mcs/mcs/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                 Type [] Types { get; }
  24                 int  Count { get; }
  25                 Type ExtensionMethodType { get; }
  26                 bool HasParams { get; }
  27                 string ParameterName (int pos);
  28                 string ParameterDesc (int pos);
  29
  30                 Parameter.Modifier ParameterModifier (int pos);
  31                 string GetSignatureForError ();
  32
  33 #if MS_COMPATIBLE
  34                 ParameterData InflateTypes (Type[] genArguments, Type[] argTypes);
  35 #endif
  36         }
  37
  38         public class ReflectionParameters : ParameterData {
  39                 ParameterInfo [] pi;
  40                 Type [] types;
  41                 int params_idx = -1;
  42                 bool is_varargs;
  43                 bool is_extension;
  44                 ParameterData gpd;
  45
  46                 public ReflectionParameters (MethodBase mb)
  47                 {
  48                         ParameterInfo [] pi = mb.GetParameters ();
  49                         is_varargs = (mb.CallingConvention & CallingConventions.VarArgs) != 0;
  50
  51                         this.pi = pi;
  52                         int count = pi.Length;
  53
  54                         if (count == 0) {
  55                                 types = Type.EmptyTypes;
  56                                 return;
  57                         }
  58
  59                         types = new Type [count];
  60                         for (int i = 0; i < count; i++)
  61                                 types [i] = pi [i].ParameterType;
  62
  63                         // TODO: This (if) should be done one level higher to correctly use
  64                         // out caching facilities.
  65                         MethodBase generic = TypeManager.DropGenericMethodArguments (mb);
  66                         if (generic != mb) {
  67                                 gpd = TypeManager.GetParameterData (generic);
  68                                 if (gpd.HasParams) {
  69                                         for (int i = gpd.Count; i != 0; --i) {
  70                                                 if ((gpd.ParameterModifier (i-1) & Parameter.Modifier.PARAMS) != 0) {
  71                                                         this.params_idx = i-1;
  72                                                         break;
  73                                                 }
  74                                         }
  75                                 }
  76                                 return;
  77                         }
  78
  79                         //
  80                         // So far, the params attribute can be used in C# for the last
  81                         // and next to last method parameters.
  82                         // If some other language can place it anywhere we will
  83                         // have to analyze all parameters and not just last 2.
  84                         //
  85                         --count;
  86                         for (int i = count; i >= 0 && i > count - 2; --i) {
  87                                 if (!pi [i].ParameterType.IsArray)
  88                                         continue;
  89
  90                                 if (pi [i].IsDefined (TypeManager.param_array_type, false)) {
  91                                         params_idx = i;
  92                                         return;
  93                                 }
  94                         }
  95
  96                         if (TypeManager.extension_attribute_type != null && mb.IsStatic &&
  97                                 (mb.DeclaringType.Attributes & Class.StaticClassAttribute) == Class.StaticClassAttribute &&
  98                                 mb.IsDefined (TypeManager.extension_attribute_type, false))
  99                                 is_extension = true;
 100                 }
 101
 102                 public override bool Equals (object obj)
 103                 {
 104                         ReflectionParameters rp = obj as ReflectionParameters;
 105                         if (rp == null)
 106                                 return false;
 107
 108                         if (Count != rp.Count)
 109                                 return false;
 110
 111                         for (int i = 0; i < Count; ++i) {
 112                         if (!types [i].Equals (rp.types [i]))
 113                                 return false;
 114                         }
 115                         return true;
 116                 }
 117
 118                 public override int GetHashCode ()
 119                 {
 120                         return base.GetHashCode ();
 121                 }
 122
 123                 public string GetSignatureForError ()
 124                 {
 125                         StringBuilder sb = new StringBuilder ("(");
 126                         for (int i = 0; i < pi.Length; ++i) {
 127                                 if (i != 0)
 128                                         sb.Append (", ");
 129                                 sb.Append (ParameterDesc (i));
 130                         }
 131                         if (is_varargs) {
 132                                 if (pi.Length > 0)
 133                                         sb.Append (", ");
 134                                 sb.Append ("__arglist");
 135                         }
 136                         sb.Append (')');
 137                         return sb.ToString ();
 138                 }
 139
 140 #if MS_COMPATIBLE
 141                 public ParameterData InflateTypes (Type[] genArguments, Type[] argTypes)
 142                 {
 143                         ReflectionParameters p = (ReflectionParameters)MemberwiseClone ();
 144
 145                         for (int i = 0; i < types.Length; ++i) {
 146                                 if (types[i].IsGenericParameter) {
 147                                         for (int ii = 0; ii < genArguments.Length; ++ii) {
 148                                                 if (types[i] != genArguments[ii])
 149                                                         continue;
 150
 151                                                 p.types[i] = argTypes[ii];
 152                                                 break;
 153                                         }
 154                                         continue;
 155                                 }
 156
 157                                 if (types[i].IsGenericType) {
 158                                         Type[] gen_arguments_open = types[i].GetGenericTypeDefinition ().GetGenericArguments ();
 159                                         Type[] gen_arguments = types[i].GetGenericArguments ();
 160                                         for (int ii = 0; ii < gen_arguments_open.Length; ++ii) {
 161                                                 if (gen_arguments [ii].IsGenericParameter) {
 162                                                         for (int iii = 0; iii < genArguments.Length; ++iii) {
 163                                                                 if (gen_arguments [ii] != genArguments [iii])
 164                                                                         continue;
 165
 166                                                                 gen_arguments_open [ii] = argTypes [iii];
 167                                                                 break;
 168                                                         }
 169                                                 } else {
 170                                                         gen_arguments_open [ii] = gen_arguments [ii];
 171                                                 }
 172                                         }
 173
 174                                         p.types[i] = types[i].GetGenericTypeDefinition ().MakeGenericType (gen_arguments_open);
 175                                 }
 176                         }
 177                         return p;
 178                 }
 179 #endif
 180
 181                 public Type ParameterType (int pos)
 182                 {
 183                         if (is_varargs && pos >= pi.Length)
 184                                 return TypeManager.runtime_argument_handle_type;
 185
 186                         return types [pos];
 187                 }
 188
 189                 public string ParameterName (int pos)
 190                 {
 191                         if (gpd != null)
 192                                 return gpd.ParameterName (pos);
 193
 194                         if (is_varargs && pos >= pi.Length)
 195                                 return "__arglist";
 196
 197                         return pi [pos].Name;
 198                 }
 199
 200                 public string ParameterDesc (int pos)
 201                 {
 202                         if (is_varargs && pos >= pi.Length)
 203                                 return "";
 204
 205                         StringBuilder sb = new StringBuilder ();
 206
 207                         if (pi [pos].IsIn)
 208                                 sb.Append ("in ");
 209
 210                         Type partype = ParameterType (pos);
 211                         if (partype.IsByRef){
 212                                 partype = TypeManager.GetElementType (partype);
 213                                 if (pi [pos].IsOut)
 214                                         sb.Append ("out ");
 215                                 else
 216                                         sb.Append ("ref ");
 217                         }
 218
 219                         if (params_idx == pos)
 220                                 sb.Append ("params ");
 221
 222                         if (pos == 0 && ExtensionMethodType != null)
 223                                 sb.Append ("this ");
 224
 225                         sb.Append (TypeManager.CSharpName (partype).Replace ("&", ""));
 226
 227                         return sb.ToString ();
 228                 }
 229
 230                 public Parameter.Modifier ParameterModifier (int pos)
 231                 {
 232                         if (pos == params_idx)
 233                                 return Parameter.Modifier.PARAMS;
 234                         else if (is_varargs && pos >= pi.Length)
 235                                 return Parameter.Modifier.ARGLIST;
 236
 237                         if (gpd != null)
 238                                 return gpd.ParameterModifier (pos);
 239
 240                         Type t = types [pos];
 241                         if (t.IsByRef){
 242                                 if ((pi [pos].Attributes & (ParameterAttributes.Out|ParameterAttributes.In)) == ParameterAttributes.Out)
 243                                         return Parameter.Modifier.OUT;
 244                                 else
 245                                         return Parameter.Modifier.REF;
 246                         }
 247
 248                         return Parameter.Modifier.NONE;
 249                 }
 250
 251                 public int Count {
 252                         get { return is_varargs ? pi.Length + 1 : pi.Length; }
 253                 }
 254
 255                 public Type ExtensionMethodType {
 256                         get {
 257                                 if (!is_extension)
 258                                         return null;
 259
 260                                 return types [0];
 261                         }
 262                 }
 263
 264                 public bool HasParams {
 265                         get { return params_idx != -1; }
 266                 }
 267
 268                 public Type[] Types {
 269                         get { return types; }
 270                 }
 271         }
 272
 273 #if GMCS_SOURCE
 274         public class ReflectionConstraints : GenericConstraints
 275         {
 276                 GenericParameterAttributes attrs;
 277                 Type base_type;
 278                 Type class_constraint;
 279                 Type[] iface_constraints;
 280                 string name;
 281
 282                 public static GenericConstraints GetConstraints (Type t)
 283                 {
 284                         Type [] constraints = t.GetGenericParameterConstraints ();
 285                         GenericParameterAttributes attrs = t.GenericParameterAttributes;
 286                         if (constraints.Length == 0 && attrs == GenericParameterAttributes.None)
 287                                 return null;
 288                         return new ReflectionConstraints (t.Name, constraints, attrs);
 289                 }
 290
 291                 private ReflectionConstraints (string name, Type [] constraints, GenericParameterAttributes attrs)
 292                 {
 293                         this.name = name;
 294                         this.attrs = attrs;
 295
 296                         if ((constraints.Length > 0) && !constraints [0].IsInterface) {
 297                                 class_constraint = constraints [0];
 298                                 iface_constraints = new Type [constraints.Length - 1];
 299                                 Array.Copy (constraints, 1, iface_constraints, 0, constraints.Length - 1);
 300                         } else
 301                                 iface_constraints = constraints;
 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 string TypeParameter {
 312                         get { return name; }
 313                 }
 314
 315                 public override GenericParameterAttributes Attributes {
 316                         get { return attrs; }
 317                 }
 318
 319                 public override Type ClassConstraint {
 320                         get { return class_constraint; }
 321                 }
 322
 323                 public override Type EffectiveBaseClass {
 324                         get { return base_type; }
 325                 }
 326
 327                 public override Type[] InterfaceConstraints {
 328                         get { return iface_constraints; }
 329                 }
 330         }
 331 #endif
 332
 333         class PtrHashtable : Hashtable {
 334                 sealed class PtrComparer : IComparer {
 335                         private PtrComparer () {}
 336
 337                         public static PtrComparer Instance = new PtrComparer ();
 338
 339                         public int Compare (object x, object y)
 340                         {
 341                                 if (x == y)
 342                                         return 0;
 343                                 else
 344                                         return 1;
 345                         }
 346                 }
 347
 348                 public PtrHashtable ()
 349                 {
 350                         comparer = PtrComparer.Instance;
 351                 }
 352         }
 353
 354         /*
 355          * Hashtable whose keys are character arrays with the same length
 356          */
 357         class CharArrayHashtable : Hashtable {
 358                 sealed class ArrComparer : IComparer {
 359                         private int len;
 360
 361                         public ArrComparer (int len) {
 362                                 this.len = len;
 363                         }
 364
 365                         public int Compare (object x, object y)
 366                         {
 367                                 char[] a = (char[])x;
 368                                 char[] b = (char[])y;
 369
 370                                 for (int i = 0; i < len; ++i)
 371                                         if (a [i] != b [i])
 372                                                 return 1;
 373                                 return 0;
 374                         }
 375                 }
 376
 377                 private int len;
 378
 379                 protected override int GetHash (Object key)
 380                 {
 381                         char[] arr = (char[])key;
 382                         int h = 0;
 383
 384                         for (int i = 0; i < len; ++i)
 385                                 h = (h << 5) - h + arr [i];
 386
 387                         return h;
 388                 }
 389
 390                 public CharArrayHashtable (int len)
 391                 {
 392                         this.len = len;
 393                         comparer = new ArrComparer (len);
 394                 }
 395         }
 396
 397         struct Pair {
 398                 public object First;
 399                 public object Second;
 400
 401                 public Pair (object f, object s)
 402                 {
 403                         First = f;
 404                         Second = s;
 405                 }
 406         }
 407
 408         public class Accessors {
 409                 public Accessor get_or_add;
 410                 public Accessor set_or_remove;
 411
 412                 // was 'set' declared before 'get'?  was 'remove' declared before 'add'?
 413                 public bool declared_in_reverse;
 414
 415                 public Accessors (Accessor get_or_add, Accessor set_or_remove)
 416                 {
 417                         this.get_or_add = get_or_add;
 418                         this.set_or_remove = set_or_remove;
 419                 }
 420         }
 421
 422         /// <summary>
 423         ///   This is a wrapper around StreamReader which is seekable backwards
 424         ///   within a window of around 2048 chars.
 425         /// </summary>
 426         public class SeekableStreamReader
 427         {
 428                 public SeekableStreamReader (TextReader reader)
 429                 {
 430                         this.reader = reader;
 431                         this.buffer = new char [AverageReadLength * 3];
 432
 433                         // Let the StreamWriter autodetect the encoder
 434                         reader.Peek ();
 435                 }
 436
 437                 public SeekableStreamReader (Stream stream, Encoding encoding)
 438                         : this (new StreamReader (stream, encoding, true))
 439                 { }
 440
 441                 TextReader reader;
 442
 443                 private const int AverageReadLength = 1024;
 444
 445                 char[] buffer;
 446                 int buffer_start;       // in chars
 447                 int char_count;         // count buffer[] valid characters
 448                 int pos;                // index into buffer[]
 449
 450                 /// <remarks>
 451                 ///   This value corresponds to the current position in a stream of characters.
 452                 ///   The StreamReader hides its manipulation of the underlying byte stream and all
 453                 ///   character set/decoding issues.  Thus, we cannot use this position to guess at
 454                 ///   the corresponding position in the underlying byte stream even though there is
 455                 ///   a correlation between them.
 456                 /// </remarks>
 457                 public int Position {
 458                         get { return buffer_start + pos; }
 459
 460                         set {
 461                                 if (value < buffer_start || value > buffer_start + char_count)
 462                                         throw new InternalErrorException ("can't seek that far back: " + (pos - value));
 463                                 pos = value - buffer_start;
 464                         }
 465                 }
 466
 467                 private bool ReadBuffer ()
 468                 {
 469                         int slack = buffer.Length - char_count;
 470                         if (slack <= AverageReadLength / 2) {
 471                                 // shift the buffer to make room for AverageReadLength number of characters
 472                                 int shift = AverageReadLength - slack;
 473                                 Array.Copy (buffer, shift, buffer, 0, char_count - shift);
 474                                 pos -= shift;
 475                                 char_count -= shift;
 476                                 buffer_start += shift;
 477                                 slack += shift;         // slack == AverageReadLength
 478                         }
 479
 480                         int chars_read = reader.Read (buffer, char_count, slack);
 481                         char_count += chars_read;
 482
 483                         return pos < char_count;
 484                 }
 485
 486                 public int Peek ()
 487                 {
 488                         if ((pos >= char_count) && !ReadBuffer ())
 489                                 return -1;
 490
 491                         return buffer [pos];
 492                 }
 493
 494                 public int Read ()
 495                 {
 496                         if ((pos >= char_count) && !ReadBuffer ())
 497                                 return -1;
 498
 499                         return buffer [pos++];
 500                 }
 501         }
 502
 503         public class DoubleHash {
 504                 const int DEFAULT_INITIAL_BUCKETS = 100;
 505
 506                 public DoubleHash () : this (DEFAULT_INITIAL_BUCKETS) {}
 507
 508                 public DoubleHash (int size)
 509                 {
 510                         count = size;
 511                         buckets = new Entry [size];
 512                 }
 513
 514                 int count;
 515                 Entry [] buckets;
 516                 int size = 0;
 517
 518                 class Entry {
 519                         public object key1;
 520                         public object key2;
 521                         public int hash;
 522                         public object value;
 523                         public Entry next;
 524
 525                         public Entry (object key1, object key2, int hash, object value, Entry next)
 526                         {
 527                                 this.key1 = key1;
 528                                 this.key2 = key2;
 529                                 this.hash = hash;
 530                                 this.next = next;
 531                                 this.value = value;
 532                         }
 533                 }
 534
 535                 public bool Lookup (object a, object b, out object res)
 536                 {
 537                         int h = (a.GetHashCode () ^ b.GetHashCode ()) & 0x7FFFFFFF;
 538
 539                         for (Entry e = buckets [h % count]; e != null; e = e.next) {
 540                                 if (e.hash == h && e.key1.Equals (a) && e.key2.Equals (b)) {
 541                                         res = e.value;
 542                                         return true;
 543                                 }
 544                         }
 545                         res = null;
 546                         return false;
 547                 }
 548
 549                 public void Insert (object a, object b, object value)
 550                 {
 551                         // Is it an existing one?
 552
 553                         int h = (a.GetHashCode () ^ b.GetHashCode ()) & 0x7FFFFFFF;
 554
 555                         for (Entry e = buckets [h % count]; e != null; e = e.next) {
 556                                 if (e.hash == h && e.key1.Equals (a) && e.key2.Equals (b))
 557                                         e.value = value;
 558                         }
 559
 560                         int bucket = h % count;
 561                         buckets [bucket] = new Entry (a, b, h, value, buckets [bucket]);
 562
 563                         // Grow whenever we double in size
 564                         if (size++ == count) {
 565                                 count <<= 1;
 566                                 count ++;
 567
 568                                 Entry [] newBuckets = new Entry [count];
 569                                 foreach (Entry root in buckets) {
 570                                         Entry e = root;
 571                                         while (e != null) {
 572                                                 int newLoc = e.hash % count;
 573                                                 Entry n = e.next;
 574                                                 e.next = newBuckets [newLoc];
 575                                                 newBuckets [newLoc] = e;
 576                                                 e = n;
 577                                         }
 578                                 }
 579
 580                                 buckets = newBuckets;
 581                         }
 582                 }
 583         }
 584 }