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 GenericConstraints {
  22                 bool HasConstructor { get; }
  23                 bool IsReferenceType { get; }
  24                 bool IsValueType { get; }
  25                 bool HasClassConstraint { get; }
  26                 Type ClassConstraint { get; }
  27                 Type[] InterfaceConstraints { get; }
  28         }
  29
  30         public interface ParameterData {
  31                 Type ParameterType (int pos);
  32                 GenericConstraints GenericConstraints (int pos);
  33                 bool HasArrayParameter { get; }
  34                 int  Count { get; }
  35                 string ParameterName (int pos);
  36                 string ParameterDesc (int pos);
  37                 Parameter.Modifier ParameterModifier (int pos);
  38         }
  39
  40         public class ReflectionParameters : ParameterData {
  41                 ParameterInfo [] pi;
  42                 bool last_arg_is_params = false;
  43                 ParameterData gpd;
  44
  45                 public ReflectionParameters (MethodBase method)
  46                 {
  47                         object [] attrs;
  48
  49                         this.pi = method.GetParameters ();
  50                         int count = pi.Length-1;
  51
  52                         if (count < 0)
  53                                 return;
  54
  55                         if (method.Mono_IsInflatedMethod) {
  56                                 MethodInfo generic = method.GetGenericMethodDefinition ();
  57                                 gpd = Invocation.GetParameterData (generic);
  58
  59                                 last_arg_is_params = gpd.HasArrayParameter;
  60                                 return;
  61                         }
  62
  63                         attrs = pi [count].GetCustomAttributes (TypeManager.param_array_type, true);
  64                         if (attrs == null)
  65                                 return;
  66
  67                         if (attrs.Length == 0)
  68                                 return;
  69
  70                         last_arg_is_params = true;
  71                 }
  72
  73                 public bool HasArrayParameter {
  74                         get { return last_arg_is_params; }
  75                 }
  76
  77                 public Type ParameterType (int pos)
  78                 {
  79                         if (last_arg_is_params && pos >= pi.Length - 1)
  80                                 return pi [pi.Length - 1].ParameterType;
  81                         else {
  82                                 Type t = pi [pos].ParameterType;
  83
  84                                 return t;
  85                         }
  86                 }
  87
  88                 public GenericConstraints GenericConstraints (int pos)
  89                 {
  90                         if (gpd != null)
  91                                 return gpd.GenericConstraints (pos);
  92
  93                         Type t = ParameterType (pos);
  94                         if (!t.IsGenericParameter)
  95                                 return null;
  96
  97                         return ReflectionConstraints.Create (t);
  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
 105                                 return pi [pos].Name;
 106                 }
 107
 108                 public string ParameterDesc (int pos)
 109                 {
 110                         StringBuilder sb = new StringBuilder ();
 111
 112                         if (pi [pos].IsIn)
 113                                 sb.Append ("in ");
 114
 115                         Type partype = ParameterType (pos);
 116                         if (partype.IsByRef){
 117                                 partype = TypeManager.GetElementType (partype);
 118                                 if (pi [pos].IsOut)
 119                                         sb.Append ("out ");
 120                                 else
 121                                         sb.Append ("ref ");
 122                         }
 123
 124                         if (pos >= pi.Length - 1 && last_arg_is_params)
 125                                 sb.Append ("params ");
 126
 127                         sb.Append (TypeManager.CSharpName (partype));
 128
 129                         return sb.ToString ();
 130
 131                 }
 132
 133                 public Parameter.Modifier ParameterModifier (int pos)
 134                 {
 135                         int len = pi.Length;
 136
 137                         if (pos >= len - 1)
 138                                 if (last_arg_is_params)
 139                                         return Parameter.Modifier.PARAMS;
 140
 141                         Type t = pi [pos].ParameterType;
 142                         if (t.IsByRef){
 143                                 if ((pi [pos].Attributes & ParameterAttributes.Out) != 0)
 144                                         return Parameter.Modifier.ISBYREF | Parameter.Modifier.OUT;
 145                                 else
 146                                         return Parameter.Modifier.ISBYREF | Parameter.Modifier.REF;
 147                         }
 148
 149                         return Parameter.Modifier.NONE;
 150                 }
 151
 152                 public int Count {
 153                         get {
 154                                 return pi.Length;
 155                         }
 156                 }
 157
 158                 protected class ReflectionConstraints : GenericConstraints
 159                 {
 160                         bool has_ctor;
 161                         bool is_reference_type;
 162                         bool is_value_type;
 163                         Type class_constraint;
 164                         Type[] iface_constraints;
 165
 166                         protected ReflectionConstraints (bool has_ctor, Type class_constr,
 167                                                          Type[] iface_constrs)
 168                         {
 169                                 this.has_ctor = has_ctor;
 170                                 this.class_constraint = class_constr;
 171                                 this.iface_constraints = iface_constrs;
 172
 173                                 if (class_constraint != null) {
 174                                         if (class_constraint == TypeManager.object_type)
 175                                                 is_reference_type = true;
 176                                         else if (class_constraint == TypeManager.value_type)
 177                                                 is_value_type = true;
 178                                 }
 179                         }
 180
 181                         public static GenericConstraints Create (Type t)
 182                         {
 183                                 Type class_constr = null;
 184                                 Type[] iface_constrs = t.GetInterfaces ();
 185                                 if (iface_constrs ==  null)
 186                                         iface_constrs = Type.EmptyTypes;
 187                                 if (t.BaseType != TypeManager.object_type)
 188                                         class_constr = t.BaseType;
 189
 190                                 return new ReflectionConstraints (
 191                                         false, class_constr, iface_constrs);
 192                         }
 193
 194                         public bool HasConstructor {
 195                                 get { return has_ctor; }
 196                         }
 197
 198                         public bool HasClassConstraint {
 199                                 get { return class_constraint != null; }
 200                         }
 201
 202                         public bool IsReferenceType {
 203                                 get { return is_reference_type; }
 204                         }
 205
 206                         public bool IsValueType {
 207                                 get { return is_value_type; }
 208                         }
 209
 210                         public Type ClassConstraint {
 211                                 get { return class_constraint; }
 212                         }
 213
 214                         public Type[] InterfaceConstraints {
 215                                 get { return iface_constraints; }
 216                         }
 217                 }
 218         }
 219
 220         public class InternalParameters : ParameterData {
 221                 Type [] param_types;
 222
 223                 public readonly Parameters Parameters;
 224
 225                 public InternalParameters (Type [] param_types, Parameters parameters)
 226                 {
 227                         this.param_types = param_types;
 228                         this.Parameters = parameters;
 229                 }
 230
 231                 public InternalParameters (DeclSpace ds, Parameters parameters)
 232                         : this (parameters.GetParameterInfo (ds), parameters)
 233                 {
 234                 }
 235
 236                 public int Count {
 237                         get {
 238                                 if (param_types == null)
 239                                         return 0;
 240
 241                                 return param_types.Length;
 242                         }
 243                 }
 244
 245                 public bool HasArrayParameter {
 246                         get { return Parameters.ArrayParameter != null; }
 247                 }
 248
 249                 Parameter GetParameter (int pos)
 250                 {
 251                         Parameter [] fixed_pars = Parameters.FixedParameters;
 252                         if (fixed_pars != null){
 253                                 int len = fixed_pars.Length;
 254                                 if (pos < len)
 255                                         return Parameters.FixedParameters [pos];
 256                         }
 257
 258                         return Parameters.ArrayParameter;
 259                 }
 260
 261                 public Type ParameterType (int pos)
 262                 {
 263                         if (param_types == null)
 264                                 return null;
 265
 266                         return GetParameter (pos).ExternalType ();
 267                 }
 268
 269                 public GenericConstraints GenericConstraints (int pos)
 270                 {
 271                         if (param_types == null)
 272                                 return null;
 273
 274                         return GetParameter (pos).GenericConstraints;
 275                 }
 276
 277                 public string ParameterName (int pos)
 278                 {
 279                         return GetParameter (pos).Name;
 280                 }
 281
 282                 public string ParameterDesc (int pos)
 283                 {
 284                         string tmp = String.Empty;
 285                         Parameter p = GetParameter (pos);
 286
 287                         //
 288                         // We need to and for REF/OUT, because if either is set the
 289                         // extra flag ISBYREF will be set as well
 290                         //
 291                         if ((p.ModFlags & Parameter.Modifier.REF) != 0)
 292                                 tmp = "ref ";
 293                         else if ((p.ModFlags & Parameter.Modifier.OUT) != 0)
 294                                 tmp = "out ";
 295                         else if (p.ModFlags == Parameter.Modifier.PARAMS)
 296                                 tmp = "params ";
 297
 298                         Type t = ParameterType (pos);
 299
 300                         return tmp + TypeManager.CSharpName (t);
 301                 }
 302
 303                 public Parameter.Modifier ParameterModifier (int pos)
 304                 {
 305                         Parameter.Modifier mod = GetParameter (pos).ModFlags;
 306
 307                         if ((mod & (Parameter.Modifier.REF | Parameter.Modifier.OUT)) != 0)
 308                                 mod |= Parameter.Modifier.ISBYREF;
 309
 310                         return mod;
 311                 }
 312
 313         }
 314
 315         class PtrHashtable : Hashtable {
 316                 sealed class PtrComparer : IComparer {
 317                         private PtrComparer () {}
 318
 319                         public static PtrComparer Instance = new PtrComparer ();
 320
 321                         public int Compare (object x, object y)
 322                         {
 323                                 if (x == y)
 324                                         return 0;
 325                                 else
 326                                         return 1;
 327                         }
 328                 }
 329
 330                 public PtrHashtable ()
 331                 {
 332                         comparer = PtrComparer.Instance;
 333                 }
 334         }
 335
 336         /*
 337          * Hashtable whose keys are character arrays with the same length
 338          */
 339         class CharArrayHashtable : Hashtable {
 340                 sealed class ArrComparer : IComparer {
 341                         private int len;
 342
 343                         public ArrComparer (int len) {
 344                                 this.len = len;
 345                         }
 346
 347                         public int Compare (object x, object y)
 348                         {
 349                                 char[] a = (char[])x;
 350                                 char[] b = (char[])y;
 351
 352                                 for (int i = 0; i < len; ++i)
 353                                         if (a [i] != b [i])
 354                                                 return 1;
 355                                 return 0;
 356                         }
 357                 }
 358
 359                 private int len;
 360
 361                 protected override int GetHash (Object key)
 362                 {
 363                         char[] arr = (char[])key;
 364                         int h = 0;
 365
 366                         for (int i = 0; i < len; ++i)
 367                                 h = (h << 5) - h + arr [i];
 368
 369                         return h;
 370                 }
 371
 372                 public CharArrayHashtable (int len)
 373                 {
 374                         this.len = len;
 375                         comparer = new ArrComparer (len);
 376                 }
 377         }
 378
 379         //
 380         // Compares member infos based on their name and
 381         // also allows one argument to be a string
 382         //
 383         class MemberInfoCompare : IComparer {
 384
 385                 public int Compare (object a, object b)
 386                 {
 387                         if (a == null || b == null){
 388                                 Console.WriteLine ("Invalid information passed");
 389                                 throw new Exception ();
 390                         }
 391
 392                         if (a is string)
 393                                 return String.Compare ((string) a, ((MemberInfo)b).Name, false, CultureInfo.InvariantCulture);
 394
 395                         if (b is string)
 396                                 return String.Compare (((MemberInfo)a).Name, (string) b, false, CultureInfo.InvariantCulture);
 397
 398                         return String.Compare (((MemberInfo)a).Name, ((MemberInfo)b).Name, false, CultureInfo.InvariantCulture);
 399                 }
 400         }
 401
 402         struct Pair {
 403                 public object First;
 404                 public object Second;
 405
 406                 public Pair (object f, object s)
 407                 {
 408                         First = f;
 409                         Second = s;
 410                 }
 411         }
 412
 413         /// <summary>
 414         ///   This is a wrapper around StreamReader which is seekable.
 415         /// </summary>
 416         public class SeekableStreamReader
 417         {
 418                 public SeekableStreamReader (StreamReader reader)
 419                 {
 420                         this.reader = reader;
 421                         this.buffer = new char [DefaultCacheSize];
 422
 423                         // Compute the preamble size
 424
 425                         // Let the StreamWriter autodetect the encoder
 426                         reader.Peek ();
 427
 428                         reader.BaseStream.Position = 0;
 429                         Encoding enc = reader.CurrentEncoding;
 430                         // First of all, get at least a char
 431
 432                         byte[] auxb = new byte [50];
 433                         int num_bytes = 0;
 434                         int num_chars = 0;
 435                         int br = 0;
 436                         do {
 437                                 br = reader.BaseStream.Read (auxb, num_bytes, auxb.Length - num_bytes);
 438                                 num_bytes += br;
 439                                 num_chars = enc.GetCharCount (auxb, 0, num_bytes);
 440                         }
 441                         while (num_chars == 0 && br > 0);
 442
 443                         if (num_chars != 0)
 444                         {
 445                                 // Now, check which bytes at the beginning have no effect in the
 446                                 // char count
 447
 448                                 int p = 0;
 449                                 while (enc.GetCharCount (auxb, p, num_bytes-p) >= num_chars)
 450                                         p++;
 451
 452                                 preamble_size = p - 1;
 453                                 reader.BaseStream.Position = 0;
 454                                 reader.DiscardBufferedData ();
 455
 456                                 buffer_start = preamble_size;
 457                         }
 458                 }
 459
 460                 public SeekableStreamReader (Stream stream, Encoding encoding, bool detect_encoding_from_bytemarks)
 461                         : this (new StreamReader (stream, encoding, detect_encoding_from_bytemarks))
 462                 { }
 463
 464                 StreamReader reader;
 465
 466                 private const int DefaultCacheSize = 1024;
 467
 468                 char[] buffer;
 469                 int buffer_start;       // in bytes
 470                 int buffer_size;        // in bytes
 471                 int char_count;         // count buffer[] valid characters
 472                 int pos;                // index into buffer[]
 473                 int preamble_size;
 474
 475                 /// <remarks>
 476                 ///   The difference to the StreamReader's BaseStream.Position is that this one is reliable; ie. it
 477                 //    always reports the correct position and if it's modified, it also takes care of the buffered data.
 478                 /// </remarks>
 479                 public int Position {
 480                         get {
 481                                 return buffer_start + reader.CurrentEncoding.GetByteCount (buffer, 0, pos);
 482                         }
 483
 484                         set {
 485                                 // This one is easy: we're modifying the position within our current
 486                                 // buffer.
 487                                 if ((value >= buffer_start) && (value < buffer_start + buffer_size)) {
 488                                         int byte_offset = value - buffer_start;
 489                                         pos = byte_offset;
 490                                         // encoded characters can take more than 1 byte length
 491                                         while (reader.CurrentEncoding.GetByteCount (buffer, 0, pos) > byte_offset)
 492                                                 pos--;
 493
 494                                         return;
 495                                 }
 496
 497                                 if (value == 0) // Skip preamble
 498                                         value = preamble_size;
 499
 500                                 // Ok, now we need to seek.
 501                                 reader.DiscardBufferedData ();
 502                                 reader.BaseStream.Position = buffer_start = value;
 503                                 char_count = buffer_size = pos = 0;
 504                         }
 505                 }
 506
 507                 private bool ReadBuffer ()
 508                 {
 509                         pos = 0;
 510                         buffer_start += buffer_size;
 511                         char_count = reader.Read (buffer, 0, buffer.Length);
 512                         buffer_size = reader.CurrentEncoding.GetByteCount (buffer, 0, char_count);
 513                         return buffer_size > 0;
 514                 }
 515
 516                 public int Peek ()
 517                 {
 518                         if ((pos >= char_count) && !ReadBuffer ())
 519                                 return -1;
 520
 521                         return buffer [pos];
 522                 }
 523
 524                 public int Read ()
 525                 {
 526                         if ((pos >= char_count) && !ReadBuffer ())
 527                                 return -1;
 528
 529                         return buffer [pos++];
 530                 }
 531         }
 532
 533         public class DoubleHash {
 534                 const int DEFAULT_INITIAL_BUCKETS = 100;
 535
 536                 public DoubleHash () : this (DEFAULT_INITIAL_BUCKETS) {}
 537
 538                 public DoubleHash (int size)
 539                 {
 540                         count = size;
 541                         buckets = new Entry [size];
 542                 }
 543
 544                 int count;
 545                 Entry [] buckets;
 546                 int size = 0;
 547
 548                 class Entry {
 549                         public object key1;
 550                         public object key2;
 551                         public int hash;
 552                         public object value;
 553                         public Entry next;
 554
 555                         public Entry (object key1, object key2, int hash, object value, Entry next)
 556                         {
 557                                 this.key1 = key1;
 558                                 this.key2 = key2;
 559                                 this.hash = hash;
 560                                 this.next = next;
 561                                 this.value = value;
 562                         }
 563                 }
 564
 565                 public bool Lookup (object a, object b, out object res)
 566                 {
 567                         int h = (a.GetHashCode () ^ b.GetHashCode ()) & 0x7FFFFFFF;
 568
 569                         for (Entry e = buckets [h % count]; e != null; e = e.next) {
 570                                 if (e.hash == h && e.key1.Equals (a) && e.key2.Equals (b)) {
 571                                         res = e.value;
 572                                         return true;
 573                                 }
 574                         }
 575                         res = null;
 576                         return false;
 577                 }
 578
 579                 public void Insert (object a, object b, object value)
 580                 {
 581                         // Is it an existing one?
 582
 583                         int h = (a.GetHashCode () ^ b.GetHashCode ()) & 0x7FFFFFFF;
 584
 585                         for (Entry e = buckets [h % count]; e != null; e = e.next) {
 586                                 if (e.hash == h && e.key1.Equals (a) && e.key2.Equals (b))
 587                                         e.value = value;
 588                         }
 589
 590                         int bucket = h % count;
 591                         buckets [bucket] = new Entry (a, b, h, value, buckets [bucket]);
 592
 593                         // Grow whenever we double in size
 594                         if (size++ == count) {
 595                                 count <<= 1;
 596                                 count ++;
 597
 598                                 Entry [] newBuckets = new Entry [count];
 599                                 foreach (Entry root in buckets) {
 600                                         Entry e = root;
 601                                         while (e != null) {
 602                                                 int newLoc = e.hash % count;
 603                                                 Entry n = e.next;
 604                                                 e.next = newBuckets [newLoc];
 605                                                 newBuckets [newLoc] = e;
 606                                                 e = n;
 607                                         }
 608                                 }
 609
 610                                 buckets = newBuckets;
 611                         }
 612                 }
 613         }
 614 }