modifier.NONE, null, Location);
 187                         Parameters const_parameters = new Parameters (fixed_pars);
 188                         const_parameters.Resolve (null);
 189
 190                         TypeManager.RegisterMethod (ConstructorBuilder, const_parameters);
 191
 192
 193                         ConstructorBuilder.SetImplementationFlags (MethodImplAttributes.Runtime);
 194
 195                         //
 196                         // Here the various methods like Invoke, BeginInvoke etc are defined
 197                         //
 198                         // First, call the `out of band' special method for
 199                         // defining recursively any types we need:
 200
 201                         if (!Parameters.Resolve (this))
 202                                 return false;
 203
 204                         //
 205                         // Invoke method
 206                         //
 207
 208                         // Check accessibility
 209                         foreach (Type partype in Parameters.Types){
 210                                 if (!Parent.AsAccessible (partype, ModFlags)) {
 211                                         Report.Error (59, Location,
 212                                                       "Inconsistent accessibility: parameter type `" +
 213                                                       TypeManager.CSharpName (partype) + "' is less " +
 214                                                       "accessible than delegate `" + Name + "'");
 215                                         return false;
 216                                 }
 217                         }
 218
 219                         ReturnType = ReturnType.ResolveAsTypeTerminal (this, false);
 220                         if (ReturnType == null)
 221                                 return false;
 222
 223                         ret_type = ReturnType.Type;
 224
 225                         if (!Parent.AsAccessible (ret_type, ModFlags)) {
 226                                 Report.Error (58, Location,
 227                                               "Inconsistent accessibility: return type `" +
 228                                               TypeManager.CSharpName (ret_type) + "' is less " +
 229                                               "accessible than delegate `" + Name + "'");
 230                                 return false;
 231                         }
 232
 233                         if (RootContext.StdLib && (ret_type == TypeManager.arg_iterator_type || ret_type == TypeManager.typed_reference_type)) {
 234                                 Method.Error1599 (Location, ret_type);
 235                                 return false;
 236                         }
 237
 238                         //
 239                         // We don't have to check any others because they are all
 240                         // guaranteed to be accessible - they are standard types.
 241                         //
 242
 243                         CallingConventions cc = Parameters.CallingConvention;
 244
 245                         const MethodAttributes mattr = MethodAttributes.Public | MethodAttributes.HideBySig | MethodAttributes.Virtual | MethodAttributes.NewSlot;
 246
 247                         InvokeBuilder = TypeBuilder.DefineMethod ("Invoke",
 248                                                                   mattr,
 249                                                                   cc,
 250                                                                   ret_type,
 251                                                                   Parameters.Types);
 252
 253                         InvokeBuilder.SetImplementationFlags (MethodImplAttributes.Runtime);
 254
 255                         TypeManager.RegisterMethod (InvokeBuilder, Parameters);
 256
 257                         //
 258                         // BeginInvoke
 259                         //
 260
 261                         Parameters async_parameters = Parameters.MergeGenerated (Parameters,
 262                                 new Parameter (TypeManager.asynccallback_type, "callback", Parameter.Modifier.NONE, null, Location),
 263                                 new Parameter (TypeManager.object_type, "object", Parameter.Modifier.NONE, null, Location));
 264
 265                         BeginInvokeBuilder = TypeBuilder.DefineMethod ("BeginInvoke",
 266                                 mattr, cc, TypeManager.iasyncresult_type, async_parameters.Types);
 267
 268                         BeginInvokeBuilder.SetImplementationFlags (MethodImplAttributes.Runtime);
 269                         TypeManager.RegisterMethod (BeginInvokeBuilder, async_parameters);
 270
 271                         //
 272                         // EndInvoke is a bit more interesting, all the parameters labeled as
 273                         // out or ref have to be duplicated here.
 274                         //
 275
 276                         //
 277                         // Define parameters, and count out/ref parameters
 278                         //
 279                         Parameters end_parameters;
 280                         int out_params = 0;
 281
 282                         foreach (Parameter p in Parameters.FixedParameters) {
 283                                 if ((p.ModFlags & Parameter.Modifier.ISBYREF) != 0)
 284                                         ++out_params;
 285                         }
 286
 287                         if (out_params > 0) {
 288                                 Type [] end_param_types = new Type [out_params];
 289                                 Parameter [] end_params = new Parameter [out_params ];
 290
 291                                 int param = 0;
 292                                 for (int i = 0; i < Parameters.FixedParameters.Length; ++i) {
 293                                         Parameter p = Parameters.FixedParameters [i];
 294                                         if ((p.ModFlags & Parameter.Modifier.ISBYREF) == 0)
 295                                                 continue;
 296
 297                                         end_param_types [param] = p.ExternalType();
 298                                         end_params [param] = p;
 299                                         ++param;
 300                                 }
 301                                 end_parameters = Parameters.CreateFullyResolved (end_params, end_param_types);
 302                         }
 303                         else {
 304                                 end_parameters = Parameters.EmptyReadOnlyParameters;
 305                         }
 306
 307                         end_parameters = Parameters.MergeGenerated (end_parameters,
 308                                 new Parameter (TypeManager.iasyncresult_type, "result", Parameter.Modifier.NONE, null, Location));
 309
 310                         //
 311                         // Create method, define parameters, register parameters with type system
 312                         //
 313                         EndInvokeBuilder = TypeBuilder.DefineMethod ("EndInvoke", mattr, cc, ret_type, end_parameters.Types);
 314                         EndInvokeBuilder.SetImplementationFlags (MethodImplAttributes.Runtime);
 315
 316                         end_parameters.ApplyAttributes (EndInvokeBuilder);
 317                         TypeManager.RegisterMethod (EndInvokeBuilder, end_parameters);
 318
 319                         return true;
 320                 }
 321
 322                 public override void Emit ()
 323                 {
 324                         Parameters.ApplyAttributes (InvokeBuilder);
 325
 326                         Parameters p = (Parameters)TypeManager.GetParameterData (BeginInvokeBuilder);
 327                         p.ApplyAttributes (BeginInvokeBuilder);
 328
 329                         if (OptAttributes != null) {
 330                                 OptAttributes.Emit ();
 331                         }
 332
 333                         base.Emit ();
 334                 }
 335
 336                 protected override TypeAttributes TypeAttr {
 337                         get {
 338                                 return Modifiers.TypeAttr (ModFlags, IsTopLevel) |
 339                                         TypeAttributes.Class | TypeAttributes.Sealed |
 340                                         base.TypeAttr;
 341                         }
 342                 }
 343
 344                 public override string[] ValidAttributeTargets {
 345                         get {
 346                                 return attribute_targets;
 347                         }
 348                 }
 349
 350                 //TODO: duplicate
 351                 protected override bool VerifyClsCompliance ()
 352                 {
 353                         if (!base.VerifyClsCompliance ()) {
 354                                 return false;
 355                         }
 356
 357                         Parameters.VerifyClsCompliance ();
 358
 359                         if (!AttributeTester.IsClsCompliant (ReturnType.Type)) {
 360                                 Report.Error (3002, Location, "Return type of `{0}' is not CLS-compliant", GetSignatureForError ());
 361                         }
 362                         return true;
 363                 }
 364
 365
 366                 public static ConstructorInfo GetConstructor (Type containerType, Type delegateType)
 367                 {
 368                         Type dt = delegateType;
 369 #if GMCS_SOURCE
 370                         Type[] g_args = null;
 371                         if (delegateType.IsGenericType) {
 372                                 g_args = delegateType.GetGenericArguments ();
 373                                 delegateType = delegateType.GetGenericTypeDefinition ();
 374                         }
 375 #endif
 376
 377                         Delegate d = TypeManager.LookupDelegate (delegateType);
 378                         if (d != null) {
 379 #if GMCS_SOURCE
 380                                 if (g_args != null)
 381                                         return TypeBuilder.GetConstructor (dt, d.ConstructorBuilder);
 382 #endif
 383                                 return d.ConstructorBuilder;
 384                         }
 385
 386                         Expression ml = Expression.MemberLookup (containerType,
 387                                 null, dt, ConstructorInfo.ConstructorName, MemberTypes.Constructor,
 388                                 BindingFlags.Public | BindingFlags.Instance | BindingFlags.DeclaredOnly, Location.Null);
 389
 390                         MethodGroupExpr mg = ml as MethodGroupExpr;
 391                         if (mg == null) {
 392                                 Report.Error (-100, Location.Null, "Internal error: could not find delegate constructor!");
 393                                 // FIXME: null will cause a crash later
 394                                 return null;
 395                         }
 396
 397                         return (ConstructorInfo) mg.Methods[0];
 398                 }
 399
 400                 //
 401                 // Returns the MethodBase for "Invoke" from a delegate type, this is used
 402                 // to extract the signature of a delegate.
 403                 //
 404                 public static MethodInfo GetInvokeMethod (Type container_type, Type delegate_type)
 405                 {
 406                         Type dt = delegate_type;
 407 #if GMCS_SOURCE
 408                         Type[] g_args = null;
 409                         if (delegate_type.IsGenericType) {
 410                                 g_args = delegate_type.GetGenericArguments ();
 411                                 delegate_type = delegate_type.GetGenericTypeDefinition ();
 412                         }
 413 #endif
 414                         Delegate d = TypeManager.LookupDelegate (delegate_type);
 415                         if (d != null) {
 416 #if GMCS_SOURCE
 417                                 if (g_args != null) {
 418                                         MethodInfo invoke = TypeBuilder.GetMethod (dt, d.InvokeBuilder);
 419 #if MS_COMPATIBLE
 420                                         Parameters p = (Parameters) d.Parameters.InflateTypes (g_args, g_args);
 421                                         TypeManager.RegisterMethod (invoke, p);
 422 #endif
 423                                         return invoke;
 424                                 }
 425 #endif
 426                                 return d.InvokeBuilder;
 427                         }
 428
 429                         Expression ml = Expression.MemberLookup (container_type, null, dt,
 430                                 "Invoke", Location.Null);
 431
 432                         MethodGroupExpr mg = ml as MethodGroupExpr;
 433                         if (mg == null) {
 434                                 Report.Error (-100, Location.Null, "Internal error: could not find Invoke method!");
 435                                 // FIXME: null will cause a crash later
 436                                 return null;
 437                         }
 438
 439                         return (MethodInfo) mg.Methods[0];
 440                 }
 441
 442                 /// <summary>
 443                 ///  Verifies whether the method in question is compatible with the delegate
 444                 ///  Returns the method itself if okay and null if not.
 445                 /// </summary>
 446                 public static MethodBase VerifyMethod (Type container_type, Type delegate_type,
 447                                                        MethodGroupExpr old_mg, MethodBase mb,
 448                                                        Location loc)
 449                 {
 450                         MethodInfo invoke_mb = GetInvokeMethod (container_type, delegate_type);
 451                         ParameterData invoke_pd = TypeManager.GetParameterData (invoke_mb);
 452
 453 #if GMCS_SOURCE
 454                         if (!old_mg.HasTypeArguments &&
 455                             !TypeManager.InferTypeArguments (invoke_pd, ref mb))
 456                                 return null;
 457 #endif
 458
 459                         ParameterData pd = TypeManager.GetParameterData (mb);
 460
 461                         if (invoke_pd.Count != pd.Count)
 462                                 return null;
 463
 464                         for (int i = pd.Count; i > 0; ) {
 465                                 i--;
 466
 467                                 Type invoke_pd_type = invoke_pd.ParameterType (i);
 468                                 Type pd_type = pd.ParameterType (i);
 469                                 Parameter.Modifier invoke_pd_type_mod = invoke_pd.ParameterModifier (i);
 470                                 Parameter.Modifier pd_type_mod = pd.ParameterModifier (i);
 471
 472                                 invoke_pd_type_mod &= ~Parameter.Modifier.PARAMS;
 473                                 pd_type_mod &= ~Parameter.Modifier.PARAMS;
 474
 475                                 if (invoke_pd_type_mod != pd_type_mod)
 476                                         return null;
 477
 478                                 if (invoke_pd_type == pd_type)
 479                                         continue;
 480
 481                                 if (!Convert.ImplicitReferenceConversionExists (new EmptyExpression (invoke_pd_type), pd_type))
 482                                         return null;
 483
 484                                 if (RootContext.Version == LanguageVersion.ISO_1)
 485                                         return null;
 486                         }
 487
 488                         Type invoke_mb_retval = ((MethodInfo) invoke_mb).ReturnType;
 489                         Type mb_retval = ((MethodInfo) mb).ReturnType;
 490                         if (invoke_mb_retval == mb_retval)
 491                                 return mb;
 492
 493                         if (!Convert.ImplicitReferenceConversionExists (new EmptyExpression (mb_retval), invoke_mb_retval))
 494                                 return null;
 495
 496                         if (RootContext.Version == LanguageVersion.ISO_1)
 497                                 return null;
 498
 499                         return mb;
 500                 }
 501
 502                 // <summary>
 503                 //  Verifies whether the invocation arguments are compatible with the
 504                 //  delegate's target method
 505                 // </summary>
 506                 public static bool VerifyApplicability (EmitContext ec, Type delegate_type,
 507                                                         ArrayList args, Location loc)
 508                 {
 509                         int arg_count;
 510
 511                         if (args == null)
 512                                 arg_count = 0;
 513                         else
 514                                 arg_count = args.Count;
 515
 516                         Expression ml = Expression.MemberLookup (
 517                                 ec.ContainerType, delegate_type, "Invoke", loc);
 518
 519                         MethodGroupExpr me = ml as MethodGroupExpr;
 520                         if (me == null) {
 521                                 Report.Error (-100, loc, "Internal error: could not find Invoke method!" + delegate_type);
 522                                 return false;
 523                         }
 524
 525                         MethodBase mb = GetInvokeMethod (ec.ContainerType, delegate_type);
 526                         ParameterData pd = TypeManager.GetParameterData (mb);
 527
 528                         int pd_count = pd.Count;
 529
 530                         bool params_method = pd.HasParams;
 531                         bool is_params_applicable = false;
 532                         bool is_applicable = me.IsApplicable (ec, args, arg_count, ref mb) == 0;
 533
 534                         if (!is_applicable && params_method &&
 535                             me.IsParamsMethodApplicable (ec, args, arg_count, ref mb))
 536                                 is_applicable = is_params_applicable = true;
 537
 538                         if (!is_applicable && !params_method && arg_count != pd_count) {
 539                                 Report.Error (1593, loc, "Delegate `{0}' does not take `{1}' arguments",
 540                                         TypeManager.CSharpName (delegate_type), arg_count.ToString ());
 541                                 return false;
 542                         }
 543
 544                         return me.VerifyArgumentsCompat (
 545                                         ec, args, arg_count, mb,
 546                                         is_params_applicable || (!is_applicable && params_method),
 547                                         delegate_type, false, loc);
 548                 }
 549
 550                 /// <summary>
 551                 ///  Verifies whether the delegate in question is compatible with this one in
 552                 ///  order to determine if instantiation from the same is possible.
 553                 /// </summary>
 554                 public static bool VerifyDelegate (EmitContext ec, Type delegate_type, Location loc)
 555                 {
 556                         Expression ml = Expression.MemberLookup (
 557                                 ec.ContainerType, delegate_type, "Invoke", loc);
 558
 559                         if (!(ml is MethodGroupExpr)) {
 560                                 Report.Error (-100, loc, "Internal error: could not find Invoke method!");
 561                                 return false;
 562                         }
 563
 564                         MethodBase mb = ((MethodGroupExpr) ml).Methods [0];
 565                         ParameterData pd = TypeManager.GetParameterData (mb);
 566
 567                         Expression probe_ml = Expression.MemberLookup (
 568                                 ec.ContainerType, delegate_type, "Invoke", loc);
 569
 570                         if (!(probe_ml is MethodGroupExpr)) {
 571                                 Report.Error (-100, loc, "Internal error: could not find Invoke method!");
 572                                 return false;
 573                         }
 574
 575                         MethodBase probe_mb = ((MethodGroupExpr) probe_ml).Methods [0];
 576                         ParameterData probe_pd = TypeManager.GetParameterData (probe_mb);
 577
 578                         if (((MethodInfo) mb).ReturnType != ((MethodInfo) probe_mb).ReturnType)
 579                                 return false;
 580
 581                         if (pd.Count != probe_pd.Count)
 582                                 return false;
 583
 584                         for (int i = pd.Count; i > 0; ) {
 585                                 i--;
 586
 587                                 if (pd.ParameterType (i) != probe_pd.ParameterType (i) ||
 588                                     pd.ParameterModifier (i) != probe_pd.ParameterModifier (i))
 589                                         return false;
 590                         }
 591
 592                         return true;
 593                 }
 594
 595                 public static string FullDelegateDesc (Type del_type, MethodBase mb, ParameterData pd)
 596                 {
 597                         StringBuilder sb = new StringBuilder ();
 598                         sb.Append (TypeManager.CSharpName (((MethodInfo) mb).ReturnType));
 599                         sb.Append (" ");
 600                         sb.Append (TypeManager.CSharpName (del_type));
 601                         sb.Append (pd.GetSignatureForError ());
 602                         return sb.ToString ();
 603                 }
 604
 605                 // Hack around System.Reflection as found everywhere else
 606                 public override MemberList FindMembers (MemberTypes mt, BindingFlags bf,
 607                                                         MemberFilter filter, object criteria)
 608                 {
 609                         ArrayList members = new ArrayList (2);
 610
 611                         if ((mt & MemberTypes.Constructor) != 0) {
 612                                 if (ConstructorBuilder != null && filter (ConstructorBuilder, criteria))
 613                                         members.Add (ConstructorBuilder);
 614                         }
 615
 616                         if ((mt & MemberTypes.Method) != 0) {
 617                                 if (InvokeBuilder != null)
 618                                 if (filter (InvokeBuilder, criteria))
 619                                         members.Add (InvokeBuilder);
 620
 621                                 if (BeginInvokeBuilder != null)
 622                                 if (filter (BeginInvokeBuilder, criteria))
 623                                         members.Add (BeginInvokeBuilder);
 624
 625                                 if (EndInvokeBuilder != null)
 626                                 if (filter (EndInvokeBuilder, criteria))
 627                                         members.Add (EndInvokeBuilder);
 628                         }
 629
 630                         return new MemberList (members);
 631                 }
 632
 633                 public override MemberCache MemberCache {
 634                         get {
 635                                 return null;
 636                         }
 637                 }
 638
 639                 public Expression InstanceExpression {
 640                         get {
 641                                 return instance_expr;
 642                         }
 643                         set {
 644                                 instance_expr = value;
 645                         }
 646                 }
 647
 648                 public MethodBase TargetMethod {
 649                         get {
 650                                 return delegate_method;
 651                         }
 652                         set {
 653                                 delegate_method = value;
 654                         }
 655                 }
 656
 657                 public Type TargetReturnType {
 658                         get {
 659                                 return ret_type;
 660                         }
 661                 }
 662
 663                 public override AttributeTargets AttributeTargets {
 664                         get {
 665                                 return AttributeTargets.Delegate;
 666                         }
 667                 }
 668
 669                 //
 670                 //   Represents header string for documentation comment.
 671                 //
 672                 public override string DocCommentHeader {
 673                         get { return "T:"; }
 674                 }
 675         }
 676
 677         //
 678         // Base class for `NewDelegate' and `ImplicitDelegateCreation'
 679         //
 680         public abstract class DelegateCreation : Expression {
 681                 protected ConstructorInfo constructor_method;
 682                 protected MethodBase delegate_method;
 683                 // We keep this to handle IsBase only
 684                 protected MethodGroupExpr method_group;
 685                 protected Expression delegate_instance_expression;
 686
 687                 protected DelegateCreation () {}
 688
 689                 static void Error_NoMatchingMethodForDelegate (EmitContext ec, MethodGroupExpr mg, Type type, Location loc)
 690                 {
 691                         string method_desc;
 692                         MethodBase found_method = mg.Methods [0];
 693
 694                         if (mg.Methods.Length > 1)
 695                                 method_desc = found_method.Name;
 696                         else
 697                                 method_desc = Invocation.FullMethodDesc (found_method);
 698
 699                         MethodInfo method = Delegate.GetInvokeMethod (ec.ContainerType, type);
 700                         ParameterData param = TypeManager.GetParameterData (method);
 701
 702                         string delegate_desc = Delegate.FullDelegateDesc (type, method, param);
 703
 704 #if GMCS_SOURCE
 705                         if (!mg.HasTypeArguments &&
 706                             !TypeManager.InferTypeArguments (param, ref found_method)) {
 707                                 Report.Error (411, loc, "The type arguments for " +
 708                                               "method `{0}' cannot be inferred from " +
 709                                               "the usage. Try specifying the type " +
 710                                               "arguments explicitly.", method_desc);
 711                                 return;
 712                         }
 713 #endif
 714                         Report.SymbolRelatedToPreviousError (found_method);
 715
 716                         if (RootContext.Version == LanguageVersion.ISO_1) {
 717                                 Report.Error (410, loc, "The method `{0}' parameters and return type must be same as delegate `{1}' parameters and return type",
 718                                         method_desc, delegate_desc);
 719                                 return;
 720                         }
 721
 722                         Type delegateType = method.ReturnType;
 723                         Type methodType = ((MethodInfo) found_method).ReturnType;
 724                         if (delegateType != methodType &&
 725                                 !Convert.ImplicitReferenceConversionExists (new EmptyExpression (methodType), delegateType)) {
 726                                 Report.Error (407, loc, "`{0}' has the wrong return type to match the delegate `{1}'", method_desc, delegate_desc);
 727                         } else {
 728                                 Report.Error (123, loc, "The method `{0}' parameters do not match delegate `{1}' parameters",
 729                                         TypeManager.CSharpSignature (found_method), delegate_desc);
 730                         }
 731                 }
 732
 733                 public override void Emit (EmitContext ec)
 734                 {
 735                         if (delegate_instance_expression == null || delegate_method.IsStatic)
 736                                 ec.ig.Emit (OpCodes.Ldnull);
 737                         else
 738                                 delegate_instance_expression.Emit (ec);
 739
 740                         if (delegate_method.IsVirtual && !method_group.IsBase) {
 741                                 ec.ig.Emit (OpCodes.Dup);
 742                                 ec.ig.Emit (OpCodes.Ldvirtftn, (MethodInfo) delegate_method);
 743                         } else
 744                                 ec.ig.Emit (OpCodes.Ldftn, (MethodInfo) delegate_method);
 745                         ec.ig.Emit (OpCodes.Newobj, constructor_method);
 746                 }
 747
 748                 protected bool ResolveConstructorMethod (EmitContext ec)
 749                 {
 750                         constructor_method = Delegate.GetConstructor (ec.ContainerType, type);
 751                         return true;
 752                 }
 753
 754                 public static MethodBase ImplicitStandardConversionExists (MethodGroupExpr mg, Type targetType)
 755                 {
 756                         foreach (MethodInfo mi in mg.Methods){
 757                                 MethodBase mb = Delegate.VerifyMethod (mg.DeclaringType, targetType, mg, mi, Location.Null);
 758                                 if (mb != null)
 759                                         return mb;
 760                         }
 761                         return null;
 762                 }
 763
 764                 protected Expression ResolveMethodGroupExpr (EmitContext ec, MethodGroupExpr mg)
 765                 {
 766                         delegate_method = ImplicitStandardConversionExists (mg, type);
 767
 768                         if (delegate_method == null) {
 769                                 Error_NoMatchingMethodForDelegate (ec, mg, type, loc);
 770                                 return null;
 771                         }
 772
 773                         //
 774                         // Check safe/unsafe of the delegate
 775                         //
 776                         if (!ec.InUnsafe){
 777                                 ParameterData param = TypeManager.GetParameterData (delegate_method);
 778                                 int count = param.Count;
 779
 780                                 for (int i = 0; i < count; i++){
 781                                         if (param.ParameterType (i).IsPointer){
 782                                                 Expression.UnsafeError (loc);
 783                                                 return null;
 784                                         }
 785                                 }
 786                         }
 787
 788                         //TODO: implement caching when performance will be low
 789                         IMethodData md = TypeManager.GetMethod (
 790                                 TypeManager.DropGenericMethodArguments (delegate_method));
 791                         if (md == null) {
 792                                 if (System.Attribute.GetCustomAttribute (delegate_method, TypeManager.conditional_attribute_type) != null) {
 793                                         Report.SymbolRelatedToPreviousError (delegate_method);
 794                                         Report.Error (1618, loc, "Cannot create delegate with `{0}' because it has a Conditional attribute", TypeManager.CSharpSignature (delegate_method));
 795                                         return null;
 796                                 }
 797                         } else {
 798                                 md.SetMemberIsUsed ();
 799                                 if (md.OptAttributes != null && md.OptAttributes.Search (TypeManager.conditional_attribute_type) != null) {
 800                                         Report.SymbolRelatedToPreviousError (delegate_method);
 801                                         Report.Error (1618, loc, "Cannot create delegate with `{0}' because it has a Conditional attribute", TypeManager.CSharpSignature (delegate_method));
 802                                         return null;
 803                                 }
 804                         }
 805
 806                         if (mg.InstanceExpression != null)
 807                                 delegate_instance_expression = mg.InstanceExpression.Resolve (ec);
 808                         else if (ec.IsStatic) {
 809                                 if (!delegate_method.IsStatic) {
 810                                         Report.Error (120, loc, "`{0}': An object reference is required for the nonstatic field, method or property",
 811                                                       TypeManager.CSharpSignature (delegate_method));
 812                                         return null;
 813                                 }
 814                                 delegate_instance_expression = null;
 815                         } else
 816                                 delegate_instance_expression = ec.GetThis (loc);
 817
 818                         if (delegate_instance_expression != null && delegate_instance_expression.Type.IsValueType)
 819                                 delegate_instance_expression = new BoxedCast (
 820                                         delegate_instance_expression, TypeManager.object_type);
 821
 822                         method_group = mg;
 823                         eclass = ExprClass.Value;
 824                         return this;
 825                 }
 826         }
 827
 828         //
 829         // Created from the conversion code
 830         //
 831         public class ImplicitDelegateCreation : DelegateCreation {
 832
 833                 ImplicitDelegateCreation (Type t, Location l)
 834                 {
 835                         type = t;
 836                         loc = l;
 837                 }
 838
 839                 public override Expression DoResolve (EmitContext ec)
 840                 {
 841                         return this;
 842                 }
 843
 844                 static public Expression Create (EmitContext ec, MethodGroupExpr mge,
 845                                                  Type target_type, Location loc)
 846                 {
 847                         ImplicitDelegateCreation d = new ImplicitDelegateCreation (target_type, loc);
 848                         if (!d.ResolveConstructorMethod (ec))
 849                                 return null;
 850
 851                         return d.ResolveMethodGroupExpr (ec, mge);
 852                 }
 853         }
 854
 855         //
 856         // A delegate-creation-expression, invoked from the `New' class
 857         //
 858         public class NewDelegate : DelegateCreation {
 859                 public ArrayList Arguments;
 860
 861                 //
 862                 // This constructor is invoked from the `New' expression
 863                 //
 864                 public NewDelegate (Type type, ArrayList Arguments, Location loc)
 865                 {
 866                         this.type = type;
 867                         this.Arguments = Arguments;
 868                         this.loc  = loc;
 869                 }
 870
 871                 public override Expression DoResolve (EmitContext ec)
 872                 {
 873                         if (Arguments == null) {
 874                                 Invocation.Error_WrongNumArguments (loc, GetSignatureForError (), 0);
 875                                 return null;
 876                         }
 877
 878                         if (!ResolveConstructorMethod (ec))
 879                                 return null;
 880
 881                         Argument a = (Argument) Arguments [0];
 882
 883                         if (!a.ResolveMethodGroup (ec))
 884                                 return null;
 885
 886                         Expression e = a.Expr;
 887
 888                         if (e is AnonymousMethodExpression && RootContext.Version != LanguageVersion.ISO_1)
 889                                 return ((AnonymousMethodExpression) e).Compatible (ec, type).Resolve (ec);
 890
 891                         MethodGroupExpr mg = e as MethodGroupExpr;
 892                         if (mg != null) {
 893                                 if (TypeManager.IsNullableType (mg.DeclaringType)) {
 894                                         Report.Error (1728, loc, "Cannot use method `{0}' as delegate creation expression because it is member of Nullable type",
 895                                                 mg.GetSignatureForError ());
 896                                         return null;
 897                                 }
 898
 899                                 return ResolveMethodGroupExpr (ec, mg);
 900                         }
 901
 902                         if (!TypeManager.IsDelegateType (e.Type)) {
 903                                 Report.Error (149, loc, "Method name expected");
 904                                 return null;
 905                         }
 906
 907                         // This is what MS' compiler reports. We could always choose
 908                         // to be more verbose and actually give delegate-level specifics
 909                         if (!Delegate.VerifyDelegate (ec, type, loc)) {
 910                                 Report.Error (29, loc, "Cannot implicitly convert type '" + e.Type + "' " +
 911                                               "to type '" + type + "'");
 912                                 return null;
 913                         }
 914
 915                         delegate_instance_expression = e;
 916                         delegate_method = Delegate.GetInvokeMethod (ec.ContainerType, type);
 917                         method_group = new MethodGroupExpr (new MemberInfo[] { delegate_method }, type, loc);
 918
 919                         eclass = ExprClass.Value;
 920                         return this;
 921                 }
 922         }
 923
 924         public class DelegateInvocation : ExpressionStatement {
 925
 926                 readonly Expression InstanceExpr;
 927                 readonly ArrayList  Arguments;
 928
 929                 MethodBase method;
 930
 931                 public DelegateInvocation (Expression instance_expr, ArrayList args, Location loc)
 932                 {
 933                         this.InstanceExpr = instance_expr;
 934                         this.Arguments = args;
 935                         this.loc = loc;
 936                 }
 937
 938                 public override Expression DoResolve (EmitContext ec)
 939                 {
 940                         if (InstanceExpr is EventExpr) {
 941
 942                                 EventInfo ei = ((EventExpr) InstanceExpr).EventInfo;
 943
 944                                 Expression ml = MemberLookup (
 945                                         ec.ContainerType, ec.ContainerType, ei.Name,
 946                                         MemberTypes.Event, AllBindingFlags | BindingFlags.DeclaredOnly, loc);
 947
 948                                 if (ml == null) {
 949                                         //
 950                                         // If this is the case, then the Event does not belong
 951                                         // to this Type and so, according to the spec
 952                                         // cannot be accessed directly
 953                                         //
 954                                         // Note that target will not appear as an EventExpr
 955                                         // in the case it is being referenced within the same type container;
 956                                         // it will appear as a FieldExpr in that case.
 957                                         //
 958
 959                                         Assign.error70 (ei, loc);
 960                                         return null;
 961                                 }
 962                         }
 963
 964
 965                         Type del_type = InstanceExpr.Type;
 966                         if (del_type == null)
 967                                 return null;
 968
 969                         if (Arguments != null){
 970                                 foreach (Argument a in Arguments){
 971                                         if (!a.Resolve (ec, loc))
 972                                                 return null;
 973                                 }
 974                         }
 975
 976                         if (!Delegate.VerifyApplicability (ec, del_type, Arguments, loc))
 977                                 return null;
 978
 979                         method = Delegate.GetInvokeMethod (ec.ContainerType, del_type);
 980                         type = ((MethodInfo) method).ReturnType;
 981                         eclass = ExprClass.Value;
 982
 983                         return this;
 984                 }
 985
 986                 public override void Emit (EmitContext ec)
 987                 {
 988                         //
 989                         // Invocation on delegates call the virtual Invoke member
 990                         // so we are always `instance' calls
 991                         //
 992                         Invocation.EmitCall (ec, false, InstanceExpr, method, Arguments, loc);
 993                 }
 994
 995                 public override void EmitStatement (EmitContext ec)
 996                 {
 997                         Emit (ec);
 998                         //
 999                         // Pop the return value if there is one
1000                         //
1001                         if (method is MethodInfo){
1002                                 Type ret = ((MethodInfo)method).ReturnType;
1003                                 if (TypeManager.TypeToCoreType (ret) != TypeManager.void_type)
1004                                         ec.ig.Emit (OpCodes.Pop);
1005                         }
1006                 }
1007
1008         }
1009 }