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