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