mcs/mcs/parameter.cs

   1 //
   2 // parameter.cs: Parameter definition.
   3 //
   4 // Author: Miguel de Icaza (miguel@gnu.org)
   5 //
   6 // Licensed under the terms of the GNU GPL
   7 //
   8 // (C) 2001 Ximian, Inc (http://www.ximian.com)
   9 //
  10 //
  11 //
  12 using System;
  13 using System.Reflection;
  14 using System.Reflection.Emit;
  15 using System.Collections;
  16
  17 namespace Mono.CSharp {
  18
  19         /// <summary>
  20         ///   Abstract Base class for parameters of a method.
  21         /// </summary>
  22         public abstract class ParameterBase : Attributable {
  23
  24                 protected ParameterBuilder builder;
  25
  26                 public ParameterBase (Attributes attrs)
  27                         : base (attrs)
  28                 {
  29                 }
  30
  31                 public override void ApplyAttributeBuilder (Attribute a, CustomAttributeBuilder cb)
  32                 {
  33                         if (a.Type == TypeManager.marshal_as_attr_type) {
  34                                 UnmanagedMarshal marshal = a.GetMarshal ();
  35                                 if (marshal != null) {
  36                                         builder.SetMarshal (marshal);
  37                                         return;
  38                                 }
  39                                 Report.Warning_T (-24, a.Location);
  40                                 return;
  41                         }
  42
  43                         builder.SetCustomAttribute (cb);
  44                 }
  45
  46                 public override bool IsClsCompliaceRequired(DeclSpace ds)
  47                 {
  48                         return false;
  49                 }
  50         }
  51
  52         /// <summary>
  53         /// Class for applying custom attributes on the return type
  54         /// </summary>
  55         public class ReturnParameter: ParameterBase {
  56                 public ReturnParameter (MethodBuilder mb, Location location):
  57                         base (null)
  58                 {
  59                         try {
  60                                 builder = mb.DefineParameter (0, ParameterAttributes.None, "");
  61                         }
  62                         catch (ArgumentOutOfRangeException) {
  63                                 Report.Warning_T (-28, location);
  64                         }
  65                 }
  66
  67                 public override void ApplyAttributeBuilder(Attribute a, CustomAttributeBuilder cb)
  68                 {
  69                         // This occurs after Warning -28
  70                         if (builder == null)
  71                                 return;
  72
  73                         base.ApplyAttributeBuilder (a, cb);
  74                 }
  75
  76                 public override AttributeTargets AttributeTargets {
  77                         get {
  78                                 return AttributeTargets.ReturnValue;
  79                         }
  80                 }
  81
  82                 /// <summary>
  83                 /// Is never called
  84                 /// </summary>
  85                 protected override string[] ValidAttributeTargets {
  86                         get {
  87                                 return null;
  88                         }
  89                 }
  90         }
  91
  92         /// <summary>
  93         /// Class for applying custom attributes on the implicit parameter type
  94         /// of the 'set' method in properties, and the 'add' and 'remove' methods in events.
  95         /// </summary>
  96         public class ImplicitParameter: ParameterBase {
  97                 public ImplicitParameter (MethodBuilder mb):
  98                         base (null)
  99                 {
 100                         builder = mb.DefineParameter (1, ParameterAttributes.None, "");
 101                 }
 102
 103                 public override AttributeTargets AttributeTargets {
 104                         get {
 105                                 return AttributeTargets.Parameter;
 106                         }
 107                 }
 108
 109                 /// <summary>
 110                 /// Is never called
 111                 /// </summary>
 112                 protected override string[] ValidAttributeTargets {
 113                         get {
 114                                 return null;
 115                         }
 116                 }
 117         }
 118
 119         /// <summary>
 120         ///   Represents a single method parameter
 121         /// </summary>
 122
 123         //TODO: Add location member to this or base class for better error location and all methods simplification.
 124         public class Parameter : ParameterBase {
 125                 [Flags]
 126                 public enum Modifier : byte {
 127                         NONE    = 0,
 128                         REF     = 1,
 129                         OUT     = 2,
 130                         PARAMS  = 4,
 131                         // This is a flag which says that it's either REF or OUT.
 132                         ISBYREF = 8,
 133                         ARGLIST = 16
 134                 }
 135
 136                 static string[] attribute_targets = new string [] { "param" };
 137
 138                 public readonly Expression TypeName;
 139                 public readonly Modifier ModFlags;
 140                 public readonly string Name;
 141                 Type parameter_type;
 142
 143                 public Parameter (Expression type, string name, Modifier mod, Attributes attrs)
 144                         : base (attrs)
 145                 {
 146                         Name = name;
 147                         ModFlags = mod;
 148                         TypeName = type;
 149                 }
 150
 151                 // <summary>
 152                 //   Resolve is used in method definitions
 153                 // </summary>
 154                 public bool Resolve (DeclSpace ds, Location l)
 155                 {
 156                         parameter_type = ds.ResolveType (TypeName, false, l);
 157
 158                         if (parameter_type == TypeManager.void_type){
 159                                 Report.Error (1536, l, "`void' parameter is not permitted");
 160                                 return false;
 161                         }
 162
 163                         if ((ModFlags & Parameter.Modifier.ISBYREF) != 0){
 164                                 if (parameter_type == TypeManager.typed_reference_type ||
 165                                     parameter_type == TypeManager.arg_iterator_type){
 166                                         Report.Error (1601, l,
 167                                                       "out or ref parameter can not be of type TypedReference or ArgIterator");
 168                                         return false;
 169                                 }
 170                         }
 171
 172                         return parameter_type != null;
 173                 }
 174
 175                 public Type ExternalType ()
 176                 {
 177                         if ((ModFlags & Parameter.Modifier.ISBYREF) != 0)
 178                                 return TypeManager.GetReferenceType (parameter_type);
 179
 180                         return parameter_type;
 181                 }
 182
 183                 public Type ParameterType {
 184                         get {
 185                                 return parameter_type;
 186                         }
 187                 }
 188
 189                 public ParameterAttributes Attributes {
 190                         get {
 191                                 int flags = ((int) ModFlags) & ~((int) Parameter.Modifier.ISBYREF);
 192                                 switch ((Modifier) flags) {
 193                                 case Modifier.NONE:
 194                                         return ParameterAttributes.None;
 195                                 case Modifier.REF:
 196                                         return ParameterAttributes.None;
 197                                 case Modifier.OUT:
 198                                         return ParameterAttributes.Out;
 199                                 case Modifier.PARAMS:
 200                                         return 0;
 201                                 }
 202
 203                                 return ParameterAttributes.None;
 204                         }
 205                 }
 206
 207                 public override AttributeTargets AttributeTargets {
 208                         get {
 209                                 return AttributeTargets.Parameter;
 210                         }
 211                 }
 212
 213                 /// <summary>
 214                 ///   Returns the signature for this parameter evaluating it on the
 215                 ///   @tc context
 216                 /// </summary>
 217                 public string GetSignature (DeclSpace ds, Location loc)
 218                 {
 219                         if (parameter_type == null){
 220                                 if (!Resolve (ds, loc))
 221                                         return null;
 222                         }
 223
 224                         return ExternalType ().FullName;
 225                 }
 226
 227                 public string GetSignatureForError ()
 228                 {
 229                         string typeName = TypeManager.CSharpName (parameter_type);
 230                         switch (ModFlags & ~Modifier.ISBYREF) {
 231                                 case Modifier.OUT:
 232                                         return "out " + typeName;
 233                                 case Modifier.PARAMS:
 234                                         return "params " + typeName;
 235                                 case Modifier.REF:
 236                                         return "ref " + typeName;
 237                         }
 238                         return typeName;
 239                 }
 240
 241                 public void DefineParameter (EmitContext ec, MethodBuilder mb, ConstructorBuilder cb, int index, Location loc)
 242                 {
 243                         ParameterAttributes par_attr = Attributes;
 244
 245                         if (mb == null)
 246                                 builder = cb.DefineParameter (index, par_attr, Name);
 247                         else
 248                                 builder = mb.DefineParameter (index, par_attr, Name);
 249
 250                         if (OptAttributes != null) {
 251                                 OptAttributes.Emit (ec, this);
 252
 253                                 if (par_attr == ParameterAttributes.Out){
 254                                         if (OptAttributes.Contains (TypeManager.in_attribute_type, ec))
 255                                                 Report.Error (36, loc,  "Can not use [In] attribute on out parameter");
 256                                 }
 257                         }
 258                 }
 259
 260                 protected override string[] ValidAttributeTargets {
 261                         get {
 262                                 return attribute_targets;
 263                         }
 264                 }
 265         }
 266
 267         /// <summary>
 268         ///   Represents the methods parameters
 269         /// </summary>
 270         public class Parameters {
 271                 public Parameter [] FixedParameters;
 272                 public readonly Parameter ArrayParameter;
 273                 public readonly bool HasArglist;
 274                 string signature;
 275                 Type [] types;
 276                 Location loc;
 277
 278                 static Parameters empty_parameters;
 279
 280                 public Parameters (Parameter [] fixed_parameters, Parameter array_parameter, Location l)
 281                 {
 282                         FixedParameters = fixed_parameters;
 283                         ArrayParameter  = array_parameter;
 284                         loc = l;
 285                 }
 286
 287                 public Parameters (Parameter [] fixed_parameters, bool has_arglist, Location l)
 288                 {
 289                         FixedParameters = fixed_parameters;
 290                         HasArglist = has_arglist;
 291                         loc = l;
 292                 }
 293
 294                 /// <summary>
 295                 ///   This is used to reuse a set of empty parameters, because they
 296                 ///   are common
 297                 /// </summary>
 298                 public static Parameters EmptyReadOnlyParameters {
 299                         get {
 300                                 if (empty_parameters == null)
 301                                         empty_parameters = new Parameters (null, null, Location.Null);
 302
 303                                 return empty_parameters;
 304                         }
 305                 }
 306
 307                 public bool Empty {
 308                         get {
 309                                 return (FixedParameters == null) && (ArrayParameter == null);
 310                         }
 311                 }
 312
 313                 public void ComputeSignature (DeclSpace ds)
 314                 {
 315                         signature = "";
 316                         if (FixedParameters != null){
 317                                 for (int i = 0; i < FixedParameters.Length; i++){
 318                                         Parameter par = FixedParameters [i];
 319
 320                                         signature += par.GetSignature (ds, loc);
 321                                 }
 322                         }
 323                         //
 324                         // Note: as per the spec, the `params' arguments (ArrayParameter)
 325                         // are not used in the signature computation for a method
 326                         //
 327                 }
 328
 329                 void Error_DuplicateParameterName (string name)
 330                 {
 331                         Report.Error (
 332                                 100, loc, "The parameter name `" + name + "' is a duplicate");
 333                 }
 334
 335                 public bool VerifyArgs ()
 336                 {
 337                         int count;
 338                         int i, j;
 339
 340                         if (FixedParameters == null)
 341                                 return true;
 342
 343                         count = FixedParameters.Length;
 344                         string array_par_name = ArrayParameter != null ? ArrayParameter.Name : null;
 345                         for (i = 0; i < count; i++){
 346                                 string base_name = FixedParameters [i].Name;
 347
 348                                 for (j = i + 1; j < count; j++){
 349                                         if (base_name != FixedParameters [j].Name)
 350                                                 continue;
 351                                         Error_DuplicateParameterName (base_name);
 352                                         return false;
 353                                 }
 354
 355                                 if (base_name == array_par_name){
 356                                         Error_DuplicateParameterName (base_name);
 357                                         return false;
 358                                 }
 359                         }
 360                         return true;
 361                 }
 362
 363                 /// <summary>
 364                 ///    Returns the signature of the Parameters evaluated in
 365                 ///    the @tc environment
 366                 /// </summary>
 367                 public string GetSignature (DeclSpace ds)
 368                 {
 369                         if (signature == null){
 370                                 VerifyArgs ();
 371                                 ComputeSignature (ds);
 372                         }
 373
 374                         return signature;
 375                 }
 376
 377                 /// <summary>
 378                 ///    Returns the paramenter information based on the name
 379                 /// </summary>
 380                 public Parameter GetParameterByName (string name, out int idx)
 381                 {
 382                         idx = 0;
 383                         int i = 0;
 384
 385                         if (FixedParameters != null){
 386                                 foreach (Parameter par in FixedParameters){
 387                                         if (par.Name == name){
 388                                                 idx = i;
 389                                                 return par;
 390                                         }
 391                                         i++;
 392                                 }
 393                         }
 394
 395                         if (ArrayParameter != null){
 396                                 if (name == ArrayParameter.Name){
 397                                         idx = i;
 398                                         return ArrayParameter;
 399                                 }
 400                         }
 401
 402                         return null;
 403                 }
 404
 405                 bool ComputeParameterTypes (DeclSpace ds)
 406                 {
 407                         int extra = (ArrayParameter != null) ? 1 : 0;
 408                         int i = 0;
 409                         int pc;
 410
 411                         if (FixedParameters == null)
 412                                 pc = extra;
 413                         else
 414                                 pc = extra + FixedParameters.Length;
 415
 416                         types = new Type [pc];
 417
 418                         if (!VerifyArgs ()){
 419                                 FixedParameters = null;
 420                                 return false;
 421                         }
 422
 423                         bool failed = false;
 424                         if (FixedParameters != null){
 425                                 foreach (Parameter p in FixedParameters){
 426                                         Type t = null;
 427
 428                                         if (p.Resolve (ds, loc))
 429                                                 t = p.ExternalType ();
 430                                         else
 431                                                 failed = true;
 432
 433                                         types [i] = t;
 434                                         i++;
 435                                 }
 436                         }
 437
 438                         if (extra > 0){
 439                                 if (ArrayParameter.Resolve (ds, loc))
 440                                         types [i] = ArrayParameter.ExternalType ();
 441                                 else
 442                                         failed = true;
 443                         }
 444
 445                         if (failed){
 446                                 types = null;
 447                                 return false;
 448                         }
 449
 450                         return true;
 451                 }
 452
 453                 //
 454                 // This variant is used by Delegates, because they need to
 455                 // resolve/define names, instead of the plain LookupType
 456                 //
 457                 public bool ComputeAndDefineParameterTypes (DeclSpace ds)
 458                 {
 459                         int extra = (ArrayParameter != null) ? 1 : 0;
 460                         int i = 0;
 461                         int pc;
 462
 463                         if (FixedParameters == null)
 464                                 pc = extra;
 465                         else
 466                                 pc = extra + FixedParameters.Length;
 467
 468                         types = new Type [pc];
 469
 470                         if (!VerifyArgs ()){
 471                                 FixedParameters = null;
 472                                 return false;
 473                         }
 474
 475                         bool ok_flag = true;
 476
 477                         if (FixedParameters != null){
 478                                 foreach (Parameter p in FixedParameters){
 479                                         Type t = null;
 480
 481                                         if (p.Resolve (ds, loc))
 482                                                 t = p.ExternalType ();
 483                                         else
 484                                                 ok_flag = false;
 485
 486                                         types [i] = t;
 487                                         i++;
 488                                 }
 489                         }
 490
 491                         if (extra > 0){
 492                                 if (ArrayParameter.Resolve (ds, loc))
 493                                         types [i] = ArrayParameter.ExternalType ();
 494                                 else
 495                                         ok_flag = false;
 496                         }
 497
 498                         //
 499                         // invalidate the cached types
 500                         //
 501                         if (!ok_flag){
 502                                 types = null;
 503                         }
 504
 505                         return ok_flag;
 506                 }
 507
 508                 /// <summary>
 509                 ///   Returns the argument types as an array
 510                 /// </summary>
 511                 static Type [] no_types = new Type [0];
 512
 513                 public Type [] GetParameterInfo (DeclSpace ds)
 514                 {
 515                         if (types != null)
 516                                 return types;
 517
 518                         if (FixedParameters == null && ArrayParameter == null)
 519                                 return no_types;
 520
 521                         if (ComputeParameterTypes (ds) == false){
 522                                 types = null;
 523                                 return null;
 524                         }
 525
 526                         return types;
 527                 }
 528
 529                 /// <summary>
 530                 ///   Returns the type of a given parameter, and stores in the `is_out'
 531                 ///   boolean whether this is an out or ref parameter.
 532                 ///
 533                 ///   Note that the returned type will not contain any dereference in this
 534                 ///   case (ie, you get "int" for a ref int instead of "int&"
 535                 /// </summary>
 536                 public Type GetParameterInfo (DeclSpace ds, int idx, out Parameter.Modifier mod)
 537                 {
 538                         mod = Parameter.Modifier.NONE;
 539
 540                         if (!VerifyArgs ()){
 541                                 FixedParameters = null;
 542                                 return null;
 543                         }
 544
 545                         if (FixedParameters == null && ArrayParameter == null)
 546                                 return null;
 547
 548                         if (types == null)
 549                                 if (ComputeParameterTypes (ds) == false)
 550                                         return null;
 551
 552                         //
 553                         // If this is a request for the variable lenght arg.
 554                         //
 555                         int array_idx = (FixedParameters != null ? FixedParameters.Length : 0);
 556                         if (idx == array_idx)
 557                                 return types [idx];
 558
 559                         //
 560                         // Otherwise, it is a fixed parameter
 561                         //
 562                         Parameter p = FixedParameters [idx];
 563                         mod = p.ModFlags;
 564
 565                         if ((mod & (Parameter.Modifier.REF | Parameter.Modifier.OUT)) != 0)
 566                                 mod |= Parameter.Modifier.ISBYREF;
 567
 568                         return p.ParameterType;
 569                 }
 570
 571                 public CallingConventions GetCallingConvention ()
 572                 {
 573                         if (HasArglist)
 574                                 return CallingConventions.VarArgs;
 575                         else
 576                                 return CallingConventions.Standard;
 577                 }
 578
 579                 //
 580                 // The method's attributes are passed in because we need to extract
 581                 // the "return:" attribute from there to apply on the return type
 582                 //
 583                 public void LabelParameters (EmitContext ec,
 584                         MethodBase builder,
 585                         Location loc) {
 586                         //
 587                         // Define each type attribute (in/out/ref) and
 588                         // the argument names.
 589                         //
 590                         int i = 0;
 591
 592                         MethodBuilder mb = builder as MethodBuilder;
 593                         ConstructorBuilder cb = builder as ConstructorBuilder;
 594
 595                         if (FixedParameters != null) {
 596                                 for (i = 0; i < FixedParameters.Length; i++) {
 597                                         FixedParameters [i].DefineParameter (ec, mb, cb, i + 1, loc);
 598                                 }
 599                         }
 600
 601                         if (ArrayParameter != null){
 602                                 ParameterBuilder pb;
 603                                 Parameter array_param = ArrayParameter;
 604
 605                                 if (mb == null)
 606                                         pb = cb.DefineParameter (
 607                                                 i + 1, array_param.Attributes,
 608                                                 array_param.Name);
 609                                 else
 610                                         pb = mb.DefineParameter (
 611                                                 i + 1, array_param.Attributes,
 612                                                 array_param.Name);
 613
 614                                 CustomAttributeBuilder a = new CustomAttributeBuilder (
 615                                         TypeManager.cons_param_array_attribute, new object [0]);
 616
 617                                 pb.SetCustomAttribute (a);
 618                         }
 619                 }
 620         }
 621 }