mcs/mcs/delegate.cs

   1 //\r
   2 // delegate.cs: Delegate Handler\r
   3 //\r
   4 // Authors:\r
   5 //     Ravi Pratap (ravi@ximian.com)\r
   6 //     Miguel de Icaza (miguel@ximian.com)\r
   7 //\r
   8 // Licensed under the terms of the GNU GPL\r
   9 //\r
  10 // (C) 2001 Ximian, Inc (http://www.ximian.com)\r
  11 //\r
  12 //\r
  13 \r
  14 using System;\r
  15 using System.Collections;\r
  16 using System.Reflection;\r
  17 using System.Reflection.Emit;\r
  18 using System.Text;\r
  19 \r
  20 namespace Mono.CSharp {\r
  21 \r
  22         /// <summary>\r
  23         ///   Holds Delegates\r
  24         /// </summary>\r
  25         public class Delegate : DeclSpace {\r
  26                 public Expression ReturnType;\r
  27                 public Parameters      Parameters;\r
  28                 public Attributes      OptAttributes;\r
  29 \r
  30                 public ConstructorBuilder ConstructorBuilder;\r
  31                 public MethodBuilder      InvokeBuilder;\r
  32                 public MethodBuilder      BeginInvokeBuilder;\r
  33                 public MethodBuilder      EndInvokeBuilder;\r
  34                 \r
  35                 Type [] param_types;\r
  36                 Type ret_type;\r
  37                 \r
  38                 Expression instance_expr;\r
  39                 MethodBase delegate_method;\r
  40         \r
  41                 const int AllowedModifiers =\r
  42                         Modifiers.NEW |\r
  43                         Modifiers.PUBLIC |\r
  44                         Modifiers.PROTECTED |\r
  45                         Modifiers.INTERNAL |\r
  46                         Modifiers.UNSAFE |\r
  47                         Modifiers.PRIVATE;\r
  48 \r
  49                 public Delegate (TypeContainer parent, Expression type, int mod_flags,\r
  50                                  string name, Parameters param_list,\r
  51                                  Attributes attrs, Location l)\r
  52                         : base (parent, name, l)\r
  53                 {\r
  54                         this.ReturnType = type;\r
  55                         ModFlags        = Modifiers.Check (AllowedModifiers, mod_flags,\r
  56                                                            IsTopLevel ? Modifiers.INTERNAL :\r
  57                                                            Modifiers.PRIVATE, l);\r
  58                         Parameters      = param_list;\r
  59                         OptAttributes   = attrs;\r
  60                 }\r
  61 \r
  62                 public override TypeBuilder DefineType ()\r
  63                 {\r
  64                         TypeAttributes attr;\r
  65 \r
  66                         if (TypeBuilder != null)\r
  67                                 return TypeBuilder;\r
  68                         \r
  69                         if (IsTopLevel) {\r
  70                                 if (TypeManager.NamespaceClash (Name))\r
  71                                         return null;\r
  72                                 \r
  73                                 ModuleBuilder builder = CodeGen.ModuleBuilder;\r
  74                                 attr = TypeAttributes.Public | TypeAttributes.Class | TypeAttributes.Sealed;\r
  75 \r
  76                                 TypeBuilder = builder.DefineType (\r
  77                                         Name, attr, TypeManager.multicast_delegate_type);\r
  78                         } else {\r
  79                                 TypeBuilder builder = Parent.TypeBuilder;\r
  80                                 attr = TypeAttributes.NestedPublic | TypeAttributes.Class |\r
  81                                         TypeAttributes.Sealed;\r
  82 \r
  83                                 string name = Name.Substring (1 + Name.LastIndexOf ('.'));\r
  84                                 TypeBuilder = builder.DefineNestedType (\r
  85                                         name, attr, TypeManager.multicast_delegate_type);\r
  86                         }\r
  87 \r
  88                         TypeManager.AddDelegateType (Name, TypeBuilder, this);\r
  89 \r
  90                         return TypeBuilder;\r
  91                 }\r
  92 \r
  93                 public override bool DefineMembers (TypeContainer container)\r
  94                 {\r
  95                         return true;\r
  96                 }\r
  97 \r
  98                 public override bool Define (TypeContainer container)\r
  99                 {\r
 100                         MethodAttributes mattr;\r
 101                         int i;\r
 102 \r
 103                         // FIXME: POSSIBLY make this static, as it is always constant\r
 104                         //\r
 105                         Type [] const_arg_types = new Type [2];\r
 106                         const_arg_types [0] = TypeManager.object_type;\r
 107                         const_arg_types [1] = TypeManager.intptr_type;\r
 108 \r
 109                         mattr = MethodAttributes.RTSpecialName | MethodAttributes.SpecialName |\r
 110                                 MethodAttributes.HideBySig | MethodAttributes.Public;\r
 111 \r
 112                         ConstructorBuilder = TypeBuilder.DefineConstructor (mattr,\r
 113                                                                             CallingConventions.Standard,\r
 114                                                                             const_arg_types);\r
 115 \r
 116                         ConstructorBuilder.DefineParameter (1, ParameterAttributes.None, "object");\r
 117                         ConstructorBuilder.DefineParameter (2, ParameterAttributes.None, "method");\r
 118                         //\r
 119                         // HACK because System.Reflection.Emit is lame\r
 120                         //\r
 121                         //\r
 122                         // FIXME: POSSIBLY make these static, as they are always the same\r
 123                         Parameter [] fixed_pars = new Parameter [2];\r
 124                         fixed_pars [0] = new Parameter (null, null, Parameter.Modifier.NONE, null);\r
 125                         fixed_pars [1] = new Parameter (null, null, Parameter.Modifier.NONE, null);\r
 126                         Parameters const_parameters = new Parameters (fixed_pars, null, Location);\r
 127                         \r
 128                         TypeManager.RegisterMethod (\r
 129                                 ConstructorBuilder,\r
 130                                 new InternalParameters (const_arg_types, const_parameters),\r
 131                                 const_arg_types);\r
 132                                 \r
 133                         \r
 134                         ConstructorBuilder.SetImplementationFlags (MethodImplAttributes.Runtime);\r
 135 \r
 136                         //\r
 137                         // Here the various methods like Invoke, BeginInvoke etc are defined\r
 138                         //\r
 139                         // First, call the `out of band' special method for\r
 140                         // defining recursively any types we need:\r
 141                         \r
 142                         if (!Parameters.ComputeAndDefineParameterTypes (this))\r
 143                                 return false;\r
 144                         \r
 145                         param_types = Parameters.GetParameterInfo (this);\r
 146                         if (param_types == null)\r
 147                                 return false;\r
 148 \r
 149                         //\r
 150                         // Invoke method\r
 151                         //\r
 152 \r
 153                         // Check accessibility\r
 154                         foreach (Type partype in param_types){\r
 155                                 if (!container.AsAccessible (partype, ModFlags)) {\r
 156                                         Report.Error (59, Location,\r
 157                                                       "Inconsistent accessibility: parameter type `" +\r
 158                                                       TypeManager.CSharpName (partype) + "` is less " +\r
 159                                                       "accessible than delegate `" + Name + "'");\r
 160                                         return false;\r
 161                                 }\r
 162                                 if (partype.IsPointer && !UnsafeOK (container))\r
 163                                         return false;\r
 164                         }\r
 165                         \r
 166                         ReturnType = ResolveTypeExpr (ReturnType, false, Location);\r
 167                         ret_type = ReturnType.Type;\r
 168                         if (ret_type == null)\r
 169                                 return false;\r
 170 \r
 171                         if (!container.AsAccessible (ret_type, ModFlags)) {\r
 172                                 Report.Error (58, Location,\r
 173                                               "Inconsistent accessibility: return type `" +\r
 174                                               TypeManager.CSharpName (ret_type) + "` is less " +\r
 175                                               "accessible than delegate `" + Name + "'");\r
 176                                 return false;\r
 177                         }\r
 178 \r
 179                         if (ret_type.IsPointer && !UnsafeOK (container))\r
 180                                 return false;\r
 181 \r
 182                         //\r
 183                         // We don't have to check any others because they are all\r
 184                         // guaranteed to be accessible - they are standard types.\r
 185                         //\r
 186                         \r
 187                         CallingConventions cc = Parameters.GetCallingConvention ();\r
 188 \r
 189                         mattr = MethodAttributes.Public | MethodAttributes.HideBySig | MethodAttributes.Virtual;\r
 190 \r
 191                         InvokeBuilder = TypeBuilder.DefineMethod ("Invoke", \r
 192                                                                   mattr,                     \r
 193                                                                   cc,\r
 194                                                                   ret_type,                  \r
 195                                                                   param_types);\r
 196 \r
 197                         //\r
 198                         // Define parameters, and count out/ref parameters\r
 199                         //\r
 200                         int out_params = 0;\r
 201                         i = 0;\r
 202                         if (Parameters.FixedParameters != null){\r
 203                                 int top = Parameters.FixedParameters.Length;\r
 204                                 Parameter p;\r
 205                                 \r
 206                                 for (; i < top; i++) {\r
 207                                         p = Parameters.FixedParameters [i];\r
 208                                         InvokeBuilder.DefineParameter (i+1, p.Attributes, p.Name);\r
 209 \r
 210                                         if ((p.ModFlags & Parameter.Modifier.ISBYREF) != 0)\r
 211                                                 out_params++;\r
 212                                 }\r
 213                         }\r
 214                         if (Parameters.ArrayParameter != null){\r
 215                                 Parameter p = Parameters.ArrayParameter;\r
 216                                 \r
 217                                 InvokeBuilder.DefineParameter (\r
 218                                         i+1, p.Attributes, p.Name);\r
 219                         }\r
 220                         \r
 221                         InvokeBuilder.SetImplementationFlags (MethodImplAttributes.Runtime);\r
 222 \r
 223                         TypeManager.RegisterMethod (InvokeBuilder,\r
 224                                                     new InternalParameters (container, Parameters),\r
 225                                                     param_types);\r
 226 \r
 227                         //\r
 228                         // BeginInvoke\r
 229                         //\r
 230                         int params_num = param_types.Length;\r
 231                         Type [] async_param_types = new Type [params_num + 2];\r
 232 \r
 233                         param_types.CopyTo (async_param_types, 0);\r
 234 \r
 235                         async_param_types [params_num] = TypeManager.asynccallback_type;\r
 236                         async_param_types [params_num + 1] = TypeManager.object_type;\r
 237 \r
 238                         mattr = MethodAttributes.Public | MethodAttributes.HideBySig |\r
 239                                 MethodAttributes.Virtual | MethodAttributes.NewSlot;\r
 240                         \r
 241                         BeginInvokeBuilder = TypeBuilder.DefineMethod ("BeginInvoke",\r
 242                                                                        mattr,\r
 243                                                                        cc,\r
 244                                                                        TypeManager.iasyncresult_type,\r
 245                                                                        async_param_types);\r
 246 \r
 247                         i = 0;\r
 248                         if (Parameters.FixedParameters != null){\r
 249                                 int top = Parameters.FixedParameters.Length;\r
 250                                 Parameter p;\r
 251                                 \r
 252                                 for (i = 0 ; i < top; i++) {\r
 253                                         p = Parameters.FixedParameters [i];\r
 254 \r
 255                                         BeginInvokeBuilder.DefineParameter (i+1, p.Attributes, p.Name);\r
 256                                 }\r
 257                         }\r
 258                         if (Parameters.ArrayParameter != null){\r
 259                                 Parameter p = Parameters.ArrayParameter;\r
 260                                 \r
 261                                 BeginInvokeBuilder.DefineParameter (i+1, p.Attributes, p.Name);\r
 262                                 i++;\r
 263                         }\r
 264 \r
 265                         BeginInvokeBuilder.DefineParameter (i + 1, ParameterAttributes.None, "callback");\r
 266                         BeginInvokeBuilder.DefineParameter (i + 2, ParameterAttributes.None, "object");\r
 267                         \r
 268                         BeginInvokeBuilder.SetImplementationFlags (MethodImplAttributes.Runtime);\r
 269 \r
 270                         Parameter [] async_params = new Parameter [params_num + 2];\r
 271                         int n = 0;\r
 272                         if (Parameters.FixedParameters != null){\r
 273                                 Parameters.FixedParameters.CopyTo (async_params, 0);\r
 274                                 n = Parameters.FixedParameters.Length;\r
 275                         }\r
 276                         if (Parameters.ArrayParameter != null)\r
 277                                 async_params [n] = Parameters.ArrayParameter;\r
 278                         \r
 279                         async_params [params_num] = new Parameter (\r
 280                                 TypeManager.system_asynccallback_expr, "callback",\r
 281                                                                    Parameter.Modifier.NONE, null);\r
 282                         async_params [params_num + 1] = new Parameter (\r
 283                                 TypeManager.system_object_expr, "object",\r
 284                                                                    Parameter.Modifier.NONE, null);\r
 285 \r
 286                         Parameters async_parameters = new Parameters (async_params, null, Location);\r
 287                         async_parameters.ComputeAndDefineParameterTypes (this);\r
 288                         \r
 289                         async_parameters.ComputeAndDefineParameterTypes (this);\r
 290                         TypeManager.RegisterMethod (BeginInvokeBuilder,\r
 291                                                     new InternalParameters (container, async_parameters),\r
 292                                                     async_param_types);\r
 293 \r
 294                         //\r
 295                         // EndInvoke is a bit more interesting, all the parameters labeled as\r
 296                         // out or ref have to be duplicated here.\r
 297                         //\r
 298                         \r
 299                         Type [] end_param_types = new Type [out_params + 1];\r
 300                         Parameter [] end_params = new Parameter [out_params + 1];\r
 301                         int param = 0; \r
 302                         if (out_params > 0){\r
 303                                 int top = Parameters.FixedParameters.Length;\r
 304                                 for (i = 0; i < top; i++){\r
 305                                         Parameter p = Parameters.FixedParameters [i];\r
 306                                         if ((p.ModFlags & Parameter.Modifier.ISBYREF) == 0)\r
 307                                                 continue;\r
 308 \r
 309                                         end_param_types [param] = param_types [i];\r
 310                                         end_params [param] = p;\r
 311                                         param++;\r
 312                                 }\r
 313                         }\r
 314                         end_param_types [out_params] = TypeManager.iasyncresult_type;\r
 315                         end_params [out_params] = new Parameter (TypeManager.system_iasyncresult_expr, "result", Parameter.Modifier.NONE, null);\r
 316 \r
 317                         //\r
 318                         // Create method, define parameters, register parameters with type system\r
 319                         //\r
 320                         EndInvokeBuilder = TypeBuilder.DefineMethod ("EndInvoke", mattr, cc, ret_type, end_param_types);\r
 321                         EndInvokeBuilder.SetImplementationFlags (MethodImplAttributes.Runtime);\r
 322 \r
 323                         //\r
 324                         // EndInvoke: Label the parameters\r
 325                         //\r
 326                         EndInvokeBuilder.DefineParameter (out_params + 1, ParameterAttributes.None, "result");\r
 327                         for (i = 0; i < end_params.Length-1; i++){\r
 328                                 EndInvokeBuilder.DefineParameter (i + 1, end_params [i].Attributes, end_params [i].Name);\r
 329                         }\r
 330 \r
 331                         Parameters end_parameters = new Parameters (end_params, null, Location);\r
 332                         end_parameters.ComputeAndDefineParameterTypes (this);\r
 333 \r
 334                         TypeManager.RegisterMethod (\r
 335                                 EndInvokeBuilder,\r
 336                                 new InternalParameters (container, end_parameters),\r
 337                                 end_param_types);\r
 338 \r
 339                         return true;\r
 340                 }\r
 341 \r
 342                 /// <summary>\r
 343                 ///  Verifies whether the method in question is compatible with the delegate\r
 344                 ///  Returns the method itself if okay and null if not.\r
 345                 /// </summary>\r
 346                 public static MethodBase VerifyMethod (EmitContext ec, Type delegate_type, MethodBase mb,\r
 347                                                        Location loc)\r
 348                 {\r
 349                         ParameterData pd = Invocation.GetParameterData (mb);\r
 350 \r
 351                         int pd_count = pd.Count;\r
 352 \r
 353                         Expression ml = Expression.MemberLookup (\r
 354                                 ec, delegate_type, "Invoke", loc);\r
 355 \r
 356                         if (!(ml is MethodGroupExpr)) {\r
 357                                 Report.Error (-100, loc, "Internal error: could not find Invoke method!");\r
 358                                 return null;\r
 359                         }\r
 360 \r
 361                         MethodBase invoke_mb = ((MethodGroupExpr) ml).Methods [0];\r
 362 \r
 363                         ParameterData invoke_pd = Invocation.GetParameterData (invoke_mb);\r
 364 \r
 365                         if (invoke_pd.Count != pd_count)\r
 366                                 return null;\r
 367 \r
 368                         for (int i = pd_count; i > 0; ) {\r
 369                                 i--;\r
 370 \r
 371                                 if (invoke_pd.ParameterType (i) == pd.ParameterType (i) &&\r
 372                                     invoke_pd.ParameterModifier (i) == pd.ParameterModifier (i))\r
 373                                         continue;\r
 374                                 else\r
 375                                         return null;\r
 376                         }\r
 377 \r
 378                         if (((MethodInfo) invoke_mb).ReturnType == ((MethodInfo) mb).ReturnType)\r
 379                                 return mb;\r
 380                         else\r
 381                                 return null;\r
 382                 }\r
 383 \r
 384                 // <summary>\r
 385                 //  Verifies whether the invocation arguments are compatible with the\r
 386                 //  delegate's target method\r
 387                 // </summary>\r
 388                 public static bool VerifyApplicability (EmitContext ec,\r
 389                                                         Type delegate_type,\r
 390                                                         ArrayList args,\r
 391                                                         Location loc)\r
 392                 {\r
 393                         int arg_count;\r
 394 \r
 395                         if (args == null)\r
 396                                 arg_count = 0;\r
 397                         else\r
 398                                 arg_count = args.Count;\r
 399 \r
 400                         Expression ml = Expression.MemberLookup (\r
 401                                 ec, delegate_type, "Invoke", loc);\r
 402 \r
 403                         if (!(ml is MethodGroupExpr)) {\r
 404                                 Report.Error (-100, loc, "Internal error: could not find Invoke method!" + delegate_type);\r
 405                                 return false;\r
 406                         }\r
 407                         \r
 408                         MethodBase mb = ((MethodGroupExpr) ml).Methods [0];\r
 409                         ParameterData pd = Invocation.GetParameterData (mb);\r
 410 \r
 411                         int pd_count = pd.Count;\r
 412 \r
 413                         bool not_params_method = (pd_count == 0) ||\r
 414                                 (pd.ParameterModifier (pd_count - 1) != Parameter.Modifier.PARAMS);\r
 415 \r
 416                         if (not_params_method && pd_count != arg_count) {\r
 417                                 Report.Error (1593, loc,\r
 418                                               "Delegate '" + delegate_type.ToString ()\r
 419                                               + "' does not take '" + arg_count + "' arguments");\r
 420                                 return false;\r
 421                         }\r
 422 \r
 423                         return Invocation.VerifyArgumentsCompat (ec, args, arg_count, mb, !not_params_method,\r
 424                                                                  delegate_type, loc);\r
 425                 }\r
 426                 \r
 427                 /// <summary>\r
 428                 ///  Verifies whether the delegate in question is compatible with this one in\r
 429                 ///  order to determine if instantiation from the same is possible.\r
 430                 /// </summary>\r
 431                 public static bool VerifyDelegate (EmitContext ec, Type delegate_type, Type probe_type, Location loc)\r
 432                 {\r
 433                         Expression ml = Expression.MemberLookup (\r
 434                                 ec, delegate_type, "Invoke", loc);\r
 435                         \r
 436                         if (!(ml is MethodGroupExpr)) {\r
 437                                 Report.Error (-100, loc, "Internal error: could not find Invoke method!");\r
 438                                 return false;\r
 439                         }\r
 440                         \r
 441                         MethodBase mb = ((MethodGroupExpr) ml).Methods [0];\r
 442                         ParameterData pd = Invocation.GetParameterData (mb);\r
 443 \r
 444                         Expression probe_ml = Expression.MemberLookup (\r
 445                                 ec, delegate_type, "Invoke", loc);\r
 446                         \r
 447                         if (!(probe_ml is MethodGroupExpr)) {\r
 448                                 Report.Error (-100, loc, "Internal error: could not find Invoke method!");\r
 449                                 return false;\r
 450                         }\r
 451                         \r
 452                         MethodBase probe_mb = ((MethodGroupExpr) probe_ml).Methods [0];\r
 453                         ParameterData probe_pd = Invocation.GetParameterData (probe_mb);\r
 454                         \r
 455                         if (((MethodInfo) mb).ReturnType != ((MethodInfo) probe_mb).ReturnType)\r
 456                                 return false;\r
 457 \r
 458                         if (pd.Count != probe_pd.Count)\r
 459                                 return false;\r
 460 \r
 461                         for (int i = pd.Count; i > 0; ) {\r
 462                                 i--;\r
 463 \r
 464                                 if (pd.ParameterType (i) != probe_pd.ParameterType (i) ||\r
 465                                     pd.ParameterModifier (i) != probe_pd.ParameterModifier (i))\r
 466                                         return false;\r
 467                         }\r
 468                         \r
 469                         return true;\r
 470                 }\r
 471                 \r
 472                 public static string FullDelegateDesc (Type del_type, MethodBase mb, ParameterData pd)\r
 473                 {\r
 474                         StringBuilder sb = new StringBuilder (TypeManager.CSharpName (((MethodInfo) mb).ReturnType));\r
 475                         \r
 476                         sb.Append (" " + del_type.ToString ());\r
 477                         sb.Append (" (");\r
 478 \r
 479                         int length = pd.Count;\r
 480                         \r
 481                         for (int i = length; i > 0; ) {\r
 482                                 i--;\r
 483 \r
 484                                 sb.Append (pd.ParameterDesc (length - i - 1));\r
 485                                 if (i != 0)\r
 486                                         sb.Append (", ");\r
 487                         }\r
 488                         \r
 489                         sb.Append (")");\r
 490                         return sb.ToString ();\r
 491                         \r
 492                 }\r
 493                 \r
 494                 // Hack around System.Reflection as found everywhere else\r
 495                 public override MemberList FindMembers (MemberTypes mt, BindingFlags bf,\r
 496                                                         MemberFilter filter, object criteria)\r
 497                 {\r
 498                         ArrayList members = new ArrayList ();\r
 499 \r
 500                         if ((mt & MemberTypes.Method) != 0) {\r
 501                                 if (ConstructorBuilder != null)\r
 502                                 if (filter (ConstructorBuilder, criteria))\r
 503                                         members.Add (ConstructorBuilder);\r
 504 \r
 505                                 if (InvokeBuilder != null)\r
 506                                 if (filter (InvokeBuilder, criteria))\r
 507                                         members.Add (InvokeBuilder);\r
 508 \r
 509                                 if (BeginInvokeBuilder != null)\r
 510                                 if (filter (BeginInvokeBuilder, criteria))\r
 511                                         members.Add (BeginInvokeBuilder);\r
 512 \r
 513                                 if (EndInvokeBuilder != null)\r
 514                                 if (filter (EndInvokeBuilder, criteria))\r
 515                                         members.Add (EndInvokeBuilder);\r
 516                         }\r
 517 \r
 518                         return new MemberList (members);\r
 519                 }\r
 520 \r
 521                 public override MemberCache MemberCache {\r
 522                         get {\r
 523                                 return null;\r
 524                         }\r
 525                 }\r
 526 \r
 527                 public Expression InstanceExpression {\r
 528                         get {\r
 529                                 return instance_expr;\r
 530                         }\r
 531                         set {\r
 532                                 instance_expr = value;\r
 533                         }\r
 534                 }\r
 535 \r
 536                 public MethodBase TargetMethod {\r
 537                         get {\r
 538                                 return delegate_method;\r
 539                         }\r
 540                         set {\r
 541                                 delegate_method = value;\r
 542                         }\r
 543                 }\r
 544 \r
 545                 public Type TargetReturnType {\r
 546                         get {\r
 547                                 return ret_type;\r
 548                         }\r
 549                 }\r
 550 \r
 551                 public Type [] ParameterTypes {\r
 552                         get {\r
 553                                 return param_types;\r
 554                         }\r
 555                 }\r
 556                 \r
 557         }\r
 558 \r
 559         public class NewDelegate : Expression {\r
 560 \r
 561                 public ArrayList Arguments;\r
 562 \r
 563                 MethodBase constructor_method;\r
 564                 MethodBase delegate_method;\r
 565                 Expression delegate_instance_expr;\r
 566 \r
 567                 public NewDelegate (Type type, ArrayList Arguments, Location loc)\r
 568                 {\r
 569                         this.type = type;\r
 570                         this.Arguments = Arguments;\r
 571                         this.loc  = loc; \r
 572                 }\r
 573 \r
 574                 public override Expression DoResolve (EmitContext ec)\r
 575                 {\r
 576                         if (Arguments == null || Arguments.Count != 1) {\r
 577                                 Report.Error (149, loc,\r
 578                                               "Method name expected");\r
 579                                 return null;\r
 580                         }\r
 581 \r
 582                         Expression ml = Expression.MemberLookup (\r
 583                                 ec, type, ".ctor", loc);\r
 584 \r
 585                         if (!(ml is MethodGroupExpr)) {\r
 586                                 Report.Error (-100, loc, "Internal error: Could not find delegate constructor!");\r
 587                                 return null;\r
 588                         }\r
 589 \r
 590                         constructor_method = ((MethodGroupExpr) ml).Methods [0];\r
 591                         Argument a = (Argument) Arguments [0];\r
 592                         \r
 593                         if (!a.ResolveMethodGroup (ec, Location))\r
 594                                 return null;\r
 595                         \r
 596                         Expression e = a.Expr;\r
 597 \r
 598                         Expression invoke_method = Expression.MemberLookup (\r
 599                                 ec, type, "Invoke", MemberTypes.Method,\r
 600                                 Expression.AllBindingFlags, loc);\r
 601 \r
 602                         if (invoke_method == null) {\r
 603                                 Report.Error (-200, loc, "Internal error ! Could not find Invoke method!");\r
 604                                 return null;\r
 605                         }\r
 606 \r
 607                         if (e is MethodGroupExpr) {\r
 608                                 MethodGroupExpr mg = (MethodGroupExpr) e;\r
 609 \r
 610                                 foreach (MethodInfo mi in mg.Methods){\r
 611                                         delegate_method  = Delegate.VerifyMethod (ec, type, mi, loc);\r
 612 \r
 613                                         if (delegate_method != null)\r
 614                                                 break;\r
 615                                 }\r
 616                                         \r
 617                                 if (delegate_method == null) {\r
 618                                         string method_desc;\r
 619                                         if (mg.Methods.Length > 1)\r
 620                                                 method_desc = mg.Methods [0].Name;\r
 621                                         else\r
 622                                                 method_desc = Invocation.FullMethodDesc (mg.Methods [0]);\r
 623 \r
 624                                         MethodBase dm = ((MethodGroupExpr) invoke_method).Methods [0];\r
 625                                         ParameterData param = Invocation.GetParameterData (dm);\r
 626                                         string delegate_desc = Delegate.FullDelegateDesc (type, dm, param);\r
 627 \r
 628                                         Report.Error (123, loc, "Method '" + method_desc + "' does not " +\r
 629                                                       "match delegate '" + delegate_desc + "'");\r
 630 \r
 631                                         return null;\r
 632                                 }\r
 633 \r
 634                                 //\r
 635                                 // Check safe/unsafe of the delegate\r
 636                                 //\r
 637                                 if (!ec.InUnsafe){\r
 638                                         ParameterData param = Invocation.GetParameterData (delegate_method);\r
 639                                         int count = param.Count;\r
 640                                         \r
 641                                         for (int i = 0; i < count; i++){\r
 642                                                 if (param.ParameterType (i).IsPointer){\r
 643                                                         Expression.UnsafeError (loc);\r
 644                                                         return null;\r
 645                                                 }\r
 646                                         }\r
 647                                 }\r
 648                                                 \r
 649                                 if (mg.InstanceExpression != null)\r
 650                                         delegate_instance_expr = mg.InstanceExpression.Resolve (ec);\r
 651                                 else {\r
 652                                         if (ec.IsStatic){\r
 653                                                 if (!delegate_method.IsStatic){\r
 654                                                         Report.Error (120, loc,\r
 655                                                                       "An object reference is required for the non-static method " +\r
 656                                                                       delegate_method.Name);\r
 657                                                         return null;\r
 658                                                 }\r
 659                                                 delegate_instance_expr = null;\r
 660                                         } else\r
 661                                                 delegate_instance_expr = ec.This;\r
 662                                 }\r
 663 \r
 664                                 if (delegate_instance_expr != null)\r
 665                                         if (delegate_instance_expr.Type.IsValueType)\r
 666                                                 delegate_instance_expr = new BoxedCast (delegate_instance_expr);\r
 667                                 \r
 668                                 eclass = ExprClass.Value;\r
 669                                 return this;\r
 670                         }\r
 671 \r
 672                         Type e_type = e.Type;\r
 673 \r
 674                         if (!TypeManager.IsDelegateType (e_type)) {\r
 675                                 e.Error_UnexpectedKind ("method");\r
 676                                 return null;\r
 677                         }\r
 678 \r
 679                         // This is what MS' compiler reports. We could always choose\r
 680                         // to be more verbose and actually give delegate-level specifics\r
 681                         \r
 682                         if (!Delegate.VerifyDelegate (ec, type, e_type, loc)) {\r
 683                                 Report.Error (29, loc, "Cannot implicitly convert type '" + e_type + "' " +\r
 684                                               "to type '" + type + "'");\r
 685                                 return null;\r
 686                         }\r
 687                                 \r
 688                         delegate_instance_expr = e;\r
 689                         delegate_method = ((MethodGroupExpr) invoke_method).Methods [0];\r
 690                         \r
 691                         eclass = ExprClass.Value;\r
 692                         return this;\r
 693                 }\r
 694                 \r
 695                 public override void Emit (EmitContext ec)\r
 696                 {\r
 697                         if (delegate_instance_expr == null ||\r
 698                             delegate_method.IsStatic)\r
 699                                 ec.ig.Emit (OpCodes.Ldnull);\r
 700                         else\r
 701                                 delegate_instance_expr.Emit (ec);\r
 702                         \r
 703                         if (delegate_method.IsVirtual) {\r
 704                                 ec.ig.Emit (OpCodes.Dup);\r
 705                                 ec.ig.Emit (OpCodes.Ldvirtftn, (MethodInfo) delegate_method);\r
 706                         } else\r
 707                                 ec.ig.Emit (OpCodes.Ldftn, (MethodInfo) delegate_method);\r
 708                         ec.ig.Emit (OpCodes.Newobj, (ConstructorInfo) constructor_method);\r
 709                 }\r
 710         }\r
 711 \r
 712         public class DelegateInvocation : ExpressionStatement {\r
 713 \r
 714                 public Expression InstanceExpr;\r
 715                 public ArrayList  Arguments;\r
 716 \r
 717                 MethodBase method;\r
 718                 \r
 719                 public DelegateInvocation (Expression instance_expr, ArrayList args, Location loc)\r
 720                 {\r
 721                         this.InstanceExpr = instance_expr;\r
 722                         this.Arguments = args;\r
 723                         this.loc = loc;\r
 724                 }\r
 725 \r
 726                 public override Expression DoResolve (EmitContext ec)\r
 727                 {\r
 728                         if (InstanceExpr is EventExpr) {\r
 729                                 \r
 730                                 EventInfo ei = ((EventExpr) InstanceExpr).EventInfo;\r
 731                                 \r
 732                                 Expression ml = MemberLookup (\r
 733                                         ec, ec.ContainerType, ei.Name,\r
 734                                         MemberTypes.Event, AllBindingFlags | BindingFlags.DeclaredOnly, loc);\r
 735 \r
 736                                 if (ml == null) {\r
 737                                         //\r
 738                                         // If this is the case, then the Event does not belong \r
 739                                         // to this Type and so, according to the spec\r
 740                                         // cannot be accessed directly\r
 741                                         //\r
 742                                         // Note that target will not appear as an EventExpr\r
 743                                         // in the case it is being referenced within the same type container;\r
 744                                         // it will appear as a FieldExpr in that case.\r
 745                                         //\r
 746                                         \r
 747                                         Assign.error70 (ei, loc);\r
 748                                         return null;\r
 749                                 }\r
 750                         }\r
 751                         \r
 752                         \r
 753                         Type del_type = InstanceExpr.Type;\r
 754                         if (del_type == null)\r
 755                                 return null;\r
 756                         \r
 757                         if (Arguments != null){\r
 758                                 foreach (Argument a in Arguments){\r
 759                                         if (!a.Resolve (ec, loc))\r
 760                                                 return null;\r
 761                                 }\r
 762                         }\r
 763                         \r
 764                         if (!Delegate.VerifyApplicability (ec, del_type, Arguments, loc))\r
 765                                 return null;\r
 766 \r
 767                         Expression lookup = Expression.MemberLookup (ec, del_type, "Invoke", loc);\r
 768                         if (!(lookup is MethodGroupExpr)) {\r
 769                                 Report.Error (-100, loc, "Internal error: could not find Invoke method!");\r
 770                                 return null;\r
 771                         }\r
 772                         \r
 773                         method = ((MethodGroupExpr) lookup).Methods [0];\r
 774                         type = ((MethodInfo) method).ReturnType;\r
 775                         eclass = ExprClass.Value;\r
 776                         \r
 777                         return this;\r
 778                 }\r
 779 \r
 780                 public override void Emit (EmitContext ec)\r
 781                 {\r
 782                         Delegate del = TypeManager.LookupDelegate (InstanceExpr.Type);\r
 783 \r
 784                         //\r
 785                         // Invocation on delegates call the virtual Invoke member\r
 786                         // so we are always `instance' calls\r
 787                         //\r
 788                         Invocation.EmitCall (ec, false, false, InstanceExpr, method, Arguments, loc);\r
 789                 }\r
 790 \r
 791                 public override void EmitStatement (EmitContext ec)\r
 792                 {\r
 793                         Emit (ec);\r
 794                         // \r
 795                         // Pop the return value if there is one\r
 796                         //\r
 797                         if (method is MethodInfo){\r
 798                                 if (((MethodInfo) method).ReturnType != TypeManager.void_type)\r
 799                                         ec.ig.Emit (OpCodes.Pop);\r
 800                         }\r
 801                 }\r
 802 \r
 803         }\r
 804 }\r