mcs/mcs/parameter.cs

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