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