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