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                 GenericConstraints GenericConstraints (int pos);
  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[] type_params;
  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 (count < 0)
  50                                 return;
  51
  52                         if (mb.Mono_IsInflatedMethod) {
  53                                 MethodInfo generic = mb.GetGenericMethodDefinition ();
  54                                 gpd = TypeManager.GetParameterData (generic);
  55
  56                                 last_arg_is_params = gpd.HasParams;
  57                                 return;
  58                         }
  59
  60                         if (mb.IsGenericMethodDefinition)
  61                                 type_params = mb.GetGenericArguments ();
  62
  63                         attrs = pi [count].GetCustomAttributes (TypeManager.param_array_type, true);
  64                         if (attrs == null)
  65                                 return;
  66
  67                         if (attrs.Length == 0)
  68                                 return;
  69
  70                         last_arg_is_params = true;
  71                 }
  72
  73                 public string GetSignatureForError ()
  74                 {
  75                         StringBuilder sb = new StringBuilder ("(");
  76                         for (int i = 0; i < pi.Length; ++i) {
  77                                 if (i != 0)
  78                                         sb.Append (", ");
  79                                 sb.Append (ParameterDesc (i));
  80                         }
  81                         sb.Append (')');
  82                         return sb.ToString ();
  83                 }
  84
  85                 public Type ParameterType (int pos)
  86                 {
  87                         if (last_arg_is_params && pos >= pi.Length - 1)
  88                                 return pi [pi.Length - 1].ParameterType;
  89                         else if (is_varargs && pos >= pi.Length)
  90                                 return TypeManager.runtime_argument_handle_type;
  91                         else {
  92                                 Type t = pi [pos].ParameterType;
  93
  94                                 return t;
  95                         }
  96                 }
  97
  98                 public GenericConstraints GenericConstraints (int pos)
  99                 {
 100                         if (gpd != null)
 101                                 return gpd.GenericConstraints (pos);
 102
 103                         if (type_params == null)
 104                                 return null;
 105
 106                         return new ReflectionConstraints (type_params [pos]);
 107                 }
 108
 109                 public string ParameterName (int pos)
 110                 {
 111                         if (gpd != null)
 112                                 return gpd.ParameterName (pos);
 113
 114                         if (last_arg_is_params && pos >= pi.Length - 1)
 115                                 return pi [pi.Length - 1].Name;
 116                         else if (is_varargs && pos >= pi.Length)
 117                                 return "__arglist";
 118                         else
 119                                 return pi [pos].Name;
 120                 }
 121
 122                 public string ParameterDesc (int pos)
 123                 {
 124                         if (is_varargs && pos >= pi.Length)
 125                                 return "";
 126
 127                         StringBuilder sb = new StringBuilder ();
 128
 129                         if (pi [pos].IsIn)
 130                                 sb.Append ("in ");
 131
 132                         Type partype = ParameterType (pos);
 133                         if (partype.IsByRef){
 134                                 partype = TypeManager.GetElementType (partype);
 135                                 if (pi [pos].IsOut)
 136                                         sb.Append ("out ");
 137                                 else
 138                                         sb.Append ("ref ");
 139                         }
 140
 141                         if (pos >= pi.Length - 1 && last_arg_is_params)
 142                                 sb.Append ("params ");
 143
 144                         sb.Append (TypeManager.CSharpName (partype).Replace ("&", ""));
 145
 146                         return sb.ToString ();
 147
 148                 }
 149
 150                 public Parameter.Modifier ParameterModifier (int pos)
 151                 {
 152                         if (last_arg_is_params && pos >= pi.Length - 1)
 153                                         return Parameter.Modifier.PARAMS;
 154                         else if (is_varargs && pos >= pi.Length)
 155                                 return Parameter.Modifier.ARGLIST;
 156
 157                         if (gpd != null)
 158                                 return gpd.ParameterModifier (pos);
 159
 160                         Type t = pi [pos].ParameterType;
 161                         if (t.IsByRef){
 162                                 if ((pi [pos].Attributes & (ParameterAttributes.Out|ParameterAttributes.In)) == ParameterAttributes.Out)
 163                                         return Parameter.Modifier.ISBYREF | Parameter.Modifier.OUT;
 164                                 else
 165                                         return Parameter.Modifier.ISBYREF | Parameter.Modifier.REF;
 166                         }
 167
 168                         return Parameter.Modifier.NONE;
 169                 }
 170
 171                 public int Count {
 172                         get {
 173                                 return is_varargs ? pi.Length + 1 : pi.Length;
 174                         }
 175                 }
 176
 177                 public bool HasParams {
 178                         get {
 179                                 return this.last_arg_is_params;
 180                         }
 181                 }
 182         }
 183
 184         public class InternalParameters : ParameterData {
 185                 Type [] param_types;
 186                 bool has_varargs;
 187                 int count;
 188
 189                 public readonly Parameters Parameters;
 190                 public readonly TypeParameter[] TypeParameters;
 191
 192                 public InternalParameters (Type [] param_types, Parameters parameters)
 193                 {
 194                         this.param_types = param_types;
 195                         this.Parameters = parameters;
 196
 197                         has_varargs = parameters.HasArglist;
 198
 199                         if (param_types == null)
 200                                 count = 0;
 201                         else
 202                                 count = param_types.Length;
 203                 }
 204
 205                 public InternalParameters (Type [] param_types, Parameters parameters,
 206                                            TypeParameter [] type_params)
 207                         : this (param_types, parameters)
 208                 {
 209                         this.TypeParameters = type_params;
 210                 }
 211
 212                 public int Count {
 213                         get {
 214                                 return has_varargs ? count + 1 : count;
 215                         }
 216                 }
 217
 218                 public bool HasParams {
 219                         get {
 220                                 return Parameters.ArrayParameter != null;
 221                         }
 222                 }
 223
 224                 Parameter GetParameter (int pos)
 225                 {
 226                         Parameter [] fixed_pars = Parameters.FixedParameters;
 227                         if (fixed_pars != null){
 228                                 int len = fixed_pars.Length;
 229                                 if (pos < len)
 230                                         return Parameters.FixedParameters [pos];
 231                         }
 232
 233                         return Parameters.ArrayParameter;
 234                 }
 235
 236                 public string GetSignatureForError ()
 237                 {
 238                         StringBuilder sb = new StringBuilder ("(");
 239                         for (int i = 0; i < count; ++i) {
 240                                 if (i != 0)
 241                                         sb.Append (", ");
 242                                 sb.Append (ParameterDesc (i));
 243                         }
 244                         sb.Append (')');
 245                         return sb.ToString ();
 246                 }
 247
 248                 public Type ParameterType (int pos)
 249                 {
 250                         if (has_varargs && pos >= count)
 251                                 return TypeManager.runtime_argument_handle_type;
 252
 253                         if (param_types == null)
 254                                 return null;
 255
 256                         return GetParameter (pos).ExternalType ();
 257                 }
 258
 259                 public GenericConstraints GenericConstraints (int pos)
 260                 {
 261                         if (TypeParameters == null)
 262                                 return null;
 263
 264                         return TypeParameters [pos].Constraints;
 265                 }
 266
 267                 public string ParameterName (int pos)
 268                 {
 269                         if (has_varargs && pos >= count)
 270                                 return "__arglist";
 271
 272                         return GetParameter (pos).Name;
 273                 }
 274
 275                 public string ParameterDesc (int pos)
 276                 {
 277                         if (has_varargs && pos >= count)
 278                                 return "__arglist";
 279
 280                         Type t = ParameterType (pos);
 281                         return (ModifierDesc (pos) + " " + TypeManager.CSharpName (t).Replace ("&", "")).TrimStart ();
 282                 }
 283
 284                 public string ModifierDesc (int pos)
 285                 {
 286                         Parameter p = GetParameter (pos);
 287
 288                         //
 289                         // We need to and for REF/OUT, because if either is set the
 290                         // extra flag ISBYREF will be set as well
 291                         //
 292                         if ((p.ModFlags & Parameter.Modifier.REF) != 0)
 293                                 return "ref";
 294                         if ((p.ModFlags & Parameter.Modifier.OUT) != 0)
 295                                 return "out";
 296                         if (p.ModFlags == Parameter.Modifier.PARAMS)
 297                                 return "params";
 298
 299                         return "";
 300                 }
 301
 302                 public Parameter.Modifier ParameterModifier (int pos)
 303                 {
 304                         if (has_varargs && pos >= count)
 305                                 return Parameter.Modifier.ARGLIST;
 306
 307                         Parameter.Modifier mod = GetParameter (pos).ModFlags;
 308
 309                         if ((mod & (Parameter.Modifier.REF | Parameter.Modifier.OUT)) != 0)
 310                                 mod |= Parameter.Modifier.ISBYREF;
 311
 312                         return mod;
 313                 }
 314
 315         }
 316
 317         public class ReflectionConstraints : GenericConstraints
 318         {
 319                 GenericParameterAttributes attrs;
 320                 Type base_type;
 321                 Type class_constraint;
 322                 Type[] iface_constraints;
 323                 string name;
 324
 325                 public ReflectionConstraints (Type t)
 326                 {
 327                         name = t.Name;
 328                         Type[] constraints = t.GetGenericParameterConstraints ();
 329                         if ((constraints.Length > 0) && !constraints [0].IsInterface) {
 330                                 class_constraint = constraints [0];
 331                                 iface_constraints = new Type [constraints.Length - 1];
 332                                 Array.Copy (constraints, 1, iface_constraints, 0, constraints.Length - 1);
 333                         } else
 334                                 iface_constraints = constraints;
 335                         attrs = t.GenericParameterAttributes;
 336
 337                         if (HasValueTypeConstraint)
 338                                 base_type = TypeManager.value_type;
 339                         else if (class_constraint != null)
 340                                 base_type = class_constraint;
 341                         else
 342                                 base_type = TypeManager.object_type;
 343                 }
 344
 345                 public override string TypeParameter {
 346                         get { return name; }
 347                 }
 348
 349                 public override GenericParameterAttributes Attributes {
 350                         get { return attrs; }
 351                 }
 352
 353                 public override Type ClassConstraint {
 354                         get { return class_constraint; }
 355                 }
 356
 357                 public override Type EffectiveBaseClass {
 358                         get { return base_type; }
 359                 }
 360
 361                 public override Type[] InterfaceConstraints {
 362                         get { return iface_constraints; }
 363                 }
 364         }
 365
 366         class PtrHashtable : Hashtable {
 367                 sealed class PtrComparer : IComparer {
 368                         private PtrComparer () {}
 369
 370                         public static PtrComparer Instance = new PtrComparer ();
 371
 372                         public int Compare (object x, object y)
 373                         {
 374                                 if (x == y)
 375                                         return 0;
 376                                 else
 377                                         return 1;
 378                         }
 379                 }
 380
 381                 public PtrHashtable ()
 382                 {
 383                         comparer = PtrComparer.Instance;
 384                 }
 385         }
 386
 387         /*
 388          * Hashtable whose keys are character arrays with the same length
 389          */
 390         class CharArrayHashtable : Hashtable {
 391                 sealed class ArrComparer : IComparer {
 392                         private int len;
 393
 394                         public ArrComparer (int len) {
 395                                 this.len = len;
 396                         }
 397
 398                         public int Compare (object x, object y)
 399                         {
 400                                 char[] a = (char[])x;
 401                                 char[] b = (char[])y;
 402
 403                                 for (int i = 0; i < len; ++i)
 404                                         if (a [i] != b [i])
 405                                                 return 1;
 406                                 return 0;
 407                         }
 408                 }
 409
 410                 private int len;
 411
 412                 protected override int GetHash (Object key)
 413                 {
 414                         char[] arr = (char[])key;
 415                         int h = 0;
 416
 417                         for (int i = 0; i < len; ++i)
 418                                 h = (h << 5) - h + arr [i];
 419
 420                         return h;
 421                 }
 422
 423                 public CharArrayHashtable (int len)
 424                 {
 425                         this.len = len;
 426                         comparer = new ArrComparer (len);
 427                 }
 428         }
 429
 430         struct Pair {
 431                 public object First;
 432                 public object Second;
 433
 434                 public Pair (object f, object s)
 435                 {
 436                         First = f;
 437                         Second = s;
 438                 }
 439         }
 440
 441         /// <summary>
 442         ///   This is a wrapper around StreamReader which is seekable backwards
 443         ///   within a window of around 2048 chars.
 444         /// </summary>
 445         public class SeekableStreamReader
 446         {
 447                 public SeekableStreamReader (StreamReader reader)
 448                 {
 449                         this.reader = reader;
 450                         this.buffer = new char [AverageReadLength * 3];
 451
 452                         // Let the StreamWriter autodetect the encoder
 453                         reader.Peek ();
 454                 }
 455
 456                 public SeekableStreamReader (Stream stream, Encoding encoding)
 457                         : this (new StreamReader (stream, encoding, true))
 458                 { }
 459
 460                 StreamReader reader;
 461
 462                 private const int AverageReadLength = 1024;
 463
 464                 char[] buffer;
 465                 int buffer_start;       // in chars
 466                 int char_count;         // count buffer[] valid characters
 467                 int pos;                // index into buffer[]
 468
 469                 /// <remarks>
 470                 ///   This value corresponds to the current position in a stream of characters.
 471                 ///   The StreamReader hides its manipulation of the underlying byte stream and all
 472                 ///   character set/decoding issues.  Thus, we cannot use this position to guess at
 473                 ///   the corresponding position in the underlying byte stream even though there is
 474                 ///   a correlation between them.
 475                 /// </remarks>
 476                 public int Position {
 477                         get { return buffer_start + pos; }
 478
 479                         set {
 480                                 if (value < buffer_start || value > buffer_start + char_count)
 481                                         throw new InternalErrorException ("can't seek that far back: " + (pos - value));
 482                                 pos = value - buffer_start;
 483                         }
 484                 }
 485
 486                 private bool ReadBuffer ()
 487                 {
 488                         int slack = buffer.Length - char_count;
 489                         if (slack <= AverageReadLength / 2) {
 490                                 // shift the buffer to make room for AverageReadLength number of characters
 491                                 int shift = AverageReadLength - slack;
 492                                 Array.Copy (buffer, shift, buffer, 0, char_count - shift);
 493                                 pos -= shift;
 494                                 char_count -= shift;
 495                                 buffer_start += shift;
 496                                 slack += shift;         // slack == AverageReadLength
 497                         }
 498
 499                         int chars_read = reader.Read (buffer, char_count, slack);
 500                         char_count += chars_read;
 501
 502                         return pos < char_count;
 503                 }
 504
 505                 public int Peek ()
 506                 {
 507                         if ((pos >= char_count) && !ReadBuffer ())
 508                                 return -1;
 509
 510                         return buffer [pos];
 511                 }
 512
 513                 public int Read ()
 514                 {
 515                         if ((pos >= char_count) && !ReadBuffer ())
 516                                 return -1;
 517
 518                         return buffer [pos++];
 519                 }
 520         }
 521
 522         public class DoubleHash {
 523                 const int DEFAULT_INITIAL_BUCKETS = 100;
 524
 525                 public DoubleHash () : this (DEFAULT_INITIAL_BUCKETS) {}
 526
 527                 public DoubleHash (int size)
 528                 {
 529                         count = size;
 530                         buckets = new Entry [size];
 531                 }
 532
 533                 int count;
 534                 Entry [] buckets;
 535                 int size = 0;
 536
 537                 class Entry {
 538                         public object key1;
 539                         public object key2;
 540                         public int hash;
 541                         public object value;
 542                         public Entry next;
 543
 544                         public Entry (object key1, object key2, int hash, object value, Entry next)
 545                         {
 546                                 this.key1 = key1;
 547                                 this.key2 = key2;
 548                                 this.hash = hash;
 549                                 this.next = next;
 550                                 this.value = value;
 551                         }
 552                 }
 553
 554                 public bool Lookup (object a, object b, out object res)
 555                 {
 556                         int h = (a.GetHashCode () ^ b.GetHashCode ()) & 0x7FFFFFFF;
 557
 558                         for (Entry e = buckets [h % count]; e != null; e = e.next) {
 559                                 if (e.hash == h && e.key1.Equals (a) && e.key2.Equals (b)) {
 560                                         res = e.value;
 561                                         return true;
 562                                 }
 563                         }
 564                         res = null;
 565                         return false;
 566                 }
 567
 568                 public void Insert (object a, object b, object value)
 569                 {
 570                         // Is it an existing one?
 571
 572                         int h = (a.GetHashCode () ^ b.GetHashCode ()) & 0x7FFFFFFF;
 573
 574                         for (Entry e = buckets [h % count]; e != null; e = e.next) {
 575                                 if (e.hash == h && e.key1.Equals (a) && e.key2.Equals (b))
 576                                         e.value = value;
 577                         }
 578
 579                         int bucket = h % count;
 580                         buckets [bucket] = new Entry (a, b, h, value, buckets [bucket]);
 581
 582                         // Grow whenever we double in size
 583                         if (size++ == count) {
 584                                 count <<= 1;
 585                                 count ++;
 586
 587                                 Entry [] newBuckets = new Entry [count];
 588                                 foreach (Entry root in buckets) {
 589                                         Entry e = root;
 590                                         while (e != null) {
 591                                                 int newLoc = e.hash % count;
 592                                                 Entry n = e.next;
 593                                                 e.next = newBuckets [newLoc];
 594                                                 newBuckets [newLoc] = e;
 595                                                 e = n;
 596                                         }
 597                                 }
 598
 599                                 buckets = newBuckets;
 600                         }
 601                 }
 602         }
 603 }