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
 149                 public InternalParameters (DeclSpace ds, Parameters parameters)
 150                         : this (parameters.GetParameterInfo (ds), parameters)
 151                 {
 152                         has_varargs = parameters.HasArglist;
 153
 154                         if (param_types == null)
 155                                 count = 0;
 156                         else
 157                                 count = param_types.Length;
 158                 }
 159
 160                 public int Count {
 161                         get {
 162                                 return has_varargs ? count + 1 : count;
 163                         }
 164                 }
 165
 166                 Parameter GetParameter (int pos)
 167                 {
 168                         Parameter [] fixed_pars = Parameters.FixedParameters;
 169                         if (fixed_pars != null){
 170                                 int len = fixed_pars.Length;
 171                                 if (pos < len)
 172                                         return Parameters.FixedParameters [pos];
 173                         }
 174
 175                         return Parameters.ArrayParameter;
 176                 }
 177
 178                 public Type ParameterType (int pos)
 179                 {
 180                         if (has_varargs && pos >= count)
 181                                 return TypeManager.runtime_argument_handle_type;
 182
 183                         if (param_types == null)
 184                                 return null;
 185
 186                         return GetParameter (pos).ExternalType ();
 187                 }
 188
 189
 190                 public string ParameterName (int pos)
 191                 {
 192                         if (has_varargs && pos >= count)
 193                                 return "__arglist";
 194
 195                         return GetParameter (pos).Name;
 196                 }
 197
 198                 public string ParameterDesc (int pos)
 199                 {
 200                         if (has_varargs && pos >= count)
 201                                 return "__arglist";
 202
 203                         string tmp = String.Empty;
 204                         Parameter p = GetParameter (pos);
 205
 206                         //
 207                         // We need to and for REF/OUT, because if either is set the
 208                         // extra flag ISBYREF will be set as well
 209                         //
 210                         if ((p.ModFlags & Parameter.Modifier.REF) != 0)
 211                                 tmp = "ref ";
 212                         else if ((p.ModFlags & Parameter.Modifier.OUT) != 0)
 213                                 tmp = "out ";
 214                         else if (p.ModFlags == Parameter.Modifier.PARAMS)
 215                                 tmp = "params ";
 216
 217                         Type t = ParameterType (pos);
 218
 219                         return tmp + TypeManager.CSharpName (t);
 220                 }
 221
 222                 public Parameter.Modifier ParameterModifier (int pos)
 223                 {
 224                         if (has_varargs && pos >= count)
 225                                 return Parameter.Modifier.ARGLIST;
 226
 227                         Parameter.Modifier mod = GetParameter (pos).ModFlags;
 228
 229                         if ((mod & (Parameter.Modifier.REF | Parameter.Modifier.OUT)) != 0)
 230                                 mod |= Parameter.Modifier.ISBYREF;
 231
 232                         return mod;
 233                 }
 234
 235         }
 236
 237         class PtrHashtable : Hashtable {
 238                 sealed class PtrComparer : IComparer {
 239                         private PtrComparer () {}
 240
 241                         public static PtrComparer Instance = new PtrComparer ();
 242
 243                         public int Compare (object x, object y)
 244                         {
 245                                 if (x == y)
 246                                         return 0;
 247                                 else
 248                                         return 1;
 249                         }
 250                 }
 251
 252                 public PtrHashtable ()
 253                 {
 254                         comparer = PtrComparer.Instance;
 255                 }
 256         }
 257
 258         /*
 259          * Hashtable whose keys are character arrays with the same length
 260          */
 261         class CharArrayHashtable : Hashtable {
 262                 sealed class ArrComparer : IComparer {
 263                         private int len;
 264
 265                         public ArrComparer (int len) {
 266                                 this.len = len;
 267                         }
 268
 269                         public int Compare (object x, object y)
 270                         {
 271                                 char[] a = (char[])x;
 272                                 char[] b = (char[])y;
 273
 274                                 for (int i = 0; i < len; ++i)
 275                                         if (a [i] != b [i])
 276                                                 return 1;
 277                                 return 0;
 278                         }
 279                 }
 280
 281                 private int len;
 282
 283                 protected override int GetHash (Object key)
 284                 {
 285                         char[] arr = (char[])key;
 286                         int h = 0;
 287
 288                         for (int i = 0; i < len; ++i)
 289                                 h = (h << 5) - h + arr [i];
 290
 291                         return h;
 292                 }
 293
 294                 public CharArrayHashtable (int len)
 295                 {
 296                         this.len = len;
 297                         comparer = new ArrComparer (len);
 298                 }
 299         }
 300
 301         struct Pair {
 302                 public object First;
 303                 public object Second;
 304
 305                 public Pair (object f, object s)
 306                 {
 307                         First = f;
 308                         Second = s;
 309                 }
 310         }
 311
 312         /// <summary>
 313         ///   This is a wrapper around StreamReader which is seekable.
 314         /// </summary>
 315         public class SeekableStreamReader
 316         {
 317                 public SeekableStreamReader (StreamReader reader)
 318                 {
 319                         this.reader = reader;
 320                         this.buffer = new char [DefaultCacheSize];
 321
 322                         // Compute the preamble size
 323
 324                         // Let the StreamWriter autodetect the encoder
 325                         reader.Peek ();
 326
 327                         reader.BaseStream.Position = 0;
 328                         Encoding enc = reader.CurrentEncoding;
 329                         // First of all, get at least a char
 330
 331                         byte[] auxb = new byte [50];
 332                         int num_bytes = 0;
 333                         int num_chars = 0;
 334                         int br = 0;
 335                         do {
 336                                 br = reader.BaseStream.Read (auxb, num_bytes, auxb.Length - num_bytes);
 337                                 num_bytes += br;
 338                                 num_chars = enc.GetCharCount (auxb, 0, num_bytes);
 339                         }
 340                         while (num_chars == 0 && br > 0);
 341
 342                         if (num_chars != 0)
 343                         {
 344                                 // Now, check which bytes at the beginning have no effect in the
 345                                 // char count
 346
 347                                 int p = 0;
 348                                 while (enc.GetCharCount (auxb, p, num_bytes-p) >= num_chars)
 349                                         p++;
 350
 351                                 preamble_size = p - 1;
 352                                 reader.BaseStream.Position = 0;
 353                                 reader.DiscardBufferedData ();
 354
 355                                 buffer_start = preamble_size;
 356                         }
 357                 }
 358
 359                 public SeekableStreamReader (Stream stream, Encoding encoding, bool detect_encoding_from_bytemarks)
 360                         : this (new StreamReader (stream, encoding, detect_encoding_from_bytemarks))
 361                 { }
 362
 363                 StreamReader reader;
 364
 365                 private const int DefaultCacheSize = 1024;
 366
 367                 char[] buffer;
 368                 int buffer_start;       // in bytes
 369                 int buffer_size;        // in bytes
 370                 int char_count;         // count buffer[] valid characters
 371                 int pos;                // index into buffer[]
 372                 int preamble_size;
 373
 374                 /// <remarks>
 375                 ///   The difference to the StreamReader's BaseStream.Position is that this one is reliable; ie. it
 376                 //    always reports the correct position and if it's modified, it also takes care of the buffered data.
 377                 /// </remarks>
 378                 public int Position {
 379                         get {
 380                                 return buffer_start + reader.CurrentEncoding.GetByteCount (buffer, 0, pos);
 381                         }
 382
 383                         set {
 384                                 // This one is easy: we're modifying the position within our current
 385                                 // buffer.
 386                                 if ((value >= buffer_start) && (value < buffer_start + buffer_size)) {
 387                                         int byte_offset = value - buffer_start;
 388                                         pos = byte_offset;
 389                                         // encoded characters can take more than 1 byte length
 390                                         while (reader.CurrentEncoding.GetByteCount (buffer, 0, pos) > byte_offset)
 391                                                 pos--;
 392
 393                                         return;
 394                                 }
 395
 396                                 if (value == 0) // Skip preamble
 397                                         value = preamble_size;
 398
 399                                 // Ok, now we need to seek.
 400                                 reader.DiscardBufferedData ();
 401                                 reader.BaseStream.Position = buffer_start = value;
 402                                 char_count = buffer_size = pos = 0;
 403                         }
 404                 }
 405
 406                 private bool ReadBuffer ()
 407                 {
 408                         pos = 0;
 409                         buffer_start += buffer_size;
 410                         char_count = reader.Read (buffer, 0, buffer.Length);
 411                         buffer_size = reader.CurrentEncoding.GetByteCount (buffer, 0, char_count);
 412                         return buffer_size > 0;
 413                 }
 414
 415                 public int Peek ()
 416                 {
 417                         if ((pos >= char_count) && !ReadBuffer ())
 418                                 return -1;
 419
 420                         return buffer [pos];
 421                 }
 422
 423                 public int Read ()
 424                 {
 425                         if ((pos >= char_count) && !ReadBuffer ())
 426                                 return -1;
 427
 428                         return buffer [pos++];
 429                 }
 430         }
 431
 432         public class DoubleHash {
 433                 const int DEFAULT_INITIAL_BUCKETS = 100;
 434
 435                 public DoubleHash () : this (DEFAULT_INITIAL_BUCKETS) {}
 436
 437                 public DoubleHash (int size)
 438                 {
 439                         count = size;
 440                         buckets = new Entry [size];
 441                 }
 442
 443                 int count;
 444                 Entry [] buckets;
 445                 int size = 0;
 446
 447                 class Entry {
 448                         public object key1;
 449                         public object key2;
 450                         public int hash;
 451                         public object value;
 452                         public Entry next;
 453
 454                         public Entry (object key1, object key2, int hash, object value, Entry next)
 455                         {
 456                                 this.key1 = key1;
 457                                 this.key2 = key2;
 458                                 this.hash = hash;
 459                                 this.next = next;
 460                                 this.value = value;
 461                         }
 462                 }
 463
 464                 public bool Lookup (object a, object b, out object res)
 465                 {
 466                         int h = (a.GetHashCode () ^ b.GetHashCode ()) & 0x7FFFFFFF;
 467
 468                         for (Entry e = buckets [h % count]; e != null; e = e.next) {
 469                                 if (e.hash == h && e.key1.Equals (a) && e.key2.Equals (b)) {
 470                                         res = e.value;
 471                                         return true;
 472                                 }
 473                         }
 474                         res = null;
 475                         return false;
 476                 }
 477
 478                 public void Insert (object a, object b, object value)
 479                 {
 480                         // Is it an existing one?
 481
 482                         int h = (a.GetHashCode () ^ b.GetHashCode ()) & 0x7FFFFFFF;
 483
 484                         for (Entry e = buckets [h % count]; e != null; e = e.next) {
 485                                 if (e.hash == h && e.key1.Equals (a) && e.key2.Equals (b))
 486                                         e.value = value;
 487                         }
 488
 489                         int bucket = h % count;
 490                         buckets [bucket] = new Entry (a, b, h, value, buckets [bucket]);
 491
 492                         // Grow whenever we double in size
 493                         if (size++ == count) {
 494                                 count <<= 1;
 495                                 count ++;
 496
 497                                 Entry [] newBuckets = new Entry [count];
 498                                 foreach (Entry root in buckets) {
 499                                         Entry e = root;
 500                                         while (e != null) {
 501                                                 int newLoc = e.hash % count;
 502                                                 Entry n = e.next;
 503                                                 e.next = newBuckets [newLoc];
 504                                                 newBuckets [newLoc] = e;
 505                                                 e = n;
 506                                         }
 507                                 }
 508
 509                                 buckets = newBuckets;
 510                         }
 511                 }
 512         }
 513 }