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