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                 int  Count { get; }
  24                 bool HasParams { get; }
  25                 string ParameterName (int pos);
  26                 string ParameterDesc (int pos);
  27                 Parameter.Modifier ParameterModifier (int pos);
  28                 string GetSignatureForError ();
  29         }
  30
  31         public class ReflectionParameters : ParameterData {
  32                 ParameterInfo [] pi;
  33                 bool last_arg_is_params = false;
  34                 bool is_varargs = false;
  35
  36                 public ReflectionParameters (MethodBase mb)
  37                 {
  38                         object [] attrs;
  39
  40                         ParameterInfo [] pi = mb.GetParameters ();
  41                         is_varargs = (mb.CallingConvention & CallingConventions.VarArgs) != 0;
  42
  43                         this.pi = pi;
  44                         int count = pi.Length-1;
  45
  46                         if (count >= 0) {
  47                                 attrs = pi [count].GetCustomAttributes (TypeManager.param_array_type, true);
  48
  49                                 if (attrs == null)
  50                                         return;
  51
  52                                 if (attrs.Length == 0)
  53                                         return;
  54
  55                                 last_arg_is_params = true;
  56                         }
  57                 }
  58
  59                 public string GetSignatureForError ()
  60                 {
  61                         StringBuilder sb = new StringBuilder ("(");
  62                         for (int i = 0; i < pi.Length; ++i) {
  63                                 if (i != 0)
  64                                         sb.Append (", ");
  65                                 sb.Append (ParameterDesc (i));
  66                         }
  67                         if (is_varargs) {
  68                                 if (pi.Length > 0)
  69                                         sb.Append (", ");
  70                                 sb.Append ("__arglist");
  71                         }
  72                         sb.Append (')');
  73                         return sb.ToString ();
  74                 }
  75
  76                 public Type ParameterType (int pos)
  77                 {
  78                         if (last_arg_is_params && pos >= pi.Length - 1)
  79                                 return pi [pi.Length - 1].ParameterType;
  80                         else if (is_varargs && pos >= pi.Length)
  81                                 return TypeManager.runtime_argument_handle_type;
  82                         else {
  83                                 Type t = pi [pos].ParameterType;
  84
  85                                 return t;
  86                         }
  87                 }
  88
  89                 public string ParameterName (int pos)
  90                 {
  91                         if (last_arg_is_params && pos >= pi.Length - 1)
  92                                 return pi [pi.Length - 1].Name;
  93                         else if (is_varargs && pos >= pi.Length)
  94                                 return "__arglist";
  95                         else
  96                                 return pi [pos].Name;
  97                 }
  98
  99                 public string ParameterDesc (int pos)
 100                 {
 101                         if (is_varargs && pos >= pi.Length)
 102                                 return "";
 103
 104                         StringBuilder sb = new StringBuilder ();
 105
 106                         if (pi [pos].IsIn)
 107                                 sb.Append ("in ");
 108
 109                         Type partype = ParameterType (pos);
 110                         if (partype.IsByRef){
 111                                 partype = TypeManager.GetElementType (partype);
 112                                 if (pi [pos].IsOut)
 113                                         sb.Append ("out ");
 114                                 else
 115                                         sb.Append ("ref ");
 116                         }
 117
 118                         if (pos >= pi.Length - 1 && last_arg_is_params)
 119                                 sb.Append ("params ");
 120
 121                         sb.Append (TypeManager.CSharpName (partype).Replace ("&", ""));
 122
 123                         return sb.ToString ();
 124
 125                 }
 126
 127                 public Parameter.Modifier ParameterModifier (int pos)
 128                 {
 129                         if (last_arg_is_params && pos >= pi.Length - 1)
 130                                 return Parameter.Modifier.PARAMS;
 131                         else if (is_varargs && pos >= pi.Length)
 132                                 return Parameter.Modifier.ARGLIST;
 133
 134                         Type t = pi [pos].ParameterType;
 135                         if (t.IsByRef){
 136                                 if ((pi [pos].Attributes & (ParameterAttributes.Out|ParameterAttributes.In)) == ParameterAttributes.Out)
 137                                         return Parameter.Modifier.ISBYREF | Parameter.Modifier.OUT;
 138                                 else
 139                                         return Parameter.Modifier.ISBYREF | Parameter.Modifier.REF;
 140                         }
 141
 142                         return Parameter.Modifier.NONE;
 143                 }
 144
 145                 public int Count {
 146                         get {
 147                                 return is_varargs ? pi.Length + 1 : pi.Length;
 148                         }
 149                 }
 150
 151                 public bool HasParams {
 152                         get {
 153                                 return this.last_arg_is_params;
 154                         }
 155                 }
 156
 157         }
 158
 159         public class InternalParameters : ParameterData {
 160                 Type [] param_types;
 161                 bool has_varargs;
 162                 int count;
 163
 164                 public readonly Parameters Parameters;
 165
 166                 public InternalParameters (Type [] param_types, Parameters parameters)
 167                 {
 168                         this.param_types = param_types;
 169                         this.Parameters = parameters;
 170
 171                         has_varargs = parameters.HasArglist;
 172
 173                         if (param_types == null)
 174                                 count = 0;
 175                         else
 176                                 count = param_types.Length;
 177                 }
 178
 179                 public int Count {
 180                         get {
 181                                 return has_varargs ? count + 1 : count;
 182                         }
 183                 }
 184
 185                 public bool HasParams {
 186                         get {
 187                                 return Parameters.ArrayParameter != null;
 188                         }
 189                 }
 190
 191                 Parameter GetParameter (int pos)
 192                 {
 193                         Parameter [] fixed_pars = Parameters.FixedParameters;
 194                         if (fixed_pars != null){
 195                                 int len = fixed_pars.Length;
 196                                 if (pos < len)
 197                                         return Parameters.FixedParameters [pos];
 198                         }
 199
 200                         return Parameters.ArrayParameter;
 201                 }
 202
 203                 public string GetSignatureForError ()
 204                 {
 205                         StringBuilder sb = new StringBuilder ("(");
 206                         for (int i = 0; i < count; ++i) {
 207                                 if (i != 0)
 208                                         sb.Append (", ");
 209                                 sb.Append (ParameterDesc (i));
 210                         }
 211                         if (has_varargs) {
 212                                 if (count > 0)
 213                                         sb.Append (", ");
 214                                 sb.Append ("__arglist");
 215                         }
 216                         sb.Append (')');
 217                         return sb.ToString ();
 218                 }
 219
 220                 public Type ParameterType (int pos)
 221                 {
 222                         if (has_varargs && pos >= count)
 223                                 return TypeManager.runtime_argument_handle_type;
 224
 225                         if (param_types == null)
 226                                 return null;
 227
 228                         return GetParameter (pos).ExternalType ();
 229                 }
 230
 231
 232                 public string ParameterName (int pos)
 233                 {
 234                         if (has_varargs && pos >= count)
 235                                 return "__arglist";
 236
 237                         return GetParameter (pos).Name;
 238                 }
 239
 240                 public string ParameterDesc (int pos)
 241                 {
 242                         if (has_varargs && pos >= count)
 243                                 return "__arglist";
 244
 245                         Type t = ParameterType (pos);
 246                         return (ModifierDesc (pos) + " " + TypeManager.CSharpName (t).Replace ("&", "")).TrimStart ();
 247                 }
 248
 249                 public string ModifierDesc (int pos)
 250                 {
 251                         Parameter p = GetParameter (pos);
 252
 253                         //
 254                         // We need to and for REF/OUT, because if either is set the
 255                         // extra flag ISBYREF will be set as well
 256                         //
 257                         if ((p.ModFlags & Parameter.Modifier.REF) != 0)
 258                                 return "ref";
 259                         if ((p.ModFlags & Parameter.Modifier.OUT) != 0)
 260                                 return "out";
 261                         if (p.ModFlags == Parameter.Modifier.PARAMS)
 262                                 return "params";
 263                         return "";
 264                 }
 265
 266                 public Parameter.Modifier ParameterModifier (int pos)
 267                 {
 268                         if (has_varargs && pos >= count)
 269                                 return Parameter.Modifier.ARGLIST;
 270
 271                         Parameter.Modifier mod = GetParameter (pos).ModFlags;
 272
 273                         if ((mod & (Parameter.Modifier.REF | Parameter.Modifier.OUT)) != 0)
 274                                 mod |= Parameter.Modifier.ISBYREF;
 275
 276                         return mod;
 277                 }
 278
 279         }
 280
 281         class PtrHashtable : Hashtable {
 282                 sealed class PtrComparer : IComparer {
 283                         private PtrComparer () {}
 284
 285                         public static PtrComparer Instance = new PtrComparer ();
 286
 287                         public int Compare (object x, object y)
 288                         {
 289                                 if (x == y)
 290                                         return 0;
 291                                 else
 292                                         return 1;
 293                         }
 294                 }
 295
 296                 public PtrHashtable ()
 297                 {
 298                         comparer = PtrComparer.Instance;
 299                 }
 300         }
 301
 302         /*
 303          * Hashtable whose keys are character arrays with the same length
 304          */
 305         class CharArrayHashtable : Hashtable {
 306                 sealed class ArrComparer : IComparer {
 307                         private int len;
 308
 309                         public ArrComparer (int len) {
 310                                 this.len = len;
 311                         }
 312
 313                         public int Compare (object x, object y)
 314                         {
 315                                 char[] a = (char[])x;
 316                                 char[] b = (char[])y;
 317
 318                                 for (int i = 0; i < len; ++i)
 319                                         if (a [i] != b [i])
 320                                                 return 1;
 321                                 return 0;
 322                         }
 323                 }
 324
 325                 private int len;
 326
 327                 protected override int GetHash (Object key)
 328                 {
 329                         char[] arr = (char[])key;
 330                         int h = 0;
 331
 332                         for (int i = 0; i < len; ++i)
 333                                 h = (h << 5) - h + arr [i];
 334
 335                         return h;
 336                 }
 337
 338                 public CharArrayHashtable (int len)
 339                 {
 340                         this.len = len;
 341                         comparer = new ArrComparer (len);
 342                 }
 343         }
 344
 345         struct Pair {
 346                 public object First;
 347                 public object Second;
 348
 349                 public Pair (object f, object s)
 350                 {
 351                         First = f;
 352                         Second = s;
 353                 }
 354         }
 355
 356         /// <summary>
 357         ///   This is a wrapper around StreamReader which is seekable backwards
 358         ///   within a window of around 2048 chars.
 359         /// </summary>
 360         public class SeekableStreamReader
 361         {
 362                 public SeekableStreamReader (StreamReader reader)
 363                 {
 364                         this.reader = reader;
 365                         this.buffer = new char [AverageReadLength * 3];
 366
 367                         // Let the StreamWriter autodetect the encoder
 368                         reader.Peek ();
 369                 }
 370
 371                 public SeekableStreamReader (Stream stream, Encoding encoding)
 372                         : this (new StreamReader (stream, encoding, true))
 373                 { }
 374
 375                 StreamReader reader;
 376
 377                 private const int AverageReadLength = 1024;
 378
 379                 char[] buffer;
 380                 int buffer_start;       // in chars
 381                 int char_count;         // count buffer[] valid characters
 382                 int pos;                // index into buffer[]
 383
 384                 /// <remarks>
 385                 ///   This value corresponds to the current position in a stream of characters.
 386                 ///   The StreamReader hides its manipulation of the underlying byte stream and all
 387                 ///   character set/decoding issues.  Thus, we cannot use this position to guess at
 388                 ///   the corresponding position in the underlying byte stream even though there is
 389                 ///   a correlation between them.
 390                 /// </remarks>
 391                 public int Position {
 392                         get { return buffer_start + pos; }
 393
 394                         set {
 395                                 if (value < buffer_start || value > buffer_start + char_count)
 396                                         throw new InternalErrorException ("can't seek that far back: " + (pos - value));
 397                                 pos = value - buffer_start;
 398                         }
 399                 }
 400
 401                 private bool ReadBuffer ()
 402                 {
 403                         int slack = buffer.Length - char_count;
 404                         if (slack <= AverageReadLength / 2) {
 405                                 // shift the buffer to make room for AverageReadLength number of characters
 406                                 int shift = AverageReadLength - slack;
 407                                 Array.Copy (buffer, shift, buffer, 0, char_count - shift);
 408                                 pos -= shift;
 409                                 char_count -= shift;
 410                                 buffer_start += shift;
 411                                 slack += shift;         // slack == AverageReadLength
 412                         }
 413
 414                         int chars_read = reader.Read (buffer, char_count, slack);
 415                         char_count += chars_read;
 416
 417                         return pos < char_count;
 418                 }
 419
 420                 public int Peek ()
 421                 {
 422                         if ((pos >= char_count) && !ReadBuffer ())
 423                                 return -1;
 424
 425                         return buffer [pos];
 426                 }
 427
 428                 public int Read ()
 429                 {
 430                         if ((pos >= char_count) && !ReadBuffer ())
 431                                 return -1;
 432
 433                         return buffer [pos++];
 434                 }
 435         }
 436
 437         public class DoubleHash {
 438                 const int DEFAULT_INITIAL_BUCKETS = 100;
 439
 440                 public DoubleHash () : this (DEFAULT_INITIAL_BUCKETS) {}
 441
 442                 public DoubleHash (int size)
 443                 {
 444                         count = size;
 445                         buckets = new Entry [size];
 446                 }
 447
 448                 int count;
 449                 Entry [] buckets;
 450                 int size = 0;
 451
 452                 class Entry {
 453                         public object key1;
 454                         public object key2;
 455                         public int hash;
 456                         public object value;
 457                         public Entry next;
 458
 459                         public Entry (object key1, object key2, int hash, object value, Entry next)
 460                         {
 461                                 this.key1 = key1;
 462                                 this.key2 = key2;
 463                                 this.hash = hash;
 464                                 this.next = next;
 465                                 this.value = value;
 466                         }
 467                 }
 468
 469                 public bool Lookup (object a, object b, out object res)
 470                 {
 471                         int h = (a.GetHashCode () ^ b.GetHashCode ()) & 0x7FFFFFFF;
 472
 473                         for (Entry e = buckets [h % count]; e != null; e = e.next) {
 474                                 if (e.hash == h && e.key1.Equals (a) && e.key2.Equals (b)) {
 475                                         res = e.value;
 476                                         return true;
 477                                 }
 478                         }
 479                         res = null;
 480                         return false;
 481                 }
 482
 483                 public void Insert (object a, object b, object value)
 484                 {
 485                         // Is it an existing one?
 486
 487                         int h = (a.GetHashCode () ^ b.GetHashCode ()) & 0x7FFFFFFF;
 488
 489                         for (Entry e = buckets [h % count]; e != null; e = e.next) {
 490                                 if (e.hash == h && e.key1.Equals (a) && e.key2.Equals (b))
 491                                         e.value = value;
 492                         }
 493
 494                         int bucket = h % count;
 495                         buckets [bucket] = new Entry (a, b, h, value, buckets [bucket]);
 496
 497                         // Grow whenever we double in size
 498                         if (size++ == count) {
 499                                 count <<= 1;
 500                                 count ++;
 501
 502                                 Entry [] newBuckets = new Entry [count];
 503                                 foreach (Entry root in buckets) {
 504                                         Entry e = root;
 505                                         while (e != null) {
 506                                                 int newLoc = e.hash % count;
 507                                                 Entry n = e.next;
 508                                                 e.next = newBuckets [newLoc];
 509                                                 newBuckets [newLoc] = e;
 510                                                 e = n;
 511                                         }
 512                                 }
 513
 514                                 buckets = newBuckets;
 515                         }
 516                 }
 517         }
 518 }