mcs/mcs/parameter.cs

   1 //
   2 // parameter.cs: Parameter definition.
   3 //
   4 // Author: Miguel de Icaza (miguel@gnu.org)
   5 //         Marek Safar (marek.safar@seznam.cz)
   6 //
   7 // Dual licensed under the terms of the MIT X11 or GNU GPL
   8 //
   9 // Copyright 2001-2003 Ximian, Inc (http://www.ximian.com)
  10 // Copyright 2003-2008 Novell, Inc.
  11 //
  12 //
  13 using System;
  14 using System.Text;
  15
  16 #if STATIC
  17 using MetaType = IKVM.Reflection.Type;
  18 using IKVM.Reflection;
  19 using IKVM.Reflection.Emit;
  20 #else
  21 using MetaType = System.Type;
  22 using System.Reflection;
  23 using System.Reflection.Emit;
  24 #endif
  25
  26 namespace Mono.CSharp {
  27
  28         /// <summary>
  29         ///   Abstract Base class for parameters of a method.
  30         /// </summary>
  31         public abstract class ParameterBase : Attributable
  32         {
  33                 protected ParameterBuilder builder;
  34
  35                 public override void ApplyAttributeBuilder (Attribute a, MethodSpec ctor, byte[] cdata, PredefinedAttributes pa)
  36                 {
  37 #if false
  38                         if (a.Type == pa.MarshalAs) {
  39                                 UnmanagedMarshal marshal = a.GetMarshal (this);
  40                                 if (marshal != null) {
  41                                         builder.SetMarshal (marshal);
  42                                 }
  43                                 return;
  44                         }
  45 #endif
  46                         if (a.HasSecurityAttribute) {
  47                                 a.Error_InvalidSecurityParent ();
  48                                 return;
  49                         }
  50
  51                         if (a.Type == pa.Dynamic) {
  52                                 a.Error_MisusedDynamicAttribute ();
  53                                 return;
  54                         }
  55
  56                         builder.SetCustomAttribute ((ConstructorInfo) ctor.GetMetaInfo (), cdata);
  57                 }
  58
  59                 public ParameterBuilder Builder {
  60                         get {
  61                                 return builder;
  62                         }
  63                 }
  64
  65                 public override bool IsClsComplianceRequired()
  66                 {
  67                         return false;
  68                 }
  69         }
  70
  71         /// <summary>
  72         /// Class for applying custom attributes on the return type
  73         /// </summary>
  74         public class ReturnParameter : ParameterBase
  75         {
  76                 MemberCore method;
  77
  78                 // TODO: merge method and mb
  79                 public ReturnParameter (MemberCore method, MethodBuilder mb, Location location)
  80                 {
  81                         this.method = method;
  82                         try {
  83                                 builder = mb.DefineParameter (0, ParameterAttributes.None, "");
  84                         }
  85                         catch (ArgumentOutOfRangeException) {
  86                                 method.Compiler.Report.RuntimeMissingSupport (location, "custom attributes on the return type");
  87                         }
  88                 }
  89
  90                 public override void ApplyAttributeBuilder (Attribute a, MethodSpec ctor, byte[] cdata, PredefinedAttributes pa)
  91                 {
  92                         if (a.Type == pa.CLSCompliant) {
  93                                 method.Compiler.Report.Warning (3023, 1, a.Location,
  94                                         "CLSCompliant attribute has no meaning when applied to return types. Try putting it on the method instead");
  95                         }
  96
  97                         // This occurs after Warning -28
  98                         if (builder == null)
  99                                 return;
 100
 101                         base.ApplyAttributeBuilder (a, ctor, cdata, pa);
 102                 }
 103
 104                 public override AttributeTargets AttributeTargets {
 105                         get {
 106                                 return AttributeTargets.ReturnValue;
 107                         }
 108                 }
 109
 110                 /// <summary>
 111                 /// Is never called
 112                 /// </summary>
 113                 public override string[] ValidAttributeTargets {
 114                         get {
 115                                 return null;
 116                         }
 117                 }
 118         }
 119
 120         public class ImplicitLambdaParameter : Parameter
 121         {
 122                 public ImplicitLambdaParameter (string name, Location loc)
 123                         : base (null, name, Modifier.NONE, null, loc)
 124                 {
 125                 }
 126
 127                 public override TypeSpec Resolve (IMemberContext ec, int index)
 128                 {
 129                         if (parameter_type == null)
 130                                 throw new InternalErrorException ("A type of implicit lambda parameter `{0}' is not set",
 131                                         Name);
 132
 133                         base.idx = index;
 134                         return parameter_type;
 135                 }
 136
 137                 public void SetParameterType (TypeSpec type)
 138                 {
 139                         parameter_type = type;
 140                 }
 141         }
 142
 143         public class ParamsParameter : Parameter {
 144                 public ParamsParameter (FullNamedExpression type, string name, Attributes attrs, Location loc):
 145                         base (type, name, Parameter.Modifier.PARAMS, attrs, loc)
 146                 {
 147                 }
 148
 149                 public override TypeSpec Resolve (IMemberContext ec, int index)
 150                 {
 151                         if (base.Resolve (ec, index) == null)
 152                                 return null;
 153
 154                         var ac = parameter_type as ArrayContainer;
 155                         if (ac == null || ac.Rank != 1) {
 156                                 ec.Module.Compiler.Report.Error (225, Location, "The params parameter must be a single dimensional array");
 157                                 return null;
 158                         }
 159
 160                         return parameter_type;
 161                 }
 162
 163                 public override void ApplyAttributes (MethodBuilder mb, ConstructorBuilder cb, int index, PredefinedAttributes pa)
 164                 {
 165                         base.ApplyAttributes (mb, cb, index, pa);
 166                         pa.ParamArray.EmitAttribute (builder);
 167                 }
 168         }
 169
 170         public class ArglistParameter : Parameter {
 171                 // Doesn't have proper type because it's never chosen for better conversion
 172                 public ArglistParameter (Location loc) :
 173                         base (null, String.Empty, Parameter.Modifier.NONE, null, loc)
 174                 {
 175                         parameter_type = InternalType.Arglist;
 176                 }
 177
 178                 public override void  ApplyAttributes (MethodBuilder mb, ConstructorBuilder cb, int index, PredefinedAttributes pa)
 179                 {
 180                         // Nothing to do
 181                 }
 182
 183                 public override bool CheckAccessibility (InterfaceMemberBase member)
 184                 {
 185                         return true;
 186                 }
 187
 188                 public override TypeSpec Resolve (IMemberContext ec, int index)
 189                 {
 190                         return parameter_type;
 191                 }
 192         }
 193
 194         public interface IParameterData
 195         {
 196                 Expression DefaultValue { get; }
 197                 bool HasExtensionMethodModifier { get; }
 198                 bool HasDefaultValue { get; }
 199                 Parameter.Modifier ModFlags { get; }
 200                 string Name { get; }
 201         }
 202
 203         //
 204         // Parameter information created by parser
 205         //
 206         public class Parameter : ParameterBase, IParameterData, ILocalVariable // TODO: INamedBlockVariable
 207         {
 208                 [Flags]
 209                 public enum Modifier : byte {
 210                         NONE    = 0,
 211                         REF     = REFMASK | ISBYREF,
 212                         OUT     = OUTMASK | ISBYREF,
 213                         PARAMS  = 4,
 214                         // This is a flag which says that it's either REF or OUT.
 215                         ISBYREF = 8,
 216                         REFMASK = 32,
 217                         OUTMASK = 64,
 218                         This    = 128
 219                 }
 220
 221                 static string[] attribute_targets = new string [] { "param" };
 222
 223                 FullNamedExpression texpr;
 224                 readonly Modifier modFlags;
 225                 string name;
 226                 Expression default_expr;
 227                 protected TypeSpec parameter_type;
 228                 readonly Location loc;
 229                 protected int idx;
 230                 public bool HasAddressTaken;
 231
 232                 TemporaryVariableReference expr_tree_variable;
 233                 static TypeExpr parameter_expr_tree_type;
 234
 235                 HoistedVariable hoisted_variant;
 236
 237                 public Parameter (FullNamedExpression type, string name, Modifier mod, Attributes attrs, Location loc)
 238                 {
 239                         this.name = name;
 240                         modFlags = mod;
 241                         this.loc = loc;
 242                         texpr = type;
 243
 244                         // Only assign, attributes will be attached during resolve
 245                         base.attributes = attrs;
 246                 }
 247
 248                 #region Properties
 249
 250                 public DefaultParameterValueExpression DefaultValue {
 251                         get {
 252                                 return default_expr as DefaultParameterValueExpression;
 253                         }
 254                         set {
 255                                 default_expr = value;
 256                         }
 257                 }
 258
 259                 Expression IParameterData.DefaultValue {
 260                         get {
 261                                 var expr = default_expr as DefaultParameterValueExpression;
 262                                 return expr == null ? default_expr : expr.Child;
 263                         }
 264                 }
 265
 266                 bool HasOptionalExpression {
 267                         get {
 268                                 return default_expr is DefaultParameterValueExpression;
 269                         }
 270                 }
 271
 272                 public Location Location {
 273                         get {
 274                                 return loc;
 275                         }
 276                 }
 277
 278                 public TypeSpec Type {
 279                         get {
 280                                 return parameter_type;
 281                         }
 282                 }
 283
 284                 public FullNamedExpression TypeExpression  {
 285                         get {
 286                                 return texpr;
 287                         }
 288                 }
 289
 290                 public override string[] ValidAttributeTargets {
 291                         get {
 292                                 return attribute_targets;
 293                         }
 294                 }
 295
 296                 #endregion
 297
 298                 public override void ApplyAttributeBuilder (Attribute a, MethodSpec ctor, byte[] cdata, PredefinedAttributes pa)
 299                 {
 300                         if (a.Type == pa.In && ModFlags == Modifier.OUT) {
 301                                 a.Report.Error (36, a.Location, "An out parameter cannot have the `In' attribute");
 302                                 return;
 303                         }
 304
 305                         if (a.Type == pa.ParamArray) {
 306                                 a.Report.Error (674, a.Location, "Do not use `System.ParamArrayAttribute'. Use the `params' keyword instead");
 307                                 return;
 308                         }
 309
 310                         if (a.Type == pa.Out && (ModFlags & Modifier.REF) == Modifier.REF &&
 311                             !OptAttributes.Contains (pa.In)) {
 312                                 a.Report.Error (662, a.Location,
 313                                         "Cannot specify only `Out' attribute on a ref parameter. Use both `In' and `Out' attributes or neither");
 314                                 return;
 315                         }
 316
 317                         if (a.Type == pa.CLSCompliant) {
 318                                 a.Report.Warning (3022, 1, a.Location, "CLSCompliant attribute has no meaning when applied to parameters. Try putting it on the method instead");
 319                         }
 320
 321                         if (a.Type == pa.DefaultParameterValue || a.Type == pa.OptionalParameter) {
 322                                 if (HasOptionalExpression) {
 323                                         a.Report.Error (1745, a.Location,
 324                                                 "Cannot specify `{0}' attribute on optional parameter `{1}'",
 325                                                 TypeManager.CSharpName (a.Type).Replace ("Attribute", ""), Name);
 326                                 }
 327
 328                                 if (a.Type == pa.DefaultParameterValue)
 329                                         return;
 330                         }
 331
 332                         base.ApplyAttributeBuilder (a, ctor, cdata, pa);
 333                 }
 334
 335                 public virtual bool CheckAccessibility (InterfaceMemberBase member)
 336                 {
 337                         if (parameter_type == null)
 338                                 return true;
 339
 340                         return member.IsAccessibleAs (parameter_type);
 341                 }
 342
 343                 public static void Reset ()
 344                 {
 345                         parameter_expr_tree_type = null;
 346                 }
 347
 348                 // <summary>
 349                 //   Resolve is used in method definitions
 350                 // </summary>
 351                 public virtual TypeSpec Resolve (IMemberContext rc, int index)
 352                 {
 353                         if (parameter_type != null)
 354                                 return parameter_type;
 355
 356                         if (attributes != null)
 357                                 attributes.AttachTo (this, rc);
 358
 359                         var expr = texpr.ResolveAsTypeTerminal (rc, false);
 360                         if (expr == null)
 361                                 return null;
 362
 363                         this.idx = index;
 364                         texpr = expr;
 365                         parameter_type = texpr.Type;
 366
 367                         if ((modFlags & Parameter.Modifier.ISBYREF) != 0 &&
 368                                 TypeManager.IsSpecialType (parameter_type)) {
 369                                 rc.Module.Compiler.Report.Error (1601, Location, "Method or delegate parameter cannot be of type `{0}'",
 370                                         GetSignatureForError ());
 371                                 return null;
 372                         }
 373
 374                         TypeManager.CheckTypeVariance (parameter_type,
 375                                 (modFlags & Parameter.Modifier.ISBYREF) != 0 ? Variance.None : Variance.Contravariant,
 376                                 rc);
 377
 378                         if (parameter_type.IsStatic) {
 379                                 rc.Module.Compiler.Report.Error (721, Location, "`{0}': static types cannot be used as parameters",
 380                                         texpr.GetSignatureForError ());
 381                                 return parameter_type;
 382                         }
 383
 384                         if ((modFlags & Modifier.This) != 0 && (parameter_type.IsPointer || parameter_type == InternalType.Dynamic)) {
 385                                 rc.Module.Compiler.Report.Error (1103, Location, "The extension method cannot be of type `{0}'",
 386                                         TypeManager.CSharpName (parameter_type));
 387                         }
 388
 389                         return parameter_type;
 390                 }
 391
 392                 public void ResolveDefaultValue (ResolveContext rc)
 393                 {
 394                         //
 395                         // Default value was specified using an expression
 396                         //
 397                         if (default_expr != null) {
 398                                 ((DefaultParameterValueExpression)default_expr).Resolve (rc, this);
 399                                 return;
 400                         }
 401
 402                         if (attributes == null)
 403                                 return;
 404
 405                         var opt_attr = attributes.Search (rc.Module.PredefinedAttributes.OptionalParameter);
 406                         var def_attr = attributes.Search (rc.Module.PredefinedAttributes.DefaultParameterValue);
 407                         if (def_attr != null) {
 408                                 if (def_attr.Resolve () == null)
 409                                         return;
 410
 411                                 var default_expr_attr = def_attr.GetParameterDefaultValue ();
 412                                 if (default_expr_attr == null)
 413                                         return;
 414
 415                                 var dpa_rc = def_attr.CreateResolveContext ();
 416                                 default_expr = default_expr_attr.Resolve (dpa_rc);
 417
 418                                 if (default_expr is BoxedCast)
 419                                         default_expr = ((BoxedCast) default_expr).Child;
 420
 421                                 Constant c = default_expr as Constant;
 422                                 if (c == null) {
 423                                         if (parameter_type.BuildinType == BuildinTypeSpec.Type.Object) {
 424                                                 rc.Report.Error (1910, default_expr.Location,
 425                                                         "Argument of type `{0}' is not applicable for the DefaultParameterValue attribute",
 426                                                         default_expr.Type.GetSignatureForError ());
 427                                         } else {
 428                                                 rc.Report.Error (1909, default_expr.Location,
 429                                                         "The DefaultParameterValue attribute is not applicable on parameters of type `{0}'",
 430                                                         default_expr.Type.GetSignatureForError ()); ;
 431                                         }
 432
 433                                         default_expr = null;
 434                                         return;
 435                                 }
 436
 437                                 if (TypeSpecComparer.IsEqual (default_expr.Type, parameter_type) ||
 438                                         (default_expr is NullConstant && TypeManager.IsReferenceType (parameter_type) && !parameter_type.IsGenericParameter) ||
 439                                         TypeSpecComparer.IsEqual (parameter_type, TypeManager.object_type)) {
 440                                         return;
 441                                 }
 442
 443                                 //
 444                                 // LAMESPEC: Some really weird csc behaviour which we have to mimic
 445                                 // User operators returning same type as parameter type are considered
 446                                 // valid for this attribute only
 447                                 //
 448                                 // struct S { public static implicit operator S (int i) {} }
 449                                 //
 450                                 // void M ([DefaultParameterValue (3)]S s)
 451                                 //
 452                                 var expr = Convert.ImplicitUserConversion (dpa_rc, default_expr, parameter_type, loc);
 453                                 if (expr != null && TypeSpecComparer.IsEqual (expr.Type, parameter_type)) {
 454                                         return;
 455                                 }
 456
 457                                 rc.Report.Error (1908, default_expr.Location, "The type of the default value should match the type of the parameter");
 458                                 return;
 459                         }
 460
 461                         if (opt_attr != null) {
 462                                 default_expr = EmptyExpression.MissingValue;
 463                         }
 464                 }
 465
 466                 public bool HasDefaultValue {
 467                         get { return default_expr != null; }
 468                 }
 469
 470                 public bool HasExtensionMethodModifier {
 471                         get { return (modFlags & Modifier.This) != 0; }
 472                 }
 473
 474                 //
 475                 // Hoisted parameter variant
 476                 //
 477                 public HoistedVariable HoistedVariant {
 478                         get {
 479                                 return hoisted_variant;
 480                         }
 481                         set {
 482                                 hoisted_variant = value;
 483                         }
 484                 }
 485
 486                 public Modifier ModFlags {
 487                         get { return modFlags & ~Modifier.This; }
 488                 }
 489
 490                 public string Name {
 491                         get { return name; }
 492                         set { name = value; }
 493                 }
 494
 495                 public override AttributeTargets AttributeTargets {
 496                         get {
 497                                 return AttributeTargets.Parameter;
 498                         }
 499                 }
 500
 501                 public virtual string GetSignatureForError ()
 502                 {
 503                         string type_name;
 504                         if (parameter_type != null)
 505                                 type_name = TypeManager.CSharpName (parameter_type);
 506                         else
 507                                 type_name = texpr.GetSignatureForError ();
 508
 509                         string mod = GetModifierSignature (modFlags);
 510                         if (mod.Length > 0)
 511                                 return String.Concat (mod, " ", type_name);
 512
 513                         return type_name;
 514                 }
 515
 516                 public static string GetModifierSignature (Modifier mod)
 517                 {
 518                         switch (mod) {
 519                         case Modifier.OUT:
 520                                 return "out";
 521                         case Modifier.PARAMS:
 522                                 return "params";
 523                         case Modifier.REF:
 524                                 return "ref";
 525                         case Modifier.This:
 526                                 return "this";
 527                         default:
 528                                 return "";
 529                         }
 530                 }
 531
 532                 public void IsClsCompliant (IMemberContext ctx)
 533                 {
 534                         if (parameter_type.IsCLSCompliant ())
 535                                 return;
 536
 537                         ctx.Module.Compiler.Report.Warning (3001, 1, Location,
 538                                 "Argument type `{0}' is not CLS-compliant", parameter_type.GetSignatureForError ());
 539                 }
 540
 541                 public virtual void ApplyAttributes (MethodBuilder mb, ConstructorBuilder cb, int index, PredefinedAttributes pa)
 542                 {
 543                         if (builder != null)
 544                                 throw new InternalErrorException ("builder already exists");
 545
 546                         var pattrs = ParametersCompiled.GetParameterAttribute (modFlags);
 547                         if (HasOptionalExpression)
 548                                 pattrs |= ParameterAttributes.Optional;
 549
 550                         if (mb == null)
 551                                 builder = cb.DefineParameter (index, pattrs, Name);
 552                         else
 553                                 builder = mb.DefineParameter (index, pattrs, Name);
 554
 555                         if (OptAttributes != null)
 556                                 OptAttributes.Emit ();
 557
 558                         if (HasDefaultValue) {
 559                                 //
 560                                 // Emit constant values for true constants only, the other
 561                                 // constant-like expressions will rely on default value expression
 562                                 //
 563                                 var def_value = DefaultValue;
 564                                 Constant c = def_value != null ? def_value.Child as Constant : default_expr as Constant;
 565                                 if (c != null) {
 566                                         if (default_expr.Type.BuildinType == BuildinTypeSpec.Type.Decimal) {
 567                                                 pa.DecimalConstant.EmitAttribute (builder, (decimal) c.GetValue (), c.Location);
 568                                         } else {
 569                                                 builder.SetConstant (c.GetValue ());
 570                                         }
 571                                 } else if (default_expr.Type.IsStruct) {
 572                                         //
 573                                         // Handles special case where default expression is used with value-type
 574                                         //
 575                                         // void Foo (S s = default (S)) {}
 576                                         //
 577                                         builder.SetConstant (null);
 578                                 }
 579                         }
 580
 581                         if (parameter_type != null) {
 582                                 if (parameter_type == InternalType.Dynamic) {
 583                                         pa.Dynamic.EmitAttribute (builder);
 584                                 } else if (parameter_type.HasDynamicElement) {
 585                                         pa.Dynamic.EmitAttribute (builder, parameter_type, Location);
 586                                 }
 587                         }
 588                 }
 589
 590                 public Parameter Clone ()
 591                 {
 592                         Parameter p = (Parameter) MemberwiseClone ();
 593                         if (attributes != null)
 594                                 p.attributes = attributes.Clone ();
 595
 596                         return p;
 597                 }
 598
 599                 public ExpressionStatement CreateExpressionTreeVariable (BlockContext ec)
 600                 {
 601                         if ((modFlags & Modifier.ISBYREF) != 0)
 602                                 ec.Report.Error (1951, Location, "An expression tree parameter cannot use `ref' or `out' modifier");
 603
 604                         expr_tree_variable = TemporaryVariableReference.Create (ResolveParameterExpressionType (ec, Location).Type, ec.CurrentBlock.ParametersBlock, Location);
 605                         expr_tree_variable = (TemporaryVariableReference) expr_tree_variable.Resolve (ec);
 606
 607                         Arguments arguments = new Arguments (2);
 608                         arguments.Add (new Argument (new TypeOf (
 609                                 new TypeExpression (parameter_type, Location), Location)));
 610                         arguments.Add (new Argument (new StringConstant (ec.BuildinTypes, Name, Location)));
 611                         return new SimpleAssign (ExpressionTreeVariableReference (),
 612                                 Expression.CreateExpressionFactoryCall (ec, "Parameter", null, arguments, Location));
 613                 }
 614
 615                 public void Emit (EmitContext ec)
 616                 {
 617                         int arg_idx = idx;
 618                         if (!ec.IsStatic)
 619                                 arg_idx++;
 620
 621                         ParameterReference.EmitLdArg (ec, arg_idx);
 622                 }
 623
 624                 public void EmitAssign (EmitContext ec)
 625                 {
 626                         int arg_idx = idx;
 627                         if (!ec.IsStatic)
 628                                 arg_idx++;
 629
 630                         if (arg_idx <= 255)
 631                                 ec.Emit (OpCodes.Starg_S, (byte) arg_idx);
 632                         else
 633                                 ec.Emit (OpCodes.Starg, arg_idx);
 634                 }
 635
 636                 public void EmitAddressOf (EmitContext ec)
 637                 {
 638                         int arg_idx = idx;
 639
 640                         if (!ec.IsStatic)
 641                                 arg_idx++;
 642
 643                         bool is_ref = (ModFlags & Modifier.ISBYREF) != 0;
 644                         if (is_ref) {
 645                                 ParameterReference.EmitLdArg (ec, arg_idx);
 646                         } else {
 647                                 if (arg_idx <= 255)
 648                                         ec.Emit (OpCodes.Ldarga_S, (byte) arg_idx);
 649                                 else
 650                                         ec.Emit (OpCodes.Ldarga, arg_idx);
 651                         }
 652                 }
 653
 654                 public TemporaryVariableReference ExpressionTreeVariableReference ()
 655                 {
 656                         return expr_tree_variable;
 657                 }
 658
 659                 //
 660                 // System.Linq.Expressions.ParameterExpression type
 661                 //
 662                 public static TypeExpr ResolveParameterExpressionType (IMemberContext ec, Location location)
 663                 {
 664                         if (parameter_expr_tree_type != null)
 665                                 return parameter_expr_tree_type;
 666
 667                         TypeSpec p_type = ec.Module.PredefinedTypes.ParameterExpression.Resolve (location);
 668                         parameter_expr_tree_type = new TypeExpression (p_type, location).
 669                                 ResolveAsTypeTerminal (ec, false);
 670
 671                         return parameter_expr_tree_type;
 672                 }
 673
 674                 public void Warning_UselessOptionalParameter (Report Report)
 675                 {
 676                         Report.Warning (1066, 1, Location,
 677                                 "The default value specified for optional parameter `{0}' will never be used",
 678                                 Name);
 679                 }
 680         }
 681
 682         //
 683         // Imported or resolved parameter information
 684         //
 685         public class ParameterData : IParameterData
 686         {
 687                 readonly string name;
 688                 readonly Parameter.Modifier modifiers;
 689                 readonly Expression default_value;
 690
 691                 public ParameterData (string name, Parameter.Modifier modifiers)
 692                 {
 693                         this.name = name;
 694                         this.modifiers = modifiers;
 695                 }
 696
 697                 public ParameterData (string name, Parameter.Modifier modifiers, Expression defaultValue)
 698                         : this (name, modifiers)
 699                 {
 700                         this.default_value = defaultValue;
 701                 }
 702
 703                 #region IParameterData Members
 704
 705                 public Expression DefaultValue {
 706                         get { return default_value; }
 707                 }
 708
 709                 public bool HasExtensionMethodModifier {
 710                         get { return (modifiers & Parameter.Modifier.This) != 0; }
 711                 }
 712
 713                 public bool HasDefaultValue {
 714                         get { return default_value != null; }
 715                 }
 716
 717                 public Parameter.Modifier ModFlags {
 718                         get { return modifiers & ~Parameter.Modifier.This; }
 719                 }
 720
 721                 public string Name {
 722                         get { return name; }
 723                 }
 724
 725                 #endregion
 726         }
 727
 728         public abstract class AParametersCollection
 729         {
 730                 protected bool has_arglist;
 731                 protected bool has_params;
 732
 733                 // Null object pattern
 734                 protected IParameterData [] parameters;
 735                 protected TypeSpec [] types;
 736
 737                 public CallingConventions CallingConvention {
 738                         get {
 739                                 return has_arglist ?
 740                                         CallingConventions.VarArgs :
 741                                         CallingConventions.Standard;
 742                         }
 743                 }
 744
 745                 public int Count {
 746                         get { return parameters.Length; }
 747                 }
 748
 749                 public TypeSpec ExtensionMethodType {
 750                         get {
 751                                 if (Count == 0)
 752                                         return null;
 753
 754                                 return FixedParameters [0].HasExtensionMethodModifier ?
 755                                         types [0] : null;
 756                         }
 757                 }
 758
 759                 public IParameterData [] FixedParameters {
 760                         get {
 761                                 return parameters;
 762                         }
 763                 }
 764
 765                 public static ParameterAttributes GetParameterAttribute (Parameter.Modifier modFlags)
 766                 {
 767                         return (modFlags & Parameter.Modifier.OUT) == Parameter.Modifier.OUT ?
 768                                 ParameterAttributes.Out : ParameterAttributes.None;
 769                 }
 770
 771                 // Very expensive operation
 772                 public MetaType[] GetMetaInfo ()
 773                 {
 774                         MetaType[] types;
 775                         if (has_arglist) {
 776                                 if (Count == 1)
 777                                         return MetaType.EmptyTypes;
 778
 779                                 types = new MetaType[Count - 1];
 780                         } else {
 781                                 if (Count == 0)
 782                                         return MetaType.EmptyTypes;
 783
 784                                 types = new MetaType[Count];
 785                         }
 786
 787                         for (int i = 0; i < types.Length; ++i) {
 788                                 types[i] = Types[i].GetMetaInfo ();
 789
 790                                 if ((FixedParameters [i].ModFlags & Parameter.Modifier.ISBYREF) == 0)
 791                                         continue;
 792
 793                                 // TODO MemberCache: Should go to MetaInfo getter
 794                                 types [i] = types [i].MakeByRefType ();
 795                         }
 796
 797                         return types;
 798                 }
 799
 800                 //
 801                 // Returns the parameter information based on the name
 802                 //
 803                 public int GetParameterIndexByName (string name)
 804                 {
 805                         for (int idx = 0; idx < Count; ++idx) {
 806                                 if (parameters [idx].Name == name)
 807                                         return idx;
 808                         }
 809
 810                         return -1;
 811                 }
 812
 813                 public string GetSignatureForError ()
 814                 {
 815                         return GetSignatureForError ("(", ")", Count);
 816                 }
 817
 818                 public string GetSignatureForError (string start, string end, int count)
 819                 {
 820                         StringBuilder sb = new StringBuilder (start);
 821                         for (int i = 0; i < count; ++i) {
 822                                 if (i != 0)
 823                                         sb.Append (", ");
 824                                 sb.Append (ParameterDesc (i));
 825                         }
 826                         sb.Append (end);
 827                         return sb.ToString ();
 828                 }
 829
 830                 public bool HasArglist {
 831                         get { return has_arglist; }
 832                 }
 833
 834                 public bool HasExtensionMethodType {
 835                         get {
 836                                 if (Count == 0)
 837                                         return false;
 838
 839                                 return FixedParameters [0].HasExtensionMethodModifier;
 840                         }
 841                 }
 842
 843                 public bool HasParams {
 844                         get { return has_params; }
 845                 }
 846
 847                 public bool IsEmpty {
 848                         get { return parameters.Length == 0; }
 849                 }
 850
 851                 public AParametersCollection Inflate (TypeParameterInflator inflator)
 852                 {
 853                         TypeSpec[] inflated_types = null;
 854                         bool default_value = false;
 855
 856                         for (int i = 0; i < Count; ++i) {
 857                                 var inflated_param = inflator.Inflate (types[i]);
 858                                 if (inflated_types == null) {
 859                                         if (inflated_param == types[i])
 860                                                 continue;
 861
 862                                         default_value |= FixedParameters[i] is DefaultValueExpression;
 863                                         inflated_types = new TypeSpec[types.Length];
 864                                         Array.Copy (types, inflated_types, types.Length);
 865                                 }
 866
 867                                 inflated_types[i] = inflated_param;
 868                         }
 869
 870                         if (inflated_types == null)
 871                                 return this;
 872
 873                         var clone = (AParametersCollection) MemberwiseClone ();
 874                         clone.types = inflated_types;
 875                         if (default_value) {
 876                                 for (int i = 0; i < Count; ++i) {
 877                                         var dve = clone.FixedParameters[i] as DefaultValueExpression;
 878                                         if (dve != null) {
 879                                                 throw new NotImplementedException ("net");
 880                                                 //      clone.FixedParameters [i].DefaultValue = new DefaultValueExpression ();
 881                                         }
 882                                 }
 883                         }
 884
 885                         return clone;
 886                 }
 887
 888                 public string ParameterDesc (int pos)
 889                 {
 890                         if (types == null || types [pos] == null)
 891                                 return ((Parameter)FixedParameters [pos]).GetSignatureForError ();
 892
 893                         string type = TypeManager.CSharpName (types [pos]);
 894                         if (FixedParameters [pos].HasExtensionMethodModifier)
 895                                 return "this " + type;
 896
 897                         Parameter.Modifier mod = FixedParameters [pos].ModFlags;
 898                         if (mod == 0)
 899                                 return type;
 900
 901                         return Parameter.GetModifierSignature (mod) + " " + type;
 902                 }
 903
 904                 public TypeSpec[] Types {
 905                         get { return types; }
 906                         set { types = value; }
 907                 }
 908         }
 909
 910         //
 911         // A collection of imported or resolved parameters
 912         //
 913         public class ParametersImported : AParametersCollection
 914         {
 915                 public ParametersImported (IParameterData [] parameters, TypeSpec [] types, bool hasArglist, bool hasParams)
 916                 {
 917                         this.parameters = parameters;
 918                         this.types = types;
 919                         this.has_arglist = hasArglist;
 920                         this.has_params = hasParams;
 921                 }
 922
 923                 public ParametersImported (IParameterData[] param, TypeSpec[] types, bool hasParams)
 924                 {
 925                         this.parameters = param;
 926                         this.types = types;
 927                         this.has_params = hasParams;
 928                 }
 929         }
 930
 931         /// <summary>
 932         ///   Represents the methods parameters
 933         /// </summary>
 934         public class ParametersCompiled : AParametersCollection
 935         {
 936                 public static readonly ParametersCompiled EmptyReadOnlyParameters = new ParametersCompiled ();
 937
 938                 // Used by C# 2.0 delegates
 939                 public static readonly ParametersCompiled Undefined = new ParametersCompiled ();
 940
 941                 private ParametersCompiled ()
 942                 {
 943                         parameters = new Parameter [0];
 944                         types = TypeSpec.EmptyTypes;
 945                 }
 946
 947                 private ParametersCompiled (IParameterData[] parameters, TypeSpec[] types)
 948                 {
 949                         this.parameters = parameters;
 950                     this.types = types;
 951                 }
 952
 953                 public ParametersCompiled (params Parameter[] parameters)
 954                 {
 955                         if (parameters == null || parameters.Length == 0)
 956                                 throw new ArgumentException ("Use EmptyReadOnlyParameters");
 957
 958                         this.parameters = parameters;
 959                         int count = parameters.Length;
 960
 961                         for (int i = 0; i < count; i++){
 962                                 has_params |= (parameters [i].ModFlags & Parameter.Modifier.PARAMS) != 0;
 963                         }
 964                 }
 965
 966                 public ParametersCompiled (Parameter [] parameters, bool has_arglist) :
 967                         this (parameters)
 968                 {
 969                         this.has_arglist = has_arglist;
 970                 }
 971
 972                 public static ParametersCompiled CreateFullyResolved (Parameter p, TypeSpec type)
 973                 {
 974                         return new ParametersCompiled (new Parameter [] { p }, new TypeSpec [] { type });
 975                 }
 976
 977                 public static ParametersCompiled CreateFullyResolved (Parameter[] parameters, TypeSpec[] types)
 978                 {
 979                         return new ParametersCompiled (parameters, types);
 980                 }
 981
 982                 //
 983                 // TODO: This does not fit here, it should go to different version of AParametersCollection
 984                 // as the underlying type is not Parameter and some methods will fail to cast
 985                 //
 986                 public static AParametersCollection CreateFullyResolved (TypeSpec[] types)
 987                 {
 988                         var pd = new ParameterData [types.Length];
 989                         for (int i = 0; i < pd.Length; ++i)
 990                                 pd[i] = new ParameterData (null, Parameter.Modifier.NONE, null);
 991
 992                         return new ParametersCompiled (pd, types);
 993                 }
 994
 995                 public static ParametersCompiled CreateImplicitParameter (FullNamedExpression texpr, Location loc)
 996                 {
 997                         return new ParametersCompiled (
 998                                 new[] { new Parameter (texpr, "value", Parameter.Modifier.NONE, null, loc) },
 999                                 null);
1000                 }
1001
1002                 //
1003                 // Returns non-zero value for equal CLS parameter signatures
1004                 //
1005                 public static int IsSameClsSignature (AParametersCollection a, AParametersCollection b)
1006                 {
1007                         int res = 0;
1008
1009                         for (int i = 0; i < a.Count; ++i) {
1010                                 var a_type = a.Types[i];
1011                                 var b_type = b.Types[i];
1012                                 if (TypeSpecComparer.Override.IsEqual (a_type, b_type)) {
1013                                         const Parameter.Modifier ref_out = Parameter.Modifier.REF | Parameter.Modifier.OUT;
1014                                         if ((a.FixedParameters[i].ModFlags & ref_out) != (b.FixedParameters[i].ModFlags & ref_out))
1015                                                 res |= 1;
1016
1017                                         continue;
1018                                 }
1019
1020                                 var ac_a = a_type as ArrayContainer;
1021                                 if (ac_a == null)
1022                                         return 0;
1023
1024                                 var ac_b = b_type as ArrayContainer;
1025                                 if (ac_b == null)
1026                                         return 0;
1027
1028                                 if (ac_a.Element is ArrayContainer || ac_b.Element is ArrayContainer) {
1029                                         res |= 2;
1030                                         continue;
1031                                 }
1032
1033                                 if (ac_a.Rank != ac_b.Rank && TypeSpecComparer.Override.IsEqual (ac_a.Element, ac_b.Element)) {
1034                                         res |= 1;
1035                                         continue;
1036                                 }
1037
1038                                 return 0;
1039                         }
1040
1041                         return res;
1042                 }
1043
1044                 public static ParametersCompiled MergeGenerated (CompilerContext ctx, ParametersCompiled userParams, bool checkConflicts, Parameter compilerParams, TypeSpec compilerTypes)
1045                 {
1046                         return MergeGenerated (ctx, userParams, checkConflicts,
1047                                 new Parameter [] { compilerParams },
1048                                 new TypeSpec [] { compilerTypes });
1049                 }
1050
1051                 //
1052                 // Use this method when you merge compiler generated parameters with user parameters
1053                 //
1054                 public static ParametersCompiled MergeGenerated (CompilerContext ctx, ParametersCompiled userParams, bool checkConflicts, Parameter[] compilerParams, TypeSpec[] compilerTypes)
1055                 {
1056                         Parameter[] all_params = new Parameter [userParams.Count + compilerParams.Length];
1057                         userParams.FixedParameters.CopyTo(all_params, 0);
1058
1059                         TypeSpec [] all_types;
1060                         if (userParams.types != null) {
1061                                 all_types = new TypeSpec [all_params.Length];
1062                                 userParams.Types.CopyTo (all_types, 0);
1063                         } else {
1064                                 all_types = null;
1065                         }
1066
1067                         int last_filled = userParams.Count;
1068                         int index = 0;
1069                         foreach (Parameter p in compilerParams) {
1070                                 for (int i = 0; i < last_filled; ++i) {
1071                                         while (p.Name == all_params [i].Name) {
1072                                                 if (checkConflicts && i < userParams.Count) {
1073                                                         ctx.Report.Error (316, userParams[i].Location,
1074                                                                 "The parameter name `{0}' conflicts with a compiler generated name", p.Name);
1075                                                 }
1076                                                 p.Name = '_' + p.Name;
1077                                         }
1078                                 }
1079                                 all_params [last_filled] = p;
1080                                 if (all_types != null)
1081                                         all_types [last_filled] = compilerTypes [index++];
1082                                 ++last_filled;
1083                         }
1084
1085                         ParametersCompiled parameters = new ParametersCompiled (all_params, all_types);
1086                         parameters.has_params = userParams.has_params;
1087                         return parameters;
1088                 }
1089
1090                 public bool Resolve (IMemberContext ec)
1091                 {
1092                         if (types != null)
1093                                 return true;
1094
1095                         types = new TypeSpec [Count];
1096
1097                         bool ok = true;
1098                         Parameter p;
1099                         for (int i = 0; i < FixedParameters.Length; ++i) {
1100                                 p = this [i];
1101                                 TypeSpec t = p.Resolve (ec, i);
1102                                 if (t == null) {
1103                                         ok = false;
1104                                         continue;
1105                                 }
1106
1107                                 types [i] = t;
1108                         }
1109
1110                         return ok;
1111                 }
1112
1113                 public void ResolveDefaultValues (MemberCore m)
1114                 {
1115                         ResolveContext rc = null;
1116                         for (int i = 0; i < parameters.Length; ++i) {
1117                                 Parameter p = (Parameter) parameters [i];
1118
1119                                 //
1120                                 // Try not to enter default values resolution if there are is not any default value possible
1121                                 //
1122                                 if (p.HasDefaultValue || p.OptAttributes != null) {
1123                                         if (rc == null)
1124                                                 rc = new ResolveContext (m);
1125
1126                                         p.ResolveDefaultValue (rc);
1127                                 }
1128                         }
1129                 }
1130
1131                 // Define each type attribute (in/out/ref) and
1132                 // the argument names.
1133                 public void ApplyAttributes (IMemberContext mc, MethodBase builder)
1134                 {
1135                         if (Count == 0)
1136                                 return;
1137
1138                         MethodBuilder mb = builder as MethodBuilder;
1139                         ConstructorBuilder cb = builder as ConstructorBuilder;
1140                         var pa = mc.Module.PredefinedAttributes;
1141
1142                         for (int i = 0; i < Count; i++) {
1143                                 this [i].ApplyAttributes (mb, cb, i + 1, pa);
1144                         }
1145                 }
1146
1147                 public void VerifyClsCompliance (IMemberContext ctx)
1148                 {
1149                         foreach (Parameter p in FixedParameters)
1150                                 p.IsClsCompliant (ctx);
1151                 }
1152
1153                 public Parameter this [int pos] {
1154                         get { return (Parameter) parameters [pos]; }
1155                 }
1156
1157                 public Expression CreateExpressionTree (BlockContext ec, Location loc)
1158                 {
1159                         var initializers = new ArrayInitializer (Count, loc);
1160                         foreach (Parameter p in FixedParameters) {
1161                                 //
1162                                 // Each parameter expression is stored to local variable
1163                                 // to save some memory when referenced later.
1164                                 //
1165                                 StatementExpression se = new StatementExpression (p.CreateExpressionTreeVariable (ec));
1166                                 if (se.Resolve (ec)) {
1167                                         ec.CurrentBlock.AddScopeStatement (new TemporaryVariableReference.Declarator (p.ExpressionTreeVariableReference ()));
1168                                         ec.CurrentBlock.AddScopeStatement (se);
1169                                 }
1170
1171                                 initializers.Add (p.ExpressionTreeVariableReference ());
1172                         }
1173
1174                         return new ArrayCreation (
1175                                 Parameter.ResolveParameterExpressionType (ec, loc),
1176                                 initializers, loc);
1177                 }
1178
1179                 public ParametersCompiled Clone ()
1180                 {
1181                         ParametersCompiled p = (ParametersCompiled) MemberwiseClone ();
1182
1183                         p.parameters = new IParameterData [parameters.Length];
1184                         for (int i = 0; i < Count; ++i)
1185                                 p.parameters [i] = this [i].Clone ();
1186
1187                         return p;
1188                 }
1189         }
1190
1191         //
1192         // Default parameter value expression. We need this wrapper to handle
1193         // default parameter values of folded constants when for indexer parameters
1194         // The expression is resolved only once but applied to two methods which
1195         // both share reference to this expression and we ensure that resolving
1196         // this expression always returns same instance
1197         //
1198         public class DefaultParameterValueExpression : CompositeExpression
1199         {
1200                 public DefaultParameterValueExpression (Expression expr)
1201                         : base (expr)
1202                 {
1203                 }
1204
1205                 protected override Expression DoResolve (ResolveContext rc)
1206                 {
1207                         return base.DoResolve (rc);
1208                 }
1209
1210                 public void Resolve (ResolveContext rc, Parameter p)
1211                 {
1212                         var expr = Resolve (rc);
1213                         if (expr == null)
1214                                 return;
1215
1216                         expr = Child;
1217
1218                         if (!(expr is Constant || expr is DefaultValueExpression || (expr is New && ((New) expr).IsDefaultStruct))) {
1219                                 rc.Report.Error (1736, Location,
1220                                         "The expression being assigned to optional parameter `{0}' must be a constant or default value",
1221                                         p.Name);
1222
1223                                 return;
1224                         }
1225
1226                         var parameter_type = p.Type;
1227                         if (type == parameter_type)
1228                                 return;
1229
1230                         var res = Convert.ImplicitConversionStandard (rc, expr, parameter_type, Location);
1231                         if (res != null) {
1232                                 if (TypeManager.IsNullableType (parameter_type) && res is Nullable.Wrap) {
1233                                         Nullable.Wrap wrap = (Nullable.Wrap) res;
1234                                         res = wrap.Child;
1235                                         if (!(res is Constant)) {
1236                                                 rc.Report.Error (1770, Location,
1237                                                         "The expression being assigned to nullable optional parameter `{0}' must be default value",
1238                                                         p.Name);
1239                                                 return;
1240                                         }
1241                                 }
1242
1243                                 if (!expr.IsNull && TypeManager.IsReferenceType (parameter_type) && parameter_type.BuildinType != BuildinTypeSpec.Type.String) {
1244                                         rc.Report.Error (1763, Location,
1245                                                 "Optional parameter `{0}' of type `{1}' can only be initialized with `null'",
1246                                                 p.Name, parameter_type.GetSignatureForError ());
1247
1248                                         return;
1249                                 }
1250
1251                                 this.expr = res;
1252                                 return;
1253                         }
1254
1255                         rc.Report.Error (1750, Location,
1256                                 "Optional parameter expression of type `{0}' cannot be converted to parameter type `{1}'",
1257                                 type.GetSignatureForError (), parameter_type.GetSignatureForError ());
1258                 }
1259         }
1260 }