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