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 {\r
  24 \r
  25                 public readonly string Name;\r
  26                 public readonly string ReturnType;\r
  27                 public int             mod_flags;\r
  28                 public Parameters      Parameters;\r
  29                 public Attributes      OptAttributes;\r
  30                 public TypeBuilder     TypeBuilder;\r
  31 \r
  32                 public ConstructorBuilder ConstructorBuilder;\r
  33                 public MethodBuilder      InvokeBuilder;\r
  34                 public MethodBuilder      BeginInvokeBuilder;\r
  35                 public MethodBuilder      EndInvokeBuilder;\r
  36                 \r
  37                 public readonly RootContext RootContext;\r
  38 \r
  39                 Type [] param_types;\r
  40                 Type ret_type;\r
  41                 \r
  42                 Expression instance_expr;\r
  43                 MethodBase delegate_method;\r
  44         \r
  45                 Location loc;\r
  46 \r
  47                 const int AllowedModifiers =\r
  48                         Modifiers.NEW |\r
  49                         Modifiers.PUBLIC |\r
  50                         Modifiers.PROTECTED |\r
  51                         Modifiers.INTERNAL |\r
  52                         Modifiers.PRIVATE;\r
  53 \r
  54                 public Delegate (RootContext rc, string type, int mod_flags, string name, Parameters param_list,\r
  55                                  Attributes attrs, Location loc)\r
  56                 {\r
  57                         this.RootContext = rc;\r
  58                         this.Name       = name;\r
  59                         this.ReturnType = type;\r
  60                         this.mod_flags  = Modifiers.Check (AllowedModifiers, mod_flags, Modifiers.PUBLIC);\r
  61                         Parameters      = param_list;\r
  62                         OptAttributes   = attrs;\r
  63                         this.loc        = loc;\r
  64                 }\r
  65 \r
  66                 public void DefineDelegate (object parent_builder)\r
  67                 {\r
  68                         TypeAttributes attr;\r
  69                         \r
  70                         if (parent_builder is ModuleBuilder) {\r
  71                                 ModuleBuilder builder = (ModuleBuilder) parent_builder;\r
  72                                 \r
  73                                 attr = TypeAttributes.Public | TypeAttributes.Class | TypeAttributes.Sealed;\r
  74 \r
  75                                 TypeBuilder = builder.DefineType (Name, attr, TypeManager.delegate_type);\r
  76                                                                   \r
  77                         } else {\r
  78                                 TypeBuilder builder = (TypeBuilder) parent_builder;\r
  79                                 \r
  80                                 attr = TypeAttributes.NestedPublic | TypeAttributes.Class | TypeAttributes.Sealed;\r
  81 \r
  82                                 TypeBuilder = builder.DefineNestedType (Name, attr, TypeManager.delegate_type);\r
  83 \r
  84                         }\r
  85 \r
  86                         RootContext.TypeManager.AddDelegateType (Name, TypeBuilder, this);\r
  87                 }\r
  88 \r
  89                 public void Populate (TypeContainer parent)\r
  90                 {\r
  91 \r
  92                         MethodAttributes mattr;\r
  93                         int i;\r
  94                         \r
  95                         Type [] const_arg_types = new Type [2];\r
  96 \r
  97                         const_arg_types [0] = TypeManager.object_type;\r
  98                         const_arg_types [1] = TypeManager.intptr_type;\r
  99 \r
 100                         mattr = MethodAttributes.RTSpecialName | MethodAttributes.SpecialName |\r
 101                                 MethodAttributes.HideBySig | MethodAttributes.Public;\r
 102 \r
 103                         ConstructorBuilder = TypeBuilder.DefineConstructor (mattr,\r
 104                                                                             CallingConventions.Standard,\r
 105                                                                             const_arg_types);\r
 106                         \r
 107                         ConstructorBuilder.SetImplementationFlags (MethodImplAttributes.Runtime);\r
 108                         \r
 109                         // Here the various methods like Invoke, BeginInvoke etc are defined\r
 110 \r
 111                         param_types = Parameters.GetParameterInfo (parent);\r
 112                         ret_type = parent.LookupType (ReturnType, false);\r
 113                         CallingConventions cc = Parameters.GetCallingConvention ();\r
 114 \r
 115                         mattr = MethodAttributes.Public | MethodAttributes.HideBySig | MethodAttributes.Virtual;\r
 116 \r
 117                         InvokeBuilder = TypeBuilder.DefineMethod ("Invoke", \r
 118                                                                   mattr,                     \r
 119                                                                   cc,\r
 120                                                                   ret_type,                  \r
 121                                                                   param_types);\r
 122 \r
 123                         for (i = 0 ; i < param_types.Length; i++) {\r
 124                                 Parameter p = Parameters.FixedParameters [i];\r
 125                                 string name = p.Name;\r
 126                                 ParameterBuilder pb = InvokeBuilder.DefineParameter (i+1, p.Attributes, name); \r
 127                         }\r
 128                         \r
 129                         InvokeBuilder.SetImplementationFlags (MethodImplAttributes.Runtime);\r
 130 \r
 131                         TypeContainer.RegisterParameterForBuilder (InvokeBuilder,\r
 132                                                                    new InternalParameters (parent, Parameters)); \r
 133 \r
 134                         int params_num = param_types.Length;\r
 135                         Type [] async_param_types = new Type [params_num + 2];\r
 136 \r
 137                         param_types.CopyTo (async_param_types, 0);\r
 138 \r
 139                         async_param_types [params_num] = TypeManager.asynccallback_type;\r
 140                         async_param_types [params_num + 1] = TypeManager.object_type;\r
 141 \r
 142                         mattr = MethodAttributes.Public | MethodAttributes.HideBySig | MethodAttributes.Virtual |\r
 143                                 MethodAttributes.NewSlot;\r
 144                         \r
 145                         BeginInvokeBuilder = TypeBuilder.DefineMethod ("BeginInvoke",\r
 146                                                                        mattr,\r
 147                                                                        cc,\r
 148                                                                        TypeManager.iasyncresult_type,\r
 149                                                                        async_param_types);\r
 150 \r
 151                         for (i = 0 ; i < param_types.Length; i++) {\r
 152                                 Parameter p = Parameters.FixedParameters [i];\r
 153                                 string name = p.Name;\r
 154                                 BeginInvokeBuilder.DefineParameter (i + 1, p.Attributes, name); \r
 155                         }\r
 156                         \r
 157                         BeginInvokeBuilder.DefineParameter (i + 1, ParameterAttributes.None, "callback");\r
 158                         BeginInvokeBuilder.DefineParameter (i + 2, ParameterAttributes.None, "object");\r
 159                         \r
 160                         BeginInvokeBuilder.SetImplementationFlags (MethodImplAttributes.Runtime);\r
 161 \r
 162                         Parameter [] async_params = new Parameter [params_num + 2];\r
 163                         Parameters.FixedParameters.CopyTo (async_params, 0);\r
 164 \r
 165                         async_params [params_num] = new Parameter ("System.AsyncCallback", "callback",\r
 166                                                                    Parameter.Modifier.NONE, null);\r
 167                         async_params [params_num + 1] = new Parameter ("System.IAsyncResult", "object",\r
 168                                                                    Parameter.Modifier.NONE, null);\r
 169                         \r
 170                         TypeContainer.RegisterParameterForBuilder (BeginInvokeBuilder,\r
 171                                         new InternalParameters (parent, new Parameters (async_params, null))); \r
 172 \r
 173                         Type [] end_param_types = new Type [1];\r
 174                         end_param_types [0] = TypeManager.iasyncresult_type;\r
 175                         \r
 176                         EndInvokeBuilder = TypeBuilder.DefineMethod ("EndInvoke",\r
 177                                                                      mattr,\r
 178                                                                      cc,\r
 179                                                                      ret_type,\r
 180                                                                      end_param_types);\r
 181                         EndInvokeBuilder.DefineParameter (1, ParameterAttributes.None, "result");\r
 182                         \r
 183                         EndInvokeBuilder.SetImplementationFlags (MethodImplAttributes.Runtime);\r
 184 \r
 185                         Parameter [] end_params = new Parameter [1];\r
 186                         end_params [0] = new Parameter ("System.IAsyncResult", "result",\r
 187                                                         Parameter.Modifier.NONE, null);\r
 188 \r
 189                         TypeContainer.RegisterParameterForBuilder (EndInvokeBuilder,\r
 190                                         new InternalParameters (parent, new Parameters (end_params, null))); \r
 191                         \r
 192                 }\r
 193 \r
 194                 // <summary>\r
 195                 //  Verifies whether the method in question is compatible with the delegate\r
 196                 //  Returns the method itself if okay and null if not.\r
 197                 // </summary>\r
 198                 public MethodBase VerifyMethod (MethodBase mb, Location loc)\r
 199                 {\r
 200                         ParameterData pd = Invocation.GetParameterData (mb);\r
 201 \r
 202                         bool mismatch = false;\r
 203                         for (int i = param_types.Length; i > 0; ) {\r
 204                                 i--;\r
 205 \r
 206                                 if (param_types [i] == pd.ParameterType (i))\r
 207                                         continue;\r
 208                                 else {\r
 209                                         mismatch = true;\r
 210                                         break;\r
 211                                 }\r
 212                         }\r
 213 \r
 214                         if (mismatch) {\r
 215                                 Report.Error (123, loc, "Method '" + Invocation.FullMethodDesc (mb) + "' does not match " +\r
 216                                               "delegate '" + FullDelegateDesc () + "'");\r
 217                                 return null;\r
 218                         }\r
 219 \r
 220                         if (ret_type == ((MethodInfo) mb).ReturnType)\r
 221                                 return mb;\r
 222                         else\r
 223                                 mismatch = true;\r
 224 \r
 225                         if (mismatch) {\r
 226                                 Report.Error (123, loc, "Method '" + Invocation.FullMethodDesc (mb) + "' does not match " +\r
 227                                               "delegate '" + FullDelegateDesc () + "'");\r
 228                                 return null;\r
 229                         }\r
 230 \r
 231                         return null;\r
 232                 }\r
 233 \r
 234                 // <summary>\r
 235                 //  Verifies whether the invocation arguments are compatible with the\r
 236                 //  delegate's target method\r
 237                 // </summary>\r
 238                 public bool VerifyApplicability (EmitContext ec, ArrayList args, Location loc)\r
 239                 {\r
 240                         int arg_count;\r
 241 \r
 242                         if (args == null)\r
 243                                 arg_count = 0;\r
 244                         else\r
 245                                 arg_count = args.Count;\r
 246                         \r
 247                         if (param_types.Length != arg_count) {\r
 248                                 Report.Error (1593, loc,\r
 249                                               "Delegate '" + Name + "' does not take '" + arg_count + "' arguments");\r
 250                                 return false;\r
 251                         }\r
 252 \r
 253                         for (int i = arg_count; i > 0;) {\r
 254                                 i--;\r
 255                                 Expression conv;\r
 256                                 Argument a = (Argument) args [i];\r
 257                                 Expression a_expr = a.Expr;\r
 258                                 \r
 259                                 if (param_types [i] != a_expr.Type) {\r
 260                                         \r
 261                                         conv = Expression.ConvertImplicitStandard (ec, a_expr, param_types [i], loc);\r
 262 \r
 263                                         if (conv == null) {\r
 264                                                 Report.Error (1594, loc,\r
 265                                                               "Delegate '" + Name + "' has some invalid arguments.");\r
 266 \r
 267                                                 Report.Error (1503, loc,\r
 268                                                        "Argument " + (i+1) +\r
 269                                                        ": Cannot convert from '" +\r
 270                                                        TypeManager.CSharpName (a_expr.Type)\r
 271                                                        + "' to '" + TypeManager.CSharpName (param_types [i]) + "'");\r
 272                                                 return false;\r
 273                                         }\r
 274 \r
 275                                         if (a_expr != conv)\r
 276                                                 a.Expr = conv;\r
 277                                 }\r
 278                         }\r
 279 \r
 280                         return true;\r
 281                 }\r
 282 \r
 283                 /// <summary>\r
 284                 ///  Verifies whether the delegate in question is compatible with this one in\r
 285                 ///  order to determine if instantiation from the same is possible.\r
 286                 /// </summary>\r
 287                 public bool VerifyDelegate (Delegate del)\r
 288                 {\r
 289                         if (ret_type != del.TargetReturnType)\r
 290                                 return false;\r
 291 \r
 292                         Type [] other_param_types = del.ParameterTypes;\r
 293                         \r
 294                         if (param_types.Length != other_param_types.Length)\r
 295                                 return false;\r
 296 \r
 297                         for (int i = param_types.Length; i > 0; ) {\r
 298                                 i--;\r
 299 \r
 300                                 if (param_types [i] != other_param_types [i])\r
 301                                         return false;\r
 302                         }\r
 303 \r
 304                         // FIXME : Hey, what about parameter modifiers ?\r
 305 \r
 306                         return true;\r
 307 \r
 308                 }\r
 309                 \r
 310                 public string FullDelegateDesc ()\r
 311                 {\r
 312                         StringBuilder sb = new StringBuilder (TypeManager.CSharpName (System.Type.GetType (ReturnType)));\r
 313                         \r
 314                         sb.Append (" " + Name);\r
 315                         sb.Append (" (");\r
 316 \r
 317                         int length = param_types.Length;\r
 318                         \r
 319                         for (int i = length; i > 0; ) {\r
 320                                 i--;\r
 321                                 \r
 322                                 sb.Append (TypeManager.CSharpName (param_types [length - i - 1]));\r
 323                                 if (i != 0)\r
 324                                         sb.Append (", ");\r
 325                         }\r
 326                         \r
 327                         sb.Append (")");\r
 328                         return sb.ToString ();\r
 329                         \r
 330                 }\r
 331                 \r
 332                 // Hack around System.Reflection as found everywhere else\r
 333                 public MemberInfo [] FindMembers (MemberTypes mt, BindingFlags bf, MemberFilter filter, object criteria)\r
 334                 {\r
 335                         ArrayList members = new ArrayList ();\r
 336 \r
 337                         if ((mt & MemberTypes.Method) != 0) {\r
 338                                 if (filter (ConstructorBuilder, criteria))\r
 339                                         members.Add (ConstructorBuilder);\r
 340 \r
 341                                 if (filter (InvokeBuilder, criteria))\r
 342                                         members.Add (InvokeBuilder);\r
 343 \r
 344                                 if (filter (BeginInvokeBuilder, criteria))\r
 345                                         members.Add (BeginInvokeBuilder);\r
 346 \r
 347                                 if (filter (EndInvokeBuilder, criteria))\r
 348                                         members.Add (EndInvokeBuilder);\r
 349                         }\r
 350 \r
 351                         int count = members.Count;\r
 352 \r
 353                         if (count > 0) {\r
 354                                 MemberInfo [] mi = new MemberInfo [count];\r
 355                                 members.CopyTo (mi, 0);\r
 356                                 return mi;\r
 357                         }\r
 358 \r
 359                         return null;\r
 360                 }\r
 361                 \r
 362                 public void CloseDelegate ()\r
 363                 {\r
 364                         TypeBuilder.CreateType ();\r
 365                 }\r
 366                 \r
 367                 public int ModFlags {\r
 368                         get {\r
 369                                 return mod_flags;\r
 370                         }\r
 371                 }\r
 372 \r
 373                 public Expression InstanceExpression {\r
 374                         get {\r
 375                                 return instance_expr;\r
 376                         }\r
 377                         set {\r
 378                                 instance_expr = value;\r
 379                         }\r
 380                 }\r
 381 \r
 382                 public MethodBase TargetMethod {\r
 383                         get {\r
 384                                 return delegate_method;\r
 385                         }\r
 386                         set {\r
 387                                 delegate_method = value;\r
 388                         }\r
 389                 }\r
 390 \r
 391                 public Type TargetReturnType {\r
 392                         get {\r
 393                                 return ret_type;\r
 394                         }\r
 395                 }\r
 396 \r
 397                 public Type [] ParameterTypes {\r
 398                         get {\r
 399                                 return param_types;\r
 400                         }\r
 401                 }\r
 402                 \r
 403         }\r
 404 \r
 405         public class NewDelegate : Expression {\r
 406 \r
 407                 public ArrayList Arguments;\r
 408 \r
 409                 MethodBase constructor_method;\r
 410                 MethodBase delegate_method;\r
 411                 Expression delegate_instance_expr;\r
 412 \r
 413                 Location Location;\r
 414                 \r
 415                 public NewDelegate (Type type, ArrayList Arguments, Location loc)\r
 416                 {\r
 417                         this.type = type;\r
 418                         this.Arguments = Arguments;\r
 419                         this.Location  = loc; \r
 420                 }\r
 421 \r
 422                 public override Expression DoResolve (EmitContext ec)\r
 423                 {\r
 424                         Delegate del = TypeManager.LookupDelegate (type);\r
 425                         constructor_method = del.ConstructorBuilder;\r
 426                         \r
 427                         if (Arguments == null) {\r
 428                                 Report.Error (-11, Location,\r
 429                                               "Delegate creation expression takes only one argument");\r
 430                                 return null;\r
 431                         }\r
 432                         \r
 433                         if (Arguments.Count != 1) {\r
 434                                 Report.Error (-11, Location,\r
 435                                               "Delegate creation expression takes only one argument");\r
 436                                 return null;\r
 437                         }\r
 438                         \r
 439                         Argument a = (Argument) Arguments [0];\r
 440                         \r
 441                         if (!a.Resolve (ec, Location))\r
 442                                 return null;\r
 443                         \r
 444                         Expression e = a.Expr;\r
 445                         \r
 446                         if (e is MethodGroupExpr) {\r
 447                                 MethodGroupExpr mg = (MethodGroupExpr) e;\r
 448                                 \r
 449                                 delegate_method  = del.VerifyMethod (mg.Methods [0], Location);\r
 450                                 \r
 451                                 if (delegate_method == null)\r
 452                                         return null;\r
 453                                 \r
 454                                 if (mg.InstanceExpression != null)\r
 455                                         delegate_instance_expr = mg.InstanceExpression.Resolve (ec);\r
 456                                 else\r
 457                                         delegate_instance_expr = null;\r
 458                                 \r
 459                                 if (delegate_instance_expr != null)\r
 460                                         if (delegate_instance_expr.Type.IsValueType)\r
 461                                                 delegate_instance_expr = new BoxedCast (delegate_instance_expr);\r
 462                                 \r
 463                                 \r
 464                                 del.InstanceExpression = delegate_instance_expr;\r
 465                                 del.TargetMethod = delegate_method;\r
 466                                 \r
 467                                 eclass = ExprClass.Value;\r
 468                                 return this;\r
 469                         }\r
 470 \r
 471                         Type e_type = e.Type;\r
 472 \r
 473                         Delegate d = TypeManager.LookupDelegate (e_type);\r
 474 \r
 475                         if (d == null) {\r
 476                                 Report.Error (-12, Location, "Cannot create a delegate from something " +\r
 477                                               "not a delegate or a method.");\r
 478                                 return null;\r
 479                         }\r
 480 \r
 481                         // This is what MS's compiler reports. We could always choose\r
 482                         // to be more verbose and actually give delegate-level specifics\r
 483                         \r
 484                         if (!d.VerifyDelegate (del)) {\r
 485                                 Report.Error (29, Location, "Cannot implicitly convert type '" + d.Name + "' " +\r
 486                                               "to type '" + del.Name + "'");\r
 487                                 return null;\r
 488                         }\r
 489 \r
 490                         delegate_instance_expr = d.InstanceExpression;\r
 491                         delegate_method        = d.TargetMethod;\r
 492                         \r
 493                         del.InstanceExpression = d.InstanceExpression;\r
 494                         del.TargetMethod       = d.TargetMethod;\r
 495                         \r
 496                         eclass = ExprClass.Value;\r
 497                         return this;\r
 498                 }\r
 499                 \r
 500                 public override void Emit (EmitContext ec)\r
 501                 {\r
 502                         if (delegate_instance_expr == null)\r
 503                                 ec.ig.Emit (OpCodes.Ldnull);\r
 504                         else\r
 505                                 delegate_instance_expr.Emit (ec);\r
 506                         \r
 507                         ec.ig.Emit (OpCodes.Ldftn, (MethodInfo) delegate_method);\r
 508                         ec.ig.Emit (OpCodes.Newobj, (ConstructorInfo) constructor_method);\r
 509                 }\r
 510         }\r
 511 \r
 512         public class DelegateInvocation : ExpressionStatement {\r
 513 \r
 514                 public Expression InstanceExpr;\r
 515                 public ArrayList  Arguments;\r
 516                 public Location   Location;\r
 517 \r
 518                 MethodBase method;\r
 519                 \r
 520                 public DelegateInvocation (Expression instance_expr, ArrayList args, Location loc)\r
 521                 {\r
 522                         this.InstanceExpr = instance_expr;\r
 523                         this.Arguments = args;\r
 524                         this.Location = loc;\r
 525                 }\r
 526 \r
 527                 public override Expression DoResolve (EmitContext ec)\r
 528                 {\r
 529                         Delegate del = TypeManager.LookupDelegate (InstanceExpr.Type);\r
 530 \r
 531                         if (del == null)\r
 532                                 return null;\r
 533 \r
 534                         if (del.TargetMethod == null)\r
 535                                 return null;\r
 536                         \r
 537                         if (Arguments != null){\r
 538                                 for (int i = Arguments.Count; i > 0;){\r
 539                                         --i;\r
 540                                         Argument a = (Argument) Arguments [i];\r
 541                                         \r
 542                                         if (!a.Resolve (ec, Location))\r
 543                                                 return null;\r
 544                                 }\r
 545                         }\r
 546                         \r
 547                         if (!del.VerifyApplicability (ec, Arguments, Location))\r
 548                                 return null;\r
 549                         \r
 550                         method = del.InvokeBuilder;\r
 551                         type = ((MethodInfo) method).ReturnType;\r
 552                         \r
 553                         eclass = ExprClass.Value;\r
 554                         \r
 555                         return this;\r
 556                 }\r
 557 \r
 558                 public override void Emit (EmitContext ec)\r
 559                 {\r
 560                         Delegate del = TypeManager.LookupDelegate (InstanceExpr.Type);\r
 561 \r
 562                         //\r
 563                         // Invocation on delegates call the virtual Invoke member\r
 564                         // so we are always `instance' calls\r
 565                         //\r
 566                         Invocation.EmitCall (ec, false, InstanceExpr, method, Arguments);\r
 567                 }\r
 568 \r
 569                 public override void EmitStatement (EmitContext ec)\r
 570                 {\r
 571                         Emit (ec);\r
 572                         // \r
 573                         // Pop the return value if there is one\r
 574                         //\r
 575                         if (method is MethodInfo){\r
 576                                 if (((MethodInfo) method).ReturnType != TypeManager.void_type)\r
 577                                         ec.ig.Emit (OpCodes.Pop);\r
 578                         }\r
 579                 }\r
 580 \r
 581         }\r
 582 }\r