class/Mono.Cecil/Mono.Cecil.Metadata/Utilities.cs

   1 //
   2 // Utilities.cs
   3 //
   4 // Author:
   5 //   Jb Evain (jbevain@gmail.com)
   6 //
   7 // Generated by /CodeGen/cecil-gen.rb do not edit
   8 // Sat Feb 16 23:23:29 +0100 2008
   9 //
  10 // (C) 2005 Jb Evain
  11 //
  12 // Permission is hereby granted, free of charge, to any person obtaining
  13 // a copy of this software and associated documentation files (the
  14 // "Software"), to deal in the Software without restriction, including
  15 // without limitation the rights to use, copy, modify, merge, publish,
  16 // distribute, sublicense, and/or sell copies of the Software, and to
  17 // permit persons to whom the Software is furnished to do so, subject to
  18 // the following conditions:
  19 //
  20 // The above copyright notice and this permission notice shall be
  21 // included in all copies or substantial portions of the Software.
  22 //
  23 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  24 // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  25 // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  26 // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
  27 // LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
  28 // OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  29 // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  30 //
  31
  32 namespace Mono.Cecil.Metadata {
  33
  34         using System;
  35         using System.Collections;
  36         using System.IO;
  37
  38         sealed class Utilities {
  39
  40                 Utilities ()
  41                 {
  42                 }
  43
  44                 public static int ReadCompressedInteger (byte [] data, int pos, out int start)
  45                 {
  46                         int integer;
  47                         start = pos;
  48                         if ((data [pos] & 0x80) == 0) {
  49                                 integer = data [pos];
  50                                 start++;
  51                         } else if ((data [pos] & 0x40) == 0) {
  52                                 integer = (data [start] & ~0x80) << 8;
  53                                 integer |= data [pos + 1];
  54                                 start += 2;
  55                         } else {
  56                                 integer = (data [start] & ~0xc0) << 24;
  57                                 integer |= data [pos + 1] << 16;
  58                                 integer |= data [pos + 2] << 8;
  59                                 integer |= data [pos + 3];
  60                                 start += 4;
  61                         }
  62                         return integer;
  63                 }
  64
  65                 public static int ReadCompressedSignedInteger (byte [] data, int pos, out int start)
  66                 {
  67                         int integer = ReadCompressedInteger (data, pos, out start) >> 1;
  68                         if ((integer & 1) == 0)
  69                                 return integer;
  70
  71                         if (integer < 0x40)
  72                                 return integer - 0x40;
  73
  74                         if (integer < 0x2000)
  75                                 return integer - 0x2000;
  76
  77                         if (integer < 0x10000000)
  78                                 return integer - 0x10000000;
  79
  80                         return integer - 0x20000000;
  81                 }
  82
  83                 public static int WriteCompressedInteger (BinaryWriter writer, int value)
  84                 {
  85                         if (value < 0x80)
  86                                 writer.Write ((byte) value);
  87                         else if (value < 0x4000) {
  88                                 writer.Write ((byte) (0x80 | (value >> 8)));
  89                                 writer.Write ((byte) (value & 0xff));
  90                         } else {
  91                                 writer.Write ((byte) ((value >> 24) | 0xc0));
  92                                 writer.Write ((byte) ((value >> 16) & 0xff));
  93                                 writer.Write ((byte) ((value >> 8) & 0xff));
  94                                 writer.Write ((byte) (value & 0xff));
  95                         }
  96                         return (int) writer.BaseStream.Position;
  97                 }
  98
  99                 public static MetadataToken GetMetadataToken (CodedIndex cidx, uint data)
 100                 {
 101                         uint rid = 0;
 102                         switch (cidx) {
 103                         case CodedIndex.TypeDefOrRef :
 104                                 rid = data >> 2;
 105                                 switch (data & 3) {
 106                                 case 0 :
 107                                         return new MetadataToken (TokenType.TypeDef, rid);
 108                                 case 1 :
 109                                         return new MetadataToken (TokenType.TypeRef, rid);
 110                                 case 2 :
 111                                         return new MetadataToken (TokenType.TypeSpec, rid);
 112                                 default :
 113                                         return MetadataToken.Zero;
 114                                 }
 115                         case CodedIndex.HasConstant :
 116                                 rid = data >> 2;
 117                                 switch (data & 3) {
 118                                 case 0 :
 119                                         return new MetadataToken (TokenType.Field, rid);
 120                                 case 1 :
 121                                         return new MetadataToken (TokenType.Param, rid);
 122                                 case 2 :
 123                                         return new MetadataToken (TokenType.Property, rid);
 124                                 default :
 125                                         return MetadataToken.Zero;
 126                                 }
 127                         case CodedIndex.HasCustomAttribute :
 128                                 rid = data >> 5;
 129                                 switch (data & 31) {
 130                                 case 0 :
 131                                         return new MetadataToken (TokenType.Method, rid);
 132                                 case 1 :
 133                                         return new MetadataToken (TokenType.Field, rid);
 134                                 case 2 :
 135                                         return new MetadataToken (TokenType.TypeRef, rid);
 136                                 case 3 :
 137                                         return new MetadataToken (TokenType.TypeDef, rid);
 138                                 case 4 :
 139                                         return new MetadataToken (TokenType.Param, rid);
 140                                 case 5 :
 141                                         return new MetadataToken (TokenType.InterfaceImpl, rid);
 142                                 case 6 :
 143                                         return new MetadataToken (TokenType.MemberRef, rid);
 144                                 case 7 :
 145                                         return new MetadataToken (TokenType.Module, rid);
 146                                 case 8 :
 147                                         return new MetadataToken (TokenType.Permission, rid);
 148                                 case 9 :
 149                                         return new MetadataToken (TokenType.Property, rid);
 150                                 case 10 :
 151                                         return new MetadataToken (TokenType.Event, rid);
 152                                 case 11 :
 153                                         return new MetadataToken (TokenType.Signature, rid);
 154                                 case 12 :
 155                                         return new MetadataToken (TokenType.ModuleRef, rid);
 156                                 case 13 :
 157                                         return new MetadataToken (TokenType.TypeSpec, rid);
 158                                 case 14 :
 159                                         return new MetadataToken (TokenType.Assembly, rid);
 160                                 case 15 :
 161                                         return new MetadataToken (TokenType.AssemblyRef, rid);
 162                                 case 16 :
 163                                         return new MetadataToken (TokenType.File, rid);
 164                                 case 17 :
 165                                         return new MetadataToken (TokenType.ExportedType, rid);
 166                                 case 18 :
 167                                         return new MetadataToken (TokenType.ManifestResource, rid);
 168                                 case 19 :
 169                                         return new MetadataToken (TokenType.GenericParam, rid);
 170                                 default :
 171                                         return MetadataToken.Zero;
 172                                 }
 173                         case CodedIndex.HasFieldMarshal :
 174                                 rid = data >> 1;
 175                                 switch (data & 1) {
 176                                 case 0 :
 177                                         return new MetadataToken (TokenType.Field, rid);
 178                                 case 1 :
 179                                         return new MetadataToken (TokenType.Param, rid);
 180                                 default :
 181                                         return MetadataToken.Zero;
 182                                 }
 183                         case CodedIndex.HasDeclSecurity :
 184                                 rid = data >> 2;
 185                                 switch (data & 3) {
 186                                 case 0 :
 187                                         return new MetadataToken (TokenType.TypeDef, rid);
 188                                 case 1 :
 189                                         return new MetadataToken (TokenType.Method, rid);
 190                                 case 2 :
 191                                         return new MetadataToken (TokenType.Assembly, rid);
 192                                 default :
 193                                         return MetadataToken.Zero;
 194                                 }
 195                         case CodedIndex.MemberRefParent :
 196                                 rid = data >> 3;
 197                                 switch (data & 7) {
 198                                 case 0 :
 199                                         return new MetadataToken (TokenType.TypeDef, rid);
 200                                 case 1 :
 201                                         return new MetadataToken (TokenType.TypeRef, rid);
 202                                 case 2 :
 203                                         return new MetadataToken (TokenType.ModuleRef, rid);
 204                                 case 3 :
 205                                         return new MetadataToken (TokenType.Method, rid);
 206                                 case 4 :
 207                                         return new MetadataToken (TokenType.TypeSpec, rid);
 208                                 default :
 209                                         return MetadataToken.Zero;
 210                                 }
 211                         case CodedIndex.HasSemantics :
 212                                 rid = data >> 1;
 213                                 switch (data & 1) {
 214                                 case 0 :
 215                                         return new MetadataToken (TokenType.Event, rid);
 216                                 case 1 :
 217                                         return new MetadataToken (TokenType.Property, rid);
 218                                 default :
 219                                         return MetadataToken.Zero;
 220                                 }
 221                         case CodedIndex.MethodDefOrRef :
 222                                 rid = data >> 1;
 223                                 switch (data & 1) {
 224                                 case 0 :
 225                                         return new MetadataToken (TokenType.Method, rid);
 226                                 case 1 :
 227                                         return new MetadataToken (TokenType.MemberRef, rid);
 228                                 default :
 229                                         return MetadataToken.Zero;
 230                                 }
 231                         case CodedIndex.MemberForwarded :
 232                                 rid = data >> 1;
 233                                 switch (data & 1) {
 234                                 case 0 :
 235                                         return new MetadataToken (TokenType.Field, rid);
 236                                 case 1 :
 237                                         return new MetadataToken (TokenType.Method, rid);
 238                                 default :
 239                                         return MetadataToken.Zero;
 240                                 }
 241                         case CodedIndex.Implementation :
 242                                 rid = data >> 2;
 243                                 switch (data & 3) {
 244                                 case 0 :
 245                                         return new MetadataToken (TokenType.File, rid);
 246                                 case 1 :
 247                                         return new MetadataToken (TokenType.AssemblyRef, rid);
 248                                 case 2 :
 249                                         return new MetadataToken (TokenType.ExportedType, rid);
 250                                 default :
 251                                         return MetadataToken.Zero;
 252                                 }
 253                         case CodedIndex.CustomAttributeType :
 254                                 rid = data >> 3;
 255                                 switch (data & 7) {
 256                                 case 2 :
 257                                         return new MetadataToken (TokenType.Method, rid);
 258                                 case 3 :
 259                                         return new MetadataToken (TokenType.MemberRef, rid);
 260                                 default :
 261                                         return MetadataToken.Zero;
 262                                 }
 263                         case CodedIndex.ResolutionScope :
 264                                 rid = data >> 2;
 265                                 switch (data & 3) {
 266                                 case 0 :
 267                                         return new MetadataToken (TokenType.Module, rid);
 268                                 case 1 :
 269                                         return new MetadataToken (TokenType.ModuleRef, rid);
 270                                 case 2 :
 271                                         return new MetadataToken (TokenType.AssemblyRef, rid);
 272                                 case 3 :
 273                                         return new MetadataToken (TokenType.TypeRef, rid);
 274                                 default :
 275                                         return MetadataToken.Zero;
 276                                 }
 277                         case CodedIndex.TypeOrMethodDef :
 278                                 rid = data >> 1;
 279                                 switch (data & 1) {
 280                                 case 0 :
 281                                         return new MetadataToken (TokenType.TypeDef, rid);
 282                                 case 1 :
 283                                         return new MetadataToken (TokenType.Method, rid);
 284                                 default :
 285                                         return MetadataToken.Zero;
 286                                 }
 287                         default :
 288                                 return MetadataToken.Zero;
 289                         }
 290                 }
 291
 292                 public static uint CompressMetadataToken (CodedIndex cidx, MetadataToken token)
 293                 {
 294                         uint ret = 0;
 295                         if (token.RID == 0)
 296                                 return ret;
 297                         switch (cidx) {
 298                         case CodedIndex.TypeDefOrRef :
 299                                 ret = token.RID << 2;
 300                                 switch (token.TokenType) {
 301                                 case TokenType.TypeDef :
 302                                         return ret | 0;
 303                                 case TokenType.TypeRef :
 304                                         return ret | 1;
 305                                 case TokenType.TypeSpec :
 306                                         return ret | 2;
 307                                 default :
 308                                         throw new MetadataFormatException("Non valid Token for TypeDefOrRef");
 309                                 }
 310                         case CodedIndex.HasConstant :
 311                                 ret = token.RID << 2;
 312                                 switch (token.TokenType) {
 313                                 case TokenType.Field :
 314                                         return ret | 0;
 315                                 case TokenType.Param :
 316                                         return ret | 1;
 317                                 case TokenType.Property :
 318                                         return ret | 2;
 319                                 default :
 320                                         throw new MetadataFormatException("Non valid Token for HasConstant");
 321                                 }
 322                         case CodedIndex.HasCustomAttribute :
 323                                 ret = token.RID << 5;
 324                                 switch (token.TokenType) {
 325                                 case TokenType.Method :
 326                                         return ret | 0;
 327                                 case TokenType.Field :
 328                                         return ret | 1;
 329                                 case TokenType.TypeRef :
 330                                         return ret | 2;
 331                                 case TokenType.TypeDef :
 332                                         return ret | 3;
 333                                 case TokenType.Param :
 334                                         return ret | 4;
 335                                 case TokenType.InterfaceImpl :
 336                                         return ret | 5;
 337                                 case TokenType.MemberRef :
 338                                         return ret | 6;
 339                                 case TokenType.Module :
 340                                         return ret | 7;
 341                                 case TokenType.Permission :
 342                                         return ret | 8;
 343                                 case TokenType.Property :
 344                                         return ret | 9;
 345                                 case TokenType.Event :
 346                                         return ret | 10;
 347                                 case TokenType.Signature :
 348                                         return ret | 11;
 349                                 case TokenType.ModuleRef :
 350                                         return ret | 12;
 351                                 case TokenType.TypeSpec :
 352                                         return ret | 13;
 353                                 case TokenType.Assembly :
 354                                         return ret | 14;
 355                                 case TokenType.AssemblyRef :
 356                                         return ret | 15;
 357                                 case TokenType.File :
 358                                         return ret | 16;
 359                                 case TokenType.ExportedType :
 360                                         return ret | 17;
 361                                 case TokenType.ManifestResource :
 362                                         return ret | 18;
 363                                 case TokenType.GenericParam :
 364                                         return ret | 19;
 365                                 default :
 366                                         throw new MetadataFormatException("Non valid Token for HasCustomAttribute");
 367                                 }
 368                         case CodedIndex.HasFieldMarshal :
 369                                 ret = token.RID << 1;
 370                                 switch (token.TokenType) {
 371                                 case TokenType.Field :
 372                                         return ret | 0;
 373                                 case TokenType.Param :
 374                                         return ret | 1;
 375                                 default :
 376                                         throw new MetadataFormatException("Non valid Token for HasFieldMarshal");
 377                                 }
 378                         case CodedIndex.HasDeclSecurity :
 379                                 ret = token.RID << 2;
 380                                 switch (token.TokenType) {
 381                                 case TokenType.TypeDef :
 382                                         return ret | 0;
 383                                 case TokenType.Method :
 384                                         return ret | 1;
 385                                 case TokenType.Assembly :
 386                                         return ret | 2;
 387                                 default :
 388                                         throw new MetadataFormatException("Non valid Token for HasDeclSecurity");
 389                                 }
 390                         case CodedIndex.MemberRefParent :
 391                                 ret = token.RID << 3;
 392                                 switch (token.TokenType) {
 393                                 case TokenType.TypeDef :
 394                                         return ret | 0;
 395                                 case TokenType.TypeRef :
 396                                         return ret | 1;
 397                                 case TokenType.ModuleRef :
 398                                         return ret | 2;
 399                                 case TokenType.Method :
 400                                         return ret | 3;
 401                                 case TokenType.TypeSpec :
 402                                         return ret | 4;
 403                                 default :
 404                                         throw new MetadataFormatException("Non valid Token for MemberRefParent");
 405                                 }
 406                         case CodedIndex.HasSemantics :
 407                                 ret = token.RID << 1;
 408                                 switch (token.TokenType) {
 409                                 case TokenType.Event :
 410                                         return ret | 0;
 411                                 case TokenType.Property :
 412                                         return ret | 1;
 413                                 default :
 414                                         throw new MetadataFormatException("Non valid Token for HasSemantics");
 415                                 }
 416                         case CodedIndex.MethodDefOrRef :
 417                                 ret = token.RID << 1;
 418                                 switch (token.TokenType) {
 419                                 case TokenType.Method :
 420                                         return ret | 0;
 421                                 case TokenType.MemberRef :
 422                                         return ret | 1;
 423                                 default :
 424                                         throw new MetadataFormatException("Non valid Token for MethodDefOrRef");
 425                                 }
 426                         case CodedIndex.MemberForwarded :
 427                                 ret = token.RID << 1;
 428                                 switch (token.TokenType) {
 429                                 case TokenType.Field :
 430                                         return ret | 0;
 431                                 case TokenType.Method :
 432                                         return ret | 1;
 433                                 default :
 434                                         throw new MetadataFormatException("Non valid Token for MemberForwarded");
 435                                 }
 436                         case CodedIndex.Implementation :
 437                                 ret = token.RID << 2;
 438                                 switch (token.TokenType) {
 439                                 case TokenType.File :
 440                                         return ret | 0;
 441                                 case TokenType.AssemblyRef :
 442                                         return ret | 1;
 443                                 case TokenType.ExportedType :
 444                                         return ret | 2;
 445                                 default :
 446                                         throw new MetadataFormatException("Non valid Token for Implementation");
 447                                 }
 448                         case CodedIndex.CustomAttributeType :
 449                                 ret = token.RID << 3;
 450                                 switch (token.TokenType) {
 451                                 case TokenType.Method :
 452                                         return ret | 2;
 453                                 case TokenType.MemberRef :
 454                                         return ret | 3;
 455                                 default :
 456                                         throw new MetadataFormatException("Non valid Token for CustomAttributeType");
 457                                 }
 458                         case CodedIndex.ResolutionScope :
 459                                 ret = token.RID << 2;
 460                                 switch (token.TokenType) {
 461                                 case TokenType.Module :
 462                                         return ret | 0;
 463                                 case TokenType.ModuleRef :
 464                                         return ret | 1;
 465                                 case TokenType.AssemblyRef :
 466                                         return ret | 2;
 467                                 case TokenType.TypeRef :
 468                                         return ret | 3;
 469                                 default :
 470                                         throw new MetadataFormatException("Non valid Token for ResolutionScope");
 471                                 }
 472                         case CodedIndex.TypeOrMethodDef :
 473                                 ret = token.RID << 1;
 474                                 switch (token.TokenType) {
 475                                 case TokenType.TypeDef :
 476                                         return ret | 0;
 477                                 case TokenType.Method :
 478                                         return ret | 1;
 479                                 default :
 480                                         throw new MetadataFormatException("Non valid Token for TypeOrMethodDef");
 481                                 }
 482                         default :
 483                                 throw new MetadataFormatException ("Non valid CodedIndex");
 484                         }
 485                 }
 486
 487                 internal static Type GetCorrespondingTable (TokenType t)
 488                 {
 489                         switch (t) {
 490                         case TokenType.Assembly :
 491                                 return typeof (AssemblyTable);
 492                         case TokenType.AssemblyRef :
 493                                 return typeof (AssemblyRefTable);
 494                         case TokenType.CustomAttribute :
 495                                 return typeof (CustomAttributeTable);
 496                         case TokenType.Event :
 497                                 return typeof (EventTable);
 498                         case TokenType.ExportedType :
 499                                 return typeof (ExportedTypeTable);
 500                         case TokenType.Field :
 501                                 return typeof (FieldTable);
 502                         case TokenType.File :
 503                                 return typeof (FileTable);
 504                         case TokenType.InterfaceImpl :
 505                                 return typeof (InterfaceImplTable);
 506                         case TokenType.MemberRef :
 507                                 return typeof (MemberRefTable);
 508                         case TokenType.Method :
 509                                 return typeof (MethodTable);
 510                         case TokenType.Module :
 511                                 return typeof (ModuleTable);
 512                         case TokenType.ModuleRef :
 513                                 return typeof (ModuleRefTable);
 514                         case TokenType.Param :
 515                                 return typeof (ParamTable);
 516                         case TokenType.Permission :
 517                                 return typeof (DeclSecurityTable);
 518                         case TokenType.Property :
 519                                 return typeof (PropertyTable);
 520                         case TokenType.Signature :
 521                                 return typeof (StandAloneSigTable);
 522                         case TokenType.TypeDef :
 523                                 return typeof (TypeDefTable);
 524                         case TokenType.TypeRef :
 525                                 return typeof (TypeRefTable);
 526                         case TokenType.TypeSpec :
 527                                 return typeof (TypeSpecTable);
 528                         default :
 529                                 return null;
 530                         }
 531                 }
 532
 533                 internal delegate int TableRowCounter (int rid);
 534
 535                 internal static int GetCodedIndexSize (CodedIndex ci, TableRowCounter rowCounter, int [] codedIndexCache)
 536                 {
 537                         int bits = 0, max = 0, index = (int) ci;
 538                         if (codedIndexCache [index] != 0)
 539                                 return codedIndexCache [index];
 540
 541                         int res = 0;
 542                         int [] rids;
 543                         switch (ci) {
 544                         case CodedIndex.TypeDefOrRef :
 545                                 bits = 2;
 546                                 rids = new int [3];
 547                                 rids [0] = TypeDefTable.RId;
 548                                 rids [1] = TypeRefTable.RId;
 549                                 rids [2] = TypeSpecTable.RId;
 550                                 break;
 551                         case CodedIndex.HasConstant :
 552                                 bits = 2;
 553                                 rids = new int [3];
 554                                 rids [0] = FieldTable.RId;
 555                                 rids [1] = ParamTable.RId;
 556                                 rids [2] = PropertyTable.RId;
 557                                 break;
 558                         case CodedIndex.HasCustomAttribute :
 559                                 bits = 5;
 560                                 rids = new int [20];
 561                                 rids [0] = MethodTable.RId;
 562                                 rids [1] = FieldTable.RId;
 563                                 rids [2] = TypeRefTable.RId;
 564                                 rids [3] = TypeDefTable.RId;
 565                                 rids [4] = ParamTable.RId;
 566                                 rids [5] = InterfaceImplTable.RId;
 567                                 rids [6] = MemberRefTable.RId;
 568                                 rids [7] = ModuleTable.RId;
 569                                 rids [8] = DeclSecurityTable.RId;
 570                                 rids [9] = PropertyTable.RId;
 571                                 rids [10] = EventTable.RId;
 572                                 rids [11] = StandAloneSigTable.RId;
 573                                 rids [12] = ModuleRefTable.RId;
 574                                 rids [13] = TypeSpecTable.RId;
 575                                 rids [14] = AssemblyTable.RId;
 576                                 rids [15] = AssemblyRefTable.RId;
 577                                 rids [16] = FileTable.RId;
 578                                 rids [17] = ExportedTypeTable.RId;
 579                                 rids [18] = ManifestResourceTable.RId;
 580                                 rids [19] = GenericParamTable.RId;
 581                                 break;
 582                         case CodedIndex.HasFieldMarshal :
 583                                 bits = 1;
 584                                 rids = new int [2];
 585                                 rids [0] = FieldTable.RId;
 586                                 rids [1] = ParamTable.RId;
 587                                 break;
 588                         case CodedIndex.HasDeclSecurity :
 589                                 bits = 2;
 590                                 rids = new int [3];
 591                                 rids [0] = TypeDefTable.RId;
 592                                 rids [1] = MethodTable.RId;
 593                                 rids [2] = AssemblyTable.RId;
 594                                 break;
 595                         case CodedIndex.MemberRefParent :
 596                                 bits = 3;
 597                                 rids = new int [5];
 598                                 rids [0] = TypeDefTable.RId;
 599                                 rids [1] = TypeRefTable.RId;
 600                                 rids [2] = ModuleRefTable.RId;
 601                                 rids [3] = MethodTable.RId;
 602                                 rids [4] = TypeSpecTable.RId;
 603                                 break;
 604                         case CodedIndex.HasSemantics :
 605                                 bits = 1;
 606                                 rids = new int [2];
 607                                 rids [0] = EventTable.RId;
 608                                 rids [1] = PropertyTable.RId;
 609                                 break;
 610                         case CodedIndex.MethodDefOrRef :
 611                                 bits = 1;
 612                                 rids = new int [2];
 613                                 rids [0] = MethodTable.RId;
 614                                 rids [1] = MemberRefTable.RId;
 615                                 break;
 616                         case CodedIndex.MemberForwarded :
 617                                 bits = 1;
 618                                 rids = new int [2];
 619                                 rids [0] = FieldTable.RId;
 620                                 rids [1] = MethodTable.RId;
 621                                 break;
 622                         case CodedIndex.Implementation :
 623                                 bits = 2;
 624                                 rids = new int [3];
 625                                 rids [0] = FileTable.RId;
 626                                 rids [1] = AssemblyRefTable.RId;
 627                                 rids [2] = ExportedTypeTable.RId;
 628                                 break;
 629                         case CodedIndex.CustomAttributeType :
 630                                 bits = 3;
 631                                 rids = new int [2];
 632                                 rids [0] = MethodTable.RId;
 633                                 rids [1] = MemberRefTable.RId;
 634                                 break;
 635                         case CodedIndex.ResolutionScope :
 636                                 bits = 2;
 637                                 rids = new int [4];
 638                                 rids [0] = ModuleTable.RId;
 639                                 rids [1] = ModuleRefTable.RId;
 640                                 rids [2] = AssemblyRefTable.RId;
 641                                 rids [3] = TypeRefTable.RId;
 642                                 break;
 643                         case CodedIndex.TypeOrMethodDef :
 644                                 bits = 1;
 645                                 rids = new int [2];
 646                                 rids [0] = TypeDefTable.RId;
 647                                 rids [1] = MethodTable.RId;
 648                                 break;
 649                         default :
 650                                 throw new MetadataFormatException ("Non valid CodedIndex");
 651                         }
 652
 653                         for (int i = 0; i < rids.Length; i++) {
 654                                 int rows = rowCounter (rids [i]);
 655                                 if (rows > max) max = rows;
 656                         }
 657
 658                         res = max < (1 << (16 - bits)) ? 2 : 4;
 659                         codedIndexCache [index] = res;
 660                         return res;
 661                 }
 662         }
 663 }