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|ParameterAttributes.In)) == ParameterAttributes.Out)
 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                         Type t = ParameterType (pos);
 211                         return ModifierDesc (pos) + " " + TypeManager.CSharpName (t);
 212                 }
 213
 214                 public string ModifierDesc (int pos)
 215                 {
 216                         Parameter p = GetParameter (pos);
 217
 218                         //
 219                         // We need to and for REF/OUT, because if either is set the
 220                         // extra flag ISBYREF will be set as well
 221                         //
 222                         if ((p.ModFlags & Parameter.Modifier.REF) != 0)
 223                                 return "ref";
 224                         if ((p.ModFlags & Parameter.Modifier.OUT) != 0)
 225                                 return "out";
 226                         if (p.ModFlags == Parameter.Modifier.PARAMS)
 227                                 return "params";
 228
 229                         return "";
 230                 }
 231
 232                 public Parameter.Modifier ParameterModifier (int pos)
 233                 {
 234                         if (has_varargs && pos >= count)
 235                                 return Parameter.Modifier.ARGLIST;
 236
 237                         Parameter.Modifier mod = GetParameter (pos).ModFlags;
 238
 239                         if ((mod & (Parameter.Modifier.REF | Parameter.Modifier.OUT)) != 0)
 240                                 mod |= Parameter.Modifier.ISBYREF;
 241
 242                         return mod;
 243                 }
 244
 245         }
 246
 247         class PtrHashtable : Hashtable {
 248                 sealed class PtrComparer : IComparer {
 249                         private PtrComparer () {}
 250
 251                         public static PtrComparer Instance = new PtrComparer ();
 252
 253                         public int Compare (object x, object y)
 254                         {
 255                                 if (x == y)
 256                                         return 0;
 257                                 else
 258                                         return 1;
 259                         }
 260                 }
 261
 262                 public PtrHashtable ()
 263                 {
 264                         comparer = PtrComparer.Instance;
 265                 }
 266         }
 267
 268         /*
 269          * Hashtable whose keys are character arrays with the same length
 270          */
 271         class CharArrayHashtable : Hashtable {
 272                 sealed class ArrComparer : IComparer {
 273                         private int len;
 274
 275                         public ArrComparer (int len) {
 276                                 this.len = len;
 277                         }
 278
 279                         public int Compare (object x, object y)
 280                         {
 281                                 char[] a = (char[])x;
 282                                 char[] b = (char[])y;
 283
 284                                 for (int i = 0; i < len; ++i)
 285                                         if (a [i] != b [i])
 286                                                 return 1;
 287                                 return 0;
 288                         }
 289                 }
 290
 291                 private int len;
 292
 293                 protected override int GetHash (Object key)
 294                 {
 295                         char[] arr = (char[])key;
 296                         int h = 0;
 297
 298                         for (int i = 0; i < len; ++i)
 299                                 h = (h << 5) - h + arr [i];
 300
 301                         return h;
 302                 }
 303
 304                 public CharArrayHashtable (int len)
 305                 {
 306                         this.len = len;
 307                         comparer = new ArrComparer (len);
 308                 }
 309         }
 310
 311         struct Pair {
 312                 public object First;
 313                 public object Second;
 314
 315                 public Pair (object f, object s)
 316                 {
 317                         First = f;
 318                         Second = s;
 319                 }
 320         }
 321
 322         /// <summary>
 323         ///   This is a wrapper around StreamReader which is seekable.
 324         /// </summary>
 325         public class SeekableStreamReader
 326         {
 327                 public SeekableStreamReader (StreamReader reader)
 328                 {
 329                         this.reader = reader;
 330                         this.buffer = new char [DefaultCacheSize];
 331
 332                         // Compute the preamble size
 333
 334                         // Let the StreamWriter autodetect the encoder
 335                         reader.Peek ();
 336
 337                         reader.BaseStream.Position = 0;
 338                         Encoding enc = reader.CurrentEncoding;
 339                         // First of all, get at least a char
 340
 341                         byte[] auxb = new byte [50];
 342                         int num_bytes = 0;
 343                         int num_chars = 0;
 344                         int br = 0;
 345                         do {
 346                                 br = reader.BaseStream.Read (auxb, num_bytes, auxb.Length - num_bytes);
 347                                 num_bytes += br;
 348                                 num_chars = enc.GetCharCount (auxb, 0, num_bytes);
 349                         }
 350                         while (num_chars == 0 && br > 0);
 351
 352                         if (num_chars != 0)
 353                         {
 354                                 // Now, check which bytes at the beginning have no effect in the
 355                                 // char count
 356
 357                                 int p = 0;
 358                                 while (enc.GetCharCount (auxb, p, num_bytes-p) >= num_chars)
 359                                         p++;
 360
 361                                 preamble_size = p - 1;
 362                                 reader.BaseStream.Position = 0;
 363                                 reader.DiscardBufferedData ();
 364
 365                                 buffer_start = preamble_size;
 366                         }
 367                 }
 368
 369                 public SeekableStreamReader (Stream stream, Encoding encoding, bool detect_encoding_from_bytemarks)
 370                         : this (new StreamReader (stream, encoding, detect_encoding_from_bytemarks))
 371                 { }
 372
 373                 StreamReader reader;
 374
 375                 private const int DefaultCacheSize = 1024;
 376
 377                 char[] buffer;
 378                 int buffer_start;       // in bytes
 379                 int buffer_size;        // in bytes
 380                 int char_count;         // count buffer[] valid characters
 381                 int pos;                // index into buffer[]
 382                 int preamble_size;
 383
 384                 /// <remarks>
 385                 ///   The difference to the StreamReader's BaseStream.Position is that this one is reliable; ie. it
 386                 //    always reports the correct position and if it's modified, it also takes care of the buffered data.
 387                 /// </remarks>
 388                 public int Position {
 389                         get {
 390                                 return buffer_start + reader.CurrentEncoding.GetByteCount (buffer, 0, pos);
 391                         }
 392
 393                         set {
 394                                 // This one is easy: we're modifying the position within our current
 395                                 // buffer.
 396                                 if ((value >= buffer_start) && (value < buffer_start + buffer_size)) {
 397                                         int byte_offset = value - buffer_start;
 398
 399                                         // pos is an index into a char
 400                                         // buffer so it might be
 401                                         // greater than the buffer
 402                                         // length now, if the buffer
 403                                         // contains multibyte chars
 404                                         pos = byte_offset;
 405
 406                                         // encoded characters can take
 407                                         // more than 1 byte length.
 408                                         while ((pos > buffer.Length) ||
 409                                                reader.CurrentEncoding.GetByteCount (buffer, 0, pos) > byte_offset) {
 410                                                 pos--;
 411                                         }
 412
 413                                         return;
 414                                 }
 415
 416                                 if (value == 0) // Skip preamble
 417                                         value = preamble_size;
 418
 419                                 // Ok, now we need to seek.
 420                                 reader.DiscardBufferedData ();
 421                                 reader.BaseStream.Position = buffer_start = value;
 422                                 char_count = buffer_size = pos = 0;
 423                         }
 424                 }
 425
 426                 private bool ReadBuffer ()
 427                 {
 428                         pos = 0;
 429                         buffer_start += buffer_size;
 430                         char_count = reader.Read (buffer, 0, buffer.Length);
 431                         buffer_size = reader.CurrentEncoding.GetByteCount (buffer, 0, char_count);
 432                         return buffer_size > 0;
 433                 }
 434
 435                 public int Peek ()
 436                 {
 437                         if ((pos >= char_count) && !ReadBuffer ())
 438                                 return -1;
 439
 440                         return buffer [pos];
 441                 }
 442
 443                 public int Read ()
 444                 {
 445                         if ((pos >= char_count) && !ReadBuffer ())
 446                                 return -1;
 447
 448                         return buffer [pos++];
 449                 }
 450         }
 451
 452         public class DoubleHash {
 453                 const int DEFAULT_INITIAL_BUCKETS = 100;
 454
 455                 public DoubleHash () : this (DEFAULT_INITIAL_BUCKETS) {}
 456
 457                 public DoubleHash (int size)
 458                 {
 459                         count = size;
 460                         buckets = new Entry [size];
 461                 }
 462
 463                 int count;
 464                 Entry [] buckets;
 465                 int size = 0;
 466
 467                 class Entry {
 468                         public object key1;
 469                         public object key2;
 470                         public int hash;
 471                         public object value;
 472                         public Entry next;
 473
 474                         public Entry (object key1, object key2, int hash, object value, Entry next)
 475                         {
 476                                 this.key1 = key1;
 477                                 this.key2 = key2;
 478                                 this.hash = hash;
 479                                 this.next = next;
 480                                 this.value = value;
 481                         }
 482                 }
 483
 484                 public bool Lookup (object a, object b, out object res)
 485                 {
 486                         int h = (a.GetHashCode () ^ b.GetHashCode ()) & 0x7FFFFFFF;
 487
 488                         for (Entry e = buckets [h % count]; e != null; e = e.next) {
 489                                 if (e.hash == h && e.key1.Equals (a) && e.key2.Equals (b)) {
 490                                         res = e.value;
 491                                         return true;
 492                                 }
 493                         }
 494                         res = null;
 495                         return false;
 496                 }
 497
 498                 public void Insert (object a, object b, object value)
 499                 {
 500                         // Is it an existing one?
 501
 502                         int h = (a.GetHashCode () ^ b.GetHashCode ()) & 0x7FFFFFFF;
 503
 504                         for (Entry e = buckets [h % count]; e != null; e = e.next) {
 505                                 if (e.hash == h && e.key1.Equals (a) && e.key2.Equals (b))
 506                                         e.value = value;
 507                         }
 508
 509                         int bucket = h % count;
 510                         buckets [bucket] = new Entry (a, b, h, value, buckets [bucket]);
 511
 512                         // Grow whenever we double in size
 513                         if (size++ == count) {
 514                                 count <<= 1;
 515                                 count ++;
 516
 517                                 Entry [] newBuckets = new Entry [count];
 518                                 foreach (Entry root in buckets) {
 519                                         Entry e = root;
 520                                         while (e != null) {
 521                                                 int newLoc = e.hash % count;
 522                                                 Entry n = e.next;
 523                                                 e.next = newBuckets [newLoc];
 524                                                 newBuckets [newLoc] = e;
 525                                                 e = n;
 526                                         }
 527                                 }
 528
 529                                 buckets = newBuckets;
 530                         }
 531                 }
 532         }
 533 }