mcs/class/Mono.CSharp.Debugger/MonoSymbolTable.cs

   1 //
   2 // System.Diagnostics.SymbolStore/MonoSymbolTable.cs
   3 //
   4 // Author:
   5 //   Martin Baulig (martin@ximian.com)
   6 //
   7 // (C) 2002 Ximian, Inc.  http://www.ximian.com
   8 //
   9
  10 using System;
  11 using System.Reflection;
  12 using System.Reflection.Emit;
  13 using System.Collections;
  14 using System.Text;
  15 using System.IO;
  16
  17 //
  18 // Parts which are actually written into the symbol file are marked with
  19 //
  20 //         #region This is actually written to the symbol file
  21 //         #endregion
  22 //
  23 // Please do not modify these regions without previously talking to me.
  24 //
  25 // All changes to the file format must be synchronized in several places:
  26 //
  27 // a) The fields in these regions (and their order) must match the actual
  28 //    contents of the symbol file.
  29 //
  30 //    This helps people to understand the symbol file format without reading
  31 //    too much source code, ie. you look at the appropriate region and then
  32 //    you know what's actually in the file.
  33 //
  34 //    It is also required to help me enforce b).
  35 //
  36 // b) The regions must be kept in sync with the unmanaged code in
  37 //    mono/metadata/debug-mono-symfile.h
  38 //
  39 // When making changes to the file format, you must also increase two version
  40 // numbers:
  41 //
  42 // i)  OffsetTable.Version in this file.
  43 // ii) MONO_SYMBOL_FILE_VERSION in mono/metadata/debug-mono-symfile.h
  44 //
  45 // After doing so, recompile everything, including the debugger.  Symbol files
  46 // with different versions are incompatible to each other and the debugger and
  47 // the runtime enfore this, so you need to recompile all your assemblies after
  48 // changing the file format.
  49 //
  50
  51 namespace Mono.CSharp.Debugger
  52 {
  53         public struct OffsetTable
  54         {
  55                 public const int  Version = 36;
  56                 public const long Magic   = 0x45e82623fd7fa614;
  57
  58                 #region This is actually written to the symbol file
  59                 public int TotalFileSize;
  60                 public int DataSectionOffset;
  61                 public int DataSectionSize;
  62                 public int SourceCount;
  63                 public int SourceTableOffset;
  64                 public int SourceTableSize;
  65                 public int MethodCount;
  66                 public int MethodTableOffset;
  67                 public int MethodTableSize;
  68                 public int TypeCount;
  69                 #endregion
  70
  71                 internal OffsetTable (BinaryReader reader)
  72                 {
  73                         TotalFileSize = reader.ReadInt32 ();
  74                         DataSectionOffset = reader.ReadInt32 ();
  75                         DataSectionSize = reader.ReadInt32 ();
  76                         SourceCount = reader.ReadInt32 ();
  77                         SourceTableOffset = reader.ReadInt32 ();
  78                         SourceTableSize = reader.ReadInt32 ();
  79                         MethodCount = reader.ReadInt32 ();
  80                         MethodTableOffset = reader.ReadInt32 ();
  81                         MethodTableSize = reader.ReadInt32 ();
  82                         TypeCount = reader.ReadInt32 ();
  83                 }
  84
  85                 internal void Write (BinaryWriter bw)
  86                 {
  87                         bw.Write (TotalFileSize);
  88                         bw.Write (DataSectionOffset);
  89                         bw.Write (DataSectionSize);
  90                         bw.Write (SourceCount);
  91                         bw.Write (SourceTableOffset);
  92                         bw.Write (SourceTableSize);
  93                         bw.Write (MethodCount);
  94                         bw.Write (MethodTableOffset);
  95                         bw.Write (MethodTableSize);
  96                         bw.Write (TypeCount);
  97                 }
  98
  99                 public override string ToString ()
 100                 {
 101                         return String.Format (
 102                                 "OffsetTable [{0} - {1}:{2} - {3}:{4}:{5} - {6}:{7}:{8} - {9}]",
 103                                 TotalFileSize, DataSectionOffset, DataSectionSize, SourceCount,
 104                                 SourceTableOffset, SourceTableSize, MethodCount, MethodTableOffset,
 105                                 MethodTableSize, TypeCount);
 106                 }
 107         }
 108
 109         public struct LineNumberEntry
 110         {
 111                 #region This is actually written to the symbol file
 112                 public readonly int Row;
 113                 public readonly int Offset;
 114                 #endregion
 115
 116                 public LineNumberEntry (int row, int offset)
 117                 {
 118                         this.Row = row;
 119                         this.Offset = offset;
 120                 }
 121
 122                 public static LineNumberEntry Null = new LineNumberEntry (0, 0);
 123
 124                 internal LineNumberEntry (BinaryReader reader)
 125                 {
 126                         Row = reader.ReadInt32 ();
 127                         Offset = reader.ReadInt32 ();
 128                 }
 129
 130                 internal void Write (BinaryWriter bw)
 131                 {
 132                         bw.Write (Row);
 133                         bw.Write (Offset);
 134                 }
 135
 136                 private class OffsetComparerClass : IComparer
 137                 {
 138                         public int Compare (object a, object b)
 139                         {
 140                                 LineNumberEntry l1 = (LineNumberEntry) a;
 141                                 LineNumberEntry l2 = (LineNumberEntry) b;
 142
 143                                 if (l1.Offset < l2.Offset)
 144                                         return -1;
 145                                 else if (l1.Offset > l2.Offset)
 146                                         return 1;
 147                                 else
 148                                         return 0;
 149                         }
 150                 }
 151
 152                 private class RowComparerClass : IComparer
 153                 {
 154                         public int Compare (object a, object b)
 155                         {
 156                                 LineNumberEntry l1 = (LineNumberEntry) a;
 157                                 LineNumberEntry l2 = (LineNumberEntry) b;
 158
 159                                 if (l1.Row < l2.Row)
 160                                         return -1;
 161                                 else if (l1.Row > l2.Row)
 162                                         return 1;
 163                                 else
 164                                         return 0;
 165                         }
 166                 }
 167
 168                 public static readonly IComparer OffsetComparer = new OffsetComparerClass ();
 169                 public static readonly IComparer RowComparer = new RowComparerClass ();
 170
 171                 public override string ToString ()
 172                 {
 173                         return String.Format ("[Line {0}:{1}]", Row, Offset);
 174                 }
 175         }
 176
 177         public class LexicalBlockEntry
 178         {
 179                 public int Index;
 180                 #region This is actually written to the symbol file
 181                 public int StartOffset;
 182                 public int EndOffset;
 183                 #endregion
 184
 185                 public LexicalBlockEntry (int index, int start_offset)
 186                 {
 187                         this.Index = index;
 188                         this.StartOffset = start_offset;
 189                 }
 190
 191                 internal LexicalBlockEntry (int index, BinaryReader reader)
 192                 {
 193                         this.Index = index;
 194                         this.StartOffset = reader.ReadInt32 ();
 195                         this.EndOffset = reader.ReadInt32 ();
 196                 }
 197
 198                 public void Close (int end_offset)
 199                 {
 200                         this.EndOffset = end_offset;
 201                 }
 202
 203                 internal void Write (BinaryWriter bw)
 204                 {
 205                         bw.Write (StartOffset);
 206                         bw.Write (EndOffset);
 207                 }
 208
 209                 public override string ToString ()
 210                 {
 211                         return String.Format ("[LexicalBlock {0}:{1}]", StartOffset, EndOffset);
 212                 }
 213         }
 214
 215         public struct LocalVariableEntry
 216         {
 217                 #region This is actually written to the symbol file
 218                 public readonly string Name;
 219                 public readonly FieldAttributes Attributes;
 220                 public readonly byte[] Signature;
 221                 public readonly int BlockIndex;
 222                 #endregion
 223
 224                 public LocalVariableEntry (string Name, FieldAttributes Attributes, byte[] Signature,
 225                                            int BlockIndex)
 226                 {
 227                         this.Name = Name;
 228                         this.Attributes = Attributes;
 229                         this.Signature = Signature;
 230                         this.BlockIndex = BlockIndex;
 231                 }
 232
 233                 internal LocalVariableEntry (BinaryReader reader)
 234                 {
 235                         int name_length = reader.ReadInt32 ();
 236                         byte[] name = reader.ReadBytes (name_length);
 237                         Name = Encoding.UTF8.GetString (name);
 238                         Attributes = (FieldAttributes) reader.ReadInt32 ();
 239                         int sig_length = reader.ReadInt32 ();
 240                         Signature = reader.ReadBytes (sig_length);
 241                         BlockIndex = reader.ReadInt32 ();
 242                 }
 243
 244                 internal void Write (MonoSymbolFile file, BinaryWriter bw)
 245                 {
 246                         file.WriteString (bw, Name);
 247                         bw.Write ((int) Attributes);
 248                         bw.Write ((int) Signature.Length);
 249                         bw.Write (Signature);
 250                         bw.Write (BlockIndex);
 251                 }
 252
 253                 public override string ToString ()
 254                 {
 255                         return String.Format ("[LocalVariable {0}:{1}]", Name, Attributes);
 256                 }
 257         }
 258
 259         public class SourceFileEntry
 260         {
 261                 #region This is actually written to the symbol file
 262                 public readonly int Index;
 263                 int Count;
 264                 int NamespaceCount;
 265                 int NameOffset;
 266                 int MethodOffset;
 267                 int NamespaceTableOffset;
 268                 #endregion
 269
 270                 MonoSymbolFile file;
 271                 string file_name;
 272                 ArrayList methods;
 273                 ArrayList namespaces;
 274                 bool creating;
 275
 276                 public static int Size {
 277                         get { return 24; }
 278                 }
 279
 280                 internal SourceFileEntry (MonoSymbolFile file, string file_name)
 281                 {
 282                         this.file = file;
 283                         this.file_name = file_name;
 284                         this.Index = file.AddSource (this);
 285
 286                         creating = true;
 287                         methods = new ArrayList ();
 288                         namespaces = new ArrayList ();
 289                 }
 290
 291                 public void DefineMethod (MethodBase method, int token, LocalVariableEntry[] locals,
 292                                           LineNumberEntry[] lines, LexicalBlockEntry[] blocks,
 293                                           int start, int end, int namespace_id)
 294                 {
 295                         if (!creating)
 296                                 throw new InvalidOperationException ();
 297
 298                         MethodEntry entry = new MethodEntry (
 299                                 file, this, method, token, locals, lines, blocks, start, end, namespace_id);
 300
 301                         methods.Add (entry);
 302                         file.AddMethod (entry);
 303                 }
 304
 305                 public int DefineNamespace (string name, string[] using_clauses, int parent)
 306                 {
 307                         if (!creating)
 308                                 throw new InvalidOperationException ();
 309
 310                         int index = file.GetNextNamespaceIndex ();
 311                         NamespaceEntry ns = new NamespaceEntry (name, index, using_clauses, parent);
 312                         namespaces.Add (ns);
 313                         return index;
 314                 }
 315
 316                 internal void WriteData (BinaryWriter bw)
 317                 {
 318                         NameOffset = (int) bw.BaseStream.Position;
 319                         file.WriteString (bw, file_name);
 320
 321                         ArrayList list = new ArrayList ();
 322                         foreach (MethodEntry entry in methods)
 323                                 list.Add (entry.Write (file, bw));
 324                         list.Sort ();
 325                         Count = list.Count;
 326
 327                         MethodOffset = (int) bw.BaseStream.Position;
 328                         foreach (MethodSourceEntry method in list)
 329                                 method.Write (bw);
 330
 331                         NamespaceCount = namespaces.Count;
 332                         NamespaceTableOffset = (int) bw.BaseStream.Position;
 333                         foreach (NamespaceEntry ns in namespaces)
 334                                 ns.Write (file, bw);
 335                 }
 336
 337                 internal void Write (BinaryWriter bw)
 338                 {
 339                         bw.Write (Index);
 340                         bw.Write (Count);
 341                         bw.Write (NamespaceCount);
 342                         bw.Write (NameOffset);
 343                         bw.Write (MethodOffset);
 344                         bw.Write (NamespaceTableOffset);
 345                 }
 346
 347                 internal SourceFileEntry (MonoSymbolFile file, BinaryReader reader)
 348                 {
 349                         this.file = file;
 350
 351                         Index = reader.ReadInt32 ();
 352                         Count = reader.ReadInt32 ();
 353                         NamespaceCount = reader.ReadInt32 ();
 354                         NameOffset = reader.ReadInt32 ();
 355                         MethodOffset = reader.ReadInt32 ();
 356                         NamespaceTableOffset = reader.ReadInt32 ();
 357
 358                         file_name = file.ReadString (NameOffset);
 359                 }
 360
 361                 public string FileName {
 362                         get { return file_name; }
 363                 }
 364
 365                 public MethodSourceEntry[] Methods {
 366                         get {
 367                                 if (creating)
 368                                         throw new InvalidOperationException ();
 369
 370                                 BinaryReader reader = file.BinaryReader;
 371                                 int old_pos = (int) reader.BaseStream.Position;
 372
 373                                 reader.BaseStream.Position = MethodOffset;
 374                                 ArrayList list = new ArrayList ();
 375                                 for (int i = 0; i < Count; i ++)
 376                                         list.Add (new MethodSourceEntry (reader));
 377                                 reader.BaseStream.Position = old_pos;
 378
 379                                 MethodSourceEntry[] retval = new MethodSourceEntry [Count];
 380                                 list.CopyTo (retval, 0);
 381                                 return retval;
 382                         }
 383                 }
 384
 385                 public override string ToString ()
 386                 {
 387                         return String.Format ("SourceFileEntry ({0}:{1}:{2})",
 388                                               Index, file_name, Count);
 389                 }
 390         }
 391
 392         public struct MethodSourceEntry : IComparable
 393         {
 394                 #region This is actually written to the symbol file
 395                 public readonly int Index;
 396                 public readonly int FileOffset;
 397                 public readonly int StartRow;
 398                 public readonly int EndRow;
 399                 #endregion
 400
 401                 public MethodSourceEntry (int index, int file_offset, int start, int end)
 402                 {
 403                         this.Index = index;
 404                         this.FileOffset = file_offset;
 405                         this.StartRow = start;
 406                         this.EndRow = end;
 407                 }
 408
 409                 internal MethodSourceEntry (BinaryReader reader)
 410                 {
 411                         Index = reader.ReadInt32 ();
 412                         FileOffset = reader.ReadInt32 ();
 413                         StartRow = reader.ReadInt32 ();
 414                         EndRow = reader.ReadInt32 ();
 415                 }
 416
 417                 public static int Size {
 418                         get { return 16; }
 419                 }
 420
 421                 internal void Write (BinaryWriter bw)
 422                 {
 423                         bw.Write (Index);
 424                         bw.Write (FileOffset);
 425                         bw.Write (StartRow);
 426                         bw.Write (EndRow);
 427                 }
 428
 429                 public int CompareTo (object obj)
 430                 {
 431                         MethodSourceEntry method = (MethodSourceEntry) obj;
 432
 433                         if (method.StartRow < StartRow)
 434                                 return -1;
 435                         else if (method.StartRow > StartRow)
 436                                 return 1;
 437                         else
 438                                 return 0;
 439                 }
 440
 441                 public override string ToString ()
 442                 {
 443                         return String.Format ("MethodSourceEntry ({0}:{1}:{2}:{3})",
 444                                               Index, FileOffset, StartRow, EndRow);
 445                 }
 446         }
 447
 448         public struct MethodIndexEntry
 449         {
 450                 #region This is actually written to the symbol file
 451                 public readonly int FileOffset;
 452                 public readonly int Token;
 453                 #endregion
 454
 455                 public static int Size {
 456                         get { return 8; }
 457                 }
 458
 459                 public MethodIndexEntry (int offset, int token)
 460                 {
 461                         this.FileOffset = offset;
 462                         this.Token = token;
 463                 }
 464
 465                 internal MethodIndexEntry (BinaryReader reader)
 466                 {
 467                         FileOffset = reader.ReadInt32 ();
 468                         Token = reader.ReadInt32 ();
 469                 }
 470
 471                 internal void Write (BinaryWriter bw)
 472                 {
 473                         bw.Write (FileOffset);
 474                         bw.Write (Token);
 475                 }
 476
 477                 public override string ToString ()
 478                 {
 479                         return String.Format ("MethodIndexEntry ({0}:{1:x})",
 480                                               FileOffset, Token);
 481                 }
 482         }
 483
 484         public class MethodEntry
 485         {
 486                 #region This is actually written to the symbol file
 487                 public readonly int SourceFileIndex;
 488                 public readonly int Token;
 489                 public readonly int StartRow;
 490                 public readonly int EndRow;
 491                 public readonly int ClassTypeIndex;
 492                 public readonly int NumParameters;
 493                 public readonly int NumLocals;
 494                 public readonly int NumLineNumbers;
 495                 public readonly int NamespaceID;
 496                 public readonly bool LocalNamesAmbiguous;
 497
 498                 int NameOffset;
 499                 int TypeIndexTableOffset;
 500                 int LocalVariableTableOffset;
 501                 int LineNumberTableOffset;
 502                 int NumLexicalBlocks;
 503                 int LexicalBlockTableOffset;
 504                 #endregion
 505
 506                 int file_offset;
 507                 string name;
 508
 509                 public readonly int Index;
 510                 public readonly SourceFileEntry SourceFile;
 511                 public readonly LineNumberEntry[] LineNumbers;
 512                 public readonly int[] ParamTypeIndices;
 513                 public readonly int[] LocalTypeIndices;
 514                 public readonly LocalVariableEntry[] Locals;
 515                 public readonly Type[] LocalTypes;
 516                 public readonly LexicalBlockEntry[] LexicalBlocks;
 517
 518                 public readonly MonoSymbolFile SymbolFile;
 519
 520                 public static int Size {
 521                         get { return 52; }
 522                 }
 523
 524                 public string Name {
 525                         get { return name; }
 526                 }
 527
 528                 public MethodBase MethodBase {
 529                         get { return MonoDebuggerSupport.GetMethod (SymbolFile.Assembly, Token); }
 530                 }
 531
 532                 internal MethodEntry (MonoSymbolFile file, BinaryReader reader, int index)
 533                 {
 534                         this.SymbolFile = file;
 535                         this.Index = index;
 536                         SourceFileIndex = reader.ReadInt32 ();
 537                         Token = reader.ReadInt32 ();
 538                         StartRow = reader.ReadInt32 ();
 539                         EndRow = reader.ReadInt32 ();
 540                         ClassTypeIndex = reader.ReadInt32 ();
 541                         NumParameters = reader.ReadInt32 ();
 542                         NumLocals = reader.ReadInt32 ();
 543                         NumLineNumbers = reader.ReadInt32 ();
 544                         NameOffset = reader.ReadInt32 ();
 545                         TypeIndexTableOffset = reader.ReadInt32 ();
 546                         LocalVariableTableOffset = reader.ReadInt32 ();
 547                         LineNumberTableOffset = reader.ReadInt32 ();
 548                         NumLexicalBlocks = reader.ReadInt32 ();
 549                         LexicalBlockTableOffset = reader.ReadInt32 ();
 550                         NamespaceID = reader.ReadInt32 ();
 551                         LocalNamesAmbiguous = reader.ReadInt32 () != 0;
 552
 553                         name = file.ReadString (NameOffset);
 554
 555                         SourceFile = file.GetSourceFile (SourceFileIndex);
 556
 557                         if (LineNumberTableOffset != 0) {
 558                                 long old_pos = reader.BaseStream.Position;
 559                                 reader.BaseStream.Position = LineNumberTableOffset;
 560
 561                                 LineNumbers = new LineNumberEntry [NumLineNumbers];
 562
 563                                 for (int i = 0; i < NumLineNumbers; i++)
 564                                         LineNumbers [i] = new LineNumberEntry (reader);
 565
 566                                 reader.BaseStream.Position = old_pos;
 567                         }
 568
 569                         if (LocalVariableTableOffset != 0) {
 570                                 long old_pos = reader.BaseStream.Position;
 571                                 reader.BaseStream.Position = LocalVariableTableOffset;
 572
 573                                 Locals = new LocalVariableEntry [NumLocals];
 574                                 LocalTypes = new Type [NumLocals];
 575
 576                                 Assembly ass = file.Assembly;
 577
 578                                 for (int i = 0; i < NumLocals; i++) {
 579                                         Locals [i] = new LocalVariableEntry (reader);
 580                                         LocalTypes [i] = MonoDebuggerSupport.GetLocalTypeFromSignature (
 581                                                 ass, Locals [i].Signature);
 582                                 }
 583
 584                                 reader.BaseStream.Position = old_pos;
 585                         }
 586
 587                         if (TypeIndexTableOffset != 0) {
 588                                 long old_pos = reader.BaseStream.Position;
 589                                 reader.BaseStream.Position = TypeIndexTableOffset;
 590
 591                                 ParamTypeIndices = new int [NumParameters];
 592                                 LocalTypeIndices = new int [NumLocals];
 593
 594                                 for (int i = 0; i < NumParameters; i++)
 595                                         ParamTypeIndices [i] = reader.ReadInt32 ();
 596                                 for (int i = 0; i < NumLocals; i++)
 597                                         LocalTypeIndices [i] = reader.ReadInt32 ();
 598
 599                                 reader.BaseStream.Position = old_pos;
 600                         }
 601
 602                         if (LexicalBlockTableOffset != 0) {
 603                                 long old_pos = reader.BaseStream.Position;
 604                                 reader.BaseStream.Position = LexicalBlockTableOffset;
 605
 606                                 LexicalBlocks = new LexicalBlockEntry [NumLexicalBlocks];
 607                                 for (int i = 0; i < NumLexicalBlocks; i++)
 608                                         LexicalBlocks [i] = new LexicalBlockEntry (i, reader);
 609
 610                                 reader.BaseStream.Position = old_pos;
 611                         }
 612                 }
 613
 614                 internal MethodEntry (MonoSymbolFile file, SourceFileEntry source, MethodBase method,
 615                                       int token, LocalVariableEntry[] locals, LineNumberEntry[] lines,
 616                                       LexicalBlockEntry[] blocks, int start_row, int end_row,
 617                                       int namespace_id)
 618                 {
 619                         this.SymbolFile = file;
 620                         Index = file.GetNextMethodIndex ();
 621
 622                         Token = token;
 623                         SourceFileIndex = source.Index;
 624                         SourceFile = source;
 625                         StartRow = start_row;
 626                         EndRow = end_row;
 627                         NamespaceID = namespace_id;
 628                         LexicalBlocks = blocks;
 629                         NumLexicalBlocks = LexicalBlocks.Length;
 630
 631                         LineNumbers = BuildLineNumberTable (lines);
 632                         NumLineNumbers = LineNumbers.Length;
 633
 634                         ParameterInfo[] parameters = method.GetParameters ();
 635                         if (parameters == null)
 636                                 parameters = new ParameterInfo [0];
 637
 638                         name = method.Name;
 639
 640                         NumParameters = parameters.Length;
 641                         ParamTypeIndices = new int [NumParameters];
 642                         for (int i = 0; i < NumParameters; i++)
 643                                 ParamTypeIndices [i] = file.DefineType (parameters [i].ParameterType);
 644
 645                         NumLocals = locals.Length;
 646                         Locals = locals;
 647
 648                         if (NumLocals <= 32) {
 649                                 // Most of the time, the O(n^2) factor is actually
 650                                 // less than the cost of allocating the hash table,
 651                                 // 32 is a rough number obtained through some testing.
 652
 653                                 for (int i = 0; i < NumLocals; i ++) {
 654                                         string nm = locals [i].Name;
 655
 656                                         for (int j = i + 1; j < NumLocals; j ++) {
 657                                                 if (locals [j].Name == nm) {
 658                                                         LocalNamesAmbiguous = true;
 659                                                         goto locals_check_done;
 660                                                 }
 661                                         }
 662                                 }
 663                         locals_check_done :
 664                                 ;
 665                         } else {
 666                                 Hashtable local_names = new Hashtable ();
 667                                 foreach (LocalVariableEntry local in locals) {
 668                                         if (local_names.Contains (local.Name)) {
 669                                                 LocalNamesAmbiguous = true;
 670                                                 break;
 671                                         }
 672                                         local_names.Add (local.Name, local);
 673                                 }
 674                         }
 675
 676                         LocalTypeIndices = new int [NumLocals];
 677                         for (int i = 0; i < NumLocals; i++)
 678                                 LocalTypeIndices [i] = file.GetNextTypeIndex ();
 679
 680                         ClassTypeIndex = file.DefineType (method.ReflectedType);
 681                 }
 682
 683                 // BuildLineNumberTable() eliminates duplicate line numbers and ensures
 684                 // we aren't going "backwards" since this would counfuse the runtime's
 685                 // debugging code (and the debugger).
 686                 //
 687                 // In the line number table, the "offset" field most be strictly
 688                 // monotonic increasing; that is, the next entry must not have an offset
 689                 // which is equal to or less than the current one.
 690                 //
 691                 // The most common case is that our input (ie. the line number table as
 692                 // we get it from mcs) contains several entries with the same offset
 693                 // (and different line numbers) - but it may also happen that the offset
 694                 // is decreasing (this can be considered as an exception, such lines will
 695                 // simply be discarded).
 696                 LineNumberEntry[] BuildLineNumberTable (LineNumberEntry[] line_numbers)
 697                 {
 698                         ArrayList list = new ArrayList ();
 699                         int last_offset = -1;
 700                         int last_row = -1;
 701
 702                         for (int i = 0; i < line_numbers.Length; i++) {
 703                                 LineNumberEntry line = (LineNumberEntry) line_numbers [i];
 704
 705                                 if (line.Offset > last_offset) {
 706                                         if (last_row >= 0)
 707                                                 list.Add (new LineNumberEntry (last_row, last_offset));
 708                                         last_row = line.Row;
 709                                         last_offset = line.Offset;
 710                                 } else if (line.Row > last_row) {
 711                                         last_row = line.Row;
 712                                 }
 713                         }
 714
 715                         if (last_row >= 0)
 716                                 list.Add (new LineNumberEntry (last_row, last_offset));
 717
 718                         LineNumberEntry[] retval = new LineNumberEntry [list.Count];
 719                         list.CopyTo (retval, 0);
 720                         return retval;
 721                 }
 722
 723                 internal MethodSourceEntry Write (MonoSymbolFile file, BinaryWriter bw)
 724                 {
 725                         NameOffset = (int) bw.BaseStream.Position;
 726                         file.WriteString (bw, name);
 727
 728                         TypeIndexTableOffset = (int) bw.BaseStream.Position;
 729
 730                         for (int i = 0; i < NumParameters; i++)
 731                                 bw.Write (ParamTypeIndices [i]);
 732                         for (int i = 0; i < NumLocals; i++)
 733                                 bw.Write (LocalTypeIndices [i]);
 734
 735                         LocalVariableTableOffset = (int) bw.BaseStream.Position;
 736                         for (int i = 0; i < NumLocals; i++)
 737                                 Locals [i].Write (file, bw);
 738                         file.LocalCount += NumLocals;
 739
 740                         LineNumberTableOffset = (int) bw.BaseStream.Position;
 741                         for (int i = 0; i < NumLineNumbers; i++)
 742                                 LineNumbers [i].Write (bw);
 743                         file.LineNumberCount += NumLineNumbers;
 744
 745                         LexicalBlockTableOffset = (int) bw.BaseStream.Position;
 746                         for (int i = 0; i < NumLexicalBlocks; i++)
 747                                 LexicalBlocks [i].Write (bw);
 748                         file_offset = (int) bw.BaseStream.Position;
 749
 750                         bw.Write (SourceFileIndex);
 751                         bw.Write (Token);
 752                         bw.Write (StartRow);
 753                         bw.Write (EndRow);
 754                         bw.Write (ClassTypeIndex);
 755                         bw.Write (NumParameters);
 756                         bw.Write (NumLocals);
 757                         bw.Write (NumLineNumbers);
 758                         bw.Write (NameOffset);
 759                         bw.Write (TypeIndexTableOffset);
 760                         bw.Write (LocalVariableTableOffset);
 761                         bw.Write (LineNumberTableOffset);
 762                         bw.Write (NumLexicalBlocks);
 763                         bw.Write (LexicalBlockTableOffset);
 764                         bw.Write (NamespaceID);
 765                         bw.Write (LocalNamesAmbiguous ? 1 : 0);
 766
 767                         return new MethodSourceEntry (Index, file_offset, StartRow, EndRow);
 768                 }
 769
 770                 internal void WriteIndex (BinaryWriter bw)
 771                 {
 772                         new MethodIndexEntry (file_offset, Token).Write (bw);
 773                 }
 774
 775                 public override string ToString ()
 776                 {
 777                         return String.Format ("[Method {0}:{1}:{2}:{3}:{4} - {6}:{7}:{8}:{9} - {5}]",
 778                                               Index, Token, SourceFileIndex, StartRow, EndRow,
 779                                               SourceFile, ClassTypeIndex, NumParameters,
 780                                               NumLocals, NumLineNumbers);
 781                 }
 782         }
 783
 784         public struct NamespaceEntry
 785         {
 786                 #region This is actually written to the symbol file
 787                 public readonly string Name;
 788                 public readonly int Index;
 789                 public readonly int Parent;
 790                 public readonly string[] UsingClauses;
 791                 #endregion
 792
 793                 public NamespaceEntry (string name, int index, string[] using_clauses, int parent)
 794                 {
 795                         this.Name = name;
 796                         this.Index = index;
 797                         this.Parent = parent;
 798                         this.UsingClauses = using_clauses != null ? using_clauses : new string [0];
 799                 }
 800
 801                 internal void Write (MonoSymbolFile file, BinaryWriter bw)
 802                 {
 803                         file.WriteString (bw, Name);
 804                         bw.Write (Index);
 805                         bw.Write (Parent);
 806                         bw.Write (UsingClauses.Length);
 807                         foreach (string uc in UsingClauses)
 808                                 file.WriteString (bw, uc);
 809                 }
 810
 811                 public override string ToString ()
 812                 {
 813                         return String.Format ("[Namespace {0}:{1}:{2}]", Name, Index, Parent);
 814                 }
 815         }
 816 }