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