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