mcs/bmcs/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                 GenericConstraints GenericConstraints (int pos);
  24                 int  Count { get; }
  25                 bool HasParams { get; }
  26                 string ParameterName (int pos);
  27                 string ParameterDesc (int pos);
  28                 Parameter.Modifier ParameterModifier (int pos);
  29         }
  30
  31         public class ReflectionParameters : ParameterData {
  32                 ParameterInfo [] pi;
  33                 Type[] type_params;
  34                 bool last_arg_is_params = false;
  35                 bool is_varargs = false;
  36                 ParameterData gpd;
  37
  38                 public ReflectionParameters (MethodBase mb)
  39                 {
  40                         object [] attrs;
  41
  42                         ParameterInfo [] pi = mb.GetParameters ();
  43                         is_varargs = (mb.CallingConvention & CallingConventions.VarArgs) != 0;
  44
  45                         this.pi = pi;
  46                         int count = pi.Length-1;
  47
  48                         if (count < 0)
  49                                 return;
  50
  51                         if (mb.Mono_IsInflatedMethod) {
  52                                 MethodInfo generic = mb.GetGenericMethodDefinition ();
  53                                 gpd = Invocation.GetParameterData (generic);
  54
  55                                 last_arg_is_params = gpd.HasParams;
  56                                 return;
  57                         }
  58
  59                         if (mb.IsGenericMethodDefinition)
  60                                 type_params = mb.GetGenericArguments ();
  61
  62                         attrs = pi [count].GetCustomAttributes (TypeManager.param_array_type, true);
  63                         if (attrs == null)
  64                                 return;
  65
  66                         if (attrs.Length == 0)
  67                                 return;
  68
  69                         last_arg_is_params = true;
  70                 }
  71
  72                 public Type ParameterType (int pos)
  73                 {
  74                         if (last_arg_is_params && pos >= pi.Length - 1)
  75                                 return pi [pi.Length - 1].ParameterType;
  76                         else if (is_varargs && pos >= pi.Length)
  77                                 return TypeManager.runtime_argument_handle_type;
  78                         else {
  79                                 Type t = pi [pos].ParameterType;
  80
  81                                 return t;
  82                         }
  83                 }
  84
  85                 public GenericConstraints GenericConstraints (int pos)
  86                 {
  87                         if (gpd != null)
  88                                 return gpd.GenericConstraints (pos);
  89
  90                         if (type_params == null)
  91                                 return null;
  92
  93                         return new ReflectionConstraints (type_params [pos]);
  94                 }
  95
  96                 public string ParameterName (int pos)
  97                 {
  98                         if (gpd != null)
  99                                 return gpd.ParameterName (pos);
 100
 101                         if (last_arg_is_params && pos >= pi.Length - 1)
 102                                 return pi [pi.Length - 1].Name;
 103                         else if (is_varargs && pos >= pi.Length)
 104                                 return "__arglist";
 105                         else
 106                                 return pi [pos].Name;
 107                 }
 108
 109                 public string ParameterDesc (int pos)
 110                 {
 111                         if (is_varargs && pos >= pi.Length)
 112                                 return "";
 113
 114                         StringBuilder sb = new StringBuilder ();
 115
 116                         if (pi [pos].IsIn)
 117                                 sb.Append ("in ");
 118
 119                         Type partype = ParameterType (pos);
 120                         if (partype.IsByRef){
 121                                 partype = TypeManager.GetElementType (partype);
 122                                 if (pi [pos].IsOut)
 123                                         sb.Append ("out ");
 124                                 else
 125                                         sb.Append ("ref ");
 126                         }
 127
 128                         if (pos >= pi.Length - 1 && last_arg_is_params)
 129                                 sb.Append ("params ");
 130
 131                         sb.Append (TypeManager.CSharpName (partype));
 132
 133                         return sb.ToString ();
 134
 135                 }
 136
 137                 public Parameter.Modifier ParameterModifier (int pos)
 138                 {
 139                         int len = pi.Length;
 140
 141                         if (last_arg_is_params && pos >= pi.Length - 1)
 142                                         return Parameter.Modifier.PARAMS;
 143                         else if (is_varargs && pos >= pi.Length)
 144                                 return Parameter.Modifier.ARGLIST;
 145
 146                         if (gpd != null)
 147                                 return gpd.ParameterModifier (pos);
 148
 149                         Type t = pi [pos].ParameterType;
 150                         if (t.IsByRef){
 151                                 if ((pi [pos].Attributes & ParameterAttributes.Out) != 0)
 152                                         return Parameter.Modifier.ISBYREF | Parameter.Modifier.OUT;
 153                                 else
 154                                         return Parameter.Modifier.ISBYREF | Parameter.Modifier.REF;
 155                         }
 156
 157                         return Parameter.Modifier.NONE;
 158                 }
 159
 160                 public int Count {
 161                         get {
 162                                 return is_varargs ? pi.Length + 1 : pi.Length;
 163                         }
 164                 }
 165
 166                 public bool HasParams {
 167                         get {
 168                                 return this.last_arg_is_params;
 169                         }
 170                 }
 171         }
 172
 173         public class InternalParameters : ParameterData {
 174                 Type [] param_types;
 175                 bool has_varargs;
 176                 int count;
 177
 178                 public readonly Parameters Parameters;
 179                 public readonly TypeParameter[] TypeParameters;
 180
 181                 public InternalParameters (Type [] param_types, Parameters parameters)
 182                 {
 183                         this.param_types = param_types;
 184                         this.Parameters = parameters;
 185
 186                         has_varargs = parameters.HasArglist;
 187
 188                         if (param_types == null)
 189                                 count = 0;
 190                         else
 191                                 count = param_types.Length;
 192                 }
 193
 194                 public InternalParameters (Type [] param_types, Parameters parameters,
 195                                            TypeParameter [] type_params)
 196                         : this (param_types, parameters)
 197                 {
 198                         this.TypeParameters = type_params;
 199                 }
 200
 201                 public int Count {
 202                         get {
 203                                 return has_varargs ? count + 1 : count;
 204                         }
 205                 }
 206
 207                 public bool HasParams {
 208                         get {
 209                                 return Parameters.ArrayParameter != null;
 210                         }
 211                 }
 212
 213                 Parameter GetParameter (int pos)
 214                 {
 215                         Parameter [] fixed_pars = Parameters.FixedParameters;
 216                         if (fixed_pars != null){
 217                                 int len = fixed_pars.Length;
 218                                 if (pos < len)
 219                                         return Parameters.FixedParameters [pos];
 220                         }
 221
 222                         return Parameters.ArrayParameter;
 223                 }
 224
 225                 public Type ParameterType (int pos)
 226                 {
 227                         if (has_varargs && pos >= count)
 228                                 return TypeManager.runtime_argument_handle_type;
 229
 230                         if (param_types == null)
 231                                 return null;
 232
 233                         return GetParameter (pos).ExternalType ();
 234                 }
 235
 236                 public GenericConstraints GenericConstraints (int pos)
 237                 {
 238                         if (TypeParameters == null)
 239                                 return null;
 240
 241                         return TypeParameters [pos].Constraints;
 242                 }
 243
 244                 public string ParameterName (int pos)
 245                 {
 246                         if (has_varargs && pos >= count)
 247                                 return "__arglist";
 248
 249                         return GetParameter (pos).Name;
 250                 }
 251
 252                 public string ParameterDesc (int pos)
 253                 {
 254                         if (has_varargs && pos >= count)
 255                                 return "__arglist";
 256
 257                         string tmp = String.Empty;
 258                         Parameter p = GetParameter (pos);
 259
 260                         //
 261                         // We need to and for REF/OUT, because if either is set the
 262                         // extra flag ISBYREF will be set as well
 263                         //
 264                         if ((p.ModFlags & Parameter.Modifier.REF) != 0)
 265                                 tmp = "ref ";
 266                         else if ((p.ModFlags & Parameter.Modifier.OUT) != 0)
 267                                 tmp = "out ";
 268                         else if (p.ModFlags == Parameter.Modifier.PARAMS)
 269                                 tmp = "params ";
 270
 271                         Type t = ParameterType (pos);
 272
 273                         return tmp + TypeManager.CSharpName (t);
 274                 }
 275
 276                 public Parameter.Modifier ParameterModifier (int pos)
 277                 {
 278                         if (has_varargs && pos >= count)
 279                                 return Parameter.Modifier.ARGLIST;
 280
 281                         Parameter.Modifier mod = GetParameter (pos).ModFlags;
 282
 283                         if ((mod & (Parameter.Modifier.REF | Parameter.Modifier.OUT)) != 0)
 284                                 mod |= Parameter.Modifier.ISBYREF;
 285
 286                         return mod;
 287                 }
 288
 289         }
 290
 291         public class ReflectionConstraints : GenericConstraints
 292         {
 293                 GenericParameterAttributes attrs;
 294                 Type base_type;
 295                 Type class_constraint;
 296                 Type[] iface_constraints;
 297
 298                 public ReflectionConstraints (Type t)
 299                 {
 300                         Type[] constraints = t.GetGenericParameterConstraints ();
 301                         if ((constraints.Length > 0) && !constraints [0].IsInterface) {
 302                                 class_constraint = constraints [0];
 303                                 iface_constraints = new Type [constraints.Length - 1];
 304                                 Array.Copy (constraints, 1, iface_constraints, 0, constraints.Length - 1);
 305                         } else
 306                                 iface_constraints = constraints;
 307                         attrs = t.GenericParameterAttributes;
 308
 309                         if (HasValueTypeConstraint)
 310                                 base_type = TypeManager.value_type;
 311                         else if (class_constraint != null)
 312                                 base_type = class_constraint;
 313                         else
 314                                 base_type = TypeManager.object_type;
 315                 }
 316
 317                 public override GenericParameterAttributes Attributes {
 318                         get { return attrs; }
 319                 }
 320
 321                 public override Type ClassConstraint {
 322                         get { return class_constraint; }
 323                 }
 324
 325                 public override Type EffectiveBaseClass {
 326                         get { return base_type; }
 327                 }
 328
 329                 public override Type[] InterfaceConstraints {
 330                         get { return iface_constraints; }
 331                 }
 332         }
 333
 334         class PtrHashtable : Hashtable {
 335                 sealed class PtrComparer : IComparer {
 336                         private PtrComparer () {}
 337
 338                         public static PtrComparer Instance = new PtrComparer ();
 339
 340                         public int Compare (object x, object y)
 341                         {
 342                                 if (x == y)
 343                                         return 0;
 344                                 else
 345                                         return 1;
 346                         }
 347                 }
 348
 349                 public PtrHashtable ()
 350                 {
 351                         comparer = PtrComparer.Instance;
 352                 }
 353         }
 354
 355         /*
 356          * Hashtable whose keys are character arrays with the same length
 357          */
 358         class CharArrayHashtable : Hashtable {
 359                 sealed class ArrComparer : IComparer {
 360                         private int len;
 361
 362                         public ArrComparer (int len) {
 363                                 this.len = len;
 364                         }
 365
 366                         public int Compare (object x, object y)
 367                         {
 368                                 char[] a = (char[])x;
 369                                 char[] b = (char[])y;
 370
 371                                 for (int i = 0; i < len; ++i)
 372                                         if (a [i] != b [i])
 373                                                 return 1;
 374                                 return 0;
 375                         }
 376                 }
 377
 378                 private int len;
 379
 380                 protected override int GetHash (Object key)
 381                 {
 382                         char[] arr = (char[])key;
 383                         int h = 0;
 384
 385                         for (int i = 0; i < len; ++i)
 386                                 h = (h << 5) - h + arr [i];
 387
 388                         return h;
 389                 }
 390
 391                 public CharArrayHashtable (int len)
 392                 {
 393                         this.len = len;
 394                         comparer = new ArrComparer (len);
 395                 }
 396         }
 397
 398         struct Pair {
 399                 public object First;
 400                 public object Second;
 401
 402                 public Pair (object f, object s)
 403                 {
 404                         First = f;
 405                         Second = s;
 406                 }
 407         }
 408
 409         /// <summary>
 410         ///   This is a wrapper around StreamReader which is seekable.
 411         /// </summary>
 412         public class SeekableStreamReader
 413         {
 414                 public SeekableStreamReader (StreamReader reader)
 415                 {
 416                         this.reader = reader;
 417                         this.buffer = new char [DefaultCacheSize];
 418
 419                         // Compute the preamble size
 420
 421                         // Let the StreamWriter autodetect the encoder
 422                         reader.Peek ();
 423
 424                         reader.BaseStream.Position = 0;
 425                         Encoding enc = reader.CurrentEncoding;
 426                         // First of all, get at least a char
 427
 428                         byte[] auxb = new byte [50];
 429                         int num_bytes = 0;
 430                         int num_chars = 0;
 431                         int br = 0;
 432                         do {
 433                                 br = reader.BaseStream.Read (auxb, num_bytes, auxb.Length - num_bytes);
 434                                 num_bytes += br;
 435                                 num_chars = enc.GetCharCount (auxb, 0, num_bytes);
 436                         }
 437                         while (num_chars == 0 && br > 0);
 438
 439                         if (num_chars != 0)
 440                         {
 441                                 // Now, check which bytes at the beginning have no effect in the
 442                                 // char count
 443
 444                                 int p = 0;
 445                                 while (enc.GetCharCount (auxb, p, num_bytes-p) >= num_chars)
 446                                         p++;
 447
 448                                 preamble_size = p - 1;
 449                                 reader.BaseStream.Position = 0;
 450                                 reader.DiscardBufferedData ();
 451
 452                                 buffer_start = preamble_size;
 453                         }
 454                 }
 455
 456                 public SeekableStreamReader (Stream stream, Encoding encoding, bool detect_encoding_from_bytemarks)
 457                         : this (new StreamReader (stream, encoding, detect_encoding_from_bytemarks))
 458                 { }
 459
 460                 StreamReader reader;
 461
 462                 private const int DefaultCacheSize = 1024;
 463
 464                 char[] buffer;
 465                 int buffer_start;       // in bytes
 466                 int buffer_size;        // in bytes
 467                 int char_count;         // count buffer[] valid characters
 468                 int pos;                // index into buffer[]
 469                 int preamble_size;
 470
 471                 /// <remarks>
 472                 ///   The difference to the StreamReader's BaseStream.Position is that this one is reliable; ie. it
 473                 //    always reports the correct position and if it's modified, it also takes care of the buffered data.
 474                 /// </remarks>
 475                 public int Position {
 476                         get {
 477                                 return buffer_start + reader.CurrentEncoding.GetByteCount (buffer, 0, pos);
 478                         }
 479
 480                         set {
 481                                 // This one is easy: we're modifying the position within our current
 482                                 // buffer.
 483                                 if ((value >= buffer_start) && (value < buffer_start + buffer_size)) {
 484                                         int byte_offset = value - buffer_start;
 485                                         pos = byte_offset;
 486                                         // encoded characters can take more than 1 byte length
 487                                         while (reader.CurrentEncoding.GetByteCount (buffer, 0, pos) > byte_offset)
 488                                                 pos--;
 489
 490                                         return;
 491                                 }
 492
 493                                 if (value == 0) // Skip preamble
 494                                         value = preamble_size;
 495
 496                                 // Ok, now we need to seek.
 497                                 reader.DiscardBufferedData ();
 498                                 reader.BaseStream.Position = buffer_start = value;
 499                                 char_count = buffer_size = pos = 0;
 500                         }
 501                 }
 502
 503                 private bool ReadBuffer ()
 504                 {
 505                         pos = 0;
 506                         buffer_start += buffer_size;
 507                         char_count = reader.Read (buffer, 0, buffer.Length);
 508                         buffer_size = reader.CurrentEncoding.GetByteCount (buffer, 0, char_count);
 509                         return buffer_size > 0;
 510                 }
 511
 512                 public int Peek ()
 513                 {
 514                         if ((pos >= char_count) && !ReadBuffer ())
 515                                 return -1;
 516
 517                         return buffer [pos];
 518                 }
 519
 520                 public int Read ()
 521                 {
 522                         if ((pos >= char_count) && !ReadBuffer ())
 523                                 return -1;
 524
 525                         return buffer [pos++];
 526                 }
 527         }
 528
 529         public class DoubleHash {
 530                 const int DEFAULT_INITIAL_BUCKETS = 100;
 531
 532                 public DoubleHash () : this (DEFAULT_INITIAL_BUCKETS) {}
 533
 534                 public DoubleHash (int size)
 535                 {
 536                         count = size;
 537                         buckets = new Entry [size];
 538                 }
 539
 540                 int count;
 541                 Entry [] buckets;
 542                 int size = 0;
 543
 544                 class Entry {
 545                         public object key1;
 546                         public object key2;
 547                         public int hash;
 548                         public object value;
 549                         public Entry next;
 550
 551                         public Entry (object key1, object key2, int hash, object value, Entry next)
 552                         {
 553                                 this.key1 = key1;
 554                                 this.key2 = key2;
 555                                 this.hash = hash;
 556                                 this.next = next;
 557                                 this.value = value;
 558                         }
 559                 }
 560
 561                 public bool Lookup (object a, object b, out object res)
 562                 {
 563                         int h = (a.GetHashCode () ^ b.GetHashCode ()) & 0x7FFFFFFF;
 564
 565                         for (Entry e = buckets [h % count]; e != null; e = e.next) {
 566                                 if (e.hash == h && e.key1.Equals (a) && e.key2.Equals (b)) {
 567                                         res = e.value;
 568                                         return true;
 569                                 }
 570                         }
 571                         res = null;
 572                         return false;
 573                 }
 574
 575                 public void Insert (object a, object b, object value)
 576                 {
 577                         // Is it an existing one?
 578
 579                         int h = (a.GetHashCode () ^ b.GetHashCode ()) & 0x7FFFFFFF;
 580
 581                         for (Entry e = buckets [h % count]; e != null; e = e.next) {
 582                                 if (e.hash == h && e.key1.Equals (a) && e.key2.Equals (b))
 583                                         e.value = value;
 584                         }
 585
 586                         int bucket = h % count;
 587                         buckets [bucket] = new Entry (a, b, h, value, buckets [bucket]);
 588
 589                         // Grow whenever we double in size
 590                         if (size++ == count) {
 591                                 count <<= 1;
 592                                 count ++;
 593
 594                                 Entry [] newBuckets = new Entry [count];
 595                                 foreach (Entry root in buckets) {
 596                                         Entry e = root;
 597                                         while (e != null) {
 598                                                 int newLoc = e.hash % count;
 599                                                 Entry n = e.next;
 600                                                 e.next = newBuckets [newLoc];
 601                                                 newBuckets [newLoc] = e;
 602                                                 e = n;
 603                                         }
 604                                 }
 605
 606                                 buckets = newBuckets;
 607                         }
 608                 }
 609         }
 610 }