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