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
 120         /// <summary>
 121         ///   Represents a single method parameter
 122         /// </summary>
 123
 124         //TODO: Add location member to this or base class for better error location and all methods simplification.
 125         public class Parameter : ParameterBase {
 126                 [Flags]
 127                 public enum Modifier : byte {
 128                         NONE    = 0,
 129                         REF     = 1,
 130                         OUT     = 2,
 131                         PARAMS  = 4,
 132                         // This is a flag which says that it's either REF or OUT.
 133                         ISBYREF = 8
 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                 string signature;
 274                 Type [] types;
 275                 Location loc;
 276
 277                 static Parameters empty_parameters;
 278
 279                 public Parameters (Parameter [] fixed_parameters, Parameter array_parameter, Location l)
 280                 {
 281                         FixedParameters = fixed_parameters;
 282                         ArrayParameter  = array_parameter;
 283                         loc = l;
 284                 }
 285
 286                 /// <summary>
 287                 ///   This is used to reuse a set of empty parameters, because they
 288                 ///   are common
 289                 /// </summary>
 290                 public static Parameters EmptyReadOnlyParameters {
 291                         get {
 292                                 if (empty_parameters == null)
 293                                         empty_parameters = new Parameters (null, null, Location.Null);
 294
 295                                 return empty_parameters;
 296                         }
 297                 }
 298
 299                 public bool Empty {
 300                         get {
 301                                 return (FixedParameters == null) && (ArrayParameter == null);
 302                         }
 303                 }
 304
 305                 public void ComputeSignature (DeclSpace ds)
 306                 {
 307                         signature = "";
 308                         if (FixedParameters != null){
 309                                 for (int i = 0; i < FixedParameters.Length; i++){
 310                                         Parameter par = FixedParameters [i];
 311
 312                                         signature += par.GetSignature (ds, loc);
 313                                 }
 314                         }
 315                         //
 316                         // Note: as per the spec, the `params' arguments (ArrayParameter)
 317                         // are not used in the signature computation for a method
 318                         //
 319                 }
 320
 321                 void Error_DuplicateParameterName (string name)
 322                 {
 323                         Report.Error (
 324                                 100, loc, "The parameter name `" + name + "' is a duplicate");
 325                 }
 326
 327                 public bool VerifyArgs ()
 328                 {
 329                         int count;
 330                         int i, j;
 331
 332                         if (FixedParameters == null)
 333                                 return true;
 334
 335                         count = FixedParameters.Length;
 336                         string array_par_name = ArrayParameter != null ? ArrayParameter.Name : null;
 337                         for (i = 0; i < count; i++){
 338                                 string base_name = FixedParameters [i].Name;
 339
 340                                 for (j = i + 1; j < count; j++){
 341                                         if (base_name != FixedParameters [j].Name)
 342                                                 continue;
 343                                         Error_DuplicateParameterName (base_name);
 344                                         return false;
 345                                 }
 346
 347                                 if (base_name == array_par_name){
 348                                         Error_DuplicateParameterName (base_name);
 349                                         return false;
 350                                 }
 351                         }
 352                         return true;
 353                 }
 354
 355                 /// <summary>
 356                 ///    Returns the signature of the Parameters evaluated in
 357                 ///    the @tc environment
 358                 /// </summary>
 359                 public string GetSignature (DeclSpace ds)
 360                 {
 361                         if (signature == null){
 362                                 VerifyArgs ();
 363                                 ComputeSignature (ds);
 364                         }
 365
 366                         return signature;
 367                 }
 368
 369                 /// <summary>
 370                 ///    Returns the paramenter information based on the name
 371                 /// </summary>
 372                 public Parameter GetParameterByName (string name, out int idx)
 373                 {
 374                         idx = 0;
 375                         int i = 0;
 376
 377                         if (FixedParameters != null){
 378                                 foreach (Parameter par in FixedParameters){
 379                                         if (par.Name == name){
 380                                                 idx = i;
 381                                                 return par;
 382                                         }
 383                                         i++;
 384                                 }
 385                         }
 386
 387                         if (ArrayParameter != null){
 388                                 if (name == ArrayParameter.Name){
 389                                         idx = i;
 390                                         return ArrayParameter;
 391                                 }
 392                         }
 393
 394                         return null;
 395                 }
 396
 397                 bool ComputeParameterTypes (DeclSpace ds)
 398                 {
 399                         int extra = (ArrayParameter != null) ? 1 : 0;
 400                         int i = 0;
 401                         int pc;
 402
 403                         if (FixedParameters == null)
 404                                 pc = extra;
 405                         else
 406                                 pc = extra + FixedParameters.Length;
 407
 408                         types = new Type [pc];
 409
 410                         if (!VerifyArgs ()){
 411                                 FixedParameters = null;
 412                                 return false;
 413                         }
 414
 415                         bool failed = false;
 416                         if (FixedParameters != null){
 417                                 foreach (Parameter p in FixedParameters){
 418                                         Type t = null;
 419
 420                                         if (p.Resolve (ds, loc))
 421                                                 t = p.ExternalType ();
 422                                         else
 423                                                 failed = true;
 424
 425                                         types [i] = t;
 426                                         i++;
 427                                 }
 428                         }
 429
 430                         if (extra > 0){
 431                                 if (ArrayParameter.Resolve (ds, loc))
 432                                         types [i] = ArrayParameter.ExternalType ();
 433                                 else
 434                                         failed = true;
 435                         }
 436
 437                         if (failed){
 438                                 types = null;
 439                                 return false;
 440                         }
 441
 442                         return true;
 443                 }
 444
 445                 //
 446                 // This variant is used by Delegates, because they need to
 447                 // resolve/define names, instead of the plain LookupType
 448                 //
 449                 public bool ComputeAndDefineParameterTypes (DeclSpace ds)
 450                 {
 451                         int extra = (ArrayParameter != null) ? 1 : 0;
 452                         int i = 0;
 453                         int pc;
 454
 455                         if (FixedParameters == null)
 456                                 pc = extra;
 457                         else
 458                                 pc = extra + FixedParameters.Length;
 459
 460                         types = new Type [pc];
 461
 462                         if (!VerifyArgs ()){
 463                                 FixedParameters = null;
 464                                 return false;
 465                         }
 466
 467                         bool ok_flag = true;
 468
 469                         if (FixedParameters != null){
 470                                 foreach (Parameter p in FixedParameters){
 471                                         Type t = null;
 472
 473                                         if (p.Resolve (ds, loc))
 474                                                 t = p.ExternalType ();
 475                                         else
 476                                                 ok_flag = false;
 477
 478                                         types [i] = t;
 479                                         i++;
 480                                 }
 481                         }
 482
 483                         if (extra > 0){
 484                                 if (ArrayParameter.Resolve (ds, loc))
 485                                         types [i] = ArrayParameter.ExternalType ();
 486                                 else
 487                                         ok_flag = false;
 488                         }
 489
 490                         //
 491                         // invalidate the cached types
 492                         //
 493                         if (!ok_flag){
 494                                 types = null;
 495                         }
 496
 497                         return ok_flag;
 498                 }
 499
 500                 /// <summary>
 501                 ///   Returns the argument types as an array
 502                 /// </summary>
 503                 static Type [] no_types = new Type [0];
 504
 505                 public Type [] GetParameterInfo (DeclSpace ds)
 506                 {
 507                         if (types != null)
 508                                 return types;
 509
 510                         if (FixedParameters == null && ArrayParameter == null)
 511                                 return no_types;
 512
 513                         if (ComputeParameterTypes (ds) == false){
 514                                 types = null;
 515                                 return null;
 516                         }
 517
 518                         return types;
 519                 }
 520
 521                 /// <summary>
 522                 ///   Returns the type of a given parameter, and stores in the `is_out'
 523                 ///   boolean whether this is an out or ref parameter.
 524                 ///
 525                 ///   Note that the returned type will not contain any dereference in this
 526                 ///   case (ie, you get "int" for a ref int instead of "int&"
 527                 /// </summary>
 528                 public Type GetParameterInfo (DeclSpace ds, int idx, out Parameter.Modifier mod)
 529                 {
 530                         mod = Parameter.Modifier.NONE;
 531
 532                         if (!VerifyArgs ()){
 533                                 FixedParameters = null;
 534                                 return null;
 535                         }
 536
 537                         if (FixedParameters == null && ArrayParameter == null)
 538                                 return null;
 539
 540                         if (types == null)
 541                                 if (ComputeParameterTypes (ds) == false)
 542                                         return null;
 543
 544                         //
 545                         // If this is a request for the variable lenght arg.
 546                         //
 547                         int array_idx = (FixedParameters != null ? FixedParameters.Length : 0);
 548                         if (idx == array_idx)
 549                                 return types [idx];
 550
 551                         //
 552                         // Otherwise, it is a fixed parameter
 553                         //
 554                         Parameter p = FixedParameters [idx];
 555                         mod = p.ModFlags;
 556
 557                         if ((mod & (Parameter.Modifier.REF | Parameter.Modifier.OUT)) != 0)
 558                                 mod |= Parameter.Modifier.ISBYREF;
 559
 560                         return p.ParameterType;
 561                 }
 562
 563                 public CallingConventions GetCallingConvention ()
 564                 {
 565                         // For now this is the only correc thing to do
 566                         return CallingConventions.Standard;
 567                 }
 568
 569                 //
 570                 // The method's attributes are passed in because we need to extract
 571                 // the "return:" attribute from there to apply on the return type
 572                 //
 573                 public void LabelParameters (EmitContext ec,
 574                         MethodBase builder,
 575                         Location loc) {
 576                         //
 577                         // Define each type attribute (in/out/ref) and
 578                         // the argument names.
 579                         //
 580                         int i = 0;
 581
 582                         MethodBuilder mb = builder as MethodBuilder;
 583                         ConstructorBuilder cb = builder as ConstructorBuilder;
 584
 585                         if (FixedParameters != null) {
 586                                 for (i = 0; i < FixedParameters.Length; i++) {
 587                                         FixedParameters [i].DefineParameter (ec, mb, cb, i + 1, loc);
 588                                 }
 589                         }
 590
 591                         if (ArrayParameter != null){
 592                                 ParameterBuilder pb;
 593                                 Parameter array_param = ArrayParameter;
 594
 595                                 if (mb == null)
 596                                         pb = cb.DefineParameter (
 597                                                 i + 1, array_param.Attributes,
 598                                                 array_param.Name);
 599                                 else
 600                                         pb = mb.DefineParameter (
 601                                                 i + 1, array_param.Attributes,
 602                                                 array_param.Name);
 603
 604                                 CustomAttributeBuilder a = new CustomAttributeBuilder (
 605                                         TypeManager.cons_param_array_attribute, new object [0]);
 606
 607                                 pb.SetCustomAttribute (a);
 608                         }
 609                 }
 610         }
 611 }