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