mcs/mcs/delegate.cs

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