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