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 (parameter_type == TypeManager.object_type ||
 262                                     (val == null && !TypeManager.IsValueType (parameter_type)) ||
 263                                     (val != null && TypeManager.TypeToCoreType (val.GetType ()) == parameter_type))
 264                                         builder.SetConstant (val);
 265                                 else
 266                                         Report.Error (1908, a.Location, "The type of the default value should match the type of the parameter");
 267                                 return;
 268                         }
 269
 270                         base.ApplyAttributeBuilder (a, cb);
 271                 }
 272
 273                 public override IResolveContext ResolveContext {
 274                         get {
 275                                 return resolve_context;
 276                         }
 277                 }
 278
 279                 // <summary>
 280                 //   Resolve is used in method definitions
 281                 // </summary>
 282                 public virtual bool Resolve (IResolveContext ec)
 283                 {
 284                         if (parameter_type != null)
 285                                 return true;
 286
 287                         this.resolve_context = ec;
 288
 289                         TypeExpr texpr = TypeName.ResolveAsTypeTerminal (ec, false);
 290                         if (texpr == null)
 291                                 return false;
 292
 293                         TypeParameterExpr tparam = texpr as TypeParameterExpr;
 294                         if (tparam != null)
 295                                 constraints = tparam.TypeParameter.Constraints;
 296
 297                         parameter_type = texpr.Type;
 298
 299                         if (parameter_type.IsAbstract && parameter_type.IsSealed) {
 300                                 Report.Error (721, Location, "`{0}': static types cannot be used as parameters", GetSignatureForError ());
 301                                 return false;
 302                         }
 303
 304                         if (parameter_type == TypeManager.void_type){
 305                                 Report.Error (1536, Location, "Invalid parameter type 'void'");
 306                                 return false;
 307                         }
 308
 309                         if ((ModFlags & Parameter.Modifier.ISBYREF) != 0){
 310                                 if (parameter_type == TypeManager.typed_reference_type ||
 311                                     parameter_type == TypeManager.arg_iterator_type){
 312                                         Report.Error (1601, Location, "Method or delegate parameter cannot be of type `{0}'",
 313                                                 GetSignatureForError ());
 314                                         return false;
 315                                 }
 316                         }
 317
 318                         return true;
 319                 }
 320
 321                 public Type ExternalType ()
 322                 {
 323                         if ((ModFlags & Parameter.Modifier.ISBYREF) != 0)
 324                                 return TypeManager.GetReferenceType (parameter_type);
 325
 326                         return parameter_type;
 327                 }
 328
 329                 public Type ParameterType {
 330                         get {
 331                                 return parameter_type;
 332                         }
 333                 }
 334
 335                 public GenericConstraints GenericConstraints {
 336                         get {
 337                                 return constraints;
 338                         }
 339                 }
 340
 341                 public ParameterAttributes Attributes {
 342                         get {
 343                                 switch (ModFlags) {
 344                                 case Modifier.NONE:
 345                                         return ParameterAttributes.None;
 346                                 case Modifier.REF:
 347                                         return ParameterAttributes.None;
 348                                 case Modifier.OUT:
 349                                         return ParameterAttributes.Out;
 350                                 case Modifier.PARAMS:
 351                                         return 0;
 352                                 }
 353
 354                                 return ParameterAttributes.None;
 355                         }
 356                 }
 357
 358                 public static ParameterAttributes GetParameterAttributes (Modifier mod)
 359                 {
 360                         int flags = ((int) mod) & ~((int) Parameter.Modifier.ISBYREF);
 361                         switch ((Modifier) flags) {
 362                         case Modifier.NONE:
 363                                 return ParameterAttributes.None;
 364                         case Modifier.REF:
 365                                 return ParameterAttributes.None;
 366                         case Modifier.OUT:
 367                                 return ParameterAttributes.Out;
 368                         case Modifier.PARAMS:
 369                                 return 0;
 370                         }
 371
 372                         return ParameterAttributes.None;
 373                 }
 374
 375                 public override AttributeTargets AttributeTargets {
 376                         get {
 377                                 return AttributeTargets.Parameter;
 378                         }
 379                 }
 380
 381                 public virtual string GetSignatureForError ()
 382                 {
 383                         string type_name;
 384                         if (parameter_type != null)
 385                                 type_name = TypeManager.CSharpName (parameter_type);
 386                         else
 387                                 type_name = TypeName.GetSignatureForError ();
 388
 389                         string mod = GetModifierSignature (ModFlags);
 390                         if (mod.Length > 0)
 391                                 return String.Concat (mod, ' ', type_name);
 392
 393                         return type_name;
 394                 }
 395
 396                 public static string GetModifierSignature (Modifier mod)
 397                 {
 398                         switch (mod) {
 399                                 case Modifier.OUT:
 400                                         return "out";
 401                                 case Modifier.PARAMS:
 402                                         return "params";
 403                                 case Modifier.REF:
 404                                         return "ref";
 405                                 case Modifier.ARGLIST:
 406                                         return "__arglist";
 407                                 default:
 408                                         return "";
 409                         }
 410                 }
 411
 412                 public void IsClsCompliant ()
 413                 {
 414                         if (AttributeTester.IsClsCompliant (ExternalType ()))
 415                                 return;
 416
 417                         Report.Error (3001, Location, "Argument type `{0}' is not CLS-compliant", GetSignatureForError ());
 418                 }
 419
 420                 public virtual void ApplyAttributes (MethodBuilder mb, ConstructorBuilder cb, int index)
 421                 {
 422                         // TODO: It should use mb.DefineGenericParameters
 423 #if !MS_COMPATIBLE
 424                         if (mb == null)
 425                                 builder = cb.DefineParameter (index, Attributes, Name);
 426                         else
 427                                 builder = mb.DefineParameter (index, Attributes, Name);
 428 #endif
 429                         if (OptAttributes != null)
 430                                 OptAttributes.Emit ();
 431                 }
 432
 433                 public override string[] ValidAttributeTargets {
 434                         get {
 435                                 return attribute_targets;
 436                         }
 437                 }
 438         }
 439
 440         /// <summary>
 441         ///   Represents the methods parameters
 442         /// </summary>
 443         public class Parameters : ParameterData {
 444                 // Null object pattern
 445                 public Parameter [] FixedParameters;
 446                 public readonly bool HasArglist;
 447                 Type [] types;
 448                 int count;
 449
 450                 public static readonly Parameters EmptyReadOnlyParameters = new Parameters ();
 451                 static readonly Parameter ArgList = new ArglistParameter ();
 452
 453                 public readonly TypeParameter[] TypeParameters;
 454
 455                 private Parameters ()
 456                 {
 457                         FixedParameters = new Parameter[0];
 458                         types = new Type [0];
 459                 }
 460
 461                 public Parameters (Parameter[] parameters, Type[] types)
 462                 {
 463                         FixedParameters = parameters;
 464                         this.types = types;
 465                         count = types.Length;
 466                 }
 467
 468                 public Parameters (Parameter[] parameters)
 469                 {
 470                         if (parameters == null)
 471                                 throw new ArgumentException ("Use EmptyReadOnlyPatameters");
 472
 473                         FixedParameters = parameters;
 474                         count = parameters.Length;
 475                 }
 476
 477                 public Parameters (Parameter[] parameters, bool has_arglist):
 478                         this (parameters)
 479                 {
 480                         HasArglist = has_arglist;
 481                 }
 482
 483                 /// <summary>
 484                 /// Use this method when you merge compiler generated argument with user arguments
 485                 /// </summary>
 486                 public static Parameters MergeGenerated (Parameters userParams, params Parameter[] compilerParams)
 487                 {
 488                         Parameter[] all_params = new Parameter [userParams.count + compilerParams.Length];
 489                         Type[] all_types = new Type[all_params.Length];
 490                         userParams.FixedParameters.CopyTo(all_params, 0);
 491                         userParams.Types.CopyTo (all_types, 0);
 492
 493                         int last_filled = userParams.Count;
 494                         foreach (Parameter p in compilerParams) {
 495                                 for (int i = 0; i < last_filled; ++i) {
 496                                         while (p.Name == all_params [i].Name) {
 497                                                 p.Name = '_' + p.Name;
 498                                         }
 499                                 }
 500                                 all_params [last_filled] = p;
 501                                 all_types [last_filled] = p.ParameterType;
 502                                 ++last_filled;
 503                         }
 504
 505                         return new Parameters (all_params, all_types);
 506                 }
 507
 508                 public bool Empty {
 509                         get {
 510                                 return count == 0;
 511                         }
 512                 }
 513
 514                 public int Count {
 515                         get {
 516                                 return HasArglist ? count + 1 : count;
 517                         }
 518                 }
 519
 520                 bool VerifyArgs ()
 521                 {
 522                         if (count < 2)
 523                                 return true;
 524
 525                         for (int i = 0; i < count; i++){
 526                                 string base_name = FixedParameters [i].Name;
 527                                 for (int j = i + 1; j < count; j++){
 528                                         if (base_name != FixedParameters [j].Name)
 529                                                 continue;
 530
 531                                         Report.Error (100, FixedParameters [i].Location,
 532                                                 "The parameter name `{0}' is a duplicate", base_name);
 533                                         return false;
 534                                 }
 535                         }
 536                         return true;
 537                 }
 538
 539
 540                 /// <summary>
 541                 ///    Returns the paramenter information based on the name
 542                 /// </summary>
 543                 public Parameter GetParameterByName (string name, out int idx)
 544                 {
 545                         idx = 0;
 546
 547                         if (count == 0)
 548                                 return null;
 549
 550                         int i = 0;
 551
 552                         foreach (Parameter par in FixedParameters){
 553                                 if (par.Name == name){
 554                                         idx = i;
 555                                         return par;
 556                                 }
 557                                 i++;
 558                         }
 559                         return null;
 560                 }
 561
 562                 public Parameter GetParameterByName (string name)
 563                 {
 564                         int idx;
 565
 566                         return GetParameterByName (name, out idx);
 567                 }
 568
 569                 public bool Resolve (IResolveContext ec)
 570                 {
 571                         if (types != null)
 572                                 return true;
 573
 574                         types = new Type [count];
 575
 576                         if (!VerifyArgs ())
 577                                 return false;
 578
 579                         bool ok = true;
 580                         Parameter p;
 581                         for (int i = 0; i < FixedParameters.Length; ++i) {
 582                                 p = FixedParameters [i];
 583                                 if (!p.Resolve (ec)) {
 584                                         ok = false;
 585                                         continue;
 586                                 }
 587                                 types [i] = p.ExternalType ();
 588                         }
 589
 590                         return ok;
 591                 }
 592
 593                 public CallingConventions CallingConvention
 594                 {
 595                         get {
 596                                 if (HasArglist)
 597                                         return CallingConventions.VarArgs;
 598                                 else
 599                                         return CallingConventions.Standard;
 600                         }
 601                 }
 602
 603                 // Define each type attribute (in/out/ref) and
 604                 // the argument names.
 605                 public void ApplyAttributes (MethodBase builder)
 606                 {
 607                         if (count == 0)
 608                                 return;
 609
 610                         MethodBuilder mb = builder as MethodBuilder;
 611                         ConstructorBuilder cb = builder as ConstructorBuilder;
 612
 613                         for (int i = 0; i < FixedParameters.Length; i++) {
 614                                 FixedParameters [i].ApplyAttributes (mb, cb, i + 1);
 615                         }
 616                 }
 617
 618                 public void VerifyClsCompliance ()
 619                 {
 620                         foreach (Parameter p in FixedParameters)
 621                                 p.IsClsCompliant ();
 622                 }
 623
 624                 public string GetSignatureForError ()
 625                 {
 626                         StringBuilder sb = new StringBuilder ("(");
 627                         if (count > 0) {
 628                                 for (int i = 0; i < FixedParameters.Length; ++i) {
 629                                         sb.Append (FixedParameters[i].GetSignatureForError ());
 630                                         if (i < FixedParameters.Length - 1)
 631                                                 sb.Append (", ");
 632                                 }
 633                         }
 634
 635                         if (HasArglist) {
 636                                 if (sb.Length > 1)
 637                                         sb.Append (", ");
 638                                 sb.Append ("__arglist");
 639                         }
 640
 641                         sb.Append (')');
 642                         return sb.ToString ();
 643                 }
 644
 645                 public Type[] Types {
 646                         get {
 647                                 return types;
 648                         }
 649                 }
 650
 651                 Parameter this [int pos]
 652                 {
 653                         get {
 654                                 if (pos >= count && (HasArglist || HasParams)) {
 655                                         if (HasArglist && (pos == 0 || pos >= count))
 656                                                 return ArgList;
 657                                         pos = count - 1;
 658                                 }
 659
 660                                 return FixedParameters [pos];
 661                         }
 662                 }
 663
 664                 #region ParameterData Members
 665
 666                 public Type ParameterType (int pos)
 667                 {
 668                         return this [pos].ExternalType ();
 669                 }
 670
 671                 public bool HasParams {
 672                         get {
 673                                 if (count == 0)
 674                                         return false;
 675
 676                                 return FixedParameters [count - 1] is ParamsParameter;
 677                         }
 678                 }
 679
 680                 public string ParameterName (int pos)
 681                 {
 682                         return this [pos].Name;
 683                 }
 684
 685                 public string ParameterDesc (int pos)
 686                 {
 687                         return this [pos].GetSignatureForError ();
 688                 }
 689
 690                 public Parameter.Modifier ParameterModifier (int pos)
 691                 {
 692                         return this [pos].ModFlags;
 693                 }
 694
 695                 #endregion
 696         }
 697 }