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