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