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 GenericConstraints {
  22                 bool HasConstructor { get; }
  23                 bool IsReferenceType { get; }
  24                 bool IsValueType { get; }
  25                 bool HasClassConstraint { get; }
  26                 Type ClassConstraint { get; }
  27                 Type[] InterfaceConstraints { get; }
  28         }
  29
  30         public interface ParameterData {
  31                 Type ParameterType (int pos);
  32                 GenericConstraints GenericConstraints (int pos);
  33                 bool HasArrayParameter { get; }
  34                 int  Count { get; }
  35                 string ParameterName (int pos);
  36                 string ParameterDesc (int pos);
  37                 Parameter.Modifier ParameterModifier (int pos);
  38         }
  39
  40         public class ReflectionParameters : ParameterData {
  41                 ParameterInfo [] pi;
  42                 bool last_arg_is_params = false;
  43                 bool is_varargs = false;
  44                 ParameterData gpd;
  45
  46                 public ReflectionParameters (MethodBase mb)
  47                 {
  48                         object [] attrs;
  49
  50                         ParameterInfo [] pi = mb.GetParameters ();
  51                         is_varargs = (mb.CallingConvention & CallingConventions.VarArgs) != 0;
  52
  53                         this.pi = pi;
  54                         int count = pi.Length-1;
  55
  56                         if (count < 0)
  57                                 return;
  58
  59                         if (mb.Mono_IsInflatedMethod) {
  60                                 MethodInfo generic = mb.GetGenericMethodDefinition ();
  61                                 gpd = Invocation.GetParameterData (generic);
  62
  63                                 last_arg_is_params = gpd.HasArrayParameter;
  64                                 return;
  65                         }
  66
  67                         attrs = pi [count].GetCustomAttributes (TypeManager.param_array_type, true);
  68                         if (attrs == null)
  69                                 return;
  70
  71                         if (attrs.Length == 0)
  72                                 return;
  73
  74                         last_arg_is_params = true;
  75                 }
  76
  77                 public bool HasArrayParameter {
  78                         get { return last_arg_is_params; }
  79                 }
  80
  81                 public Type ParameterType (int pos)
  82                 {
  83                         if (last_arg_is_params && pos >= pi.Length - 1)
  84                                 return pi [pi.Length - 1].ParameterType;
  85                         else if (is_varargs && pos >= pi.Length)
  86                                 return TypeManager.runtime_argument_handle_type;
  87                         else {
  88                                 Type t = pi [pos].ParameterType;
  89
  90                                 return t;
  91                         }
  92                 }
  93
  94                 public GenericConstraints GenericConstraints (int pos)
  95                 {
  96                         if (gpd != null)
  97                                 return gpd.GenericConstraints (pos);
  98
  99                         Type t = ParameterType (pos);
 100                         if (!t.IsGenericParameter)
 101                                 return null;
 102
 103                         return ReflectionConstraints.Create (t);
 104                 }
 105
 106                 public string ParameterName (int pos)
 107                 {
 108                         if (last_arg_is_params && pos >= pi.Length - 1)
 109                                 return pi [pi.Length - 1].Name;
 110                         else if (is_varargs && pos >= pi.Length)
 111                                 return "__arglist";
 112                         else
 113                                 return pi [pos].Name;
 114                 }
 115
 116                 public string ParameterDesc (int pos)
 117                 {
 118                         if (is_varargs && pos >= pi.Length)
 119                                 return "";
 120
 121                         StringBuilder sb = new StringBuilder ();
 122
 123                         if (pi [pos].IsIn)
 124                                 sb.Append ("in ");
 125
 126                         Type partype = ParameterType (pos);
 127                         if (partype.IsByRef){
 128                                 partype = TypeManager.GetElementType (partype);
 129                                 if (pi [pos].IsOut)
 130                                         sb.Append ("out ");
 131                                 else
 132                                         sb.Append ("ref ");
 133                         }
 134
 135                         if (pos >= pi.Length - 1 && last_arg_is_params)
 136                                 sb.Append ("params ");
 137
 138                         sb.Append (TypeManager.CSharpName (partype));
 139
 140                         return sb.ToString ();
 141
 142                 }
 143
 144                 public Parameter.Modifier ParameterModifier (int pos)
 145                 {
 146                         int len = pi.Length;
 147
 148                         if (last_arg_is_params && pos >= pi.Length - 1)
 149                                         return Parameter.Modifier.PARAMS;
 150                         else if (is_varargs && pos >= pi.Length)
 151                                 return Parameter.Modifier.ARGLIST;
 152
 153                         Type t = pi [pos].ParameterType;
 154                         if (t.IsByRef){
 155                                 if ((pi [pos].Attributes & ParameterAttributes.Out) != 0)
 156                                         return Parameter.Modifier.ISBYREF | Parameter.Modifier.OUT;
 157                                 else
 158                                         return Parameter.Modifier.ISBYREF | Parameter.Modifier.REF;
 159                         }
 160
 161                         return Parameter.Modifier.NONE;
 162                 }
 163
 164                 public int Count {
 165                         get {
 166                                 return is_varargs ? pi.Length + 1 : pi.Length;
 167                         }
 168                 }
 169
 170                 protected class ReflectionConstraints : GenericConstraints
 171                 {
 172                         bool has_ctor;
 173                         bool is_reference_type;
 174                         bool is_value_type;
 175                         Type class_constraint;
 176                         Type[] iface_constraints;
 177
 178                         protected ReflectionConstraints (bool has_ctor, Type class_constr,
 179                                                          Type[] iface_constrs)
 180                         {
 181                                 this.has_ctor = has_ctor;
 182                                 this.class_constraint = class_constr;
 183                                 this.iface_constraints = iface_constrs;
 184
 185                                 if (class_constraint != null) {
 186                                         if (class_constraint == TypeManager.object_type)
 187                                                 is_reference_type = true;
 188                                         else if (class_constraint == TypeManager.value_type)
 189                                                 is_value_type = true;
 190                                 }
 191                         }
 192
 193                         public static GenericConstraints Create (Type t)
 194                         {
 195                                 Type class_constr = null;
 196                                 Type[] iface_constrs = t.GetInterfaces ();
 197                                 if (iface_constrs ==  null)
 198                                         iface_constrs = Type.EmptyTypes;
 199                                 if (t.BaseType != TypeManager.object_type)
 200                                         class_constr = t.BaseType;
 201
 202                                 return new ReflectionConstraints (
 203                                         false, class_constr, iface_constrs);
 204                         }
 205
 206                         public bool HasConstructor {
 207                                 get { return has_ctor; }
 208                         }
 209
 210                         public bool HasClassConstraint {
 211                                 get { return class_constraint != null; }
 212                         }
 213
 214                         public bool IsReferenceType {
 215                                 get { return is_reference_type; }
 216                         }
 217
 218                         public bool IsValueType {
 219                                 get { return is_value_type; }
 220                         }
 221
 222                         public Type ClassConstraint {
 223                                 get { return class_constraint; }
 224                         }
 225
 226                         public Type[] InterfaceConstraints {
 227                                 get { return iface_constraints; }
 228                         }
 229                 }
 230         }
 231
 232         public class InternalParameters : ParameterData {
 233                 Type [] param_types;
 234                 bool has_varargs;
 235                 int count;
 236
 237                 public readonly Parameters Parameters;
 238
 239                 public InternalParameters (Type [] param_types, Parameters parameters)
 240                 {
 241                         this.param_types = param_types;
 242                         this.Parameters = parameters;
 243                 }
 244
 245                 public InternalParameters (DeclSpace ds, Parameters parameters)
 246                         : this (parameters.GetParameterInfo (ds), parameters)
 247                 {
 248                         has_varargs = parameters.HasArglist;
 249
 250                         if (param_types == null)
 251                                 count = 0;
 252                         else
 253                                 count = param_types.Length;
 254                 }
 255
 256                 public int Count {
 257                         get {
 258                                 return has_varargs ? count + 1 : count;
 259                         }
 260                 }
 261
 262                 public bool HasArrayParameter {
 263                         get { return Parameters.ArrayParameter != null; }
 264                 }
 265
 266                 Parameter GetParameter (int pos)
 267                 {
 268                         Parameter [] fixed_pars = Parameters.FixedParameters;
 269                         if (fixed_pars != null){
 270                                 int len = fixed_pars.Length;
 271                                 if (pos < len)
 272                                         return Parameters.FixedParameters [pos];
 273                         }
 274
 275                         return Parameters.ArrayParameter;
 276                 }
 277
 278                 public Type ParameterType (int pos)
 279                 {
 280                         if (has_varargs && pos >= count)
 281                                 return TypeManager.runtime_argument_handle_type;
 282
 283                         if (param_types == null)
 284                                 return null;
 285
 286                         return GetParameter (pos).ExternalType ();
 287                 }
 288
 289                 public GenericConstraints GenericConstraints (int pos)
 290                 {
 291                         if (param_types == null)
 292                                 return null;
 293
 294                         return GetParameter (pos).GenericConstraints;
 295                 }
 296
 297                 public string ParameterName (int pos)
 298                 {
 299                         if (has_varargs && pos >= count)
 300                                 return "__arglist";
 301
 302                         return GetParameter (pos).Name;
 303                 }
 304
 305                 public string ParameterDesc (int pos)
 306                 {
 307                         if (has_varargs && pos >= count)
 308                                 return "__arglist";
 309
 310                         string tmp = String.Empty;
 311                         Parameter p = GetParameter (pos);
 312
 313                         //
 314                         // We need to and for REF/OUT, because if either is set the
 315                         // extra flag ISBYREF will be set as well
 316                         //
 317                         if ((p.ModFlags & Parameter.Modifier.REF) != 0)
 318                                 tmp = "ref ";
 319                         else if ((p.ModFlags & Parameter.Modifier.OUT) != 0)
 320                                 tmp = "out ";
 321                         else if (p.ModFlags == Parameter.Modifier.PARAMS)
 322                                 tmp = "params ";
 323
 324                         Type t = ParameterType (pos);
 325
 326                         return tmp + TypeManager.CSharpName (t);
 327                 }
 328
 329                 public Parameter.Modifier ParameterModifier (int pos)
 330                 {
 331                         if (has_varargs && pos >= count)
 332                                 return Parameter.Modifier.ARGLIST;
 333
 334                         Parameter.Modifier mod = GetParameter (pos).ModFlags;
 335
 336                         if ((mod & (Parameter.Modifier.REF | Parameter.Modifier.OUT)) != 0)
 337                                 mod |= Parameter.Modifier.ISBYREF;
 338
 339                         return mod;
 340                 }
 341
 342         }
 343
 344         class PtrHashtable : Hashtable {
 345                 sealed class PtrComparer : IComparer {
 346                         private PtrComparer () {}
 347
 348                         public static PtrComparer Instance = new PtrComparer ();
 349
 350                         public int Compare (object x, object y)
 351                         {
 352                                 if (x == y)
 353                                         return 0;
 354                                 else
 355                                         return 1;
 356                         }
 357                 }
 358
 359                 public PtrHashtable ()
 360                 {
 361                         comparer = PtrComparer.Instance;
 362                 }
 363         }
 364
 365         /*
 366          * Hashtable whose keys are character arrays with the same length
 367          */
 368         class CharArrayHashtable : Hashtable {
 369                 sealed class ArrComparer : IComparer {
 370                         private int len;
 371
 372                         public ArrComparer (int len) {
 373                                 this.len = len;
 374                         }
 375
 376                         public int Compare (object x, object y)
 377                         {
 378                                 char[] a = (char[])x;
 379                                 char[] b = (char[])y;
 380
 381                                 for (int i = 0; i < len; ++i)
 382                                         if (a [i] != b [i])
 383                                                 return 1;
 384                                 return 0;
 385                         }
 386                 }
 387
 388                 private int len;
 389
 390                 protected override int GetHash (Object key)
 391                 {
 392                         char[] arr = (char[])key;
 393                         int h = 0;
 394
 395                         for (int i = 0; i < len; ++i)
 396                                 h = (h << 5) - h + arr [i];
 397
 398                         return h;
 399                 }
 400
 401                 public CharArrayHashtable (int len)
 402                 {
 403                         this.len = len;
 404                         comparer = new ArrComparer (len);
 405                 }
 406         }
 407
 408         struct Pair {
 409                 public object First;
 410                 public object Second;
 411
 412                 public Pair (object f, object s)
 413                 {
 414                         First = f;
 415                         Second = s;
 416                 }
 417         }
 418
 419         /// <summary>
 420         ///   This is a wrapper around StreamReader which is seekable.
 421         /// </summary>
 422         public class SeekableStreamReader
 423         {
 424                 public SeekableStreamReader (StreamReader reader)
 425                 {
 426                         this.reader = reader;
 427                         this.buffer = new char [DefaultCacheSize];
 428
 429                         // Compute the preamble size
 430
 431                         // Let the StreamWriter autodetect the encoder
 432                         reader.Peek ();
 433
 434                         reader.BaseStream.Position = 0;
 435                         Encoding enc = reader.CurrentEncoding;
 436                         // First of all, get at least a char
 437
 438                         byte[] auxb = new byte [50];
 439                         int num_bytes = 0;
 440                         int num_chars = 0;
 441                         int br = 0;
 442                         do {
 443                                 br = reader.BaseStream.Read (auxb, num_bytes, auxb.Length - num_bytes);
 444                                 num_bytes += br;
 445                                 num_chars = enc.GetCharCount (auxb, 0, num_bytes);
 446                         }
 447                         while (num_chars == 0 && br > 0);
 448
 449                         if (num_chars != 0)
 450                         {
 451                                 // Now, check which bytes at the beginning have no effect in the
 452                                 // char count
 453
 454                                 int p = 0;
 455                                 while (enc.GetCharCount (auxb, p, num_bytes-p) >= num_chars)
 456                                         p++;
 457
 458                                 preamble_size = p - 1;
 459                                 reader.BaseStream.Position = 0;
 460                                 reader.DiscardBufferedData ();
 461
 462                                 buffer_start = preamble_size;
 463                         }
 464                 }
 465
 466                 public SeekableStreamReader (Stream stream, Encoding encoding, bool detect_encoding_from_bytemarks)
 467                         : this (new StreamReader (stream, encoding, detect_encoding_from_bytemarks))
 468                 { }
 469
 470                 StreamReader reader;
 471
 472                 private const int DefaultCacheSize = 1024;
 473
 474                 char[] buffer;
 475                 int buffer_start;       // in bytes
 476                 int buffer_size;        // in bytes
 477                 int char_count;         // count buffer[] valid characters
 478                 int pos;                // index into buffer[]
 479                 int preamble_size;
 480
 481                 /// <remarks>
 482                 ///   The difference to the StreamReader's BaseStream.Position is that this one is reliable; ie. it
 483                 //    always reports the correct position and if it's modified, it also takes care of the buffered data.
 484                 /// </remarks>
 485                 public int Position {
 486                         get {
 487                                 return buffer_start + reader.CurrentEncoding.GetByteCount (buffer, 0, pos);
 488                         }
 489
 490                         set {
 491                                 // This one is easy: we're modifying the position within our current
 492                                 // buffer.
 493                                 if ((value >= buffer_start) && (value < buffer_start + buffer_size)) {
 494                                         int byte_offset = value - buffer_start;
 495                                         pos = byte_offset;
 496                                         // encoded characters can take more than 1 byte length
 497                                         while (reader.CurrentEncoding.GetByteCount (buffer, 0, pos) > byte_offset)
 498                                                 pos--;
 499
 500                                         return;
 501                                 }
 502
 503                                 if (value == 0) // Skip preamble
 504                                         value = preamble_size;
 505
 506                                 // Ok, now we need to seek.
 507                                 reader.DiscardBufferedData ();
 508                                 reader.BaseStream.Position = buffer_start = value;
 509                                 char_count = buffer_size = pos = 0;
 510                         }
 511                 }
 512
 513                 private bool ReadBuffer ()
 514                 {
 515                         pos = 0;
 516                         buffer_start += buffer_size;
 517                         char_count = reader.Read (buffer, 0, buffer.Length);
 518                         buffer_size = reader.CurrentEncoding.GetByteCount (buffer, 0, char_count);
 519                         return buffer_size > 0;
 520                 }
 521
 522                 public int Peek ()
 523                 {
 524                         if ((pos >= char_count) && !ReadBuffer ())
 525                                 return -1;
 526
 527                         return buffer [pos];
 528                 }
 529
 530                 public int Read ()
 531                 {
 532                         if ((pos >= char_count) && !ReadBuffer ())
 533                                 return -1;
 534
 535                         return buffer [pos++];
 536                 }
 537         }
 538
 539         public class DoubleHash {
 540                 const int DEFAULT_INITIAL_BUCKETS = 100;
 541
 542                 public DoubleHash () : this (DEFAULT_INITIAL_BUCKETS) {}
 543
 544                 public DoubleHash (int size)
 545                 {
 546                         count = size;
 547                         buckets = new Entry [size];
 548                 }
 549
 550                 int count;
 551                 Entry [] buckets;
 552                 int size = 0;
 553
 554                 class Entry {
 555                         public object key1;
 556                         public object key2;
 557                         public int hash;
 558                         public object value;
 559                         public Entry next;
 560
 561                         public Entry (object key1, object key2, int hash, object value, Entry next)
 562                         {
 563                                 this.key1 = key1;
 564                                 this.key2 = key2;
 565                                 this.hash = hash;
 566                                 this.next = next;
 567                                 this.value = value;
 568                         }
 569                 }
 570
 571                 public bool Lookup (object a, object b, out object res)
 572                 {
 573                         int h = (a.GetHashCode () ^ b.GetHashCode ()) & 0x7FFFFFFF;
 574
 575                         for (Entry e = buckets [h % count]; e != null; e = e.next) {
 576                                 if (e.hash == h && e.key1.Equals (a) && e.key2.Equals (b)) {
 577                                         res = e.value;
 578                                         return true;
 579                                 }
 580                         }
 581                         res = null;
 582                         return false;
 583                 }
 584
 585                 public void Insert (object a, object b, object value)
 586                 {
 587                         // Is it an existing one?
 588
 589                         int h = (a.GetHashCode () ^ b.GetHashCode ()) & 0x7FFFFFFF;
 590
 591                         for (Entry e = buckets [h % count]; e != null; e = e.next) {
 592                                 if (e.hash == h && e.key1.Equals (a) && e.key2.Equals (b))
 593                                         e.value = value;
 594                         }
 595
 596                         int bucket = h % count;
 597                         buckets [bucket] = new Entry (a, b, h, value, buckets [bucket]);
 598
 599                         // Grow whenever we double in size
 600                         if (size++ == count) {
 601                                 count <<= 1;
 602                                 count ++;
 603
 604                                 Entry [] newBuckets = new Entry [count];
 605                                 foreach (Entry root in buckets) {
 606                                         Entry e = root;
 607                                         while (e != null) {
 608                                                 int newLoc = e.hash % count;
 609                                                 Entry n = e.next;
 610                                                 e.next = newBuckets [newLoc];
 611                                                 newBuckets [newLoc] = e;
 612                                                 e = n;
 613                                         }
 614                                 }
 615
 616                                 buckets = newBuckets;
 617                         }
 618                 }
 619         }
 620 }