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