mcs/mcs/delegate.cs

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