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                         \r
  91                         Type [] const_arg_types = new Type [2];\r
  92 \r
  93                         const_arg_types [0] = TypeManager.object_type;\r
  94                         const_arg_types [1] = TypeManager.intptr_type;\r
  95 \r
  96                         mattr = MethodAttributes.RTSpecialName | MethodAttributes.SpecialName |\r
  97                                 MethodAttributes.HideBySig | MethodAttributes.Public;\r
  98 \r
  99                         ConstructorBuilder = TypeBuilder.DefineConstructor (mattr,\r
 100                                                                             CallingConventions.Standard,\r
 101                                                                             const_arg_types);\r
 102                         \r
 103                         ConstructorBuilder.SetImplementationFlags (MethodImplAttributes.Runtime);\r
 104                         \r
 105                         // Here the various methods like Invoke, BeginInvoke etc are defined\r
 106 \r
 107                         param_types = Parameters.GetParameterInfo (parent);\r
 108                         ret_type = parent.LookupType (ReturnType, false);\r
 109                         CallingConventions cc = Parameters.GetCallingConvention ();\r
 110 \r
 111                         mattr = MethodAttributes.Public | MethodAttributes.HideBySig | MethodAttributes.Virtual;\r
 112 \r
 113                         InvokeBuilder = TypeBuilder.DefineMethod ("Invoke", \r
 114                                                                   mattr,                     \r
 115                                                                   cc,\r
 116                                                                   ret_type,                  \r
 117                                                                   param_types);\r
 118                         \r
 119                         InvokeBuilder.SetImplementationFlags (MethodImplAttributes.Runtime);\r
 120 \r
 121                         int params_num = param_types.Length;\r
 122                         Type [] async_param_types = new Type [params_num + 2];\r
 123 \r
 124                         param_types.CopyTo (async_param_types, 0);\r
 125 \r
 126                         async_param_types [params_num] = TypeManager.asynccallback_type;\r
 127                         async_param_types [params_num + 1] = TypeManager.object_type;\r
 128 \r
 129                         mattr = MethodAttributes.Public | MethodAttributes.HideBySig | MethodAttributes.Virtual |\r
 130                                 MethodAttributes.NewSlot;\r
 131                         \r
 132                         BeginInvokeBuilder = TypeBuilder.DefineMethod ("BeginInvoke",\r
 133                                                                        mattr,\r
 134                                                                        cc,\r
 135                                                                        TypeManager.iasyncresult_type,\r
 136                                                                        async_param_types);\r
 137                         \r
 138                         BeginInvokeBuilder.SetImplementationFlags (MethodImplAttributes.Runtime);\r
 139 \r
 140                         Type [] end_param_types = new Type [1];\r
 141 \r
 142                         end_param_types [0] = TypeManager.iasyncresult_type;\r
 143                         \r
 144                         EndInvokeBuilder = TypeBuilder.DefineMethod ("EndInvoke",\r
 145                                                                      mattr,\r
 146                                                                      cc,\r
 147                                                                      ret_type,\r
 148                                                                      end_param_types);\r
 149 \r
 150                         EndInvokeBuilder.SetImplementationFlags (MethodImplAttributes.Runtime);\r
 151                         \r
 152                 }\r
 153 \r
 154                 // <summary>\r
 155                 //  Verifies whether the method in question is compatible with the delegate\r
 156                 //  Returns the method itself if okay and null if not.\r
 157                 // </summary>\r
 158                 public MethodBase VerifyMethod (MethodBase mb, Location loc)\r
 159                 {\r
 160                         ParameterData pd = Invocation.GetParameterData (mb);\r
 161 \r
 162                         bool mismatch = false;\r
 163                         for (int i = param_types.Length; i > 0; ) {\r
 164                                 i--;\r
 165 \r
 166                                 if (param_types [i] == pd.ParameterType (i))\r
 167                                         continue;\r
 168                                 else {\r
 169                                         mismatch = true;\r
 170                                         break;\r
 171                                 }\r
 172                         }\r
 173 \r
 174                         if (mismatch) {\r
 175                                 Report.Error (123, loc, "Method '" + Invocation.FullMethodDesc (mb) + "' does not match " +\r
 176                                               "delegate '" + FullDelegateDesc () + "'");\r
 177                                 return null;\r
 178                         }\r
 179 \r
 180                         if (ret_type == ((MethodInfo) mb).ReturnType)\r
 181                                 return mb;\r
 182                         else\r
 183                                 mismatch = true;\r
 184 \r
 185                         if (mismatch) {\r
 186                                 Report.Error (123, loc, "Method '" + Invocation.FullMethodDesc (mb) + "' does not match " +\r
 187                                               "delegate '" + FullDelegateDesc () + "'");\r
 188                                 return null;\r
 189                         }\r
 190 \r
 191                         return null;\r
 192                 }\r
 193 \r
 194                 // <summary>\r
 195                 //  Verifies whether the invocation arguments are compatible with the\r
 196                 //  delegate's target method\r
 197                 // </summary>\r
 198                 public bool VerifyApplicability (EmitContext ec, ArrayList args, Location loc)\r
 199                 {\r
 200                         int arg_count;\r
 201 \r
 202                         if (args == null)\r
 203                                 arg_count = 0;\r
 204                         else\r
 205                                 arg_count = args.Count;\r
 206                         \r
 207                         if (param_types.Length != arg_count) {\r
 208                                 Report.Error (1593, loc,\r
 209                                               "Delegate '" + Name + "' does not take '" + arg_count + "' arguments");\r
 210                                 return false;\r
 211                         }\r
 212 \r
 213                         for (int i = arg_count; i > 0;) {\r
 214                                 i--;\r
 215                                 Expression conv;\r
 216                                 Argument a = (Argument) args [i];\r
 217                                 Expression a_expr = a.Expr;\r
 218                                 \r
 219                                 if (param_types [i] != a_expr.Type) {\r
 220                                         \r
 221                                         conv = Expression.ConvertImplicitStandard (ec, a_expr, param_types [i], loc);\r
 222 \r
 223                                         if (conv == null) {\r
 224                                                 Report.Error (1594, loc,\r
 225                                                               "Delegate '" + Name + "' has some invalid arguments.");\r
 226 \r
 227                                                 Report.Error (1503, loc,\r
 228                                                        "Argument " + (i+1) +\r
 229                                                        ": Cannot convert from '" +\r
 230                                                        TypeManager.CSharpName (a_expr.Type)\r
 231                                                        + "' to '" + TypeManager.CSharpName (param_types [i]) + "'");\r
 232                                                 return false;\r
 233                                         }\r
 234 \r
 235                                         if (a_expr != conv)\r
 236                                                 a.Expr = conv;\r
 237                                 }\r
 238                         }\r
 239 \r
 240                         return true;\r
 241                 }\r
 242 \r
 243                 // <summary>\r
 244                 //  Verifies whether the delegate in question is compatible with this one in\r
 245                 //  order to determine if instantiation from the same is possible.\r
 246                 // </summary>\r
 247                 public bool VerifyDelegate (Delegate del)\r
 248                 {\r
 249                         if (ret_type != del.TargetReturnType)\r
 250                                 return false;\r
 251 \r
 252                         Type [] other_param_types = del.ParameterTypes;\r
 253                         \r
 254                         if (param_types.Length != other_param_types.Length)\r
 255                                 return false;\r
 256 \r
 257                         for (int i = param_types.Length; i > 0; ) {\r
 258                                 i--;\r
 259 \r
 260                                 if (param_types [i] != other_param_types [i])\r
 261                                         return false;\r
 262                         }\r
 263 \r
 264                         // FIXME : Hey, what about parameter modifiers ?\r
 265 \r
 266                         return true;\r
 267 \r
 268                 }\r
 269                 \r
 270                 public string FullDelegateDesc ()\r
 271                 {\r
 272                         StringBuilder sb = new StringBuilder (TypeManager.CSharpName (System.Type.GetType (ReturnType)));\r
 273                         \r
 274                         sb.Append (" " + Name);\r
 275                         sb.Append (" (");\r
 276 \r
 277                         int length = param_types.Length;\r
 278                         \r
 279                         for (int i = length; i > 0; ) {\r
 280                                 i--;\r
 281                                 \r
 282                                 sb.Append (TypeManager.CSharpName (param_types [length - i - 1]));\r
 283                                 if (i != 0)\r
 284                                         sb.Append (", ");\r
 285                         }\r
 286                         \r
 287                         sb.Append (")");\r
 288                         return sb.ToString ();\r
 289                         \r
 290                 }\r
 291                 \r
 292                 public void CloseDelegate ()\r
 293                 {\r
 294                         TypeBuilder.CreateType ();\r
 295                 }\r
 296                 \r
 297                 public int ModFlags {\r
 298                         get {\r
 299                                 return mod_flags;\r
 300                         }\r
 301                 }\r
 302 \r
 303                 public Expression InstanceExpression {\r
 304                         get {\r
 305                                 return instance_expr;\r
 306                         }\r
 307                         set {\r
 308                                 instance_expr = value;\r
 309                         }\r
 310                 }\r
 311 \r
 312                 public MethodBase TargetMethod {\r
 313                         get {\r
 314                                 return delegate_method;\r
 315                         }\r
 316                         set {\r
 317                                 delegate_method = value;\r
 318                         }\r
 319                 }\r
 320 \r
 321                 public Type TargetReturnType {\r
 322                         get {\r
 323                                 return ret_type;\r
 324                         }\r
 325                 }\r
 326 \r
 327                 public Type [] ParameterTypes {\r
 328                         get {\r
 329                                 return param_types;\r
 330                         }\r
 331                 }\r
 332                 \r
 333         }\r
 334 \r
 335         public class NewDelegate : Expression {\r
 336 \r
 337                 public ArrayList Arguments;\r
 338 \r
 339                 MethodBase constructor_method;\r
 340                 MethodBase delegate_method;\r
 341                 Expression delegate_instance_expr;\r
 342 \r
 343                 Location Location;\r
 344                 \r
 345                 public NewDelegate (Type type, ArrayList Arguments, Location loc)\r
 346                 {\r
 347                         this.type = type;\r
 348                         this.Arguments = Arguments;\r
 349                         this.Location  = loc; \r
 350                 }\r
 351 \r
 352                 public override Expression DoResolve (EmitContext ec)\r
 353                 {\r
 354                         Delegate del = TypeManager.LookupDelegate (type);\r
 355                         constructor_method = del.ConstructorBuilder;\r
 356                         \r
 357                         if (Arguments == null) {\r
 358                                 Report.Error (-11, Location,\r
 359                                               "Delegate creation expression takes only one argument");\r
 360                                 return null;\r
 361                         }\r
 362                         \r
 363                         if (Arguments.Count != 1) {\r
 364                                 Report.Error (-11, Location,\r
 365                                               "Delegate creation expression takes only one argument");\r
 366                                 return null;\r
 367                         }\r
 368                         \r
 369                         Argument a = (Argument) Arguments [0];\r
 370                         \r
 371                         if (!a.Resolve (ec))\r
 372                                 return null;\r
 373                         \r
 374                         Expression e = a.Expr;\r
 375                         \r
 376                         if (e is MethodGroupExpr) {\r
 377                                 MethodGroupExpr mg = (MethodGroupExpr) e;\r
 378                                 \r
 379                                 delegate_method  = del.VerifyMethod (mg.Methods [0], Location);\r
 380                                 \r
 381                                 if (delegate_method == null)\r
 382                                         return null;\r
 383                                 \r
 384                                 if (mg.InstanceExpression != null)\r
 385                                         delegate_instance_expr = mg.InstanceExpression.Resolve (ec);\r
 386                                 else\r
 387                                         delegate_instance_expr = null;\r
 388                                 \r
 389                                 if (delegate_instance_expr != null)\r
 390                                         if (delegate_instance_expr.Type.IsValueType)\r
 391                                                 delegate_instance_expr = new BoxedCast (delegate_instance_expr);\r
 392                                 \r
 393                                 \r
 394                                 del.InstanceExpression = delegate_instance_expr;\r
 395                                 del.TargetMethod = delegate_method;\r
 396                                 \r
 397                                 eclass = ExprClass.Value;\r
 398                                 return this;\r
 399                         }\r
 400 \r
 401                         Type e_type = e.Type;\r
 402 \r
 403                         Delegate d = TypeManager.LookupDelegate (e_type);\r
 404 \r
 405                         if (d == null) {\r
 406                                 Report.Error (-12, Location, "Cannot create a delegate from something " +\r
 407                                               "not a delegate or a method.");\r
 408                                 return null;\r
 409                         }\r
 410 \r
 411                         // This is what MS's compiler reports. We could always choose\r
 412                         // to be more verbose and actually give delegate-level specifics\r
 413                         \r
 414                         if (!d.VerifyDelegate (del)) {\r
 415                                 Report.Error (29, Location, "Cannot implicitly convert type '" + d.Name + "' " +\r
 416                                               "to type '" + del.Name + "'");\r
 417                                 return null;\r
 418                         }\r
 419 \r
 420                         delegate_instance_expr = d.InstanceExpression;\r
 421                         delegate_method        = d.TargetMethod;\r
 422                         \r
 423                         del.InstanceExpression = d.InstanceExpression;\r
 424                         del.TargetMethod       = d.TargetMethod;\r
 425                         \r
 426                         eclass = ExprClass.Value;\r
 427                         return this;\r
 428                 }\r
 429                 \r
 430                 public override void Emit (EmitContext ec)\r
 431                 {\r
 432                         if (delegate_instance_expr == null)\r
 433                                 ec.ig.Emit (OpCodes.Ldnull);\r
 434                         else\r
 435                                 delegate_instance_expr.Emit (ec);\r
 436                         \r
 437                         ec.ig.Emit (OpCodes.Ldftn, (MethodInfo) delegate_method);\r
 438                         ec.ig.Emit (OpCodes.Newobj, (ConstructorInfo) constructor_method);\r
 439                 }\r
 440         }\r
 441 \r
 442         public class DelegateInvocation : Expression {\r
 443 \r
 444                 public Expression InstanceExpr;\r
 445                 public ArrayList  Arguments;\r
 446                 public Location   Location;\r
 447 \r
 448                 MethodBase method;\r
 449                 \r
 450                 public DelegateInvocation (Expression instance_expr, ArrayList args, Location loc)\r
 451                 {\r
 452                         this.InstanceExpr = instance_expr;\r
 453                         this.Arguments = args;\r
 454                         this.Location = loc;\r
 455                 }\r
 456 \r
 457                 public override Expression DoResolve (EmitContext ec)\r
 458                 {\r
 459                         Delegate del = TypeManager.LookupDelegate (InstanceExpr.Type);\r
 460 \r
 461                         if (del == null)\r
 462                                 return null;\r
 463 \r
 464                         if (del.TargetMethod == null)\r
 465                                 return null;\r
 466                         \r
 467                         if (Arguments != null){\r
 468                                 for (int i = Arguments.Count; i > 0;){\r
 469                                         --i;\r
 470                                         Argument a = (Argument) Arguments [i];\r
 471                                         \r
 472                                         if (!a.Resolve (ec))\r
 473                                                 return null;\r
 474                                 }\r
 475                         }\r
 476                         \r
 477                         if (!del.VerifyApplicability (ec, Arguments, Location))\r
 478                                 return null;\r
 479                         \r
 480                         method = del.InvokeBuilder;\r
 481                         type = ((MethodInfo) method).ReturnType;\r
 482                         \r
 483                         eclass = ExprClass.Value;\r
 484                         \r
 485                         return this;\r
 486                 }\r
 487 \r
 488                 public override void Emit (EmitContext ec)\r
 489                 {\r
 490                         Delegate del = TypeManager.LookupDelegate (InstanceExpr.Type);\r
 491                         Invocation.EmitCall (ec, del.TargetMethod.IsStatic, InstanceExpr, method, Arguments);\r
 492                 }\r
 493 \r
 494         }\r
 495 }\r