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