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 // 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                 protected Type parameter_type;
 212                 public readonly Location Location;
 213
 214                 IResolveContext resolve_context;
 215
 216                 public Parameter (Expression type, string name, Modifier mod, Attributes attrs, Location loc)
 217                         : base (attrs)
 218                 {
 219                         Name = name;
 220                         ModFlags = mod;
 221                         TypeName = type;
 222                         Location = loc;
 223                 }
 224
 225                 public Parameter (Type type, string name, Modifier mod, Attributes attrs, Location loc)
 226                         : base (attrs)
 227                 {
 228                         Name = name;
 229                         ModFlags = mod;
 230                         parameter_type = type;
 231                         Location = loc;
 232                 }
 233
 234                 public override void ApplyAttributeBuilder (Attribute a, CustomAttributeBuilder cb)
 235                 {
 236                         if (a.Type == TypeManager.in_attribute_type && ModFlags == Modifier.OUT) {
 237                                 Report.Error (36, a.Location, "An out parameter cannot have the `In' attribute");
 238                                 return;
 239                         }
 240
 241                         if (a.Type == TypeManager.param_array_type) {
 242                                 Report.Error (674, a.Location, "Do not use `System.ParamArrayAttribute'. Use the `params' keyword instead");
 243                                 return;
 244                         }
 245
 246                         if (a.Type == TypeManager.out_attribute_type && (ModFlags & Modifier.REF) == Modifier.REF &&
 247                             !OptAttributes.Contains (TypeManager.in_attribute_type)) {
 248                                 Report.Error (662, a.Location,
 249                                         "Cannot specify only `Out' attribute on a ref parameter. Use both `In' and `Out' attributes or neither");
 250                                 return;
 251                         }
 252
 253                         if (a.Type == TypeManager.cls_compliant_attribute_type) {
 254                                 Report.Warning (3022, 1, a.Location, "CLSCompliant attribute has no meaning when applied to parameters. Try putting it on the method instead");
 255                         }
 256
 257                         // TypeManager.default_parameter_value_attribute_type is null if !NET_2_0
 258                         if (a.Type == TypeManager.default_parameter_value_attribute_type) {
 259                                 object val = a.GetParameterDefaultValue ();
 260                                 if (val != null) {
 261                                         Type t = val.GetType ();
 262                                         if (t.IsArray || TypeManager.IsSubclassOf (t, TypeManager.type_type)) {
 263                                                 if (parameter_type == TypeManager.object_type) {
 264                                                         if (!t.IsArray)
 265                                                                 t = TypeManager.type_type;
 266
 267                                                         Report.Error (1910, a.Location, "Argument of type `{0}' is not applicable for the DefaultValue attribute",
 268                                                                 TypeManager.CSharpName (t));
 269                                                 } else {
 270                                                         Report.Error (1909, a.Location, "The DefaultValue attribute is not applicable on parameters of type `{0}'",
 271                                                                 TypeManager.CSharpName (parameter_type)); ;
 272                                                 }
 273                                                 return;
 274                                         }
 275                                 }
 276
 277                                 if (parameter_type == TypeManager.object_type ||
 278                                     (val == null && !TypeManager.IsValueType (parameter_type)) ||
 279                                     (val != null && TypeManager.TypeToCoreType (val.GetType ()) == parameter_type))
 280                                         builder.SetConstant (val);
 281                                 else
 282                                         Report.Error (1908, a.Location, "The type of the default value should match the type of the parameter");
 283                                 return;
 284                         }
 285
 286                         base.ApplyAttributeBuilder (a, cb);
 287                 }
 288
 289                 public override IResolveContext ResolveContext {
 290                         get {
 291                                 return resolve_context;
 292                         }
 293                 }
 294
 295                 // <summary>
 296                 //   Resolve is used in method definitions
 297                 // </summary>
 298                 public virtual bool Resolve (IResolveContext ec)
 299                 {
 300                         if (parameter_type != null)
 301                                 return true;
 302
 303                         this.resolve_context = ec;
 304
 305                         TypeExpr texpr = TypeName.ResolveAsTypeTerminal (ec, false);
 306                         if (texpr == null)
 307                                 return false;
 308
 309                         parameter_type = texpr.Type;
 310
 311                         if (parameter_type.IsAbstract && parameter_type.IsSealed) {
 312                                 Report.Error (721, Location, "`{0}': static types cannot be used as parameters", GetSignatureForError ());
 313                                 return false;
 314                         }
 315
 316                         if (parameter_type == TypeManager.void_type){
 317                                 Report.Error (1536, Location, "Invalid parameter type 'void'");
 318                                 return false;
 319                         }
 320
 321                         if ((ModFlags & Parameter.Modifier.ISBYREF) != 0){
 322                                 if (parameter_type == TypeManager.typed_reference_type ||
 323                                     parameter_type == TypeManager.arg_iterator_type){
 324                                         Report.Error (1601, Location, "Method or delegate parameter cannot be of type `{0}'",
 325                                                 GetSignatureForError ());
 326                                         return false;
 327                                 }
 328                         }
 329
 330                         return true;
 331                 }
 332
 333                 public Type ExternalType ()
 334                 {
 335                         if ((ModFlags & Parameter.Modifier.ISBYREF) != 0)
 336                                 return TypeManager.GetReferenceType (parameter_type);
 337
 338                         return parameter_type;
 339                 }
 340
 341                 public Type ParameterType {
 342                         get {
 343                                 return parameter_type;
 344                         }
 345                 }
 346
 347                 public ParameterAttributes Attributes {
 348                         get {
 349                                 switch (ModFlags) {
 350                                 case Modifier.NONE:
 351                                         return ParameterAttributes.None;
 352                                 case Modifier.REF:
 353                                         return ParameterAttributes.None;
 354                                 case Modifier.OUT:
 355                                         return ParameterAttributes.Out;
 356                                 case Modifier.PARAMS:
 357                                         return 0;
 358                                 }
 359
 360                                 return ParameterAttributes.None;
 361                         }
 362                 }
 363
 364                 public override AttributeTargets AttributeTargets {
 365                         get {
 366                                 return AttributeTargets.Parameter;
 367                         }
 368                 }
 369
 370                 public virtual string GetSignatureForError ()
 371                 {
 372                         string type_name;
 373                         if (parameter_type != null)
 374                                 type_name = TypeManager.CSharpName (parameter_type);
 375                         else
 376                                 type_name = TypeName.GetSignatureForError ();
 377
 378                         string mod = GetModifierSignature (ModFlags);
 379                         if (mod.Length > 0)
 380                                 return String.Concat (mod, ' ', type_name);
 381
 382                         return type_name;
 383                 }
 384
 385                 public static string GetModifierSignature (Modifier mod)
 386                 {
 387                         switch (mod) {
 388                                 case Modifier.OUT:
 389                                         return "out";
 390                                 case Modifier.PARAMS:
 391                                         return "params";
 392                                 case Modifier.REF:
 393                                         return "ref";
 394                                 case Modifier.ARGLIST:
 395                                         return "__arglist";
 396                                 default:
 397                                         return "";
 398                         }
 399                 }
 400
 401                 public void IsClsCompliant ()
 402                 {
 403                         if (AttributeTester.IsClsCompliant (ExternalType ()))
 404                                 return;
 405
 406                         Report.Error (3001, Location, "Argument type `{0}' is not CLS-compliant", GetSignatureForError ());
 407                 }
 408
 409                 public virtual void ApplyAttributes (MethodBuilder mb, ConstructorBuilder cb, int index)
 410                 {
 411                         if (mb == null)
 412                                 builder = cb.DefineParameter (index, Attributes, Name);
 413                         else
 414                                 builder = mb.DefineParameter (index, Attributes, Name);
 415
 416                         if (OptAttributes != null)
 417                                 OptAttributes.Emit ();
 418                 }
 419
 420                 public override string[] ValidAttributeTargets {
 421                         get {
 422                                 return attribute_targets;
 423                         }
 424                 }
 425         }
 426
 427         /// <summary>
 428         ///   Represents the methods parameters
 429         /// </summary>
 430         public class Parameters : ParameterData {
 431                 // Null object pattern
 432                 public Parameter [] FixedParameters;
 433                 public readonly bool HasArglist;
 434                 Type [] types;
 435                 int count;
 436
 437                 public static readonly Parameters EmptyReadOnlyParameters = new Parameters ();
 438                 static readonly Parameter ArgList = new ArglistParameter ();
 439
 440                 private Parameters ()
 441                 {
 442                         FixedParameters = new Parameter[0];
 443                         types = new Type [0];
 444                 }
 445
 446                 public Parameters (Parameter[] parameters, Type[] types)
 447                 {
 448                         FixedParameters = parameters;
 449                         this.types = types;
 450                         count = types.Length;
 451                 }
 452
 453                 public Parameters (Parameter[] parameters)
 454                 {
 455                         if (parameters == null)
 456                                 throw new ArgumentException ("Use EmptyReadOnlyPatameters");
 457
 458                         FixedParameters = parameters;
 459                         count = parameters.Length;
 460                 }
 461
 462                 public Parameters (Parameter[] parameters, bool has_arglist):
 463                         this (parameters)
 464                 {
 465                         HasArglist = has_arglist;
 466                 }
 467
 468                 /// <summary>
 469                 /// Use this method when you merge compiler generated argument with user arguments
 470                 /// </summary>
 471                 public static Parameters MergeGenerated (Parameters userParams, params Parameter[] compilerParams)
 472                 {
 473                         Parameter[] all_params = new Parameter [userParams.count + compilerParams.Length];
 474                         Type[] all_types = new Type[all_params.Length];
 475                         userParams.FixedParameters.CopyTo(all_params, 0);
 476                         userParams.Types.CopyTo (all_types, 0);
 477
 478                         int last_filled = userParams.Count;
 479                         foreach (Parameter p in compilerParams) {
 480                                 for (int i = 0; i < last_filled; ++i) {
 481                                         while (p.Name == all_params [i].Name) {
 482                                                 p.Name = '_' + p.Name;
 483                                         }
 484                                 }
 485                                 all_params [last_filled] = p;
 486                                 all_types [last_filled] = p.ParameterType;
 487                                 ++last_filled;
 488                         }
 489
 490                         return new Parameters (all_params, all_types);
 491                 }
 492
 493                 public bool Empty {
 494                         get {
 495                                 return count == 0;
 496                         }
 497                 }
 498
 499                 public int Count {
 500                         get {
 501                                 return HasArglist ? count + 1 : count;
 502                         }
 503                 }
 504
 505                 bool VerifyArgs ()
 506                 {
 507                         if (count < 2)
 508                                 return true;
 509
 510                         for (int i = 0; i < count; i++){
 511                                 string base_name = FixedParameters [i].Name;
 512                                 for (int j = i + 1; j < count; j++){
 513                                         if (base_name != FixedParameters [j].Name)
 514                                                 continue;
 515
 516                                         Report.Error (100, FixedParameters [i].Location,
 517                                                 "The parameter name `{0}' is a duplicate", base_name);
 518                                         return false;
 519                                 }
 520                         }
 521                         return true;
 522                 }
 523
 524
 525                 /// <summary>
 526                 ///    Returns the paramenter information based on the name
 527                 /// </summary>
 528                 public Parameter GetParameterByName (string name, out int idx)
 529                 {
 530                         idx = 0;
 531
 532                         if (count == 0)
 533                                 return null;
 534
 535                         int i = 0;
 536
 537                         foreach (Parameter par in FixedParameters){
 538                                 if (par.Name == name){
 539                                         idx = i;
 540                                         return par;
 541                                 }
 542                                 i++;
 543                         }
 544                         return null;
 545                 }
 546
 547                 public Parameter GetParameterByName (string name)
 548                 {
 549                         int idx;
 550
 551                         return GetParameterByName (name, out idx);
 552                 }
 553
 554                 public bool Resolve (IResolveContext ec)
 555                 {
 556                         if (types != null)
 557                                 return true;
 558
 559                         types = new Type [count];
 560
 561                         if (!VerifyArgs ())
 562                                 return false;
 563
 564                         bool ok = true;
 565                         Parameter p;
 566                         for (int i = 0; i < FixedParameters.Length; ++i) {
 567                                 p = FixedParameters [i];
 568                                 if (!p.Resolve (ec)) {
 569                                         ok = false;
 570                                         continue;
 571                                 }
 572                                 types [i] = p.ExternalType ();
 573                         }
 574
 575                         return ok;
 576                 }
 577
 578                 public CallingConventions CallingConvention
 579                 {
 580                         get {
 581                                 if (HasArglist)
 582                                         return CallingConventions.VarArgs;
 583                                 else
 584                                         return CallingConventions.Standard;
 585                         }
 586                 }
 587
 588                 // Define each type attribute (in/out/ref) and
 589                 // the argument names.
 590                 public void ApplyAttributes (MethodBase builder)
 591                 {
 592                         if (count == 0)
 593                                 return;
 594
 595                         MethodBuilder mb = builder as MethodBuilder;
 596                         ConstructorBuilder cb = builder as ConstructorBuilder;
 597
 598                         for (int i = 0; i < FixedParameters.Length; i++) {
 599                                 FixedParameters [i].ApplyAttributes (mb, cb, i + 1);
 600                         }
 601                 }
 602
 603                 public void VerifyClsCompliance ()
 604                 {
 605                         foreach (Parameter p in FixedParameters)
 606                                 p.IsClsCompliant ();
 607                 }
 608
 609                 public string GetSignatureForError ()
 610                 {
 611                         StringBuilder sb = new StringBuilder ("(");
 612                         if (count > 0) {
 613                                 for (int i = 0; i < FixedParameters.Length; ++i) {
 614                                         sb.Append (FixedParameters[i].GetSignatureForError ());
 615                                         if (i < FixedParameters.Length - 1)
 616                                                 sb.Append (", ");
 617                                 }
 618                         }
 619
 620                         if (HasArglist) {
 621                                 if (sb.Length > 1)
 622                                         sb.Append (", ");
 623                                 sb.Append ("__arglist");
 624                         }
 625
 626                         sb.Append (')');
 627                         return sb.ToString ();
 628                 }
 629
 630                 public Type[] Types {
 631                         get {
 632                                 return types;
 633                         }
 634                 }
 635
 636                 Parameter this [int pos]
 637                 {
 638                         get {
 639                                 if (pos >= count && (HasArglist || HasParams)) {
 640                                         if (HasArglist && (pos == 0 || pos >= count))
 641                                                 return ArgList;
 642                                         pos = count - 1;
 643                                 }
 644
 645                                 return FixedParameters [pos];
 646                         }
 647                 }
 648
 649                 #region ParameterData Members
 650
 651                 public Type ParameterType (int pos)
 652                 {
 653                         return this [pos].ExternalType ();
 654                 }
 655
 656                 public bool HasParams {
 657                         get {
 658                                 if (count == 0)
 659                                         return false;
 660
 661                                 return FixedParameters [count - 1] is ParamsParameter;
 662                         }
 663                 }
 664
 665                 public string ParameterName (int pos)
 666                 {
 667                         return this [pos].Name;
 668                 }
 669
 670                 public string ParameterDesc (int pos)
 671                 {
 672                         return this [pos].GetSignatureForError ();
 673                 }
 674
 675                 public Parameter.Modifier ParameterModifier (int pos)
 676                 {
 677                         return this [pos].ModFlags;
 678                 }
 679
 680                 #endregion
 681         }
 682 }