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