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