mcs/gmcs/support.cs

   1 //
   2 // support.cs: Support routines to work around the fact that System.Reflection.Emit
   3 // can not introspect types that are being constructed
   4 //
   5 // Author:
   6 //   Miguel de Icaza (miguel@ximian.com)
   7 //
   8 // (C) 2001 Ximian, Inc (http://www.ximian.com)
   9 //
  10
  11 using System;
  12 using System.IO;
  13 using System.Text;
  14 using System.Reflection;
  15 using System.Collections;
  16 using System.Reflection.Emit;
  17 using System.Globalization;
  18
  19 namespace Mono.CSharp {
  20
  21         public interface ParameterData {
  22                 Type ParameterType (int pos);
  23                 GenericConstraints GenericConstraints (int pos);
  24                 int  Count { get; }
  25                 bool HasParams { get; }
  26                 string ParameterName (int pos);
  27                 string ParameterDesc (int pos);
  28                 Parameter.Modifier ParameterModifier (int pos);
  29                 string GetSignatureForError ();
  30         }
  31
  32         public class ReflectionParameters : ParameterData {
  33                 ParameterInfo [] pi;
  34                 Type[] type_params;
  35                 bool last_arg_is_params = false;
  36                 bool is_varargs = false;
  37                 ParameterData gpd;
  38
  39                 public ReflectionParameters (MethodBase mb)
  40                 {
  41                         object [] attrs;
  42
  43                         ParameterInfo [] pi = mb.GetParameters ();
  44                         is_varargs = (mb.CallingConvention & CallingConventions.VarArgs) != 0;
  45
  46                         this.pi = pi;
  47                         int count = pi.Length-1;
  48
  49                         if (count < 0)
  50                                 return;
  51
  52                         if (mb.Mono_IsInflatedMethod) {
  53                                 MethodInfo generic = mb.GetGenericMethodDefinition ();
  54                                 gpd = TypeManager.GetParameterData (generic);
  55
  56                                 last_arg_is_params = gpd.HasParams;
  57                                 return;
  58                         }
  59
  60                         if (mb.IsGenericMethodDefinition)
  61                                 type_params = mb.GetGenericArguments ();
  62
  63                         attrs = pi [count].GetCustomAttributes (TypeManager.param_array_type, true);
  64                         if (attrs == null)
  65                                 return;
  66
  67                         if (attrs.Length == 0)
  68                                 return;
  69
  70                         last_arg_is_params = true;
  71                 }
  72
  73                 public string GetSignatureForError ()
  74                 {
  75                         StringBuilder sb = new StringBuilder ("(");
  76                         for (int i = 0; i < pi.Length; ++i) {
  77                                 if (i != 0)
  78                                         sb.Append (", ");
  79                                 sb.Append (ParameterDesc (i));
  80                         }
  81                         sb.Append (')');
  82                         return sb.ToString ();
  83                 }
  84
  85                 public Type ParameterType (int pos)
  86                 {
  87                         if (last_arg_is_params && pos >= pi.Length - 1)
  88                                 return pi [pi.Length - 1].ParameterType;
  89                         else if (is_varargs && pos >= pi.Length)
  90                                 return TypeManager.runtime_argument_handle_type;
  91                         else {
  92                                 Type t = pi [pos].ParameterType;
  93
  94                                 return t;
  95                         }
  96                 }
  97
  98                 public GenericConstraints GenericConstraints (int pos)
  99                 {
 100                         if (gpd != null)
 101                                 return gpd.GenericConstraints (pos);
 102
 103                         if (type_params == null)
 104                                 return null;
 105
 106                         return new ReflectionConstraints (type_params [pos]);
 107                 }
 108
 109                 public string ParameterName (int pos)
 110                 {
 111                         if (gpd != null)
 112                                 return gpd.ParameterName (pos);
 113
 114                         if (last_arg_is_params && pos >= pi.Length - 1)
 115                                 return pi [pi.Length - 1].Name;
 116                         else if (is_varargs && pos >= pi.Length)
 117                                 return "__arglist";
 118                         else
 119                                 return pi [pos].Name;
 120                 }
 121
 122                 public string ParameterDesc (int pos)
 123                 {
 124                         if (is_varargs && pos >= pi.Length)
 125                                 return "";
 126
 127                         StringBuilder sb = new StringBuilder ();
 128
 129                         if (pi [pos].IsIn)
 130                                 sb.Append ("in ");
 131
 132                         Type partype = ParameterType (pos);
 133                         if (partype.IsByRef){
 134                                 partype = TypeManager.GetElementType (partype);
 135                                 if (pi [pos].IsOut)
 136                                         sb.Append ("out ");
 137                                 else
 138                                         sb.Append ("ref ");
 139                         }
 140
 141                         if (pos >= pi.Length - 1 && last_arg_is_params)
 142                                 sb.Append ("params ");
 143
 144                         sb.Append (TypeManager.CSharpName (partype).Replace ("&", ""));
 145
 146                         return sb.ToString ();
 147
 148                 }
 149
 150                 public Parameter.Modifier ParameterModifier (int pos)
 151                 {
 152                         if (last_arg_is_params && pos >= pi.Length - 1)
 153                                         return Parameter.Modifier.PARAMS;
 154                         else if (is_varargs && pos >= pi.Length)
 155                                 return Parameter.Modifier.ARGLIST;
 156
 157                         if (gpd != null)
 158                                 return gpd.ParameterModifier (pos);
 159
 160                         Type t = pi [pos].ParameterType;
 161                         if (t.IsByRef){
 162                                 if ((pi [pos].Attributes & (ParameterAttributes.Out|ParameterAttributes.In)) == ParameterAttributes.Out)
 163                                         return Parameter.Modifier.ISBYREF | Parameter.Modifier.OUT;
 164                                 else
 165                                         return Parameter.Modifier.ISBYREF | Parameter.Modifier.REF;
 166                         }
 167
 168                         return Parameter.Modifier.NONE;
 169                 }
 170
 171                 public int Count {
 172                         get {
 173                                 return is_varargs ? pi.Length + 1 : pi.Length;
 174                         }
 175                 }
 176
 177                 public bool HasParams {
 178                         get {
 179                                 return this.last_arg_is_params;
 180                         }
 181                 }
 182         }
 183
 184         public class InternalParameters : ParameterData {
 185                 Type [] param_types;
 186                 bool has_varargs;
 187                 int count;
 188
 189                 public readonly Parameters Parameters;
 190                 public readonly TypeParameter[] TypeParameters;
 191
 192                 public InternalParameters (Type [] param_types, Parameters parameters)
 193                 {
 194                         this.param_types = param_types;
 195                         this.Parameters = parameters;
 196
 197                         has_varargs = parameters.HasArglist;
 198
 199                         if (param_types == null)
 200                                 count = 0;
 201                         else
 202                                 count = param_types.Length;
 203                 }
 204
 205                 public InternalParameters (Type [] param_types, Parameters parameters,
 206                                            TypeParameter [] type_params)
 207                         : this (param_types, parameters)
 208                 {
 209                         this.TypeParameters = type_params;
 210                 }
 211
 212                 public int Count {
 213                         get {
 214                                 return has_varargs ? count + 1 : count;
 215                         }
 216                 }
 217
 218                 public bool HasParams {
 219                         get {
 220                                 return Parameters.ArrayParameter != null;
 221                         }
 222                 }
 223
 224                 Parameter GetParameter (int pos)
 225                 {
 226                         Parameter [] fixed_pars = Parameters.FixedParameters;
 227                         if (fixed_pars != null){
 228                                 int len = fixed_pars.Length;
 229                                 if (pos < len)
 230                                         return Parameters.FixedParameters [pos];
 231                         }
 232
 233                         return Parameters.ArrayParameter;
 234                 }
 235
 236                 public string GetSignatureForError ()
 237                 {
 238                         StringBuilder sb = new StringBuilder ("(");
 239                         for (int i = 0; i < count; ++i) {
 240                                 if (i != 0)
 241                                         sb.Append (", ");
 242                                 sb.Append (ParameterDesc (i));
 243                         }
 244                         sb.Append (')');
 245                         return sb.ToString ();
 246                 }
 247
 248                 public Type ParameterType (int pos)
 249                 {
 250                         if (has_varargs && pos >= count)
 251                                 return TypeManager.runtime_argument_handle_type;
 252
 253                         if (param_types == null)
 254                                 return null;
 255
 256                         return GetParameter (pos).ExternalType ();
 257                 }
 258
 259                 public GenericConstraints GenericConstraints (int pos)
 260                 {
 261                         if (TypeParameters == null)
 262                                 return null;
 263
 264                         return TypeParameters [pos].Constraints;
 265                 }
 266
 267                 public string ParameterName (int pos)
 268                 {
 269                         if (has_varargs && pos >= count)
 270                                 return "__arglist";
 271
 272                         return GetParameter (pos).Name;
 273                 }
 274
 275                 public string ParameterDesc (int pos)
 276                 {
 277                         if (has_varargs && pos >= count)
 278                                 return "__arglist";
 279
 280                         Type t = ParameterType (pos);
 281                         return (ModifierDesc (pos) + " " + TypeManager.CSharpName (t).Replace ("&", "")).TrimStart ();
 282                 }
 283
 284                 public string ModifierDesc (int pos)
 285                 {
 286                         Parameter p = GetParameter (pos);
 287
 288                         //
 289                         // We need to and for REF/OUT, because if either is set the
 290                         // extra flag ISBYREF will be set as well
 291                         //
 292                         if ((p.ModFlags & Parameter.Modifier.REF) != 0)
 293                                 return "ref";
 294                         if ((p.ModFlags & Parameter.Modifier.OUT) != 0)
 295                                 return "out";
 296                         if (p.ModFlags == Parameter.Modifier.PARAMS)
 297                                 return "params";
 298
 299                         return "";
 300                 }
 301
 302                 public Parameter.Modifier ParameterModifier (int pos)
 303                 {
 304                         if (has_varargs && pos >= count)
 305                                 return Parameter.Modifier.ARGLIST;
 306
 307                         Parameter.Modifier mod = GetParameter (pos).ModFlags;
 308
 309                         if ((mod & (Parameter.Modifier.REF | Parameter.Modifier.OUT)) != 0)
 310                                 mod |= Parameter.Modifier.ISBYREF;
 311
 312                         return mod;
 313                 }
 314
 315         }
 316
 317         public class ReflectionConstraints : GenericConstraints
 318         {
 319                 GenericParameterAttributes attrs;
 320                 Type base_type;
 321                 Type class_constraint;
 322                 Type[] iface_constraints;
 323
 324                 public ReflectionConstraints (Type t)
 325                 {
 326                         Type[] constraints = t.GetGenericParameterConstraints ();
 327                         if ((constraints.Length > 0) && !constraints [0].IsInterface) {
 328                                 class_constraint = constraints [0];
 329                                 iface_constraints = new Type [constraints.Length - 1];
 330                                 Array.Copy (constraints, 1, iface_constraints, 0, constraints.Length - 1);
 331                         } else
 332                                 iface_constraints = constraints;
 333                         attrs = t.GenericParameterAttributes;
 334
 335                         if (HasValueTypeConstraint)
 336                                 base_type = TypeManager.value_type;
 337                         else if (class_constraint != null)
 338                                 base_type = class_constraint;
 339                         else
 340                                 base_type = TypeManager.object_type;
 341                 }
 342
 343                 public override GenericParameterAttributes Attributes {
 344                         get { return attrs; }
 345                 }
 346
 347                 public override Type ClassConstraint {
 348                         get { return class_constraint; }
 349                 }
 350
 351                 public override Type EffectiveBaseClass {
 352                         get { return base_type; }
 353                 }
 354
 355                 public override Type[] InterfaceConstraints {
 356                         get { return iface_constraints; }
 357                 }
 358         }
 359
 360         class PtrHashtable : Hashtable {
 361                 sealed class PtrComparer : IComparer {
 362                         private PtrComparer () {}
 363
 364                         public static PtrComparer Instance = new PtrComparer ();
 365
 366                         public int Compare (object x, object y)
 367                         {
 368                                 if (x == y)
 369                                         return 0;
 370                                 else
 371                                         return 1;
 372                         }
 373                 }
 374
 375                 public PtrHashtable ()
 376                 {
 377                         comparer = PtrComparer.Instance;
 378                 }
 379         }
 380
 381         /*
 382          * Hashtable whose keys are character arrays with the same length
 383          */
 384         class CharArrayHashtable : Hashtable {
 385                 sealed class ArrComparer : IComparer {
 386                         private int len;
 387
 388                         public ArrComparer (int len) {
 389                                 this.len = len;
 390                         }
 391
 392                         public int Compare (object x, object y)
 393                         {
 394                                 char[] a = (char[])x;
 395                                 char[] b = (char[])y;
 396
 397                                 for (int i = 0; i < len; ++i)
 398                                         if (a [i] != b [i])
 399                                                 return 1;
 400                                 return 0;
 401                         }
 402                 }
 403
 404                 private int len;
 405
 406                 protected override int GetHash (Object key)
 407                 {
 408                         char[] arr = (char[])key;
 409                         int h = 0;
 410
 411                         for (int i = 0; i < len; ++i)
 412                                 h = (h << 5) - h + arr [i];
 413
 414                         return h;
 415                 }
 416
 417                 public CharArrayHashtable (int len)
 418                 {
 419                         this.len = len;
 420                         comparer = new ArrComparer (len);
 421                 }
 422         }
 423
 424         struct Pair {
 425                 public object First;
 426                 public object Second;
 427
 428                 public Pair (object f, object s)
 429                 {
 430                         First = f;
 431                         Second = s;
 432                 }
 433         }
 434
 435         /// <summary>
 436         ///   This is a wrapper around StreamReader which is seekable.
 437         /// </summary>
 438         public class SeekableStreamReader
 439         {
 440                 public SeekableStreamReader (StreamReader reader)
 441                 {
 442                         this.reader = reader;
 443                         this.buffer = new char [DefaultCacheSize];
 444
 445                         // Compute the preamble size
 446
 447                         // Let the StreamWriter autodetect the encoder
 448                         reader.Peek ();
 449
 450                         preamble_size = (int) reader.BaseStream.Position;
 451                 }
 452
 453                 public SeekableStreamReader (Stream stream, Encoding encoding)
 454                         : this (new StreamReader (stream, encoding, true))
 455                 { }
 456
 457                 StreamReader reader;
 458
 459                 private const int DefaultCacheSize = 1024;
 460
 461                 char[] buffer;
 462                 int buffer_start;       // in bytes
 463                 int buffer_size;        // in bytes
 464                 int char_count;         // count buffer[] valid characters
 465                 int pos;                // index into buffer[]
 466                 int preamble_size;
 467
 468                 /// <remarks>
 469                 ///   The difference to the StreamReader's BaseStream.Position is that this one is reliable; ie. it
 470                 //    always reports the correct position and if it's modified, it also takes care of the buffered data.
 471                 /// </remarks>
 472                 public int Position {
 473                         get {
 474                                 return buffer_start + reader.CurrentEncoding.GetByteCount (buffer, 0, pos);
 475                         }
 476
 477                         set {
 478                                 // This one is easy: we're modifying the position within our current
 479                                 // buffer.
 480                                 if ((value >= buffer_start) && (value < buffer_start + buffer_size)) {
 481                                         int byte_offset = value - buffer_start;
 482
 483                                         // If we have an uni-byte encoding, 'pos' will be the same as
 484                                         // 'byte_offset'.  If we have a multi-byte encoding, 'byte_offset'
 485                                         // can be bigger than the desired value of 'pos', but not smaller.
 486                                         // (IOW, the number of characters <= number of bytes)
 487                                         //
 488                                         // So, we start pos off at byte_offset, and fix it up.
 489                                         pos = byte_offset;
 490                                         if (pos > char_count)
 491                                                 pos = char_count;
 492                                         while (reader.CurrentEncoding.GetByteCount (buffer, 0, pos) > byte_offset)
 493                                                 --pos;
 494                                         return;
 495                                 }
 496
 497                                 if (value == 0) // Skip preamble
 498                                         value = preamble_size;
 499
 500                                 // Ok, now we need to seek.
 501                                 reader.DiscardBufferedData ();
 502                                 reader.BaseStream.Position = buffer_start = value;
 503                                 char_count = buffer_size = pos = 0;
 504                         }
 505                 }
 506
 507                 private bool ReadBuffer ()
 508                 {
 509                         pos = 0;
 510                         buffer_start += buffer_size;
 511                         char_count = reader.Read (buffer, 0, buffer.Length);
 512                         buffer_size = reader.CurrentEncoding.GetByteCount (buffer, 0, char_count);
 513                         return buffer_size > 0;
 514                 }
 515
 516                 public int Peek ()
 517                 {
 518                         if ((pos >= char_count) && !ReadBuffer ())
 519                                 return -1;
 520
 521                         return buffer [pos];
 522                 }
 523
 524                 public int Read ()
 525                 {
 526                         if ((pos >= char_count) && !ReadBuffer ())
 527                                 return -1;
 528
 529                         return buffer [pos++];
 530                 }
 531         }
 532
 533         public class DoubleHash {
 534                 const int DEFAULT_INITIAL_BUCKETS = 100;
 535
 536                 public DoubleHash () : this (DEFAULT_INITIAL_BUCKETS) {}
 537
 538                 public DoubleHash (int size)
 539                 {
 540                         count = size;
 541                         buckets = new Entry [size];
 542                 }
 543
 544                 int count;
 545                 Entry [] buckets;
 546                 int size = 0;
 547
 548                 class Entry {
 549                         public object key1;
 550                         public object key2;
 551                         public int hash;
 552                         public object value;
 553                         public Entry next;
 554
 555                         public Entry (object key1, object key2, int hash, object value, Entry next)
 556                         {
 557                                 this.key1 = key1;
 558                                 this.key2 = key2;
 559                                 this.hash = hash;
 560                                 this.next = next;
 561                                 this.value = value;
 562                         }
 563                 }
 564
 565                 public bool Lookup (object a, object b, out object res)
 566                 {
 567                         int h = (a.GetHashCode () ^ b.GetHashCode ()) & 0x7FFFFFFF;
 568
 569                         for (Entry e = buckets [h % count]; e != null; e = e.next) {
 570                                 if (e.hash == h && e.key1.Equals (a) && e.key2.Equals (b)) {
 571                                         res = e.value;
 572                                         return true;
 573                                 }
 574                         }
 575                         res = null;
 576                         return false;
 577                 }
 578
 579                 public void Insert (object a, object b, object value)
 580                 {
 581                         // Is it an existing one?
 582
 583                         int h = (a.GetHashCode () ^ b.GetHashCode ()) & 0x7FFFFFFF;
 584
 585                         for (Entry e = buckets [h % count]; e != null; e = e.next) {
 586                                 if (e.hash == h && e.key1.Equals (a) && e.key2.Equals (b))
 587                                         e.value = value;
 588                         }
 589
 590                         int bucket = h % count;
 591                         buckets [bucket] = new Entry (a, b, h, value, buckets [bucket]);
 592
 593                         // Grow whenever we double in size
 594                         if (size++ == count) {
 595                                 count <<= 1;
 596                                 count ++;
 597
 598                                 Entry [] newBuckets = new Entry [count];
 599                                 foreach (Entry root in buckets) {
 600                                         Entry e = root;
 601                                         while (e != null) {
 602                                                 int newLoc = e.hash % count;
 603                                                 Entry n = e.next;
 604                                                 e.next = newBuckets [newLoc];
 605                                                 newBuckets [newLoc] = e;
 606                                                 e = n;
 607                                         }
 608                                 }
 609
 610                                 buckets = newBuckets;
 611                         }
 612                 }
 613         }
 614 }