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 // Copyright 2001 Ximian, Inc (http://www.ximian.com)
   9 // Copyright 2003-2008 Novell, Inc
  10 //
  11
  12 using System;
  13 using System.IO;
  14 using System.Text;
  15 using System.Reflection;
  16 using System.Collections;
  17 using System.Reflection.Emit;
  18 using System.Globalization;
  19
  20 namespace Mono.CSharp {
  21
  22 #if GMCS_SOURCE
  23         public class ReflectionConstraints : GenericConstraints
  24         {
  25                 GenericParameterAttributes attrs;
  26                 Type base_type;
  27                 Type class_constraint;
  28                 Type[] iface_constraints;
  29                 string name;
  30
  31                 public static GenericConstraints GetConstraints (Type t)
  32                 {
  33                         Type [] constraints = t.GetGenericParameterConstraints ();
  34                         GenericParameterAttributes attrs = t.GenericParameterAttributes;
  35                         if (constraints.Length == 0 && attrs == GenericParameterAttributes.None)
  36                                 return null;
  37                         return new ReflectionConstraints (t.Name, constraints, attrs);
  38                 }
  39
  40                 private ReflectionConstraints (string name, Type [] constraints, GenericParameterAttributes attrs)
  41                 {
  42                         this.name = name;
  43                         this.attrs = attrs;
  44
  45                         if ((constraints.Length > 0) && !constraints [0].IsInterface) {
  46                                 class_constraint = constraints [0];
  47                                 iface_constraints = new Type [constraints.Length - 1];
  48                                 Array.Copy (constraints, 1, iface_constraints, 0, constraints.Length - 1);
  49                         } else
  50                                 iface_constraints = constraints;
  51
  52                         if (HasValueTypeConstraint)
  53                                 base_type = TypeManager.value_type;
  54                         else if (class_constraint != null)
  55                                 base_type = class_constraint;
  56                         else
  57                                 base_type = TypeManager.object_type;
  58                 }
  59
  60                 public override string TypeParameter {
  61                         get { return name; }
  62                 }
  63
  64                 public override GenericParameterAttributes Attributes {
  65                         get { return attrs; }
  66                 }
  67
  68                 public override Type ClassConstraint {
  69                         get { return class_constraint; }
  70                 }
  71
  72                 public override Type EffectiveBaseClass {
  73                         get { return base_type; }
  74                 }
  75
  76                 public override Type[] InterfaceConstraints {
  77                         get { return iface_constraints; }
  78                 }
  79         }
  80 #endif
  81
  82         class PtrHashtable : Hashtable {
  83                 sealed class PtrComparer : IComparer {
  84                         private PtrComparer () {}
  85
  86                         public static PtrComparer Instance = new PtrComparer ();
  87
  88                         public int Compare (object x, object y)
  89                         {
  90                                 if (x == y)
  91                                         return 0;
  92                                 else
  93                                         return 1;
  94                         }
  95                 }
  96
  97                 public PtrHashtable ()
  98                 {
  99                         comparer = PtrComparer.Instance;
 100                 }
 101
 102 #if MS_COMPATIBLE
 103                 //
 104                 // Workaround System.InvalidOperationException for enums
 105                 //
 106                 protected override int GetHash (object key)
 107                 {
 108                         TypeBuilder tb = key as TypeBuilder;
 109                         if (tb != null && tb.BaseType == TypeManager.enum_type)
 110                                 key = tb.BaseType;
 111
 112                         return base.GetHash (key);
 113                 }
 114 #endif
 115         }
 116
 117         /*
 118          * Hashtable whose keys are character arrays with the same length
 119          */
 120         class CharArrayHashtable : Hashtable {
 121                 sealed class ArrComparer : IComparer {
 122                         private int len;
 123
 124                         public ArrComparer (int len) {
 125                                 this.len = len;
 126                         }
 127
 128                         public int Compare (object x, object y)
 129                         {
 130                                 char[] a = (char[])x;
 131                                 char[] b = (char[])y;
 132
 133                                 for (int i = 0; i < len; ++i)
 134                                         if (a [i] != b [i])
 135                                                 return 1;
 136                                 return 0;
 137                         }
 138                 }
 139
 140                 private int len;
 141
 142                 protected override int GetHash (Object key)
 143                 {
 144                         char[] arr = (char[])key;
 145                         int h = 0;
 146
 147                         for (int i = 0; i < len; ++i)
 148                                 h = (h << 5) - h + arr [i];
 149
 150                         return h;
 151                 }
 152
 153                 public CharArrayHashtable (int len)
 154                 {
 155                         this.len = len;
 156                         comparer = new ArrComparer (len);
 157                 }
 158         }
 159
 160         struct Pair {
 161                 public object First;
 162                 public object Second;
 163
 164                 public Pair (object f, object s)
 165                 {
 166                         First = f;
 167                         Second = s;
 168                 }
 169         }
 170
 171         public class Accessors {
 172                 public Accessor get_or_add;
 173                 public Accessor set_or_remove;
 174
 175                 // was 'set' declared before 'get'?  was 'remove' declared before 'add'?
 176                 public bool declared_in_reverse;
 177
 178                 public Accessors (Accessor get_or_add, Accessor set_or_remove)
 179                 {
 180                         this.get_or_add = get_or_add;
 181                         this.set_or_remove = set_or_remove;
 182                 }
 183         }
 184
 185         /// <summary>
 186         ///   This is a wrapper around StreamReader which is seekable backwards
 187         ///   within a window of around 2048 chars.
 188         /// </summary>
 189         public class SeekableStreamReader
 190         {
 191                 const int AverageReadLength = 1024;
 192                 TextReader reader;
 193                 Stream stream;
 194                 Encoding encoding;
 195
 196                 char[] buffer;
 197                 int buffer_start;       // in chars
 198                 int char_count;         // count buffer[] valid characters
 199                 int pos;                // index into buffer[]
 200
 201                 public SeekableStreamReader (Stream stream, Encoding encoding)
 202                 {
 203                         this.stream = stream;
 204                         this.encoding = encoding;
 205
 206                         this.reader = new StreamReader (stream, encoding, true);
 207                         this.buffer = new char [AverageReadLength * 3];
 208
 209                         // Let the StreamWriter autodetect the encoder
 210                         reader.Peek ();
 211                 }
 212
 213                 /// <remarks>
 214                 ///   This value corresponds to the current position in a stream of characters.
 215                 ///   The StreamReader hides its manipulation of the underlying byte stream and all
 216                 ///   character set/decoding issues.  Thus, we cannot use this position to guess at
 217                 ///   the corresponding position in the underlying byte stream even though there is
 218                 ///   a correlation between them.
 219                 /// </remarks>
 220                 public int Position {
 221                         get { return buffer_start + pos; }
 222
 223                         set {
 224                                 if (value > buffer_start + char_count)
 225                                         throw new InternalErrorException ("can't seek that far forward: " + (pos - value));
 226
 227                                 if (value < buffer_start){
 228                                         // Reinitialize.
 229                                         stream.Position = 0;
 230                                         reader = new StreamReader (stream, encoding, true);
 231                                         buffer_start = 0;
 232                                         char_count = 0;
 233                                         pos = 0;
 234                                         Peek ();
 235
 236                                         while (value > buffer_start + char_count){
 237                                                 pos = char_count+1;
 238                                                 Peek ();
 239                                         }
 240                                         pos = value - buffer_start;
 241                                 }
 242
 243                                 pos = value - buffer_start;
 244                         }
 245                 }
 246
 247                 private bool ReadBuffer ()
 248                 {
 249                         int slack = buffer.Length - char_count;
 250                         if (slack <= AverageReadLength / 2) {
 251                                 // shift the buffer to make room for AverageReadLength number of characters
 252                                 int shift = AverageReadLength - slack;
 253                                 Array.Copy (buffer, shift, buffer, 0, char_count - shift);
 254                                 pos -= shift;
 255                                 char_count -= shift;
 256                                 buffer_start += shift;
 257                                 slack += shift;         // slack == AverageReadLength
 258                         }
 259
 260                         int chars_read = reader.Read (buffer, char_count, slack);
 261                         char_count += chars_read;
 262
 263                         return pos < char_count;
 264                 }
 265
 266                 public int Peek ()
 267                 {
 268                         if ((pos >= char_count) && !ReadBuffer ())
 269                                 return -1;
 270
 271                         return buffer [pos];
 272                 }
 273
 274                 public int Read ()
 275                 {
 276                         if ((pos >= char_count) && !ReadBuffer ())
 277                                 return -1;
 278
 279                         return buffer [pos++];
 280                 }
 281         }
 282
 283         public class DoubleHash {
 284                 const int DEFAULT_INITIAL_BUCKETS = 100;
 285
 286                 public DoubleHash () : this (DEFAULT_INITIAL_BUCKETS) {}
 287
 288                 public DoubleHash (int size)
 289                 {
 290                         count = size;
 291                         buckets = new Entry [size];
 292                 }
 293
 294                 int count;
 295                 Entry [] buckets;
 296                 int size = 0;
 297
 298                 class Entry {
 299                         public object key1;
 300                         public object key2;
 301                         public int hash;
 302                         public object value;
 303                         public Entry next;
 304
 305                         public Entry (object key1, object key2, int hash, object value, Entry next)
 306                         {
 307                                 this.key1 = key1;
 308                                 this.key2 = key2;
 309                                 this.hash = hash;
 310                                 this.next = next;
 311                                 this.value = value;
 312                         }
 313                 }
 314
 315                 public bool Lookup (object a, object b, out object res)
 316                 {
 317                         int h = (a.GetHashCode () ^ b.GetHashCode ()) & 0x7FFFFFFF;
 318
 319                         for (Entry e = buckets [h % count]; e != null; e = e.next) {
 320                                 if (e.hash == h && e.key1.Equals (a) && e.key2.Equals (b)) {
 321                                         res = e.value;
 322                                         return true;
 323                                 }
 324                         }
 325                         res = null;
 326                         return false;
 327                 }
 328
 329                 public void Insert (object a, object b, object value)
 330                 {
 331                         // Is it an existing one?
 332
 333                         int h = (a.GetHashCode () ^ b.GetHashCode ()) & 0x7FFFFFFF;
 334
 335                         for (Entry e = buckets [h % count]; e != null; e = e.next) {
 336                                 if (e.hash == h && e.key1.Equals (a) && e.key2.Equals (b))
 337                                         e.value = value;
 338                         }
 339
 340                         int bucket = h % count;
 341                         buckets [bucket] = new Entry (a, b, h, value, buckets [bucket]);
 342
 343                         // Grow whenever we double in size
 344                         if (size++ == count) {
 345                                 count <<= 1;
 346                                 count ++;
 347
 348                                 Entry [] newBuckets = new Entry [count];
 349                                 foreach (Entry root in buckets) {
 350                                         Entry e = root;
 351                                         while (e != null) {
 352                                                 int newLoc = e.hash % count;
 353                                                 Entry n = e.next;
 354                                                 e.next = newBuckets [newLoc];
 355                                                 newBuckets [newLoc] = e;
 356                                                 e = n;
 357                                         }
 358                                 }
 359
 360                                 buckets = newBuckets;
 361                         }
 362                 }
 363         }
 364
 365         class PartialMethodDefinitionInfo : MethodInfo
 366         {
 367                 MethodOrOperator mc;
 368                 MethodAttributes attrs;
 369
 370                 public PartialMethodDefinitionInfo (MethodOrOperator mc)
 371                 {
 372                         this.mc = mc;
 373                         if ((mc.ModFlags & Modifiers.STATIC) != 0)
 374                                 attrs = MethodAttributes.Static;
 375                 }
 376
 377                 public override MethodInfo GetBaseDefinition ()
 378                 {
 379                         throw new NotImplementedException ();
 380                 }
 381
 382                 public override ICustomAttributeProvider ReturnTypeCustomAttributes
 383                 {
 384                         get { throw new NotImplementedException (); }
 385                 }
 386
 387                 public override MethodAttributes Attributes
 388                 {
 389                         get { return attrs; }
 390                 }
 391
 392                 public override MethodImplAttributes GetMethodImplementationFlags ()
 393                 {
 394                         throw new NotImplementedException ();
 395                 }
 396
 397                 public override ParameterInfo [] GetParameters ()
 398                 {
 399                         throw new NotImplementedException ();
 400                 }
 401
 402                 public override object Invoke (object obj, BindingFlags invokeAttr, Binder binder, object [] parameters, CultureInfo culture)
 403                 {
 404                         throw new NotImplementedException ();
 405                 }
 406
 407                 public override RuntimeMethodHandle MethodHandle
 408                 {
 409                         get { throw new NotImplementedException (); }
 410                 }
 411
 412                 public override Type DeclaringType
 413                 {
 414                         get { return mc.Parent.TypeBuilder; }
 415                 }
 416
 417                 public override object [] GetCustomAttributes (Type attributeType, bool inherit)
 418                 {
 419                         throw new NotImplementedException ();
 420                 }
 421
 422                 public override object [] GetCustomAttributes (bool inherit)
 423                 {
 424                         throw new NotImplementedException ();
 425                 }
 426
 427                 public override Type ReturnType {
 428                         get {
 429                                 return mc.MemberType;
 430                         }
 431                 }
 432
 433                 public override bool IsDefined (Type attributeType, bool inherit)
 434                 {
 435                         throw new NotImplementedException ();
 436                 }
 437
 438                 public override string Name
 439                 {
 440                         get { return mc.Name; }
 441                 }
 442
 443                 public override Type ReflectedType
 444                 {
 445                         get { throw new NotImplementedException (); }
 446                 }
 447         }
 448
 449 }