mcs/gmcs/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 // Licensed under the terms of the GNU GPL
   8 //
   9 // (C) 2001 Ximian, Inc (http://www.ximian.com)
  10 //
  11 //
  12 //
  13 using System;
  14 using System.Reflection;
  15 using System.Reflection.Emit;
  16 using System.Collections;
  17 using System.Text;
  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                 protected ParameterBase (Attributes attrs)
  29                         : base (attrs)
  30                 {
  31                 }
  32
  33                 public override void ApplyAttributeBuilder (Attribute a, CustomAttributeBuilder cb)
  34                 {
  35                         if (a.Type == TypeManager.marshal_as_attr_type) {
  36                                 UnmanagedMarshal marshal = a.GetMarshal (this);
  37                                 if (marshal != null) {
  38                                         builder.SetMarshal (marshal);
  39                                 }
  40                                 return;
  41                         }
  42
  43                         if (a.Type.IsSubclassOf (TypeManager.security_attr_type)) {
  44                                 a.Error_InvalidSecurityParent ();
  45                                 return;
  46                         }
  47
  48                         builder.SetCustomAttribute (cb);
  49                 }
  50
  51                 public override bool IsClsComplianceRequired()
  52                 {
  53                         return false;
  54                 }
  55         }
  56
  57         /// <summary>
  58         /// Class for applying custom attributes on the return type
  59         /// </summary>
  60         public class ReturnParameter : ParameterBase {
  61                 public ReturnParameter (MethodBuilder mb, Location location):
  62                         base (null)
  63                 {
  64                         try {
  65                                 builder = mb.DefineParameter (0, ParameterAttributes.None, "");
  66                         }
  67                         catch (ArgumentOutOfRangeException) {
  68                                 Report.RuntimeMissingSupport (location, "custom attributes on the return type");
  69                         }
  70                 }
  71
  72                 public override void ApplyAttributeBuilder(Attribute a, CustomAttributeBuilder cb)
  73                 {
  74                         if (a.Type == TypeManager.cls_compliant_attribute_type) {
  75                                 Report.Warning (3023, 1, a.Location, "CLSCompliant attribute has no meaning when applied to return types. Try putting it on the method instead");
  76                         }
  77
  78                         // This occurs after Warning -28
  79                         if (builder == null)
  80                                 return;
  81
  82                         base.ApplyAttributeBuilder (a, cb);
  83                 }
  84
  85                 public override AttributeTargets AttributeTargets {
  86                         get {
  87                                 return AttributeTargets.ReturnValue;
  88                         }
  89                 }
  90
  91                 public override IResolveContext ResolveContext {
  92                         get {
  93                                 throw new NotSupportedException ();
  94                         }
  95                 }
  96
  97                 /// <summary>
  98                 /// Is never called
  99                 /// </summary>
 100                 public override string[] ValidAttributeTargets {
 101                         get {
 102                                 return null;
 103                         }
 104                 }
 105         }
 106
 107         /// <summary>
 108         /// Class for applying custom attributes on the implicit parameter type
 109         /// of the 'set' method in properties, and the 'add' and 'remove' methods in events.
 110         /// </summary>
 111         ///
 112         // TODO: should use more code from Parameter.ApplyAttributeBuilder
 113         public class ImplicitParameter : ParameterBase {
 114                 public ImplicitParameter (MethodBuilder mb):
 115                         base (null)
 116                 {
 117                         builder = mb.DefineParameter (1, ParameterAttributes.None, "");
 118                 }
 119
 120                 public override AttributeTargets AttributeTargets {
 121                         get {
 122                                 return AttributeTargets.Parameter;
 123                         }
 124                 }
 125
 126                 public override IResolveContext ResolveContext {
 127                         get {
 128                                 throw new NotSupportedException ();
 129                         }
 130                 }
 131
 132                 /// <summary>
 133                 /// Is never called
 134                 /// </summary>
 135                 public override string[] ValidAttributeTargets {
 136                         get {
 137                                 return null;
 138                         }
 139                 }
 140         }
 141
 142         public class ParamsParameter : Parameter {
 143                 public ParamsParameter (Expression type, string name, Attributes attrs, Location loc):
 144                         base (type, name, Parameter.Modifier.PARAMS, attrs, loc)
 145                 {
 146                 }
 147
 148                 public override bool Resolve (IResolveContext ec)
 149                 {
 150                         if (!base.Resolve (ec))
 151                                 return false;
 152
 153                         if (!parameter_type.IsArray || parameter_type.GetArrayRank () != 1) {
 154                                 Report.Error (225, Location, "The params parameter must be a single dimensional array");
 155                                 return false;
 156                         }
 157                         return true;
 158                 }
 159
 160                 public override void ApplyAttributes (MethodBuilder mb, ConstructorBuilder cb, int index)
 161                 {
 162                         base.ApplyAttributes (mb, cb, index);
 163
 164                         CustomAttributeBuilder a = new CustomAttributeBuilder (
 165                                 TypeManager.ConsParamArrayAttribute, new object [0]);
 166
 167                         builder.SetCustomAttribute (a);
 168                 }
 169         }
 170
 171         public class ArglistParameter : Parameter {
 172                 // Doesn't have proper type because it's never choosed for better conversion
 173                 public ArglistParameter () :
 174                         base (typeof (ArglistParameter), "", Parameter.Modifier.ARGLIST, null, Location.Null)
 175                 {
 176                 }
 177
 178                 public override bool Resolve (IResolveContext ec)
 179                 {
 180                         return true;
 181                 }
 182
 183                 public override string GetSignatureForError ()
 184                 {
 185                         return "__arglist";
 186                 }
 187         }
 188
 189         /// <summary>
 190         ///   Represents a single method parameter
 191         /// </summary>
 192         public class Parameter : ParameterBase {
 193                 [Flags]
 194                 public enum Modifier : byte {
 195                         NONE    = 0,
 196                         REF     = REFMASK | ISBYREF,
 197                         OUT     = OUTMASK | ISBYREF,
 198                         PARAMS  = 4,
 199                         // This is a flag which says that it's either REF or OUT.
 200                         ISBYREF = 8,
 201                         ARGLIST = 16,
 202                         REFMASK = 32,
 203                         OUTMASK = 64
 204                 }
 205
 206                 static string[] attribute_targets = new string [] { "param" };
 207
 208                 public Expression TypeName;
 209                 public readonly Modifier ModFlags;
 210                 public string Name;
 211                 GenericConstraints constraints;
 212                 protected Type parameter_type;
 213                 public readonly Location Location;
 214
 215                 IResolveContext resolve_context;
 216
 217                 public Parameter (Expression type, string name, Modifier mod, Attributes attrs, Location loc)
 218                         : base (attrs)
 219                 {
 220                         Name = name;
 221                         ModFlags = mod;
 222                         TypeName = type;
 223                         Location = loc;
 224                 }
 225
 226                 public Parameter (Type type, string name, Modifier mod, Attributes attrs, Location loc)
 227                         : base (attrs)
 228                 {
 229                         Name = name;
 230                         ModFlags = mod;
 231                         parameter_type = type;
 232                         Location = loc;
 233                 }
 234
 235                 public override void ApplyAttributeBuilder (Attribute a, CustomAttributeBuilder cb)
 236                 {
 237                         if (a.Type == TypeManager.in_attribute_type && ModFlags == Modifier.OUT) {
 238                                 Report.Error (36, a.Location, "An out parameter cannot have the `In' attribute");
 239                                 return;
 240                         }
 241
 242                         if (a.Type == TypeManager.param_array_type) {
 243                                 Report.Error (674, a.Location, "Do not use `System.ParamArrayAttribute'. Use the `params' keyword instead");
 244                                 return;
 245                         }
 246
 247                         if (a.Type == TypeManager.out_attribute_type && (ModFlags & Modifier.REF) == Modifier.REF &&
 248                             !OptAttributes.Contains (TypeManager.in_attribute_type)) {
 249                                 Report.Error (662, a.Location,
 250                                         "Cannot specify only `Out' attribute on a ref parameter. Use both `In' and `Out' attributes or neither");
 251                                 return;
 252                         }
 253
 254                         if (a.Type == TypeManager.cls_compliant_attribute_type) {
 255                                 Report.Warning (3022, 1, a.Location, "CLSCompliant attribute has no meaning when applied to parameters. Try putting it on the method instead");
 256                         }
 257
 258                         // TypeManager.default_parameter_value_attribute_type is null if !NET_2_0
 259                         if (a.Type == TypeManager.default_parameter_value_attribute_type) {
 260                                 object val = a.GetParameterDefaultValue ();
 261                                 if (val != null) {
 262                                         Type t = val.GetType ();
 263                                         if (t.IsArray || TypeManager.IsSubclassOf (t, TypeManager.type_type)) {
 264                                                 if (parameter_type == TypeManager.object_type) {
 265                                                         if (!t.IsArray)
 266                                                                 t = TypeManager.type_type;
 267
 268                                                         Report.Error (1910, a.Location, "Argument of type `{0}' is not applicable for the DefaultValue attribute",
 269                                                                 TypeManager.CSharpName (t));
 270                                                 } else {
 271                                                         Report.Error (1909, a.Location, "The DefaultValue attribute is not applicable on parameters of type `{0}'",
 272                                                                 TypeManager.CSharpName (parameter_type)); ;
 273                                                 }
 274                                                 return;
 275                                         }
 276                                 }
 277
 278                                 if (parameter_type == TypeManager.object_type ||
 279                                     (val == null && !TypeManager.IsValueType (parameter_type)) ||
 280                                     (val != null && TypeManager.TypeToCoreType (val.GetType ()) == parameter_type))
 281                                         builder.SetConstant (val);
 282                                 else
 283                                         Report.Error (1908, a.Location, "The type of the default value should match the type of the parameter");
 284                                 return;
 285                         }
 286
 287                         base.ApplyAttributeBuilder (a, cb);
 288                 }
 289
 290                 public override IResolveContext ResolveContext {
 291                         get {
 292                                 return resolve_context;
 293                         }
 294                 }
 295
 296                 // <summary>
 297                 //   Resolve is used in method definitions
 298                 // </summary>
 299                 public virtual bool Resolve (IResolveContext ec)
 300                 {
 301                         if (parameter_type != null)
 302                                 return true;
 303
 304                         this.resolve_context = ec;
 305
 306                         TypeExpr texpr = TypeName.ResolveAsTypeTerminal (ec, false);
 307                         if (texpr == null)
 308                                 return false;
 309
 310                         TypeParameterExpr tparam = texpr as TypeParameterExpr;
 311                         if (tparam != null)
 312                                 constraints = tparam.TypeParameter.Constraints;
 313
 314                         parameter_type = texpr.Type;
 315
 316                         if (parameter_type.IsAbstract && parameter_type.IsSealed) {
 317                                 Report.Error (721, Location, "`{0}': static types cannot be used as parameters", GetSignatureForError ());
 318                                 return false;
 319                         }
 320
 321                         if (parameter_type == TypeManager.void_type){
 322                                 Report.Error (1536, Location, "Invalid parameter type 'void'");
 323                                 return false;
 324                         }
 325
 326                         if ((ModFlags & Parameter.Modifier.ISBYREF) != 0){
 327                                 if (parameter_type == TypeManager.typed_reference_type ||
 328                                     parameter_type == TypeManager.arg_iterator_type){
 329                                         Report.Error (1601, Location, "Method or delegate parameter cannot be of type `{0}'",
 330                                                 GetSignatureForError ());
 331                                         return false;
 332                                 }
 333                         }
 334
 335                         return true;
 336                 }
 337
 338                 public Type ExternalType ()
 339                 {
 340                         if ((ModFlags & Parameter.Modifier.ISBYREF) != 0)
 341                                 return TypeManager.GetReferenceType (parameter_type);
 342
 343                         return parameter_type;
 344                 }
 345
 346                 public Type ParameterType {
 347                         get {
 348                                 return parameter_type;
 349                         }
 350                 }
 351
 352                 public GenericConstraints GenericConstraints {
 353                         get {
 354                                 return constraints;
 355                         }
 356                 }
 357
 358                 public ParameterAttributes Attributes {
 359                         get {
 360                                 switch (ModFlags) {
 361                                 case Modifier.NONE:
 362                                         return ParameterAttributes.None;
 363                                 case Modifier.REF:
 364                                         return ParameterAttributes.None;
 365                                 case Modifier.OUT:
 366                                         return ParameterAttributes.Out;
 367                                 case Modifier.PARAMS:
 368                                         return 0;
 369                                 }
 370
 371                                 return ParameterAttributes.None;
 372                         }
 373                 }
 374
 375                 public static ParameterAttributes GetParameterAttributes (Modifier mod)
 376                 {
 377                         int flags = ((int) mod) & ~((int) Parameter.Modifier.ISBYREF);
 378                         switch ((Modifier) flags) {
 379                         case Modifier.NONE:
 380                                 return ParameterAttributes.None;
 381                         case Modifier.REF:
 382                                 return ParameterAttributes.None;
 383                         case Modifier.OUT:
 384                                 return ParameterAttributes.Out;
 385                         case Modifier.PARAMS:
 386                                 return 0;
 387                         }
 388
 389                         return ParameterAttributes.None;
 390                 }
 391
 392                 public override AttributeTargets AttributeTargets {
 393                         get {
 394                                 return AttributeTargets.Parameter;
 395                         }
 396                 }
 397
 398                 public virtual string GetSignatureForError ()
 399                 {
 400                         string type_name;
 401                         if (parameter_type != null)
 402                                 type_name = TypeManager.CSharpName (parameter_type);
 403                         else
 404                                 type_name = TypeName.GetSignatureForError ();
 405
 406                         string mod = GetModifierSignature (ModFlags);
 407                         if (mod.Length > 0)
 408                                 return String.Concat (mod, ' ', type_name);
 409
 410                         return type_name;
 411                 }
 412
 413                 public static string GetModifierSignature (Modifier mod)
 414                 {
 415                         switch (mod) {
 416                                 case Modifier.OUT:
 417                                         return "out";
 418                                 case Modifier.PARAMS:
 419                                         return "params";
 420                                 case Modifier.REF:
 421                                         return "ref";
 422                                 case Modifier.ARGLIST:
 423                                         return "__arglist";
 424                                 default:
 425                                         return "";
 426                         }
 427                 }
 428
 429                 public void IsClsCompliant ()
 430                 {
 431                         if (AttributeTester.IsClsCompliant (ExternalType ()))
 432                                 return;
 433
 434                         Report.Error (3001, Location, "Argument type `{0}' is not CLS-compliant", GetSignatureForError ());
 435                 }
 436
 437                 public virtual void ApplyAttributes (MethodBuilder mb, ConstructorBuilder cb, int index)
 438                 {
 439                         // TODO: It should use mb.DefineGenericParameters
 440 #if !MS_COMPATIBLE
 441                         if (mb == null)
 442                                 builder = cb.DefineParameter (index, Attributes, Name);
 443                         else
 444                                 builder = mb.DefineParameter (index, Attributes, Name);
 445 #endif
 446                         if (OptAttributes != null)
 447                                 OptAttributes.Emit ();
 448                 }
 449
 450                 public override string[] ValidAttributeTargets {
 451                         get {
 452                                 return attribute_targets;
 453                         }
 454                 }
 455         }
 456
 457         /// <summary>
 458         ///   Represents the methods parameters
 459         /// </summary>
 460         public class Parameters : ParameterData {
 461                 // Null object pattern
 462                 public Parameter [] FixedParameters;
 463                 public readonly bool HasArglist;
 464                 Type [] types;
 465                 int count;
 466
 467                 public static readonly Parameters EmptyReadOnlyParameters = new Parameters ();
 468                 static readonly Parameter ArgList = new ArglistParameter ();
 469
 470                 public readonly TypeParameter[] TypeParameters;
 471
 472                 private Parameters ()
 473                 {
 474                         FixedParameters = new Parameter[0];
 475                         types = new Type [0];
 476                 }
 477
 478                 public Parameters (Parameter[] parameters, Type[] types)
 479                 {
 480                         FixedParameters = parameters;
 481                         this.types = types;
 482                         count = types.Length;
 483                 }
 484
 485                 public Parameters (Parameter[] parameters)
 486                 {
 487                         if (parameters == null)
 488                                 throw new ArgumentException ("Use EmptyReadOnlyPatameters");
 489
 490                         FixedParameters = parameters;
 491                         count = parameters.Length;
 492                 }
 493
 494                 public Parameters (Parameter[] parameters, bool has_arglist):
 495                         this (parameters)
 496                 {
 497                         HasArglist = has_arglist;
 498                 }
 499
 500                 /// <summary>
 501                 /// Use this method when you merge compiler generated argument with user arguments
 502                 /// </summary>
 503                 public static Parameters MergeGenerated (Parameters userParams, params Parameter[] compilerParams)
 504                 {
 505                         Parameter[] all_params = new Parameter [userParams.count + compilerParams.Length];
 506                         Type[] all_types = new Type[all_params.Length];
 507                         userParams.FixedParameters.CopyTo(all_params, 0);
 508                         userParams.Types.CopyTo (all_types, 0);
 509
 510                         int last_filled = userParams.Count;
 511                         foreach (Parameter p in compilerParams) {
 512                                 for (int i = 0; i < last_filled; ++i) {
 513                                         while (p.Name == all_params [i].Name) {
 514                                                 p.Name = '_' + p.Name;
 515                                         }
 516                                 }
 517                                 all_params [last_filled] = p;
 518                                 all_types [last_filled] = p.ParameterType;
 519                                 ++last_filled;
 520                         }
 521
 522                         return new Parameters (all_params, all_types);
 523                 }
 524
 525                 public bool Empty {
 526                         get {
 527                                 return count == 0;
 528                         }
 529                 }
 530
 531                 public int Count {
 532                         get {
 533                                 return HasArglist ? count + 1 : count;
 534                         }
 535                 }
 536
 537                 bool VerifyArgs ()
 538                 {
 539                         if (count < 2)
 540                                 return true;
 541
 542                         for (int i = 0; i < count; i++){
 543                                 string base_name = FixedParameters [i].Name;
 544                                 for (int j = i + 1; j < count; j++){
 545                                         if (base_name != FixedParameters [j].Name)
 546                                                 continue;
 547
 548                                         Report.Error (100, FixedParameters [i].Location,
 549                                                 "The parameter name `{0}' is a duplicate", base_name);
 550                                         return false;
 551                                 }
 552                         }
 553                         return true;
 554                 }
 555
 556
 557                 /// <summary>
 558                 ///    Returns the paramenter information based on the name
 559                 /// </summary>
 560                 public Parameter GetParameterByName (string name, out int idx)
 561                 {
 562                         idx = 0;
 563
 564                         if (count == 0)
 565                                 return null;
 566
 567                         int i = 0;
 568
 569                         foreach (Parameter par in FixedParameters){
 570                                 if (par.Name == name){
 571                                         idx = i;
 572                                         return par;
 573                                 }
 574                                 i++;
 575                         }
 576                         return null;
 577                 }
 578
 579                 public Parameter GetParameterByName (string name)
 580                 {
 581                         int idx;
 582
 583                         return GetParameterByName (name, out idx);
 584                 }
 585
 586                 public bool Resolve (IResolveContext ec)
 587                 {
 588                         if (types != null)
 589                                 return true;
 590
 591                         types = new Type [count];
 592
 593                         if (!VerifyArgs ())
 594                                 return false;
 595
 596                         bool ok = true;
 597                         Parameter p;
 598                         for (int i = 0; i < FixedParameters.Length; ++i) {
 599                                 p = FixedParameters [i];
 600                                 if (!p.Resolve (ec)) {
 601                                         ok = false;
 602                                         continue;
 603                                 }
 604                                 types [i] = p.ExternalType ();
 605                         }
 606
 607                         return ok;
 608                 }
 609
 610                 public CallingConventions CallingConvention
 611                 {
 612                         get {
 613                                 if (HasArglist)
 614                                         return CallingConventions.VarArgs;
 615                                 else
 616                                         return CallingConventions.Standard;
 617                         }
 618                 }
 619
 620                 // Define each type attribute (in/out/ref) and
 621                 // the argument names.
 622                 public void ApplyAttributes (MethodBase builder)
 623                 {
 624                         if (count == 0)
 625                                 return;
 626
 627                         MethodBuilder mb = builder as MethodBuilder;
 628                         ConstructorBuilder cb = builder as ConstructorBuilder;
 629
 630                         for (int i = 0; i < FixedParameters.Length; i++) {
 631                                 FixedParameters [i].ApplyAttributes (mb, cb, i + 1);
 632                         }
 633                 }
 634
 635                 public void VerifyClsCompliance ()
 636                 {
 637                         foreach (Parameter p in FixedParameters)
 638                                 p.IsClsCompliant ();
 639                 }
 640
 641                 public string GetSignatureForError ()
 642                 {
 643                         StringBuilder sb = new StringBuilder ("(");
 644                         if (count > 0) {
 645                                 for (int i = 0; i < FixedParameters.Length; ++i) {
 646                                         sb.Append (FixedParameters[i].GetSignatureForError ());
 647                                         if (i < FixedParameters.Length - 1)
 648                                                 sb.Append (", ");
 649                                 }
 650                         }
 651
 652                         if (HasArglist) {
 653                                 if (sb.Length > 1)
 654                                         sb.Append (", ");
 655                                 sb.Append ("__arglist");
 656                         }
 657
 658                         sb.Append (')');
 659                         return sb.ToString ();
 660                 }
 661
 662                 public Type[] Types {
 663                         get {
 664                                 return types;
 665                         }
 666                 }
 667
 668                 Parameter this [int pos]
 669                 {
 670                         get {
 671                                 if (pos >= count && (HasArglist || HasParams)) {
 672                                         if (HasArglist && (pos == 0 || pos >= count))
 673                                                 return ArgList;
 674                                         pos = count - 1;
 675                                 }
 676
 677                                 return FixedParameters [pos];
 678                         }
 679                 }
 680
 681                 #region ParameterData Members
 682
 683                 public Type ParameterType (int pos)
 684                 {
 685                         return this [pos].ExternalType ();
 686                 }
 687
 688                 public bool HasParams {
 689                         get {
 690                                 if (count == 0)
 691                                         return false;
 692
 693                                 return FixedParameters [count - 1] is ParamsParameter;
 694                         }
 695                 }
 696
 697                 public string ParameterName (int pos)
 698                 {
 699                         return this [pos].Name;
 700                 }
 701
 702                 public string ParameterDesc (int pos)
 703                 {
 704                         return this [pos].GetSignatureForError ();
 705                 }
 706
 707                 public Parameter.Modifier ParameterModifier (int pos)
 708                 {
 709                         return this [pos].ModFlags;
 710                 }
 711
 712                 #endregion
 713         }
 714 }