mcs/gmcs/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 = TypeManager.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                         if (last_arg_is_params && pos >= pi.Length - 1)
 140                                         return Parameter.Modifier.PARAMS;
 141                         else if (is_varargs && pos >= pi.Length)
 142                                 return Parameter.Modifier.ARGLIST;
 143
 144                         if (gpd != null)
 145                                 return gpd.ParameterModifier (pos);
 146
 147                         Type t = pi [pos].ParameterType;
 148                         if (t.IsByRef){
 149                                 if ((pi [pos].Attributes & (ParameterAttributes.Out|ParameterAttributes.In)) == ParameterAttributes.Out)
 150                                         return Parameter.Modifier.ISBYREF | Parameter.Modifier.OUT;
 151                                 else
 152                                         return Parameter.Modifier.ISBYREF | Parameter.Modifier.REF;
 153                         }
 154
 155                         return Parameter.Modifier.NONE;
 156                 }
 157
 158                 public int Count {
 159                         get {
 160                                 return is_varargs ? pi.Length + 1 : pi.Length;
 161                         }
 162                 }
 163
 164                 public bool HasParams {
 165                         get {
 166                                 return this.last_arg_is_params;
 167                         }
 168                 }
 169         }
 170
 171         public class InternalParameters : ParameterData {
 172                 Type [] param_types;
 173                 bool has_varargs;
 174                 int count;
 175
 176                 public readonly Parameters Parameters;
 177                 public readonly TypeParameter[] TypeParameters;
 178
 179                 public InternalParameters (Type [] param_types, Parameters parameters)
 180                 {
 181                         this.param_types = param_types;
 182                         this.Parameters = parameters;
 183
 184                         has_varargs = parameters.HasArglist;
 185
 186                         if (param_types == null)
 187                                 count = 0;
 188                         else
 189                                 count = param_types.Length;
 190                 }
 191
 192                 public InternalParameters (Type [] param_types, Parameters parameters,
 193                                            TypeParameter [] type_params)
 194                         : this (param_types, parameters)
 195                 {
 196                         this.TypeParameters = type_params;
 197                 }
 198
 199                 public int Count {
 200                         get {
 201                                 return has_varargs ? count + 1 : count;
 202                         }
 203                 }
 204
 205                 public bool HasParams {
 206                         get {
 207                                 return Parameters.ArrayParameter != null;
 208                         }
 209                 }
 210
 211                 Parameter GetParameter (int pos)
 212                 {
 213                         Parameter [] fixed_pars = Parameters.FixedParameters;
 214                         if (fixed_pars != null){
 215                                 int len = fixed_pars.Length;
 216                                 if (pos < len)
 217                                         return Parameters.FixedParameters [pos];
 218                         }
 219
 220                         return Parameters.ArrayParameter;
 221                 }
 222
 223                 public Type ParameterType (int pos)
 224                 {
 225                         if (has_varargs && pos >= count)
 226                                 return TypeManager.runtime_argument_handle_type;
 227
 228                         if (param_types == null)
 229                                 return null;
 230
 231                         return GetParameter (pos).ExternalType ();
 232                 }
 233
 234                 public GenericConstraints GenericConstraints (int pos)
 235                 {
 236                         if (TypeParameters == null)
 237                                 return null;
 238
 239                         return TypeParameters [pos].Constraints;
 240                 }
 241
 242                 public string ParameterName (int pos)
 243                 {
 244                         if (has_varargs && pos >= count)
 245                                 return "__arglist";
 246
 247                         return GetParameter (pos).Name;
 248                 }
 249
 250                 public string ParameterDesc (int pos)
 251                 {
 252                         if (has_varargs && pos >= count)
 253                                 return "__arglist";
 254
 255                         Type t = ParameterType (pos);
 256                         return ModifierDesc (pos) + " " + TypeManager.CSharpName (t);
 257                 }
 258
 259                 public string ModifierDesc (int pos)
 260                 {
 261                         Parameter p = GetParameter (pos);
 262
 263                         //
 264                         // We need to and for REF/OUT, because if either is set the
 265                         // extra flag ISBYREF will be set as well
 266                         //
 267                         if ((p.ModFlags & Parameter.Modifier.REF) != 0)
 268                                 return "ref";
 269                         if ((p.ModFlags & Parameter.Modifier.OUT) != 0)
 270                                 return "out";
 271                         if (p.ModFlags == Parameter.Modifier.PARAMS)
 272                                 return "params";
 273
 274                         return "";
 275                 }
 276
 277                 public Parameter.Modifier ParameterModifier (int pos)
 278                 {
 279                         if (has_varargs && pos >= count)
 280                                 return Parameter.Modifier.ARGLIST;
 281
 282                         Parameter.Modifier mod = GetParameter (pos).ModFlags;
 283
 284                         if ((mod & (Parameter.Modifier.REF | Parameter.Modifier.OUT)) != 0)
 285                                 mod |= Parameter.Modifier.ISBYREF;
 286
 287                         return mod;
 288                 }
 289
 290         }
 291
 292         public class ReflectionConstraints : GenericConstraints
 293         {
 294                 GenericParameterAttributes attrs;
 295                 Type base_type;
 296                 Type class_constraint;
 297                 Type[] iface_constraints;
 298
 299                 public ReflectionConstraints (Type t)
 300                 {
 301                         Type[] constraints = t.GetGenericParameterConstraints ();
 302                         if ((constraints.Length > 0) && !constraints [0].IsInterface) {
 303                                 class_constraint = constraints [0];
 304                                 iface_constraints = new Type [constraints.Length - 1];
 305                                 Array.Copy (constraints, 1, iface_constraints, 0, constraints.Length - 1);
 306                         } else
 307                                 iface_constraints = constraints;
 308                         attrs = t.GenericParameterAttributes;
 309
 310                         if (HasValueTypeConstraint)
 311                                 base_type = TypeManager.value_type;
 312                         else if (class_constraint != null)
 313                                 base_type = class_constraint;
 314                         else
 315                                 base_type = TypeManager.object_type;
 316                 }
 317
 318                 public override GenericParameterAttributes Attributes {
 319                         get { return attrs; }
 320                 }
 321
 322                 public override Type ClassConstraint {
 323                         get { return class_constraint; }
 324                 }
 325
 326                 public override Type EffectiveBaseClass {
 327                         get { return base_type; }
 328                 }
 329
 330                 public override Type[] InterfaceConstraints {
 331                         get { return iface_constraints; }
 332                 }
 333         }
 334
 335         class PtrHashtable : Hashtable {
 336                 sealed class PtrComparer : IComparer {
 337                         private PtrComparer () {}
 338
 339                         public static PtrComparer Instance = new PtrComparer ();
 340
 341                         public int Compare (object x, object y)
 342                         {
 343                                 if (x == y)
 344                                         return 0;
 345                                 else
 346                                         return 1;
 347                         }
 348                 }
 349
 350                 public PtrHashtable ()
 351                 {
 352                         comparer = PtrComparer.Instance;
 353                 }
 354         }
 355
 356         /*
 357          * Hashtable whose keys are character arrays with the same length
 358          */
 359         class CharArrayHashtable : Hashtable {
 360                 sealed class ArrComparer : IComparer {
 361                         private int len;
 362
 363                         public ArrComparer (int len) {
 364                                 this.len = len;
 365                         }
 366
 367                         public int Compare (object x, object y)
 368                         {
 369                                 char[] a = (char[])x;
 370                                 char[] b = (char[])y;
 371
 372                                 for (int i = 0; i < len; ++i)
 373                                         if (a [i] != b [i])
 374                                                 return 1;
 375                                 return 0;
 376                         }
 377                 }
 378
 379                 private int len;
 380
 381                 protected override int GetHash (Object key)
 382                 {
 383                         char[] arr = (char[])key;
 384                         int h = 0;
 385
 386                         for (int i = 0; i < len; ++i)
 387                                 h = (h << 5) - h + arr [i];
 388
 389                         return h;
 390                 }
 391
 392                 public CharArrayHashtable (int len)
 393                 {
 394                         this.len = len;
 395                         comparer = new ArrComparer (len);
 396                 }
 397         }
 398
 399         struct Pair {
 400                 public object First;
 401                 public object Second;
 402
 403                 public Pair (object f, object s)
 404                 {
 405                         First = f;
 406                         Second = s;
 407                 }
 408         }
 409
 410         /// <summary>
 411         ///   This is a wrapper around StreamReader which is seekable.
 412         /// </summary>
 413         public class SeekableStreamReader
 414         {
 415                 public SeekableStreamReader (StreamReader reader)
 416                 {
 417                         this.reader = reader;
 418                         this.buffer = new char [DefaultCacheSize];
 419
 420                         // Compute the preamble size
 421
 422                         // Let the StreamWriter autodetect the encoder
 423                         reader.Peek ();
 424
 425                         reader.BaseStream.Position = 0;
 426                         Encoding enc = reader.CurrentEncoding;
 427                         // First of all, get at least a char
 428
 429                         byte[] auxb = new byte [50];
 430                         int num_bytes = 0;
 431                         int num_chars = 0;
 432                         int br = 0;
 433                         do {
 434                                 br = reader.BaseStream.Read (auxb, num_bytes, auxb.Length - num_bytes);
 435                                 num_bytes += br;
 436                                 num_chars = enc.GetCharCount (auxb, 0, num_bytes);
 437                         }
 438                         while (num_chars == 0 && br > 0);
 439
 440                         if (num_chars != 0)
 441                         {
 442                                 // Now, check which bytes at the beginning have no effect in the
 443                                 // char count
 444
 445                                 int p = 0;
 446                                 while (enc.GetCharCount (auxb, p, num_bytes-p) >= num_chars)
 447                                         p++;
 448
 449                                 preamble_size = p - 1;
 450                                 reader.BaseStream.Position = 0;
 451                                 reader.DiscardBufferedData ();
 452
 453                                 buffer_start = preamble_size;
 454                         }
 455                 }
 456
 457                 public SeekableStreamReader (Stream stream, Encoding encoding, bool detect_encoding_from_bytemarks)
 458                         : this (new StreamReader (stream, encoding, detect_encoding_from_bytemarks))
 459                 { }
 460
 461                 StreamReader reader;
 462
 463                 private const int DefaultCacheSize = 1024;
 464
 465                 char[] buffer;
 466                 int buffer_start;       // in bytes
 467                 int buffer_size;        // in bytes
 468                 int char_count;         // count buffer[] valid characters
 469                 int pos;                // index into buffer[]
 470                 int preamble_size;
 471
 472                 /// <remarks>
 473                 ///   The difference to the StreamReader's BaseStream.Position is that this one is reliable; ie. it
 474                 //    always reports the correct position and if it's modified, it also takes care of the buffered data.
 475                 /// </remarks>
 476                 public int Position {
 477                         get {
 478                                 return buffer_start + reader.CurrentEncoding.GetByteCount (buffer, 0, pos);
 479                         }
 480
 481                         set {
 482                                 // This one is easy: we're modifying the position within our current
 483                                 // buffer.
 484                                 if ((value >= buffer_start) && (value < buffer_start + buffer_size)) {
 485                                         int byte_offset = value - buffer_start;
 486
 487                                         // pos is an index into a char
 488                                         // buffer so it might be
 489                                         // greater than the buffer
 490                                         // length now, if the buffer
 491                                         // contains multibyte chars
 492                                         pos = byte_offset;
 493
 494                                         // encoded characters can take
 495                                         // more than 1 byte length.
 496                                         while ((pos > buffer.Length) ||
 497                                                reader.CurrentEncoding.GetByteCount (buffer, 0, pos) > byte_offset) {
 498                                                 pos--;
 499                                         }
 500
 501                                         return;
 502                                 }
 503
 504                                 if (value == 0) // Skip preamble
 505                                         value = preamble_size;
 506
 507                                 // Ok, now we need to seek.
 508                                 reader.DiscardBufferedData ();
 509                                 reader.BaseStream.Position = buffer_start = value;
 510                                 char_count = buffer_size = pos = 0;
 511                         }
 512                 }
 513
 514                 private bool ReadBuffer ()
 515                 {
 516                         pos = 0;
 517                         buffer_start += buffer_size;
 518                         char_count = reader.Read (buffer, 0, buffer.Length);
 519                         buffer_size = reader.CurrentEncoding.GetByteCount (buffer, 0, char_count);
 520                         return buffer_size > 0;
 521                 }
 522
 523                 public int Peek ()
 524                 {
 525                         if ((pos >= char_count) && !ReadBuffer ())
 526                                 return -1;
 527
 528                         return buffer [pos];
 529                 }
 530
 531                 public int Read ()
 532                 {
 533                         if ((pos >= char_count) && !ReadBuffer ())
 534                                 return -1;
 535
 536                         return buffer [pos++];
 537                 }
 538         }
 539
 540         public class DoubleHash {
 541                 const int DEFAULT_INITIAL_BUCKETS = 100;
 542
 543                 public DoubleHash () : this (DEFAULT_INITIAL_BUCKETS) {}
 544
 545                 public DoubleHash (int size)
 546                 {
 547                         count = size;
 548                         buckets = new Entry [size];
 549                 }
 550
 551                 int count;
 552                 Entry [] buckets;
 553                 int size = 0;
 554
 555                 class Entry {
 556                         public object key1;
 557                         public object key2;
 558                         public int hash;
 559                         public object value;
 560                         public Entry next;
 561
 562                         public Entry (object key1, object key2, int hash, object value, Entry next)
 563                         {
 564                                 this.key1 = key1;
 565                                 this.key2 = key2;
 566                                 this.hash = hash;
 567                                 this.next = next;
 568                                 this.value = value;
 569                         }
 570                 }
 571
 572                 public bool Lookup (object a, object b, out object res)
 573                 {
 574                         int h = (a.GetHashCode () ^ b.GetHashCode ()) & 0x7FFFFFFF;
 575
 576                         for (Entry e = buckets [h % count]; e != null; e = e.next) {
 577                                 if (e.hash == h && e.key1.Equals (a) && e.key2.Equals (b)) {
 578                                         res = e.value;
 579                                         return true;
 580                                 }
 581                         }
 582                         res = null;
 583                         return false;
 584                 }
 585
 586                 public void Insert (object a, object b, object value)
 587                 {
 588                         // Is it an existing one?
 589
 590                         int h = (a.GetHashCode () ^ b.GetHashCode ()) & 0x7FFFFFFF;
 591
 592                         for (Entry e = buckets [h % count]; e != null; e = e.next) {
 593                                 if (e.hash == h && e.key1.Equals (a) && e.key2.Equals (b))
 594                                         e.value = value;
 595                         }
 596
 597                         int bucket = h % count;
 598                         buckets [bucket] = new Entry (a, b, h, value, buckets [bucket]);
 599
 600                         // Grow whenever we double in size
 601                         if (size++ == count) {
 602                                 count <<= 1;
 603                                 count ++;
 604
 605                                 Entry [] newBuckets = new Entry [count];
 606                                 foreach (Entry root in buckets) {
 607                                         Entry e = root;
 608                                         while (e != null) {
 609                                                 int newLoc = e.hash % count;
 610                                                 Entry n = e.next;
 611                                                 e.next = newBuckets [newLoc];
 612                                                 newBuckets [newLoc] = e;
 613                                                 e = n;
 614                                         }
 615                                 }
 616
 617                                 buckets = newBuckets;
 618                         }
 619                 }
 620         }
 621 }