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