mcs/gmcs/support.cs

   1 //
   2 // support.cs: Support routines to work around the fact that System.Reflection.Emit
   3 // can not introspect types that are being constructed
   4 //
   5 // Author:
   6 //   Miguel de Icaza (miguel@ximian.com)
   7 //
   8 // (C) 2001 Ximian, Inc (http://www.ximian.com)
   9 //
  10
  11 using System;
  12 using System.IO;
  13 using System.Text;
  14 using System.Reflection;
  15 using System.Collections;
  16 using System.Reflection.Emit;
  17 using System.Globalization;
  18
  19 namespace Mono.CSharp {
  20
  21         public interface ParameterData {
  22                 Type ParameterType (int pos);
  23                 Type [] Types { get; }
  24                 int  Count { get; }
  25                 bool HasParams { get; }
  26                 string ParameterName (int pos);
  27                 string ParameterDesc (int pos);
  28                 Parameter.Modifier ParameterModifier (int pos);
  29                 string GetSignatureForError ();
  30         }
  31
  32         public class ReflectionParameters : ParameterData {
  33                 ParameterInfo [] pi;
  34                 Type [] types;
  35                 bool last_arg_is_params = false;
  36                 bool is_varargs = false;
  37                 ParameterData gpd;
  38
  39                 public ReflectionParameters (MethodBase mb)
  40                 {
  41                         object [] attrs;
  42
  43                         ParameterInfo [] pi = mb.GetParameters ();
  44                         is_varargs = (mb.CallingConvention & CallingConventions.VarArgs) != 0;
  45
  46                         this.pi = pi;
  47                         int count = pi.Length-1;
  48
  49                         if (pi.Length == 0) {
  50                                 types = Type.EmptyTypes;
  51                         } else {
  52                                 types = new Type [pi.Length];
  53                                 for (int i = 0; i < pi.Length; i++)
  54                                         types [i] = pi [i].ParameterType;
  55                         }
  56
  57                         if (count < 0)
  58                                 return;
  59
  60                         MethodBase generic = TypeManager.DropGenericMethodArguments (mb);
  61                         if (generic != mb) {
  62                                 gpd = TypeManager.GetParameterData (generic);
  63                                 last_arg_is_params = gpd.HasParams;
  64                                 return;
  65                         }
  66
  67                         attrs = pi [count].GetCustomAttributes (TypeManager.param_array_type, true);
  68                         if (attrs == null)
  69                                 return;
  70
  71                         if (attrs.Length == 0)
  72                                 return;
  73
  74                         last_arg_is_params = true;
  75                 }
  76
  77                 public string GetSignatureForError ()
  78                 {
  79                         StringBuilder sb = new StringBuilder ("(");
  80                         for (int i = 0; i < pi.Length; ++i) {
  81                                 if (i != 0)
  82                                         sb.Append (", ");
  83                                 sb.Append (ParameterDesc (i));
  84                         }
  85                         if (is_varargs) {
  86                                 if (pi.Length > 0)
  87                                         sb.Append (", ");
  88                                 sb.Append ("__arglist");
  89                         }
  90                         sb.Append (')');
  91                         return sb.ToString ();
  92                 }
  93
  94                 public Type ParameterType (int pos)
  95                 {
  96                         if (last_arg_is_params && pos >= pi.Length - 1)
  97                                 return pi [pi.Length - 1].ParameterType;
  98                         else if (is_varargs && pos >= pi.Length)
  99                                 return TypeManager.runtime_argument_handle_type;
 100                         else {
 101                                 Type t = pi [pos].ParameterType;
 102
 103                                 return t;
 104                         }
 105                 }
 106
 107                 public string ParameterName (int pos)
 108                 {
 109                         if (gpd != null)
 110                                 return gpd.ParameterName (pos);
 111
 112                         if (last_arg_is_params && pos >= pi.Length - 1)
 113                                 return pi [pi.Length - 1].Name;
 114                         else if (is_varargs && pos >= pi.Length)
 115                                 return "__arglist";
 116                         else
 117                                 return pi [pos].Name;
 118                 }
 119
 120                 public string ParameterDesc (int pos)
 121                 {
 122                         if (is_varargs && pos >= pi.Length)
 123                                 return "";
 124
 125                         StringBuilder sb = new StringBuilder ();
 126
 127                         if (pi [pos].IsIn)
 128                                 sb.Append ("in ");
 129
 130                         Type partype = ParameterType (pos);
 131                         if (partype.IsByRef){
 132                                 partype = TypeManager.GetElementType (partype);
 133                                 if (pi [pos].IsOut)
 134                                         sb.Append ("out ");
 135                                 else
 136                                         sb.Append ("ref ");
 137                         }
 138
 139                         if (pos >= pi.Length - 1 && last_arg_is_params)
 140                                 sb.Append ("params ");
 141
 142                         sb.Append (TypeManager.CSharpName (partype).Replace ("&", ""));
 143
 144                         return sb.ToString ();
 145
 146                 }
 147
 148                 public Parameter.Modifier ParameterModifier (int pos)
 149                 {
 150                         if (last_arg_is_params && pos >= pi.Length - 1)
 151                                         return Parameter.Modifier.PARAMS;
 152                         else if (is_varargs && pos >= pi.Length)
 153                                 return Parameter.Modifier.ARGLIST;
 154
 155                         if (gpd != null)
 156                                 return gpd.ParameterModifier (pos);
 157
 158                         Type t = pi [pos].ParameterType;
 159                         if (t.IsByRef){
 160                                 if ((pi [pos].Attributes & (ParameterAttributes.Out|ParameterAttributes.In)) == ParameterAttributes.Out)
 161                                         return Parameter.Modifier.OUT;
 162                                 else
 163                                         return Parameter.Modifier.REF;
 164                         }
 165
 166                         return Parameter.Modifier.NONE;
 167                 }
 168
 169                 public int Count {
 170                         get {
 171                                 return is_varargs ? pi.Length + 1 : pi.Length;
 172                         }
 173                 }
 174
 175                 public bool HasParams {
 176                         get {
 177                                 return this.last_arg_is_params;
 178                         }
 179                 }
 180
 181                 public Type[] Types {
 182                         get {
 183                                 return types;
 184                         }
 185                 }
 186         }
 187
 188         public class ReflectionConstraints : GenericConstraints
 189         {
 190                 GenericParameterAttributes attrs;
 191                 Type base_type;
 192                 Type class_constraint;
 193                 Type[] iface_constraints;
 194                 string name;
 195
 196                 public static GenericConstraints GetConstraints (Type t)
 197                 {
 198                         Type [] constraints = t.GetGenericParameterConstraints ();
 199                         GenericParameterAttributes attrs = t.GenericParameterAttributes;
 200                         if (constraints.Length == 0 && attrs == GenericParameterAttributes.None)
 201                                 return null;
 202                         return new ReflectionConstraints (t.Name, constraints, attrs);
 203                 }
 204
 205                 private ReflectionConstraints (string name, Type [] constraints, GenericParameterAttributes attrs)
 206                 {
 207                         this.name = name;
 208                         this.attrs = attrs;
 209
 210                         if ((constraints.Length > 0) && !constraints [0].IsInterface) {
 211                                 class_constraint = constraints [0];
 212                                 iface_constraints = new Type [constraints.Length - 1];
 213                                 Array.Copy (constraints, 1, iface_constraints, 0, constraints.Length - 1);
 214                         } else
 215                                 iface_constraints = constraints;
 216
 217                         if (HasValueTypeConstraint)
 218                                 base_type = TypeManager.value_type;
 219                         else if (class_constraint != null)
 220                                 base_type = class_constraint;
 221                         else
 222                                 base_type = TypeManager.object_type;
 223                 }
 224
 225                 public override string TypeParameter {
 226                         get { return name; }
 227                 }
 228
 229                 public override GenericParameterAttributes Attributes {
 230                         get { return attrs; }
 231                 }
 232
 233                 public override Type ClassConstraint {
 234                         get { return class_constraint; }
 235                 }
 236
 237                 public override Type EffectiveBaseClass {
 238                         get { return base_type; }
 239                 }
 240
 241                 public override Type[] InterfaceConstraints {
 242                         get { return iface_constraints; }
 243                 }
 244         }
 245
 246         class PtrHashtable : Hashtable {
 247                 sealed class PtrComparer : IComparer {
 248                         private PtrComparer () {}
 249
 250                         public static PtrComparer Instance = new PtrComparer ();
 251
 252                         public int Compare (object x, object y)
 253                         {
 254                                 if (x == y)
 255                                         return 0;
 256                                 else
 257                                         return 1;
 258                         }
 259                 }
 260
 261                 public PtrHashtable ()
 262                 {
 263                         comparer = PtrComparer.Instance;
 264                 }
 265         }
 266
 267         /*
 268          * Hashtable whose keys are character arrays with the same length
 269          */
 270         class CharArrayHashtable : Hashtable {
 271                 sealed class ArrComparer : IComparer {
 272                         private int len;
 273
 274                         public ArrComparer (int len) {
 275                                 this.len = len;
 276                         }
 277
 278                         public int Compare (object x, object y)
 279                         {
 280                                 char[] a = (char[])x;
 281                                 char[] b = (char[])y;
 282
 283                                 for (int i = 0; i < len; ++i)
 284                                         if (a [i] != b [i])
 285                                                 return 1;
 286                                 return 0;
 287                         }
 288                 }
 289
 290                 private int len;
 291
 292                 protected override int GetHash (Object key)
 293                 {
 294                         char[] arr = (char[])key;
 295                         int h = 0;
 296
 297                         for (int i = 0; i < len; ++i)
 298                                 h = (h << 5) - h + arr [i];
 299
 300                         return h;
 301                 }
 302
 303                 public CharArrayHashtable (int len)
 304                 {
 305                         this.len = len;
 306                         comparer = new ArrComparer (len);
 307                 }
 308         }
 309
 310         struct Pair {
 311                 public object First;
 312                 public object Second;
 313
 314                 public Pair (object f, object s)
 315                 {
 316                         First = f;
 317                         Second = s;
 318                 }
 319         }
 320
 321         /// <summary>
 322         ///   This is a wrapper around StreamReader which is seekable backwards
 323         ///   within a window of around 2048 chars.
 324         /// </summary>
 325         public class SeekableStreamReader
 326         {
 327                 public SeekableStreamReader (StreamReader reader)
 328                 {
 329                         this.reader = reader;
 330                         this.buffer = new char [AverageReadLength * 3];
 331
 332                         // Let the StreamWriter autodetect the encoder
 333                         reader.Peek ();
 334                 }
 335
 336                 public SeekableStreamReader (Stream stream, Encoding encoding)
 337                         : this (new StreamReader (stream, encoding, true))
 338                 { }
 339
 340                 StreamReader reader;
 341
 342                 private const int AverageReadLength = 1024;
 343
 344                 char[] buffer;
 345                 int buffer_start;       // in chars
 346                 int char_count;         // count buffer[] valid characters
 347                 int pos;                // index into buffer[]
 348
 349                 /// <remarks>
 350                 ///   This value corresponds to the current position in a stream of characters.
 351                 ///   The StreamReader hides its manipulation of the underlying byte stream and all
 352                 ///   character set/decoding issues.  Thus, we cannot use this position to guess at
 353                 ///   the corresponding position in the underlying byte stream even though there is
 354                 ///   a correlation between them.
 355                 /// </remarks>
 356                 public int Position {
 357                         get { return buffer_start + pos; }
 358
 359                         set {
 360                                 if (value < buffer_start || value > buffer_start + char_count)
 361                                         throw new InternalErrorException ("can't seek that far back: " + (pos - value));
 362                                 pos = value - buffer_start;
 363                         }
 364                 }
 365
 366                 private bool ReadBuffer ()
 367                 {
 368                         int slack = buffer.Length - char_count;
 369                         if (slack <= AverageReadLength / 2) {
 370                                 // shift the buffer to make room for AverageReadLength number of characters
 371                                 int shift = AverageReadLength - slack;
 372                                 Array.Copy (buffer, shift, buffer, 0, char_count - shift);
 373                                 pos -= shift;
 374                                 char_count -= shift;
 375                                 buffer_start += shift;
 376                                 slack += shift;         // slack == AverageReadLength
 377                         }
 378
 379                         int chars_read = reader.Read (buffer, char_count, slack);
 380                         char_count += chars_read;
 381
 382                         return pos < char_count;
 383                 }
 384
 385                 public int Peek ()
 386                 {
 387                         if ((pos >= char_count) && !ReadBuffer ())
 388                                 return -1;
 389
 390                         return buffer [pos];
 391                 }
 392
 393                 public int Read ()
 394                 {
 395                         if ((pos >= char_count) && !ReadBuffer ())
 396                                 return -1;
 397
 398                         return buffer [pos++];
 399                 }
 400         }
 401
 402         public class DoubleHash {
 403                 const int DEFAULT_INITIAL_BUCKETS = 100;
 404
 405                 public DoubleHash () : this (DEFAULT_INITIAL_BUCKETS) {}
 406
 407                 public DoubleHash (int size)
 408                 {
 409                         count = size;
 410                         buckets = new Entry [size];
 411                 }
 412
 413                 int count;
 414                 Entry [] buckets;
 415                 int size = 0;
 416
 417                 class Entry {
 418                         public object key1;
 419                         public object key2;
 420                         public int hash;
 421                         public object value;
 422                         public Entry next;
 423
 424                         public Entry (object key1, object key2, int hash, object value, Entry next)
 425                         {
 426                                 this.key1 = key1;
 427                                 this.key2 = key2;
 428                                 this.hash = hash;
 429                                 this.next = next;
 430                                 this.value = value;
 431                         }
 432                 }
 433
 434                 public bool Lookup (object a, object b, out object res)
 435                 {
 436                         int h = (a.GetHashCode () ^ b.GetHashCode ()) & 0x7FFFFFFF;
 437
 438                         for (Entry e = buckets [h % count]; e != null; e = e.next) {
 439                                 if (e.hash == h && e.key1.Equals (a) && e.key2.Equals (b)) {
 440                                         res = e.value;
 441                                         return true;
 442                                 }
 443                         }
 444                         res = null;
 445                         return false;
 446                 }
 447
 448                 public void Insert (object a, object b, object value)
 449                 {
 450                         // Is it an existing one?
 451
 452                         int h = (a.GetHashCode () ^ b.GetHashCode ()) & 0x7FFFFFFF;
 453
 454                         for (Entry e = buckets [h % count]; e != null; e = e.next) {
 455                                 if (e.hash == h && e.key1.Equals (a) && e.key2.Equals (b))
 456                                         e.value = value;
 457                         }
 458
 459                         int bucket = h % count;
 460                         buckets [bucket] = new Entry (a, b, h, value, buckets [bucket]);
 461
 462                         // Grow whenever we double in size
 463                         if (size++ == count) {
 464                                 count <<= 1;
 465                                 count ++;
 466
 467                                 Entry [] newBuckets = new Entry [count];
 468                                 foreach (Entry root in buckets) {
 469                                         Entry e = root;
 470                                         while (e != null) {
 471                                                 int newLoc = e.hash % count;
 472                                                 Entry n = e.next;
 473                                                 e.next = newBuckets [newLoc];
 474                                                 newBuckets [newLoc] = e;
 475                                                 e = n;
 476                                         }
 477                                 }
 478
 479                                 buckets = newBuckets;
 480                         }
 481                 }
 482         }
 483 }