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                 void 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 void InflateTypes (Type[] genArguments, Type[] argTypes)
 142                 {
 143                         for (int i = 0; i < types.Length; ++i) {
 144                                 if (types[i].IsGenericParameter) {
 145                                         for (int ii = 0; ii < genArguments.Length; ++ii) {
 146                                                 if (types[i] != genArguments[ii])
 147                                                         continue;
 148
 149                                                 types[i] = argTypes[ii];
 150                                                 break;
 151                                         }
 152                                         continue;
 153                                 }
 154
 155                                 if (types[i].IsGenericType) {
 156                                         Type[] gen_arguments_open = types[i].GetGenericTypeDefinition ().GetGenericArguments ();
 157                                         Type[] gen_arguments = types[i].GetGenericArguments ();
 158                                         for (int ii = 0; ii < gen_arguments_open.Length; ++ii) {
 159                                                 if (gen_arguments[ii].IsGenericParameter)
 160                                                         gen_arguments_open[ii] = argTypes[gen_arguments_open[ii].GenericParameterPosition];
 161                                                 else
 162                                                         gen_arguments_open[ii] = gen_arguments[ii];
 163                                         }
 164
 165                                         types[i] = types[i].GetGenericTypeDefinition ().MakeGenericType (gen_arguments_open);
 166                                 }
 167                         }
 168                 }
 169 #endif
 170
 171                 public Type ParameterType (int pos)
 172                 {
 173                         if (is_varargs && pos >= pi.Length)
 174                                 return TypeManager.runtime_argument_handle_type;
 175
 176                         return types [pos];
 177                 }
 178
 179                 public string ParameterName (int pos)
 180                 {
 181                         if (gpd != null)
 182                                 return gpd.ParameterName (pos);
 183
 184                         if (is_varargs && pos >= pi.Length)
 185                                 return "__arglist";
 186
 187                         return pi [pos].Name;
 188                 }
 189
 190                 public string ParameterDesc (int pos)
 191                 {
 192                         if (is_varargs && pos >= pi.Length)
 193                                 return "";
 194
 195                         StringBuilder sb = new StringBuilder ();
 196
 197                         if (pi [pos].IsIn)
 198                                 sb.Append ("in ");
 199
 200                         Type partype = ParameterType (pos);
 201                         if (partype.IsByRef){
 202                                 partype = TypeManager.GetElementType (partype);
 203                                 if (pi [pos].IsOut)
 204                                         sb.Append ("out ");
 205                                 else
 206                                         sb.Append ("ref ");
 207                         }
 208
 209                         if (params_idx == pos)
 210                                 sb.Append ("params ");
 211
 212                         if (pos == 0 && ExtensionMethodType != null)
 213                                 sb.Append ("this ");
 214
 215                         sb.Append (TypeManager.CSharpName (partype).Replace ("&", ""));
 216
 217                         return sb.ToString ();
 218                 }
 219
 220                 public Parameter.Modifier ParameterModifier (int pos)
 221                 {
 222                         if (pos == params_idx)
 223                                 return Parameter.Modifier.PARAMS;
 224                         else if (is_varargs && pos >= pi.Length)
 225                                 return Parameter.Modifier.ARGLIST;
 226
 227                         if (gpd != null)
 228                                 return gpd.ParameterModifier (pos);
 229
 230                         Type t = types [pos];
 231                         if (t.IsByRef){
 232                                 if ((pi [pos].Attributes & (ParameterAttributes.Out|ParameterAttributes.In)) == ParameterAttributes.Out)
 233                                         return Parameter.Modifier.OUT;
 234                                 else
 235                                         return Parameter.Modifier.REF;
 236                         }
 237
 238                         return Parameter.Modifier.NONE;
 239                 }
 240
 241                 public int Count {
 242                         get { return is_varargs ? pi.Length + 1 : pi.Length; }
 243                 }
 244
 245                 public Type ExtensionMethodType {
 246                         get {
 247                                 if (!is_extension)
 248                                         return null;
 249
 250                                 return types [0];
 251                         }
 252                 }
 253
 254                 public bool HasParams {
 255                         get { return params_idx != -1; }
 256                 }
 257
 258                 public Type[] Types {
 259                         get { return types; }
 260                 }
 261         }
 262
 263 #if GMCS_SOURCE
 264         public class ReflectionConstraints : GenericConstraints
 265         {
 266                 GenericParameterAttributes attrs;
 267                 Type base_type;
 268                 Type class_constraint;
 269                 Type[] iface_constraints;
 270                 string name;
 271
 272                 public static GenericConstraints GetConstraints (Type t)
 273                 {
 274                         Type [] constraints = t.GetGenericParameterConstraints ();
 275                         GenericParameterAttributes attrs = t.GenericParameterAttributes;
 276                         if (constraints.Length == 0 && attrs == GenericParameterAttributes.None)
 277                                 return null;
 278                         return new ReflectionConstraints (t.Name, constraints, attrs);
 279                 }
 280
 281                 private ReflectionConstraints (string name, Type [] constraints, GenericParameterAttributes attrs)
 282                 {
 283                         this.name = name;
 284                         this.attrs = attrs;
 285
 286                         if ((constraints.Length > 0) && !constraints [0].IsInterface) {
 287                                 class_constraint = constraints [0];
 288                                 iface_constraints = new Type [constraints.Length - 1];
 289                                 Array.Copy (constraints, 1, iface_constraints, 0, constraints.Length - 1);
 290                         } else
 291                                 iface_constraints = constraints;
 292
 293                         if (HasValueTypeConstraint)
 294                                 base_type = TypeManager.value_type;
 295                         else if (class_constraint != null)
 296                                 base_type = class_constraint;
 297                         else
 298                                 base_type = TypeManager.object_type;
 299                 }
 300
 301                 public override string TypeParameter {
 302                         get { return name; }
 303                 }
 304
 305                 public override GenericParameterAttributes Attributes {
 306                         get { return attrs; }
 307                 }
 308
 309                 public override Type ClassConstraint {
 310                         get { return class_constraint; }
 311                 }
 312
 313                 public override Type EffectiveBaseClass {
 314                         get { return base_type; }
 315                 }
 316
 317                 public override Type[] InterfaceConstraints {
 318                         get { return iface_constraints; }
 319                 }
 320         }
 321 #endif
 322
 323         class PtrHashtable : Hashtable {
 324                 sealed class PtrComparer : IComparer {
 325                         private PtrComparer () {}
 326
 327                         public static PtrComparer Instance = new PtrComparer ();
 328
 329                         public int Compare (object x, object y)
 330                         {
 331                                 if (x == y)
 332                                         return 0;
 333                                 else
 334                                         return 1;
 335                         }
 336                 }
 337
 338                 public PtrHashtable ()
 339                 {
 340                         comparer = PtrComparer.Instance;
 341                 }
 342         }
 343
 344         /*
 345          * Hashtable whose keys are character arrays with the same length
 346          */
 347         class CharArrayHashtable : Hashtable {
 348                 sealed class ArrComparer : IComparer {
 349                         private int len;
 350
 351                         public ArrComparer (int len) {
 352                                 this.len = len;
 353                         }
 354
 355                         public int Compare (object x, object y)
 356                         {
 357                                 char[] a = (char[])x;
 358                                 char[] b = (char[])y;
 359
 360                                 for (int i = 0; i < len; ++i)
 361                                         if (a [i] != b [i])
 362                                                 return 1;
 363                                 return 0;
 364                         }
 365                 }
 366
 367                 private int len;
 368
 369                 protected override int GetHash (Object key)
 370                 {
 371                         char[] arr = (char[])key;
 372                         int h = 0;
 373
 374                         for (int i = 0; i < len; ++i)
 375                                 h = (h << 5) - h + arr [i];
 376
 377                         return h;
 378                 }
 379
 380                 public CharArrayHashtable (int len)
 381                 {
 382                         this.len = len;
 383                         comparer = new ArrComparer (len);
 384                 }
 385         }
 386
 387         struct Pair {
 388                 public object First;
 389                 public object Second;
 390
 391                 public Pair (object f, object s)
 392                 {
 393                         First = f;
 394                         Second = s;
 395                 }
 396         }
 397
 398         public class Accessors {
 399                 public Accessor get_or_add;
 400                 public Accessor set_or_remove;
 401
 402                 // was 'set' declared before 'get'?  was 'remove' declared before 'add'?
 403                 public bool declared_in_reverse;
 404
 405                 public Accessors (Accessor get_or_add, Accessor set_or_remove)
 406                 {
 407                         this.get_or_add = get_or_add;
 408                         this.set_or_remove = set_or_remove;
 409                 }
 410         }
 411
 412         /// <summary>
 413         ///   This is a wrapper around StreamReader which is seekable backwards
 414         ///   within a window of around 2048 chars.
 415         /// </summary>
 416         public class SeekableStreamReader
 417         {
 418                 public SeekableStreamReader (TextReader reader)
 419                 {
 420                         this.reader = reader;
 421                         this.buffer = new char [AverageReadLength * 3];
 422
 423                         // Let the StreamWriter autodetect the encoder
 424                         reader.Peek ();
 425                 }
 426
 427                 public SeekableStreamReader (Stream stream, Encoding encoding)
 428                         : this (new StreamReader (stream, encoding, true))
 429                 { }
 430
 431                 TextReader reader;
 432
 433                 private const int AverageReadLength = 1024;
 434
 435                 char[] buffer;
 436                 int buffer_start;       // in chars
 437                 int char_count;         // count buffer[] valid characters
 438                 int pos;                // index into buffer[]
 439
 440                 /// <remarks>
 441                 ///   This value corresponds to the current position in a stream of characters.
 442                 ///   The StreamReader hides its manipulation of the underlying byte stream and all
 443                 ///   character set/decoding issues.  Thus, we cannot use this position to guess at
 444                 ///   the corresponding position in the underlying byte stream even though there is
 445                 ///   a correlation between them.
 446                 /// </remarks>
 447                 public int Position {
 448                         get { return buffer_start + pos; }
 449
 450                         set {
 451                                 if (value < buffer_start || value > buffer_start + char_count)
 452                                         throw new InternalErrorException ("can't seek that far back: " + (pos - value));
 453                                 pos = value - buffer_start;
 454                         }
 455                 }
 456
 457                 private bool ReadBuffer ()
 458                 {
 459                         int slack = buffer.Length - char_count;
 460                         if (slack <= AverageReadLength / 2) {
 461                                 // shift the buffer to make room for AverageReadLength number of characters
 462                                 int shift = AverageReadLength - slack;
 463                                 Array.Copy (buffer, shift, buffer, 0, char_count - shift);
 464                                 pos -= shift;
 465                                 char_count -= shift;
 466                                 buffer_start += shift;
 467                                 slack += shift;         // slack == AverageReadLength
 468                         }
 469
 470                         int chars_read = reader.Read (buffer, char_count, slack);
 471                         char_count += chars_read;
 472
 473                         return pos < char_count;
 474                 }
 475
 476                 public int Peek ()
 477                 {
 478                         if ((pos >= char_count) && !ReadBuffer ())
 479                                 return -1;
 480
 481                         return buffer [pos];
 482                 }
 483
 484                 public int Read ()
 485                 {
 486                         if ((pos >= char_count) && !ReadBuffer ())
 487                                 return -1;
 488
 489                         return buffer [pos++];
 490                 }
 491         }
 492
 493         public class DoubleHash {
 494                 const int DEFAULT_INITIAL_BUCKETS = 100;
 495
 496                 public DoubleHash () : this (DEFAULT_INITIAL_BUCKETS) {}
 497
 498                 public DoubleHash (int size)
 499                 {
 500                         count = size;
 501                         buckets = new Entry [size];
 502                 }
 503
 504                 int count;
 505                 Entry [] buckets;
 506                 int size = 0;
 507
 508                 class Entry {
 509                         public object key1;
 510                         public object key2;
 511                         public int hash;
 512                         public object value;
 513                         public Entry next;
 514
 515                         public Entry (object key1, object key2, int hash, object value, Entry next)
 516                         {
 517                                 this.key1 = key1;
 518                                 this.key2 = key2;
 519                                 this.hash = hash;
 520                                 this.next = next;
 521                                 this.value = value;
 522                         }
 523                 }
 524
 525                 public bool Lookup (object a, object b, out object res)
 526                 {
 527                         int h = (a.GetHashCode () ^ b.GetHashCode ()) & 0x7FFFFFFF;
 528
 529                         for (Entry e = buckets [h % count]; e != null; e = e.next) {
 530                                 if (e.hash == h && e.key1.Equals (a) && e.key2.Equals (b)) {
 531                                         res = e.value;
 532                                         return true;
 533                                 }
 534                         }
 535                         res = null;
 536                         return false;
 537                 }
 538
 539                 public void Insert (object a, object b, object value)
 540                 {
 541                         // Is it an existing one?
 542
 543                         int h = (a.GetHashCode () ^ b.GetHashCode ()) & 0x7FFFFFFF;
 544
 545                         for (Entry e = buckets [h % count]; e != null; e = e.next) {
 546                                 if (e.hash == h && e.key1.Equals (a) && e.key2.Equals (b))
 547                                         e.value = value;
 548                         }
 549
 550                         int bucket = h % count;
 551                         buckets [bucket] = new Entry (a, b, h, value, buckets [bucket]);
 552
 553                         // Grow whenever we double in size
 554                         if (size++ == count) {
 555                                 count <<= 1;
 556                                 count ++;
 557
 558                                 Entry [] newBuckets = new Entry [count];
 559                                 foreach (Entry root in buckets) {
 560                                         Entry e = root;
 561                                         while (e != null) {
 562                                                 int newLoc = e.hash % count;
 563                                                 Entry n = e.next;
 564                                                 e.next = newBuckets [newLoc];
 565                                                 newBuckets [newLoc] = e;
 566                                                 e = n;
 567                                         }
 568                                 }
 569
 570                                 buckets = newBuckets;
 571                         }
 572                 }
 573         }
 574 }