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 //
   8 // Licensed under the terms of the GNU GPL
   9 //
  10 // (C) 2001 Ximian, Inc (http://www.ximian.com)
  11 //
  12 //
  13
  14 using System;
  15 using System.Collections;
  16 using System.Reflection;
  17 using System.Reflection.Emit;
  18 using System.Text;
  19
  20 namespace Mono.CSharp {
  21
  22         /// <summary>
  23         ///   Holds Delegates
  24         /// </summary>
  25         public class Delegate : DeclSpace {
  26                 public Expression ReturnType;
  27                 public Parameters      Parameters;
  28
  29                 public ConstructorBuilder ConstructorBuilder;
  30                 public MethodBuilder      InvokeBuilder;
  31                 public MethodBuilder      BeginInvokeBuilder;
  32                 public MethodBuilder      EndInvokeBuilder;
  33
  34                 Type [] param_types;
  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, TypeContainer parent, Expression type,
  52                                  int mod_flags, MemberName name, Parameters param_list,
  53                                  Attributes attrs, Location l)
  54                         : base (ns, parent, name, attrs, l)
  55
  56                 {
  57                         this.ReturnType = type;
  58                         ModFlags        = Modifiers.Check (AllowedModifiers, mod_flags,
  59                                                            IsTopLevel ? Modifiers.INTERNAL :
  60                                                            Modifiers.PRIVATE, l);
  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                         ec = new EmitContext (this, this, Location, null, null, ModFlags, false);
  83
  84                         if (TypeManager.multicast_delegate_type == null && !RootContext.StdLib) {
  85                                 Namespace system = Namespace.LookupNamespace ("System", true);
  86                                 TypeExpr expr = system.Lookup (this, "MulticastDelegate", Location) as TypeExpr;
  87                                 TypeManager.multicast_delegate_type = expr.ResolveType (ec);
  88                         }
  89
  90                         if (TypeManager.multicast_delegate_type == null)
  91                                 throw new InternalErrorException ("System.MulticastDelegate unresolved");
  92
  93                         if (IsTopLevel) {
  94                                 if (TypeManager.NamespaceClash (Name, Location))
  95                                         return null;
  96
  97                                 ModuleBuilder builder = CodeGen.Module.Builder;
  98
  99                                 TypeBuilder = builder.DefineType (
 100                                         Name, TypeAttr, TypeManager.multicast_delegate_type);
 101                         } else {
 102                                 TypeBuilder builder = Parent.TypeBuilder;
 103
 104                                 string name = Name.Substring (1 + Name.LastIndexOf ('.'));
 105                                 TypeBuilder = builder.DefineNestedType (
 106                                         name, TypeAttr, TypeManager.multicast_delegate_type);
 107                         }
 108
 109                         TypeManager.AddDelegateType (Name, TypeBuilder, this);
 110
 111                         return TypeBuilder;
 112                 }
 113
 114                 public override bool DefineMembers (TypeContainer container)
 115                 {
 116                         return true;
 117                 }
 118
 119                 public override bool Define ()
 120                 {
 121                         MethodAttributes mattr;
 122                         int i;
 123
 124                         if (ec == null)
 125                                 throw new InternalErrorException ("Define called before DefineType?");
 126
 127                         // FIXME: POSSIBLY make this static, as it is always constant
 128                         //
 129                         Type [] const_arg_types = new Type [2];
 130                         const_arg_types [0] = TypeManager.object_type;
 131                         const_arg_types [1] = TypeManager.intptr_type;
 132
 133                         mattr = MethodAttributes.RTSpecialName | MethodAttributes.SpecialName |
 134                                 MethodAttributes.HideBySig | MethodAttributes.Public;
 135
 136                         ConstructorBuilder = TypeBuilder.DefineConstructor (mattr,
 137                                                                             CallingConventions.Standard,
 138                                                                             const_arg_types);
 139
 140                         ConstructorBuilder.DefineParameter (1, ParameterAttributes.None, "object");
 141                         ConstructorBuilder.DefineParameter (2, ParameterAttributes.None, "method");
 142                         //
 143                         // HACK because System.Reflection.Emit is lame
 144                         //
 145                         Parameter [] fixed_pars = new Parameter [2];
 146                         fixed_pars [0] = new Parameter (TypeManager.system_object_expr, "object",
 147                                                         Parameter.Modifier.NONE, null, Location);
 148                         fixed_pars [1] = new Parameter (TypeManager.system_intptr_expr, "method",
 149                                                         Parameter.Modifier.NONE, null, Location);
 150                         Parameters const_parameters = new Parameters (fixed_pars, null);
 151
 152                         TypeManager.RegisterMethod (
 153                                 ConstructorBuilder,
 154                                 new InternalParameters (const_arg_types, const_parameters),
 155                                 const_arg_types);
 156
 157
 158                         ConstructorBuilder.SetImplementationFlags (MethodImplAttributes.Runtime);
 159
 160                         //
 161                         // Here the various methods like Invoke, BeginInvoke etc are defined
 162                         //
 163                         // First, call the `out of band' special method for
 164                         // defining recursively any types we need:
 165
 166                         param_types = Parameters.GetParameterInfo (ec);
 167                         if (param_types == null)
 168                                 return false;
 169
 170                         //
 171                         // Invoke method
 172                         //
 173
 174                         // Check accessibility
 175                         foreach (Type partype in param_types){
 176                                 if (!Parent.AsAccessible (partype, ModFlags)) {
 177                                         Report.Error (59, Location,
 178                                                       "Inconsistent accessibility: parameter type `" +
 179                                                       TypeManager.CSharpName (partype) + "` is less " +
 180                                                       "accessible than delegate `" + Name + "'");
 181                                         return false;
 182                                 }
 183                                 if (partype.IsPointer && !UnsafeOK (Parent))
 184                                         return false;
 185                         }
 186
 187                         ReturnType = ReturnType.ResolveAsTypeTerminal (ec, false);
 188                         if (ReturnType == null)
 189                             return false;
 190
 191                         ret_type = ReturnType.Type;
 192                         if (ret_type == null)
 193                                 return false;
 194
 195                         if (!Parent.AsAccessible (ret_type, ModFlags)) {
 196                                 Report.Error (58, Location,
 197                                               "Inconsistent accessibility: return type `" +
 198                                               TypeManager.CSharpName (ret_type) + "` is less " +
 199                                               "accessible than delegate `" + Name + "'");
 200                                 return false;
 201                         }
 202
 203                         if (ret_type.IsPointer && !UnsafeOK (Parent))
 204                                 return false;
 205
 206                         if (RootContext.StdLib && (ret_type == TypeManager.arg_iterator_type || ret_type == TypeManager.typed_reference_type)) {
 207                                 Method.Error1599 (Location, ret_type);
 208                                 return false;
 209                         }
 210
 211                         //
 212                         // We don't have to check any others because they are all
 213                         // guaranteed to be accessible - they are standard types.
 214                         //
 215
 216                         CallingConventions cc = Parameters.GetCallingConvention ();
 217
 218                         mattr = MethodAttributes.Public | MethodAttributes.HideBySig | MethodAttributes.Virtual;
 219
 220                         InvokeBuilder = TypeBuilder.DefineMethod ("Invoke",
 221                                                                   mattr,
 222                                                                   cc,
 223                                                                   ret_type,
 224                                                                   param_types);
 225
 226                         //
 227                         // Define parameters, and count out/ref parameters
 228                         //
 229                         int out_params = 0;
 230                         i = 0;
 231                         if (Parameters.FixedParameters != null){
 232                                 int top = Parameters.FixedParameters.Length;
 233                                 Parameter p;
 234
 235                                 for (; i < top; i++) {
 236                                         p = Parameters.FixedParameters [i];
 237                                         p.DefineParameter (ec, InvokeBuilder, null, i + 1, Location);
 238
 239                                         if ((p.ModFlags & Parameter.Modifier.ISBYREF) != 0)
 240                                                 out_params++;
 241                                 }
 242                         }
 243                         if (Parameters.ArrayParameter != null){
 244                                 Parameter p = Parameters.ArrayParameter;
 245
 246                                 if (TypeManager.param_array_type == null && !RootContext.StdLib) {
 247                                         Namespace system = Namespace.LookupNamespace ("System", true);
 248                                         TypeExpr expr = system.Lookup (this, "ParamArrayAttribute", Location) as TypeExpr;
 249                                         TypeManager.param_array_type = expr.ResolveType (ec);
 250                                 }
 251
 252                                 if (TypeManager.cons_param_array_attribute == null) {
 253                                         Type [] void_arg = { };
 254                                         TypeManager.cons_param_array_attribute = TypeManager.GetConstructor (
 255                                                 TypeManager.param_array_type, void_arg);
 256                                 }
 257
 258                                 ParameterBuilder pb = InvokeBuilder.DefineParameter (
 259                                         i + 1, Parameters.ArrayParameter.Attributes,Parameters.ArrayParameter.Name);
 260
 261                                 pb.SetCustomAttribute (
 262                                         new CustomAttributeBuilder (TypeManager.cons_param_array_attribute, new object [0]));
 263                         }
 264
 265                         InvokeBuilder.SetImplementationFlags (MethodImplAttributes.Runtime);
 266
 267                         TypeManager.RegisterMethod (InvokeBuilder,
 268                                                     new InternalParameters (param_types, Parameters),
 269                                                     param_types);
 270
 271                         //
 272                         // BeginInvoke
 273                         //
 274                         int params_num = param_types.Length;
 275                         Type [] async_param_types = new Type [params_num + 2];
 276
 277                         param_types.CopyTo (async_param_types, 0);
 278
 279                         async_param_types [params_num] = TypeManager.asynccallback_type;
 280                         async_param_types [params_num + 1] = TypeManager.object_type;
 281
 282                         mattr = MethodAttributes.Public | MethodAttributes.HideBySig |
 283                                 MethodAttributes.Virtual | MethodAttributes.NewSlot;
 284
 285                         BeginInvokeBuilder = TypeBuilder.DefineMethod ("BeginInvoke",
 286                                                                        mattr,
 287                                                                        cc,
 288                                                                        TypeManager.iasyncresult_type,
 289                                                                        async_param_types);
 290
 291                         i = 0;
 292                         if (Parameters.FixedParameters != null){
 293                                 int top = Parameters.FixedParameters.Length;
 294                                 Parameter p;
 295
 296                                 for (i = 0 ; i < top; i++) {
 297                                         p = Parameters.FixedParameters [i];
 298
 299                                         p.DefineParameter (ec, BeginInvokeBuilder, null, i + 1, Location);
 300                                 }
 301                         }
 302                         if (Parameters.ArrayParameter != null){
 303                                 Parameter p = Parameters.ArrayParameter;
 304                                 p.DefineParameter (ec, BeginInvokeBuilder, null, i + 1, Location);
 305
 306                                 i++;
 307                         }
 308
 309                         BeginInvokeBuilder.DefineParameter (i + 1, ParameterAttributes.None, "callback");
 310                         BeginInvokeBuilder.DefineParameter (i + 2, ParameterAttributes.None, "object");
 311
 312                         BeginInvokeBuilder.SetImplementationFlags (MethodImplAttributes.Runtime);
 313
 314                         Parameter [] async_params = new Parameter [params_num + 2];
 315                         int n = 0;
 316                         if (Parameters.FixedParameters != null){
 317                                 Parameters.FixedParameters.CopyTo (async_params, 0);
 318                                 n = Parameters.FixedParameters.Length;
 319                         }
 320                         if (Parameters.ArrayParameter != null)
 321                                 async_params [n] = Parameters.ArrayParameter;
 322
 323                         async_params [params_num] = new Parameter (
 324                                 TypeManager.system_asynccallback_expr, "callback",
 325                                                                    Parameter.Modifier.NONE, null, Location);
 326                         async_params [params_num + 1] = new Parameter (
 327                                 TypeManager.system_object_expr, "object",
 328                                                                    Parameter.Modifier.NONE, null, Location);
 329
 330                         Parameters async_parameters = new Parameters (async_params, null);
 331
 332                         TypeManager.RegisterMethod (BeginInvokeBuilder,
 333                                                     new InternalParameters (async_parameters.GetParameterInfo (ec), async_parameters),
 334                                                     async_param_types);
 335
 336                         //
 337                         // EndInvoke is a bit more interesting, all the parameters labeled as
 338                         // out or ref have to be duplicated here.
 339                         //
 340
 341                         Type [] end_param_types = new Type [out_params + 1];
 342                         Parameter [] end_params = new Parameter [out_params + 1];
 343                         int param = 0;
 344                         if (out_params > 0){
 345                                 int top = Parameters.FixedParameters.Length;
 346                                 for (i = 0; i < top; i++){
 347                                         Parameter p = Parameters.FixedParameters [i];
 348                                         if ((p.ModFlags & Parameter.Modifier.ISBYREF) == 0)
 349                                                 continue;
 350
 351                                         end_param_types [param] = param_types [i];
 352                                         end_params [param] = p;
 353                                         param++;
 354                                 }
 355                         }
 356                         end_param_types [out_params] = TypeManager.iasyncresult_type;
 357                         end_params [out_params] = new Parameter (TypeManager.system_iasyncresult_expr, "result", Parameter.Modifier.NONE, null, Location);
 358
 359                         //
 360                         // Create method, define parameters, register parameters with type system
 361                         //
 362                         EndInvokeBuilder = TypeBuilder.DefineMethod ("EndInvoke", mattr, cc, ret_type, end_param_types);
 363                         EndInvokeBuilder.SetImplementationFlags (MethodImplAttributes.Runtime);
 364
 365                         //
 366                         // EndInvoke: Label the parameters
 367                         //
 368                         EndInvokeBuilder.DefineParameter (out_params + 1, ParameterAttributes.None, "result");
 369                         for (i = 0; i < end_params.Length-1; i++){
 370                                 EndInvokeBuilder.DefineParameter (i + 1, end_params [i].Attributes, end_params [i].Name);
 371                         }
 372
 373                         Parameters end_parameters = new Parameters (end_params, null);
 374
 375                         TypeManager.RegisterMethod (
 376                                 EndInvokeBuilder,
 377                                 new InternalParameters (end_parameters.GetParameterInfo (ec), end_parameters),
 378                                 end_param_types);
 379
 380                         return true;
 381                 }
 382
 383                 public override void Emit ()
 384                 {
 385                         if (OptAttributes != null) {
 386                                 Parameters.LabelParameters (ec, InvokeBuilder, Location);
 387                                 OptAttributes.Emit (ec, this);
 388                         }
 389
 390                         base.Emit ();
 391                 }
 392
 393                 protected override TypeAttributes TypeAttr {
 394                         get {
 395                                 return Modifiers.TypeAttr (ModFlags, IsTopLevel) |
 396                                         TypeAttributes.Class | TypeAttributes.Sealed |
 397                                         base.TypeAttr;
 398                         }
 399                 }
 400
 401                 public override string[] ValidAttributeTargets {
 402                         get {
 403                                 return attribute_targets;
 404                         }
 405                 }
 406
 407                 //TODO: duplicate
 408                 protected override bool VerifyClsCompliance (DeclSpace ds)
 409                 {
 410                         if (!base.VerifyClsCompliance (ds)) {
 411                                 return false;
 412                         }
 413
 414                         AttributeTester.AreParametersCompliant (Parameters.FixedParameters, Location);
 415
 416                         if (!AttributeTester.IsClsCompliant (ReturnType.Type)) {
 417                                 Report.Error (3002, Location, "Return type of '{0}' is not CLS-compliant", GetSignatureForError ());
 418                         }
 419                         return true;
 420                 }
 421
 422                 //
 423                 // Returns the MethodBase for "Invoke" from a delegate type, this is used
 424                 // to extract the signature of a delegate.
 425                 //
 426                 public static MethodInfo GetInvokeMethod (EmitContext ec, Type delegate_type, Location loc)
 427                 {
 428                         Expression ml = Expression.MemberLookup (
 429                                 ec, delegate_type, "Invoke", loc);
 430
 431                         if (!(ml is MethodGroupExpr)) {
 432                                 Report.Error (-100, loc, "Internal error: could not find Invoke method!");
 433                                 return null;
 434                         }
 435
 436                         return (MethodInfo) (((MethodGroupExpr) ml).Methods [0]);
 437                 }
 438
 439                 /// <summary>
 440                 ///  Verifies whether the method in question is compatible with the delegate
 441                 ///  Returns the method itself if okay and null if not.
 442                 /// </summary>
 443                 public static MethodBase VerifyMethod (EmitContext ec, Type delegate_type, MethodBase mb,
 444                                                        Location loc)
 445                 {
 446                         ParameterData pd = TypeManager.GetParameterData (mb);
 447
 448                         int pd_count = pd.Count;
 449
 450                         MethodBase invoke_mb = GetInvokeMethod (ec, delegate_type, loc);
 451                         if (invoke_mb == null)
 452                                 return null;
 453
 454                         ParameterData invoke_pd = TypeManager.GetParameterData (invoke_mb);
 455
 456                         if (invoke_pd.Count != pd_count)
 457                                 return null;
 458
 459                         for (int i = pd_count; i > 0; ) {
 460                                 i--;
 461
 462                                 Type invoke_pd_type = invoke_pd.ParameterType (i);
 463                                 Type pd_type = pd.ParameterType (i);
 464                                 Parameter.Modifier invoke_pd_type_mod = invoke_pd.ParameterModifier (i);
 465                                 Parameter.Modifier pd_type_mod = pd.ParameterModifier (i);
 466
 467                                 if (invoke_pd_type == pd_type &&
 468                                     invoke_pd_type_mod == pd_type_mod)
 469                                         continue;
 470
 471                                 if (invoke_pd_type.IsSubclassOf (pd_type) &&
 472                                                 invoke_pd_type_mod == pd_type_mod)
 473                                         if (RootContext.Version == LanguageVersion.ISO_1) {
 474                                                 Report.FeatureIsNotStandardized (loc, "contravariance");
 475                                                 return null;
 476                                         } else
 477                                                 continue;
 478
 479                                 return null;
 480                         }
 481
 482                         Type invoke_mb_retval = ((MethodInfo) invoke_mb).ReturnType;
 483                         Type mb_retval = ((MethodInfo) mb).ReturnType;
 484                         if (invoke_mb_retval == mb_retval)
 485                                 return mb;
 486
 487                         if (mb_retval.IsSubclassOf (invoke_mb_retval))
 488                                 if (RootContext.Version == LanguageVersion.ISO_1) {
 489                                         Report.FeatureIsNotStandardized (loc, "covariance");
 490                                         return null;
 491                                 }
 492                                 else
 493                                         return mb;
 494
 495                         return null;
 496                 }
 497
 498                 // <summary>
 499                 //  Verifies whether the invocation arguments are compatible with the
 500                 //  delegate's target method
 501                 // </summary>
 502                 public static bool VerifyApplicability (EmitContext ec, Type delegate_type,
 503                                                         ArrayList args, Location loc)
 504                 {
 505                         int arg_count;
 506
 507                         if (args == null)
 508                                 arg_count = 0;
 509                         else
 510                                 arg_count = args.Count;
 511
 512                         Expression ml = Expression.MemberLookup (
 513                                 ec, delegate_type, "Invoke", loc);
 514
 515                         MethodGroupExpr me = ml as MethodGroupExpr;
 516                         if (me == null) {
 517                                 Report.Error (-100, loc, "Internal error: could not find Invoke method!" + delegate_type);
 518                                 return false;
 519                         }
 520
 521                         MethodBase mb = me.Methods [0];
 522                         ParameterData pd = TypeManager.GetParameterData (mb);
 523
 524                         int pd_count = pd.Count;
 525
 526                         bool params_method = (pd_count != 0) &&
 527                                 (pd.ParameterModifier (pd_count - 1) == Parameter.Modifier.PARAMS);
 528
 529                         bool is_params_applicable = false;
 530                         bool is_applicable = Invocation.IsApplicable (ec, me, args, arg_count, ref mb);
 531
 532                         if (!is_applicable && params_method &&
 533                             Invocation.IsParamsMethodApplicable (ec, me, args, arg_count, ref mb))
 534                                 is_applicable = is_params_applicable = true;
 535
 536                         if (!is_applicable && !params_method && arg_count != pd_count) {
 537                                 Report.Error (1593, loc,
 538                                               "Delegate '{0}' does not take {1} arguments",
 539                                               delegate_type.ToString (), arg_count);
 540                                 return false;
 541                         }
 542
 543                         return Invocation.VerifyArgumentsCompat (
 544                                         ec, args, arg_count, mb,
 545                                         is_params_applicable || (!is_applicable && params_method),
 546                                         delegate_type, false, loc);
 547                 }
 548
 549                 /// <summary>
 550                 ///  Verifies whether the delegate in question is compatible with this one in
 551                 ///  order to determine if instantiation from the same is possible.
 552                 /// </summary>
 553                 public static bool VerifyDelegate (EmitContext ec, Type delegate_type, Type probe_type, Location loc)
 554                 {
 555                         Expression ml = Expression.MemberLookup (
 556                                 ec, delegate_type, "Invoke", loc);
 557
 558                         if (!(ml is MethodGroupExpr)) {
 559                                 Report.Error (-100, loc, "Internal error: could not find Invoke method!");
 560                                 return false;
 561                         }
 562
 563                         MethodBase mb = ((MethodGroupExpr) ml).Methods [0];
 564                         ParameterData pd = TypeManager.GetParameterData (mb);
 565
 566                         Expression probe_ml = Expression.MemberLookup (
 567                                 ec, delegate_type, "Invoke", loc);
 568
 569                         if (!(probe_ml is MethodGroupExpr)) {
 570                                 Report.Error (-100, loc, "Internal error: could not find Invoke method!");
 571                                 return false;
 572                         }
 573
 574                         MethodBase probe_mb = ((MethodGroupExpr) probe_ml).Methods [0];
 575                         ParameterData probe_pd = TypeManager.GetParameterData (probe_mb);
 576
 577                         if (((MethodInfo) mb).ReturnType != ((MethodInfo) probe_mb).ReturnType)
 578                                 return false;
 579
 580                         if (pd.Count != probe_pd.Count)
 581                                 return false;
 582
 583                         for (int i = pd.Count; i > 0; ) {
 584                                 i--;
 585
 586                                 if (pd.ParameterType (i) != probe_pd.ParameterType (i) ||
 587                                     pd.ParameterModifier (i) != probe_pd.ParameterModifier (i))
 588                                         return false;
 589                         }
 590
 591                         return true;
 592                 }
 593
 594                 public static string FullDelegateDesc (Type del_type, MethodBase mb, ParameterData pd)
 595                 {
 596                         StringBuilder sb = new StringBuilder (TypeManager.CSharpName (((MethodInfo) mb).ReturnType));
 597
 598                         sb.Append (" " + del_type.ToString ());
 599                         sb.Append (" (");
 600
 601                         int length = pd.Count;
 602
 603                         for (int i = length; i > 0; ) {
 604                                 i--;
 605
 606                                 sb.Append (pd.ParameterDesc (length - i - 1));
 607                                 if (i != 0)
 608                                         sb.Append (", ");
 609                         }
 610
 611                         sb.Append (")");
 612                         return sb.ToString ();
 613
 614                 }
 615
 616                 // Hack around System.Reflection as found everywhere else
 617                 public override MemberList FindMembers (MemberTypes mt, BindingFlags bf,
 618                                                         MemberFilter filter, object criteria)
 619                 {
 620                         ArrayList members = new ArrayList ();
 621
 622                         if ((mt & MemberTypes.Method) != 0) {
 623                                 if (ConstructorBuilder != null)
 624                                 if (filter (ConstructorBuilder, criteria))
 625                                         members.Add (ConstructorBuilder);
 626
 627                                 if (InvokeBuilder != null)
 628                                 if (filter (InvokeBuilder, criteria))
 629                                         members.Add (InvokeBuilder);
 630
 631                                 if (BeginInvokeBuilder != null)
 632                                 if (filter (BeginInvokeBuilder, criteria))
 633                                         members.Add (BeginInvokeBuilder);
 634
 635                                 if (EndInvokeBuilder != null)
 636                                 if (filter (EndInvokeBuilder, criteria))
 637                                         members.Add (EndInvokeBuilder);
 638                         }
 639
 640                         return new MemberList (members);
 641                 }
 642
 643                 public override MemberCache MemberCache {
 644                         get {
 645                                 return null;
 646                         }
 647                 }
 648
 649                 public Expression InstanceExpression {
 650                         get {
 651                                 return instance_expr;
 652                         }
 653                         set {
 654                                 instance_expr = value;
 655                         }
 656                 }
 657
 658                 public MethodBase TargetMethod {
 659                         get {
 660                                 return delegate_method;
 661                         }
 662                         set {
 663                                 delegate_method = value;
 664                         }
 665                 }
 666
 667                 public Type TargetReturnType {
 668                         get {
 669                                 return ret_type;
 670                         }
 671                 }
 672
 673                 public Type [] ParameterTypes {
 674                         get {
 675                                 return param_types;
 676                         }
 677                 }
 678
 679                 public override AttributeTargets AttributeTargets {
 680                         get {
 681                                 return AttributeTargets.Delegate;
 682                         }
 683                 }
 684
 685                 //
 686                 //   Represents header string for documentation comment.
 687                 //
 688                 public override string DocCommentHeader {
 689                         get { return "T:"; }
 690                 }
 691
 692                 protected override void VerifyObsoleteAttribute()
 693                 {
 694                         CheckUsageOfObsoleteAttribute (ret_type);
 695
 696                         foreach (Type type in param_types) {
 697                                 CheckUsageOfObsoleteAttribute (type);
 698                         }
 699                 }
 700         }
 701
 702         //
 703         // Base class for `NewDelegate' and `ImplicitDelegateCreation'
 704         //
 705         public abstract class DelegateCreation : Expression {
 706                 protected MethodBase constructor_method;
 707                 protected MethodBase delegate_method;
 708                 protected MethodGroupExpr method_group;
 709                 protected Expression delegate_instance_expression;
 710
 711                 public DelegateCreation () {}
 712
 713                 public static void Error_NoMatchingMethodForDelegate (EmitContext ec, MethodGroupExpr mg, Type type, Location loc)
 714                 {
 715                         string method_desc;
 716                         MethodInfo found_method = (MethodInfo)mg.Methods [0];
 717
 718                         if (mg.Methods.Length > 1)
 719                                 method_desc = found_method.Name;
 720                         else
 721                                 method_desc = Invocation.FullMethodDesc (found_method);
 722
 723                         Expression invoke_method = Expression.MemberLookup (
 724                                 ec, type, "Invoke", MemberTypes.Method,
 725                                 Expression.AllBindingFlags, loc);
 726                         MethodInfo method = ((MethodGroupExpr) invoke_method).Methods [0] as MethodInfo;
 727
 728                         ParameterData param = TypeManager.GetParameterData (method);
 729                         string delegate_desc = Delegate.FullDelegateDesc (type, method, param);
 730
 731                         if (method.ReturnType != found_method.ReturnType) {
 732                                 Report.Error (407, loc, "'{0}' has the wrong return type to match delegate '{1}'", method_desc, delegate_desc);
 733                         } else {
 734                                 Report.Error (123, loc, "Method '" + method_desc + "' does not " +
 735                                         "match delegate '" + delegate_desc + "'");
 736                         }
 737                 }
 738
 739                 public override void Emit (EmitContext ec)
 740                 {
 741                         if (delegate_instance_expression == null || delegate_method.IsStatic)
 742                                 ec.ig.Emit (OpCodes.Ldnull);
 743                         else
 744                                 delegate_instance_expression.Emit (ec);
 745
 746                         if (delegate_method.IsVirtual && !method_group.IsBase) {
 747                                 ec.ig.Emit (OpCodes.Dup);
 748                                 ec.ig.Emit (OpCodes.Ldvirtftn, (MethodInfo) delegate_method);
 749                         } else
 750                                 ec.ig.Emit (OpCodes.Ldftn, (MethodInfo) delegate_method);
 751                         ec.ig.Emit (OpCodes.Newobj, (ConstructorInfo) constructor_method);
 752                 }
 753
 754                 protected bool ResolveConstructorMethod (EmitContext ec)
 755                 {
 756                         Expression ml = Expression.MemberLookup (
 757                                 ec, type, ".ctor", loc);
 758
 759                         if (!(ml is MethodGroupExpr)) {
 760                                 Report.Error (-100, loc, "Internal error: Could not find delegate constructor!");
 761                                 return false;
 762                         }
 763
 764                         constructor_method = ((MethodGroupExpr) ml).Methods [0];
 765                         return true;
 766                 }
 767
 768                 protected Expression ResolveMethodGroupExpr (EmitContext ec, MethodGroupExpr mg,
 769                                                              bool check_only)
 770                 {
 771                         foreach (MethodInfo mi in mg.Methods){
 772                                 delegate_method  = Delegate.VerifyMethod (ec, type, mi, loc);
 773
 774                                 if (delegate_method != null)
 775                                         break;
 776                         }
 777
 778                         if (delegate_method == null) {
 779                                 if (!check_only)
 780                                         Error_NoMatchingMethodForDelegate (ec, mg, type, loc);
 781                                 return null;
 782                         }
 783
 784                         //
 785                         // Check safe/unsafe of the delegate
 786                         //
 787                         if (!ec.InUnsafe){
 788                                 ParameterData param = TypeManager.GetParameterData (delegate_method);
 789                                 int count = param.Count;
 790
 791                                 for (int i = 0; i < count; i++){
 792                                         if (param.ParameterType (i).IsPointer){
 793                                                 Expression.UnsafeError (loc);
 794                                                 return null;
 795                                         }
 796                                 }
 797                         }
 798
 799                         //TODO: implement caching when performance will be low
 800                         IMethodData md = TypeManager.GetMethod (delegate_method);
 801                         if (md == null) {
 802                                 if (System.Attribute.GetCustomAttribute (delegate_method, TypeManager.conditional_attribute_type) != null) {
 803                                         Report.Error (1618, loc, "Cannot create delegate with '{0}' because it has a Conditional attribute", TypeManager.CSharpSignature (delegate_method));
 804                                 }
 805                         } else {
 806                                 md.SetMemberIsUsed ();
 807                                 if (md.OptAttributes != null && md.OptAttributes.Search (TypeManager.conditional_attribute_type, ec) != null) {
 808                                         Report.Error (1618, loc, "Cannot create delegate with '{0}' because it has a Conditional attribute", TypeManager.CSharpSignature (delegate_method));
 809                                 }
 810                         }
 811
 812                         if (mg.InstanceExpression != null)
 813                                 delegate_instance_expression = mg.InstanceExpression.Resolve (ec);
 814                         else if (ec.IsStatic) {
 815                                 if (!delegate_method.IsStatic) {
 816                                         Report.Error (120, loc,
 817                                                       "An object reference is required for the non-static method " +
 818                                                       delegate_method.Name);
 819                                         return null;
 820                                 }
 821                                 delegate_instance_expression = null;
 822                         } else
 823                                 delegate_instance_expression = ec.GetThis (loc);
 824
 825                         if (delegate_instance_expression != null && delegate_instance_expression.Type.IsValueType)
 826                                 delegate_instance_expression = new BoxedCast (delegate_instance_expression);
 827
 828                         method_group = mg;
 829                         eclass = ExprClass.Value;
 830                         return this;
 831                 }
 832         }
 833
 834         //
 835         // Created from the conversion code
 836         //
 837         public class ImplicitDelegateCreation : DelegateCreation {
 838
 839                 ImplicitDelegateCreation (Type t, Location l)
 840                 {
 841                         type = t;
 842                         loc = l;
 843                 }
 844
 845                 public override Expression DoResolve (EmitContext ec)
 846                 {
 847                         return this;
 848                 }
 849
 850                 static public Expression Create (EmitContext ec, MethodGroupExpr mge,
 851                                                  Type target_type, bool check_only, Location loc)
 852                 {
 853                         ImplicitDelegateCreation d = new ImplicitDelegateCreation (target_type, loc);
 854                         if (d.ResolveConstructorMethod (ec))
 855                                 return d.ResolveMethodGroupExpr (ec, mge, check_only);
 856                         else
 857                                 return null;
 858                 }
 859         }
 860
 861         //
 862         // A delegate-creation-expression, invoked from the `New' class
 863         //
 864         public class NewDelegate : DelegateCreation {
 865                 public ArrayList Arguments;
 866
 867                 //
 868                 // This constructor is invoked from the `New' expression
 869                 //
 870                 public NewDelegate (Type type, ArrayList Arguments, Location loc)
 871                 {
 872                         this.type = type;
 873                         this.Arguments = Arguments;
 874                         this.loc  = loc;
 875                 }
 876
 877                 public override Expression DoResolve (EmitContext ec)
 878                 {
 879                         if (Arguments == null || Arguments.Count != 1) {
 880                                 Report.Error (149, loc,
 881                                               "Method name expected");
 882                                 return null;
 883                         }
 884
 885                         if (!ResolveConstructorMethod (ec))
 886                                 return null;
 887
 888                         Argument a = (Argument) Arguments [0];
 889
 890                         if (!a.ResolveMethodGroup (ec, loc))
 891                                 return null;
 892
 893                         Expression e = a.Expr;
 894
 895                         if (e is AnonymousMethod && RootContext.Version != LanguageVersion.ISO_1)
 896                                 return ((AnonymousMethod) e).Compatible (ec, type, false);
 897
 898                         MethodGroupExpr mg = e as MethodGroupExpr;
 899                         if (mg != null)
 900                                 return ResolveMethodGroupExpr (ec, mg, false);
 901
 902                         Type e_type = e.Type;
 903
 904                         if (!TypeManager.IsDelegateType (e_type)) {
 905                                 Report.Error (149, loc, "Method name expected");
 906                                 return null;
 907                         }
 908
 909                         method_group = Expression.MemberLookup (
 910                                 ec, type, "Invoke", MemberTypes.Method,
 911                                 Expression.AllBindingFlags, loc) as MethodGroupExpr;
 912
 913                         if (method_group == null) {
 914                                 Report.Error (-200, loc, "Internal error ! Could not find Invoke method!");
 915                                 return null;
 916                         }
 917
 918                         // This is what MS' compiler reports. We could always choose
 919                         // to be more verbose and actually give delegate-level specifics
 920                         if (!Delegate.VerifyDelegate (ec, type, e_type, loc)) {
 921                                 Report.Error (29, loc, "Cannot implicitly convert type '" + e_type + "' " +
 922                                               "to type '" + type + "'");
 923                                 return null;
 924                         }
 925
 926                         delegate_instance_expression = e;
 927                         delegate_method = method_group.Methods [0];
 928
 929                         eclass = ExprClass.Value;
 930                         return this;
 931                 }
 932         }
 933
 934         public class DelegateInvocation : ExpressionStatement {
 935
 936                 public Expression InstanceExpr;
 937                 public ArrayList  Arguments;
 938
 939                 MethodBase method;
 940
 941                 public DelegateInvocation (Expression instance_expr, ArrayList args, Location loc)
 942                 {
 943                         this.InstanceExpr = instance_expr;
 944                         this.Arguments = args;
 945                         this.loc = loc;
 946                 }
 947
 948                 public override Expression DoResolve (EmitContext ec)
 949                 {
 950                         if (InstanceExpr is EventExpr) {
 951
 952                                 EventInfo ei = ((EventExpr) InstanceExpr).EventInfo;
 953
 954                                 Expression ml = MemberLookup (
 955                                         ec, ec.ContainerType, ei.Name,
 956                                         MemberTypes.Event, AllBindingFlags | BindingFlags.DeclaredOnly, loc);
 957
 958                                 if (ml == null) {
 959                                         //
 960                                         // If this is the case, then the Event does not belong
 961                                         // to this Type and so, according to the spec
 962                                         // cannot be accessed directly
 963                                         //
 964                                         // Note that target will not appear as an EventExpr
 965                                         // in the case it is being referenced within the same type container;
 966                                         // it will appear as a FieldExpr in that case.
 967                                         //
 968
 969                                         Assign.error70 (ei, loc);
 970                                         return null;
 971                                 }
 972                         }
 973
 974
 975                         Type del_type = InstanceExpr.Type;
 976                         if (del_type == null)
 977                                 return null;
 978
 979                         if (Arguments != null){
 980                                 foreach (Argument a in Arguments){
 981                                         if (!a.Resolve (ec, loc))
 982                                                 return null;
 983                                 }
 984                         }
 985
 986                         if (!Delegate.VerifyApplicability (ec, del_type, Arguments, loc))
 987                                 return null;
 988
 989                         Expression lookup = Expression.MemberLookup (ec, del_type, "Invoke", loc);
 990                         if (!(lookup is MethodGroupExpr)) {
 991                                 Report.Error (-100, loc, "Internal error: could not find Invoke method!");
 992                                 return null;
 993                         }
 994
 995                         method = ((MethodGroupExpr) lookup).Methods [0];
 996                         type = ((MethodInfo) method).ReturnType;
 997                         eclass = ExprClass.Value;
 998
 999                         return this;
1000                 }
1001
1002                 public override void Emit (EmitContext ec)
1003                 {
1004                         //
1005                         // Invocation on delegates call the virtual Invoke member
1006                         // so we are always `instance' calls
1007                         //
1008                         Invocation.EmitCall (ec, false, false, InstanceExpr, method, Arguments, loc);
1009                 }
1010
1011                 public override void EmitStatement (EmitContext ec)
1012                 {
1013                         Emit (ec);
1014                         //
1015                         // Pop the return value if there is one
1016                         //
1017                         if (method is MethodInfo){
1018                                 if (((MethodInfo) method).ReturnType != TypeManager.void_type)
1019                                         ec.ig.Emit (OpCodes.Pop);
1020                         }
1021                 }
1022
1023         }
1024 }