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                 string GetSignatureForError ();
  29         }
  30
  31         public class ReflectionParameters : ParameterData {
  32                 ParameterInfo [] pi;
  33                 bool last_arg_is_params = false;
  34                 bool is_varargs = false;
  35
  36                 public ReflectionParameters (MethodBase mb)
  37                 {
  38                         object [] attrs;
  39
  40                         ParameterInfo [] pi = mb.GetParameters ();
  41                         is_varargs = (mb.CallingConvention & CallingConventions.VarArgs) != 0;
  42
  43                         this.pi = pi;
  44                         int count = pi.Length-1;
  45
  46                         if (count >= 0) {
  47                                 attrs = pi [count].GetCustomAttributes (TypeManager.param_array_type, true);
  48
  49                                 if (attrs == null)
  50                                         return;
  51
  52                                 if (attrs.Length == 0)
  53                                         return;
  54
  55                                 last_arg_is_params = true;
  56                         }
  57                 }
  58
  59                 public string GetSignatureForError ()
  60                 {
  61                         StringBuilder sb = new StringBuilder ("(");
  62                         for (int i = 0; i < pi.Length; ++i) {
  63                                 if (i != 0)
  64                                         sb.Append (", ");
  65                                 sb.Append (ParameterDesc (i));
  66                         }
  67                         sb.Append (')');
  68                         return sb.ToString ();
  69                 }
  70
  71                 public Type ParameterType (int pos)
  72                 {
  73                         if (last_arg_is_params && pos >= pi.Length - 1)
  74                                 return pi [pi.Length - 1].ParameterType;
  75                         else if (is_varargs && pos >= pi.Length)
  76                                 return TypeManager.runtime_argument_handle_type;
  77                         else {
  78                                 Type t = pi [pos].ParameterType;
  79
  80                                 return t;
  81                         }
  82                 }
  83
  84                 public string ParameterName (int pos)
  85                 {
  86                         if (last_arg_is_params && pos >= pi.Length - 1)
  87                                 return pi [pi.Length - 1].Name;
  88                         else if (is_varargs && pos >= pi.Length)
  89                                 return "__arglist";
  90                         else
  91                                 return pi [pos].Name;
  92                 }
  93
  94                 public string ParameterDesc (int pos)
  95                 {
  96                         if (is_varargs && pos >= pi.Length)
  97                                 return "";
  98
  99                         StringBuilder sb = new StringBuilder ();
 100
 101                         if (pi [pos].IsIn)
 102                                 sb.Append ("in ");
 103
 104                         Type partype = ParameterType (pos);
 105                         if (partype.IsByRef){
 106                                 partype = TypeManager.GetElementType (partype);
 107                                 if (pi [pos].IsOut)
 108                                         sb.Append ("out ");
 109                                 else
 110                                         sb.Append ("ref ");
 111                         }
 112
 113                         if (pos >= pi.Length - 1 && last_arg_is_params)
 114                                 sb.Append ("params ");
 115
 116                         sb.Append (TypeManager.CSharpName (partype).Replace ("&", ""));
 117
 118                         return sb.ToString ();
 119
 120                 }
 121
 122                 public Parameter.Modifier ParameterModifier (int pos)
 123                 {
 124                         if (last_arg_is_params && pos >= pi.Length - 1)
 125                                 return Parameter.Modifier.PARAMS;
 126                         else if (is_varargs && pos >= pi.Length)
 127                                 return Parameter.Modifier.ARGLIST;
 128
 129                         Type t = pi [pos].ParameterType;
 130                         if (t.IsByRef){
 131                                 if ((pi [pos].Attributes & (ParameterAttributes.Out|ParameterAttributes.In)) == ParameterAttributes.Out)
 132                                         return Parameter.Modifier.ISBYREF | Parameter.Modifier.OUT;
 133                                 else
 134                                         return Parameter.Modifier.ISBYREF | Parameter.Modifier.REF;
 135                         }
 136
 137                         return Parameter.Modifier.NONE;
 138                 }
 139
 140                 public int Count {
 141                         get {
 142                                 return is_varargs ? pi.Length + 1 : pi.Length;
 143                         }
 144                 }
 145
 146                 public bool HasParams {
 147                         get {
 148                                 return this.last_arg_is_params;
 149                         }
 150                 }
 151
 152         }
 153
 154         public class InternalParameters : ParameterData {
 155                 Type [] param_types;
 156                 bool has_varargs;
 157                 int count;
 158
 159                 public readonly Parameters Parameters;
 160
 161                 public InternalParameters (Type [] param_types, Parameters parameters)
 162                 {
 163                         this.param_types = param_types;
 164                         this.Parameters = parameters;
 165
 166                         has_varargs = parameters.HasArglist;
 167
 168                         if (param_types == null)
 169                                 count = 0;
 170                         else
 171                                 count = param_types.Length;
 172                 }
 173
 174                 public int Count {
 175                         get {
 176                                 return has_varargs ? count + 1 : count;
 177                         }
 178                 }
 179
 180                 public bool HasParams {
 181                         get {
 182                                 return Parameters.ArrayParameter != null;
 183                         }
 184                 }
 185
 186                 Parameter GetParameter (int pos)
 187                 {
 188                         Parameter [] fixed_pars = Parameters.FixedParameters;
 189                         if (fixed_pars != null){
 190                                 int len = fixed_pars.Length;
 191                                 if (pos < len)
 192                                         return Parameters.FixedParameters [pos];
 193                         }
 194
 195                         return Parameters.ArrayParameter;
 196                 }
 197
 198                 public string GetSignatureForError ()
 199                 {
 200                         StringBuilder sb = new StringBuilder ("(");
 201                         for (int i = 0; i < count; ++i) {
 202                                 if (i != 0)
 203                                         sb.Append (", ");
 204                                 sb.Append (ParameterDesc (i));
 205                         }
 206                         sb.Append (')');
 207                         return sb.ToString ();
 208                 }
 209
 210                 public Type ParameterType (int pos)
 211                 {
 212                         if (has_varargs && pos >= count)
 213                                 return TypeManager.runtime_argument_handle_type;
 214
 215                         if (param_types == null)
 216                                 return null;
 217
 218                         return GetParameter (pos).ExternalType ();
 219                 }
 220
 221
 222                 public string ParameterName (int pos)
 223                 {
 224                         if (has_varargs && pos >= count)
 225                                 return "__arglist";
 226
 227                         return GetParameter (pos).Name;
 228                 }
 229
 230                 public string ParameterDesc (int pos)
 231                 {
 232                         if (has_varargs && pos >= count)
 233                                 return "__arglist";
 234
 235                         Type t = ParameterType (pos);
 236                         return (ModifierDesc (pos) + " " + TypeManager.CSharpName (t).Replace ("&", "")).TrimStart ();
 237                 }
 238
 239                 public string ModifierDesc (int pos)
 240                 {
 241                         Parameter p = GetParameter (pos);
 242
 243                         //
 244                         // We need to and for REF/OUT, because if either is set the
 245                         // extra flag ISBYREF will be set as well
 246                         //
 247                         if ((p.ModFlags & Parameter.Modifier.REF) != 0)
 248                                 return "ref";
 249                         if ((p.ModFlags & Parameter.Modifier.OUT) != 0)
 250                                 return "out";
 251                         if (p.ModFlags == Parameter.Modifier.PARAMS)
 252                                 return "params";
 253
 254                         return "";
 255                 }
 256
 257                 public Parameter.Modifier ParameterModifier (int pos)
 258                 {
 259                         if (has_varargs && pos >= count)
 260                                 return Parameter.Modifier.ARGLIST;
 261
 262                         Parameter.Modifier mod = GetParameter (pos).ModFlags;
 263
 264                         if ((mod & (Parameter.Modifier.REF | Parameter.Modifier.OUT)) != 0)
 265                                 mod |= Parameter.Modifier.ISBYREF;
 266
 267                         return mod;
 268                 }
 269
 270         }
 271
 272         class PtrHashtable : Hashtable {
 273                 sealed class PtrComparer : IComparer {
 274                         private PtrComparer () {}
 275
 276                         public static PtrComparer Instance = new PtrComparer ();
 277
 278                         public int Compare (object x, object y)
 279                         {
 280                                 if (x == y)
 281                                         return 0;
 282                                 else
 283                                         return 1;
 284                         }
 285                 }
 286
 287                 public PtrHashtable ()
 288                 {
 289                         comparer = PtrComparer.Instance;
 290                 }
 291         }
 292
 293         /*
 294          * Hashtable whose keys are character arrays with the same length
 295          */
 296         class CharArrayHashtable : Hashtable {
 297                 sealed class ArrComparer : IComparer {
 298                         private int len;
 299
 300                         public ArrComparer (int len) {
 301                                 this.len = len;
 302                         }
 303
 304                         public int Compare (object x, object y)
 305                         {
 306                                 char[] a = (char[])x;
 307                                 char[] b = (char[])y;
 308
 309                                 for (int i = 0; i < len; ++i)
 310                                         if (a [i] != b [i])
 311                                                 return 1;
 312                                 return 0;
 313                         }
 314                 }
 315
 316                 private int len;
 317
 318                 protected override int GetHash (Object key)
 319                 {
 320                         char[] arr = (char[])key;
 321                         int h = 0;
 322
 323                         for (int i = 0; i < len; ++i)
 324                                 h = (h << 5) - h + arr [i];
 325
 326                         return h;
 327                 }
 328
 329                 public CharArrayHashtable (int len)
 330                 {
 331                         this.len = len;
 332                         comparer = new ArrComparer (len);
 333                 }
 334         }
 335
 336         struct Pair {
 337                 public object First;
 338                 public object Second;
 339
 340                 public Pair (object f, object s)
 341                 {
 342                         First = f;
 343                         Second = s;
 344                 }
 345         }
 346
 347         /// <summary>
 348         ///   This is a wrapper around StreamReader which is seekable.
 349         /// </summary>
 350         public class SeekableStreamReader
 351         {
 352                 public SeekableStreamReader (StreamReader reader)
 353                 {
 354                         this.reader = reader;
 355                         this.buffer = new char [DefaultCacheSize];
 356
 357                         // Compute the preamble size
 358
 359                         // Let the StreamWriter autodetect the encoder
 360                         reader.Peek ();
 361
 362                         Encoding enc = reader.CurrentEncoding;
 363                         preamble_size = (int) reader.BaseStream.Position;
 364                 }
 365
 366                 public SeekableStreamReader (Stream stream, Encoding encoding)
 367                         : this (new StreamReader (stream, encoding, true))
 368                 { }
 369
 370                 StreamReader reader;
 371
 372                 private const int DefaultCacheSize = 1024;
 373
 374                 char[] buffer;
 375                 int buffer_start;       // in bytes
 376                 int buffer_size;        // in bytes
 377                 int char_count;         // count buffer[] valid characters
 378                 int pos;                // index into buffer[]
 379                 int preamble_size;
 380
 381                 /// <remarks>
 382                 ///   The difference to the StreamReader's BaseStream.Position is that this one is reliable; ie. it
 383                 //    always reports the correct position and if it's modified, it also takes care of the buffered data.
 384                 /// </remarks>
 385                 public int Position {
 386                         get {
 387                                 return buffer_start + reader.CurrentEncoding.GetByteCount (buffer, 0, pos);
 388                         }
 389
 390                         set {
 391                                 // This one is easy: we're modifying the position within our current
 392                                 // buffer.
 393                                 if ((value >= buffer_start) && (value < buffer_start + buffer_size)) {
 394                                         int byte_offset = value - buffer_start;
 395
 396                                         // If we have an uni-byte encoding, 'pos' will be the same as
 397                                         // 'byte_offset'.  If we have a multi-byte encoding, 'byte_offset'
 398                                         // can be bigger than the desired value of 'pos', but not smaller.
 399                                         // (IOW, the number of characters <= number of bytes)
 400                                         //
 401                                         // So, we start pos off at byte_offset, and fix it up.
 402                                         pos = byte_offset;
 403                                         if (pos > char_count)
 404                                                 pos = char_count;
 405                                         while (reader.CurrentEncoding.GetByteCount (buffer, 0, pos) > byte_offset)
 406                                                 --pos;
 407                                         return;
 408                                 }
 409
 410                                 if (value == 0) // Skip preamble
 411                                         value = preamble_size;
 412
 413                                 // Ok, now we need to seek.
 414                                 reader.DiscardBufferedData ();
 415                                 reader.BaseStream.Position = buffer_start = value;
 416                                 char_count = buffer_size = pos = 0;
 417                         }
 418                 }
 419
 420                 private bool ReadBuffer ()
 421                 {
 422                         pos = 0;
 423                         buffer_start += buffer_size;
 424                         char_count = reader.Read (buffer, 0, buffer.Length);
 425                         buffer_size = reader.CurrentEncoding.GetByteCount (buffer, 0, char_count);
 426                         return buffer_size > 0;
 427                 }
 428
 429                 public int Peek ()
 430                 {
 431                         if ((pos >= char_count) && !ReadBuffer ())
 432                                 return -1;
 433
 434                         return buffer [pos];
 435                 }
 436
 437                 public int Read ()
 438                 {
 439                         if ((pos >= char_count) && !ReadBuffer ())
 440                                 return -1;
 441
 442                         return buffer [pos++];
 443                 }
 444         }
 445
 446         public class DoubleHash {
 447                 const int DEFAULT_INITIAL_BUCKETS = 100;
 448
 449                 public DoubleHash () : this (DEFAULT_INITIAL_BUCKETS) {}
 450
 451                 public DoubleHash (int size)
 452                 {
 453                         count = size;
 454                         buckets = new Entry [size];
 455                 }
 456
 457                 int count;
 458                 Entry [] buckets;
 459                 int size = 0;
 460
 461                 class Entry {
 462                         public object key1;
 463                         public object key2;
 464                         public int hash;
 465                         public object value;
 466                         public Entry next;
 467
 468                         public Entry (object key1, object key2, int hash, object value, Entry next)
 469                         {
 470                                 this.key1 = key1;
 471                                 this.key2 = key2;
 472                                 this.hash = hash;
 473                                 this.next = next;
 474                                 this.value = value;
 475                         }
 476                 }
 477
 478                 public bool Lookup (object a, object b, out object res)
 479                 {
 480                         int h = (a.GetHashCode () ^ b.GetHashCode ()) & 0x7FFFFFFF;
 481
 482                         for (Entry e = buckets [h % count]; e != null; e = e.next) {
 483                                 if (e.hash == h && e.key1.Equals (a) && e.key2.Equals (b)) {
 484                                         res = e.value;
 485                                         return true;
 486                                 }
 487                         }
 488                         res = null;
 489                         return false;
 490                 }
 491
 492                 public void Insert (object a, object b, object value)
 493                 {
 494                         // Is it an existing one?
 495
 496                         int h = (a.GetHashCode () ^ b.GetHashCode ()) & 0x7FFFFFFF;
 497
 498                         for (Entry e = buckets [h % count]; e != null; e = e.next) {
 499                                 if (e.hash == h && e.key1.Equals (a) && e.key2.Equals (b))
 500                                         e.value = value;
 501                         }
 502
 503                         int bucket = h % count;
 504                         buckets [bucket] = new Entry (a, b, h, value, buckets [bucket]);
 505
 506                         // Grow whenever we double in size
 507                         if (size++ == count) {
 508                                 count <<= 1;
 509                                 count ++;
 510
 511                                 Entry [] newBuckets = new Entry [count];
 512                                 foreach (Entry root in buckets) {
 513                                         Entry e = root;
 514                                         while (e != null) {
 515                                                 int newLoc = e.hash % count;
 516                                                 Entry n = e.next;
 517                                                 e.next = newBuckets [newLoc];
 518                                                 newBuckets [newLoc] = e;
 519                                                 e = n;
 520                                         }
 521                                 }
 522
 523                                 buckets = newBuckets;
 524                         }
 525                 }
 526         }
 527 }