source/Plugins/SymbolFile/DWARF/DWARFDebugLine.cpp

   1 //===-- DWARFDebugLine.cpp --------------------------------------*- C++ -*-===//
   2 //
   3 //                     The LLVM Compiler Infrastructure
   4 //
   5 // This file is distributed under the University of Illinois Open Source
   6 // License. See LICENSE.TXT for details.
   7 //
   8 //===----------------------------------------------------------------------===//
   9
  10 #include "DWARFDebugLine.h"
  11
  12 //#define ENABLE_DEBUG_PRINTF   // DO NOT LEAVE THIS DEFINED: DEBUG ONLY!!!
  13 #include <assert.h>
  14
  15 #include "lldb/Core/FileSpecList.h"
  16 #include "lldb/Core/Log.h"
  17 #include "lldb/Core/Module.h"
  18 #include "lldb/Core/Timer.h"
  19 #include "lldb/Host/Host.h"
  20
  21 #include "SymbolFileDWARF.h"
  22 #include "LogChannelDWARF.h"
  23
  24 using namespace lldb;
  25 using namespace lldb_private;
  26 using namespace std;
  27
  28 //----------------------------------------------------------------------
  29 // Parse
  30 //
  31 // Parse all information in the debug_line_data into an internal
  32 // representation.
  33 //----------------------------------------------------------------------
  34 void
  35 DWARFDebugLine::Parse(const DWARFDataExtractor& debug_line_data)
  36 {
  37     m_lineTableMap.clear();
  38     lldb::offset_t offset = 0;
  39     LineTable::shared_ptr line_table_sp(new LineTable);
  40     while (debug_line_data.ValidOffset(offset))
  41     {
  42         const lldb::offset_t debug_line_offset = offset;
  43
  44         if (line_table_sp.get() == NULL)
  45             break;
  46
  47         if (ParseStatementTable(debug_line_data, &offset, line_table_sp.get()))
  48         {
  49             // Make sure we don't don't loop infinitely
  50             if (offset <= debug_line_offset)
  51                 break;
  52             //DEBUG_PRINTF("m_lineTableMap[0x%8.8x] = line_table_sp\n", debug_line_offset);
  53             m_lineTableMap[debug_line_offset] = line_table_sp;
  54             line_table_sp.reset(new LineTable);
  55         }
  56         else
  57             ++offset;   // Try next byte in line table
  58     }
  59 }
  60
  61 void
  62 DWARFDebugLine::ParseIfNeeded(const DWARFDataExtractor& debug_line_data)
  63 {
  64     if (m_lineTableMap.empty())
  65         Parse(debug_line_data);
  66 }
  67
  68
  69 //----------------------------------------------------------------------
  70 // DWARFDebugLine::GetLineTable
  71 //----------------------------------------------------------------------
  72 DWARFDebugLine::LineTable::shared_ptr
  73 DWARFDebugLine::GetLineTable(const dw_offset_t offset) const
  74 {
  75     DWARFDebugLine::LineTable::shared_ptr line_table_shared_ptr;
  76     LineTableConstIter pos = m_lineTableMap.find(offset);
  77     if (pos != m_lineTableMap.end())
  78         line_table_shared_ptr = pos->second;
  79     return line_table_shared_ptr;
  80 }
  81
  82
  83 //----------------------------------------------------------------------
  84 // DumpStateToFile
  85 //----------------------------------------------------------------------
  86 static void
  87 DumpStateToFile (dw_offset_t offset, const DWARFDebugLine::State& state, void* userData)
  88 {
  89     Log *log = (Log *)userData;
  90     if (state.row == DWARFDebugLine::State::StartParsingLineTable)
  91     {
  92         // If the row is zero we are being called with the prologue only
  93         state.prologue->Dump (log);
  94         log->PutCString ("Address            Line   Column File");
  95         log->PutCString ("------------------ ------ ------ ------");
  96     }
  97     else if (state.row == DWARFDebugLine::State::DoneParsingLineTable)
  98     {
  99         // Done parsing line table
 100     }
 101     else
 102     {
 103         log->Printf( "0x%16.16" PRIx64 " %6u %6u %6u%s\n", state.address, state.line, state.column, state.file, state.end_sequence ? " END" : "");
 104     }
 105 }
 106
 107 //----------------------------------------------------------------------
 108 // DWARFDebugLine::DumpLineTableRows
 109 //----------------------------------------------------------------------
 110 bool
 111 DWARFDebugLine::DumpLineTableRows(Log *log, SymbolFileDWARF* dwarf2Data, dw_offset_t debug_line_offset)
 112 {
 113     const DWARFDataExtractor& debug_line_data = dwarf2Data->get_debug_line_data();
 114
 115     if (debug_line_offset == DW_INVALID_OFFSET)
 116     {
 117         // Dump line table to a single file only
 118         debug_line_offset = 0;
 119         while (debug_line_data.ValidOffset(debug_line_offset))
 120             debug_line_offset = DumpStatementTable (log, debug_line_data, debug_line_offset);
 121     }
 122     else
 123     {
 124         // Dump line table to a single file only
 125         DumpStatementTable (log, debug_line_data, debug_line_offset);
 126     }
 127     return false;
 128 }
 129
 130 //----------------------------------------------------------------------
 131 // DWARFDebugLine::DumpStatementTable
 132 //----------------------------------------------------------------------
 133 dw_offset_t
 134 DWARFDebugLine::DumpStatementTable(Log *log, const DWARFDataExtractor& debug_line_data, const dw_offset_t debug_line_offset)
 135 {
 136     if (debug_line_data.ValidOffset(debug_line_offset))
 137     {
 138         lldb::offset_t offset = debug_line_offset;
 139         log->Printf(  "----------------------------------------------------------------------\n"
 140                     "debug_line[0x%8.8x]\n"
 141                     "----------------------------------------------------------------------\n", debug_line_offset);
 142
 143         if (ParseStatementTable(debug_line_data, &offset, DumpStateToFile, log))
 144             return offset;
 145         else
 146             return debug_line_offset + 1;   // Skip to next byte in .debug_line section
 147     }
 148
 149     return DW_INVALID_OFFSET;
 150 }
 151
 152
 153 //----------------------------------------------------------------------
 154 // DumpOpcodes
 155 //----------------------------------------------------------------------
 156 bool
 157 DWARFDebugLine::DumpOpcodes(Log *log, SymbolFileDWARF* dwarf2Data, dw_offset_t debug_line_offset, uint32_t dump_flags)
 158 {
 159     const DWARFDataExtractor& debug_line_data = dwarf2Data->get_debug_line_data();
 160
 161     if (debug_line_data.GetByteSize() == 0)
 162     {
 163         log->Printf( "< EMPTY >\n");
 164         return false;
 165     }
 166
 167     if (debug_line_offset == DW_INVALID_OFFSET)
 168     {
 169         // Dump line table to a single file only
 170         debug_line_offset = 0;
 171         while (debug_line_data.ValidOffset(debug_line_offset))
 172             debug_line_offset = DumpStatementOpcodes (log, debug_line_data, debug_line_offset, dump_flags);
 173     }
 174     else
 175     {
 176         // Dump line table to a single file only
 177         DumpStatementOpcodes (log, debug_line_data, debug_line_offset, dump_flags);
 178     }
 179     return false;
 180 }
 181
 182 //----------------------------------------------------------------------
 183 // DumpStatementOpcodes
 184 //----------------------------------------------------------------------
 185 dw_offset_t
 186 DWARFDebugLine::DumpStatementOpcodes(Log *log, const DWARFDataExtractor& debug_line_data, const dw_offset_t debug_line_offset, uint32_t flags)
 187 {
 188     lldb::offset_t offset = debug_line_offset;
 189     if (debug_line_data.ValidOffset(offset))
 190     {
 191         Prologue prologue;
 192
 193         if (ParsePrologue(debug_line_data, &offset, &prologue))
 194         {
 195             log->PutCString ("----------------------------------------------------------------------");
 196             log->Printf     ("debug_line[0x%8.8x]", debug_line_offset);
 197             log->PutCString ("----------------------------------------------------------------------\n");
 198             prologue.Dump (log);
 199         }
 200         else
 201         {
 202             offset = debug_line_offset;
 203             log->Printf( "0x%8.8" PRIx64 ": skipping pad byte %2.2x", offset, debug_line_data.GetU8(&offset));
 204             return offset;
 205         }
 206
 207         Row row(prologue.default_is_stmt);
 208         const dw_offset_t end_offset = debug_line_offset + prologue.total_length + sizeof(prologue.total_length);
 209
 210         assert(debug_line_data.ValidOffset(end_offset-1));
 211
 212         while (offset < end_offset)
 213         {
 214             const uint32_t op_offset = offset;
 215             uint8_t opcode = debug_line_data.GetU8(&offset);
 216             switch (opcode)
 217             {
 218             case 0: // Extended Opcodes always start with a zero opcode followed by
 219                 {   // a uleb128 length so you can skip ones you don't know about
 220
 221                     dw_offset_t ext_offset = offset;
 222                     dw_uleb128_t len = debug_line_data.GetULEB128(&offset);
 223                     dw_offset_t arg_size = len - (offset - ext_offset);
 224                     uint8_t sub_opcode = debug_line_data.GetU8(&offset);
 225 //                    if (verbose)
 226 //                        log->Printf( "Extended: <%u> %2.2x ", len, sub_opcode);
 227
 228                     switch (sub_opcode)
 229                     {
 230                     case DW_LNE_end_sequence    :
 231                         log->Printf( "0x%8.8x: DW_LNE_end_sequence", op_offset);
 232                         row.Dump(log);
 233                         row.Reset(prologue.default_is_stmt);
 234                         break;
 235
 236                     case DW_LNE_set_address     :
 237                         {
 238                             row.address = debug_line_data.GetMaxU64(&offset, arg_size);
 239                             log->Printf( "0x%8.8x: DW_LNE_set_address (0x%" PRIx64 ")", op_offset, row.address);
 240                         }
 241                         break;
 242
 243                     case DW_LNE_define_file:
 244                         {
 245                             FileNameEntry fileEntry;
 246                             fileEntry.name      = debug_line_data.GetCStr(&offset);
 247                             fileEntry.dir_idx   = debug_line_data.GetULEB128(&offset);
 248                             fileEntry.mod_time  = debug_line_data.GetULEB128(&offset);
 249                             fileEntry.length    = debug_line_data.GetULEB128(&offset);
 250                             log->Printf( "0x%8.8x: DW_LNE_define_file('%s', dir=%i, mod_time=0x%8.8x, length=%i )",
 251                                     op_offset,
 252                                     fileEntry.name,
 253                                     fileEntry.dir_idx,
 254                                     fileEntry.mod_time,
 255                                     fileEntry.length);
 256                             prologue.file_names.push_back(fileEntry);
 257                         }
 258                         break;
 259
 260                     case DW_LNE_set_discriminator:
 261                         {
 262                             uint64_t discriminator = debug_line_data.GetULEB128(&offset);
 263                             log->Printf( "0x%8.8x: DW_LNE_set_discriminator (0x%" PRIx64 ")", op_offset, discriminator);
 264                         }
 265                         break;
 266                     default:
 267                         log->Printf( "0x%8.8x: DW_LNE_??? (%2.2x) - Skipping unknown upcode", op_offset, opcode);
 268                         // Length doesn't include the zero opcode byte or the length itself, but
 269                         // it does include the sub_opcode, so we have to adjust for that below
 270                         offset += arg_size;
 271                         break;
 272                     }
 273                 }
 274                 break;
 275
 276             // Standard Opcodes
 277             case DW_LNS_copy:
 278                 log->Printf( "0x%8.8x: DW_LNS_copy", op_offset);
 279                 row.Dump (log);
 280                 break;
 281
 282             case DW_LNS_advance_pc:
 283                 {
 284                     dw_uleb128_t addr_offset_n = debug_line_data.GetULEB128(&offset);
 285                     dw_uleb128_t addr_offset = addr_offset_n * prologue.min_inst_length;
 286                     log->Printf( "0x%8.8x: DW_LNS_advance_pc (0x%x)", op_offset, addr_offset);
 287                     row.address += addr_offset;
 288                 }
 289                 break;
 290
 291             case DW_LNS_advance_line:
 292                 {
 293                     dw_sleb128_t line_offset = debug_line_data.GetSLEB128(&offset);
 294                     log->Printf( "0x%8.8x: DW_LNS_advance_line (%i)", op_offset, line_offset);
 295                     row.line += line_offset;
 296                 }
 297                 break;
 298
 299             case DW_LNS_set_file:
 300                 row.file = debug_line_data.GetULEB128(&offset);
 301                 log->Printf( "0x%8.8x: DW_LNS_set_file (%u)", op_offset, row.file);
 302                 break;
 303
 304             case DW_LNS_set_column:
 305                 row.column = debug_line_data.GetULEB128(&offset);
 306                 log->Printf( "0x%8.8x: DW_LNS_set_column (%u)", op_offset, row.column);
 307                 break;
 308
 309             case DW_LNS_negate_stmt:
 310                 row.is_stmt = !row.is_stmt;
 311                 log->Printf( "0x%8.8x: DW_LNS_negate_stmt", op_offset);
 312                 break;
 313
 314             case DW_LNS_set_basic_block:
 315                 row.basic_block = true;
 316                 log->Printf( "0x%8.8x: DW_LNS_set_basic_block", op_offset);
 317                 break;
 318
 319             case DW_LNS_const_add_pc:
 320                 {
 321                     uint8_t adjust_opcode = 255 - prologue.opcode_base;
 322                     dw_addr_t addr_offset = (adjust_opcode / prologue.line_range) * prologue.min_inst_length;
 323                     log->Printf( "0x%8.8x: DW_LNS_const_add_pc (0x%8.8" PRIx64 ")", op_offset, addr_offset);
 324                     row.address += addr_offset;
 325                 }
 326                 break;
 327
 328             case DW_LNS_fixed_advance_pc:
 329                 {
 330                     uint16_t pc_offset = debug_line_data.GetU16(&offset);
 331                     log->Printf( "0x%8.8x: DW_LNS_fixed_advance_pc (0x%4.4x)", op_offset, pc_offset);
 332                     row.address += pc_offset;
 333                 }
 334                 break;
 335
 336             case DW_LNS_set_prologue_end:
 337                 row.prologue_end = true;
 338                 log->Printf( "0x%8.8x: DW_LNS_set_prologue_end", op_offset);
 339                 break;
 340
 341             case DW_LNS_set_epilogue_begin:
 342                 row.epilogue_begin = true;
 343                 log->Printf( "0x%8.8x: DW_LNS_set_epilogue_begin", op_offset);
 344                 break;
 345
 346             case DW_LNS_set_isa:
 347                 row.isa = debug_line_data.GetULEB128(&offset);
 348                 log->Printf( "0x%8.8x: DW_LNS_set_isa (%u)", op_offset, row.isa);
 349                 break;
 350
 351             // Special Opcodes
 352             default:
 353                 if (opcode < prologue.opcode_base)
 354                 {
 355                     // We have an opcode that this parser doesn't know about, skip
 356                     // the number of ULEB128 numbers that is says to skip in the
 357                     // prologue's standard_opcode_lengths array
 358                     uint8_t n = prologue.standard_opcode_lengths[opcode-1];
 359                     log->Printf( "0x%8.8x: Special : Unknown skipping %u ULEB128 values.", op_offset, n);
 360                     while (n > 0)
 361                     {
 362                         debug_line_data.GetULEB128(&offset);
 363                         --n;
 364                     }
 365                 }
 366                 else
 367                 {
 368                     uint8_t adjust_opcode = opcode - prologue.opcode_base;
 369                     dw_addr_t addr_offset = (adjust_opcode / prologue.line_range) * prologue.min_inst_length;
 370                     int32_t line_offset = prologue.line_base + (adjust_opcode % prologue.line_range);
 371                     log->Printf("0x%8.8x: address += 0x%" PRIx64 ",  line += %i\n", op_offset, (uint64_t)addr_offset, line_offset);
 372                     row.address += addr_offset;
 373                     row.line += line_offset;
 374                     row.Dump (log);
 375                 }
 376                 break;
 377             }
 378         }
 379         return end_offset;
 380     }
 381     return DW_INVALID_OFFSET;
 382 }
 383
 384
 385
 386
 387 //----------------------------------------------------------------------
 388 // Parse
 389 //
 390 // Parse the entire line table contents calling callback each time a
 391 // new prologue is parsed and every time a new row is to be added to
 392 // the line table.
 393 //----------------------------------------------------------------------
 394 void
 395 DWARFDebugLine::Parse(const DWARFDataExtractor& debug_line_data, DWARFDebugLine::State::Callback callback, void* userData)
 396 {
 397     lldb::offset_t offset = 0;
 398     if (debug_line_data.ValidOffset(offset))
 399     {
 400         if (!ParseStatementTable(debug_line_data, &offset, callback, userData))
 401             ++offset;   // Skip to next byte in .debug_line section
 402     }
 403 }
 404
 405
 406 //----------------------------------------------------------------------
 407 // DWARFDebugLine::ParsePrologue
 408 //----------------------------------------------------------------------
 409 bool
 410 DWARFDebugLine::ParsePrologue(const DWARFDataExtractor& debug_line_data, lldb::offset_t* offset_ptr, Prologue* prologue)
 411 {
 412     const lldb::offset_t prologue_offset = *offset_ptr;
 413
 414     //DEBUG_PRINTF("0x%8.8x: ParsePrologue()\n", *offset_ptr);
 415
 416     prologue->Clear();
 417     uint32_t i;
 418     const char * s;
 419     prologue->total_length      = debug_line_data.GetDWARFInitialLength(offset_ptr);
 420     prologue->version           = debug_line_data.GetU16(offset_ptr);
 421     if (prologue->version < 2 || prologue->version > 4)
 422       return false;
 423
 424     prologue->prologue_length   = debug_line_data.GetDWARFOffset(offset_ptr);
 425     const lldb::offset_t end_prologue_offset = prologue->prologue_length + *offset_ptr;
 426     prologue->min_inst_length   = debug_line_data.GetU8(offset_ptr);
 427     if (prologue->version >= 4)
 428         prologue->maximum_operations_per_instruction = debug_line_data.GetU8(offset_ptr);
 429     else
 430         prologue->maximum_operations_per_instruction = 1;
 431     prologue->default_is_stmt   = debug_line_data.GetU8(offset_ptr);
 432     prologue->line_base         = debug_line_data.GetU8(offset_ptr);
 433     prologue->line_range        = debug_line_data.GetU8(offset_ptr);
 434     prologue->opcode_base       = debug_line_data.GetU8(offset_ptr);
 435
 436     prologue->standard_opcode_lengths.reserve(prologue->opcode_base-1);
 437
 438     for (i=1; i<prologue->opcode_base; ++i)
 439     {
 440         uint8_t op_len = debug_line_data.GetU8(offset_ptr);
 441         prologue->standard_opcode_lengths.push_back(op_len);
 442     }
 443
 444     while (*offset_ptr < end_prologue_offset)
 445     {
 446         s = debug_line_data.GetCStr(offset_ptr);
 447         if (s && s[0])
 448             prologue->include_directories.push_back(s);
 449         else
 450             break;
 451     }
 452
 453     while (*offset_ptr < end_prologue_offset)
 454     {
 455         const char* name = debug_line_data.GetCStr( offset_ptr );
 456         if (name && name[0])
 457         {
 458             FileNameEntry fileEntry;
 459             fileEntry.name      = name;
 460             fileEntry.dir_idx   = debug_line_data.GetULEB128( offset_ptr );
 461             fileEntry.mod_time  = debug_line_data.GetULEB128( offset_ptr );
 462             fileEntry.length    = debug_line_data.GetULEB128( offset_ptr );
 463             prologue->file_names.push_back(fileEntry);
 464         }
 465         else
 466             break;
 467     }
 468
 469     // XXX GNU as is broken for 64-Bit DWARF
 470     if (*offset_ptr != end_prologue_offset)
 471     {
 472         Host::SystemLog (Host::eSystemLogWarning,
 473                          "warning: parsing line table prologue at 0x%8.8" PRIx64 " should have ended at 0x%8.8" PRIx64 " but it ended at 0x%8.8" PRIx64 "\n",
 474                          prologue_offset,
 475                          end_prologue_offset,
 476                          *offset_ptr);
 477     }
 478     return end_prologue_offset;
 479 }
 480
 481 bool
 482 DWARFDebugLine::ParseSupportFiles (const lldb::ModuleSP &module_sp,
 483                                    const DWARFDataExtractor& debug_line_data,
 484                                    const char *cu_comp_dir,
 485                                    dw_offset_t stmt_list,
 486                                    FileSpecList &support_files)
 487 {
 488     lldb::offset_t offset = stmt_list;
 489
 490     Prologue prologue;
 491     if (!ParsePrologue(debug_line_data, &offset, &prologue))
 492     {
 493         Host::SystemLog (Host::eSystemLogError, "error: parsing line table prologue at 0x%8.8x (parsing ended around 0x%8.8" PRIx64 "\n", stmt_list, offset);
 494         return false;
 495     }
 496
 497     FileSpec file_spec;
 498     std::string remapped_file;
 499
 500     for (uint32_t file_idx = 1; prologue.GetFile(file_idx, cu_comp_dir, file_spec); ++file_idx)
 501     {
 502         if (module_sp->RemapSourceFile(file_spec.GetCString(), remapped_file))
 503             file_spec.SetFile(remapped_file, false);
 504         support_files.Append(file_spec);
 505
 506     }
 507     return true;
 508 }
 509
 510 //----------------------------------------------------------------------
 511 // ParseStatementTable
 512 //
 513 // Parse a single line table (prologue and all rows) and call the
 514 // callback function once for the prologue (row in state will be zero)
 515 // and each time a row is to be added to the line table.
 516 //----------------------------------------------------------------------
 517 bool
 518 DWARFDebugLine::ParseStatementTable
 519 (
 520     const DWARFDataExtractor& debug_line_data,
 521     lldb::offset_t* offset_ptr,
 522     DWARFDebugLine::State::Callback callback,
 523     void* userData
 524 )
 525 {
 526     Log *log (LogChannelDWARF::GetLogIfAll(DWARF_LOG_DEBUG_LINE));
 527     Prologue::shared_ptr prologue(new Prologue());
 528
 529
 530     const dw_offset_t debug_line_offset = *offset_ptr;
 531
 532     Timer scoped_timer (__PRETTY_FUNCTION__,
 533                         "DWARFDebugLine::ParseStatementTable (.debug_line[0x%8.8x])",
 534                         debug_line_offset);
 535
 536     if (!ParsePrologue(debug_line_data, offset_ptr, prologue.get()))
 537     {
 538         if (log)
 539             log->Error ("failed to parse DWARF line table prologue");
 540         // Restore our offset and return false to indicate failure!
 541         *offset_ptr = debug_line_offset;
 542         return false;
 543     }
 544
 545     if (log)
 546         prologue->Dump (log);
 547
 548     const dw_offset_t end_offset = debug_line_offset + prologue->total_length + (debug_line_data.GetDWARFSizeofInitialLength());
 549
 550     State state(prologue, log, callback, userData);
 551
 552     while (*offset_ptr < end_offset)
 553     {
 554         //DEBUG_PRINTF("0x%8.8x: ", *offset_ptr);
 555         uint8_t opcode = debug_line_data.GetU8(offset_ptr);
 556
 557         if (opcode == 0)
 558         {
 559             // Extended Opcodes always start with a zero opcode followed by
 560             // a uleb128 length so you can skip ones you don't know about
 561             lldb::offset_t ext_offset = *offset_ptr;
 562             dw_uleb128_t len = debug_line_data.GetULEB128(offset_ptr);
 563             dw_offset_t arg_size = len - (*offset_ptr - ext_offset);
 564
 565             //DEBUG_PRINTF("Extended: <%2u> ", len);
 566             uint8_t sub_opcode = debug_line_data.GetU8(offset_ptr);
 567             switch (sub_opcode)
 568             {
 569             case DW_LNE_end_sequence:
 570                 // Set the end_sequence register of the state machine to true and
 571                 // append a row to the matrix using the current values of the
 572                 // state-machine registers. Then reset the registers to the initial
 573                 // values specified above. Every statement program sequence must end
 574                 // with a DW_LNE_end_sequence instruction which creates a row whose
 575                 // address is that of the byte after the last target machine instruction
 576                 // of the sequence.
 577                 state.end_sequence = true;
 578                 state.AppendRowToMatrix(*offset_ptr);
 579                 state.Reset();
 580                 break;
 581
 582             case DW_LNE_set_address:
 583                 // Takes a single relocatable address as an operand. The size of the
 584                 // operand is the size appropriate to hold an address on the target
 585                 // machine. Set the address register to the value given by the
 586                 // relocatable address. All of the other statement program opcodes
 587                 // that affect the address register add a delta to it. This instruction
 588                 // stores a relocatable value into it instead.
 589                 if (arg_size == 4)
 590                     state.address = debug_line_data.GetU32(offset_ptr);
 591                 else // arg_size == 8
 592                     state.address = debug_line_data.GetU64(offset_ptr);
 593                 break;
 594
 595             case DW_LNE_define_file:
 596                 // Takes 4 arguments. The first is a null terminated string containing
 597                 // a source file name. The second is an unsigned LEB128 number representing
 598                 // the directory index of the directory in which the file was found. The
 599                 // third is an unsigned LEB128 number representing the time of last
 600                 // modification of the file. The fourth is an unsigned LEB128 number
 601                 // representing the length in bytes of the file. The time and length
 602                 // fields may contain LEB128(0) if the information is not available.
 603                 //
 604                 // The directory index represents an entry in the include_directories
 605                 // section of the statement program prologue. The index is LEB128(0)
 606                 // if the file was found in the current directory of the compilation,
 607                 // LEB128(1) if it was found in the first directory in the
 608                 // include_directories section, and so on. The directory index is
 609                 // ignored for file names that represent full path names.
 610                 //
 611                 // The files are numbered, starting at 1, in the order in which they
 612                 // appear; the names in the prologue come before names defined by
 613                 // the DW_LNE_define_file instruction. These numbers are used in the
 614                 // file register of the state machine.
 615                 {
 616                     FileNameEntry fileEntry;
 617                     fileEntry.name      = debug_line_data.GetCStr(offset_ptr);
 618                     fileEntry.dir_idx   = debug_line_data.GetULEB128(offset_ptr);
 619                     fileEntry.mod_time  = debug_line_data.GetULEB128(offset_ptr);
 620                     fileEntry.length    = debug_line_data.GetULEB128(offset_ptr);
 621                     state.prologue->file_names.push_back(fileEntry);
 622                 }
 623                 break;
 624
 625             default:
 626                 // Length doesn't include the zero opcode byte or the length itself, but
 627                 // it does include the sub_opcode, so we have to adjust for that below
 628                 (*offset_ptr) += arg_size;
 629                 break;
 630             }
 631         }
 632         else if (opcode < prologue->opcode_base)
 633         {
 634             switch (opcode)
 635             {
 636             // Standard Opcodes
 637             case DW_LNS_copy:
 638                 // Takes no arguments. Append a row to the matrix using the
 639                 // current values of the state-machine registers. Then set
 640                 // the basic_block register to false.
 641                 state.AppendRowToMatrix(*offset_ptr);
 642                 break;
 643
 644             case DW_LNS_advance_pc:
 645                 // Takes a single unsigned LEB128 operand, multiplies it by the
 646                 // min_inst_length field of the prologue, and adds the
 647                 // result to the address register of the state machine.
 648                 state.address += debug_line_data.GetULEB128(offset_ptr) * prologue->min_inst_length;
 649                 break;
 650
 651             case DW_LNS_advance_line:
 652                 // Takes a single signed LEB128 operand and adds that value to
 653                 // the line register of the state machine.
 654                 state.line += debug_line_data.GetSLEB128(offset_ptr);
 655                 break;
 656
 657             case DW_LNS_set_file:
 658                 // Takes a single unsigned LEB128 operand and stores it in the file
 659                 // register of the state machine.
 660                 state.file = debug_line_data.GetULEB128(offset_ptr);
 661                 break;
 662
 663             case DW_LNS_set_column:
 664                 // Takes a single unsigned LEB128 operand and stores it in the
 665                 // column register of the state machine.
 666                 state.column = debug_line_data.GetULEB128(offset_ptr);
 667                 break;
 668
 669             case DW_LNS_negate_stmt:
 670                 // Takes no arguments. Set the is_stmt register of the state
 671                 // machine to the logical negation of its current value.
 672                 state.is_stmt = !state.is_stmt;
 673                 break;
 674
 675             case DW_LNS_set_basic_block:
 676                 // Takes no arguments. Set the basic_block register of the
 677                 // state machine to true
 678                 state.basic_block = true;
 679                 break;
 680
 681             case DW_LNS_const_add_pc:
 682                 // Takes no arguments. Add to the address register of the state
 683                 // machine the address increment value corresponding to special
 684                 // opcode 255. The motivation for DW_LNS_const_add_pc is this:
 685                 // when the statement program needs to advance the address by a
 686                 // small amount, it can use a single special opcode, which occupies
 687                 // a single byte. When it needs to advance the address by up to
 688                 // twice the range of the last special opcode, it can use
 689                 // DW_LNS_const_add_pc followed by a special opcode, for a total
 690                 // of two bytes. Only if it needs to advance the address by more
 691                 // than twice that range will it need to use both DW_LNS_advance_pc
 692                 // and a special opcode, requiring three or more bytes.
 693                 {
 694                     uint8_t adjust_opcode = 255 - prologue->opcode_base;
 695                     dw_addr_t addr_offset = (adjust_opcode / prologue->line_range) * prologue->min_inst_length;
 696                     state.address += addr_offset;
 697                 }
 698                 break;
 699
 700             case DW_LNS_fixed_advance_pc:
 701                 // Takes a single uhalf operand. Add to the address register of
 702                 // the state machine the value of the (unencoded) operand. This
 703                 // is the only extended opcode that takes an argument that is not
 704                 // a variable length number. The motivation for DW_LNS_fixed_advance_pc
 705                 // is this: existing assemblers cannot emit DW_LNS_advance_pc or
 706                 // special opcodes because they cannot encode LEB128 numbers or
 707                 // judge when the computation of a special opcode overflows and
 708                 // requires the use of DW_LNS_advance_pc. Such assemblers, however,
 709                 // can use DW_LNS_fixed_advance_pc instead, sacrificing compression.
 710                 state.address += debug_line_data.GetU16(offset_ptr);
 711                 break;
 712
 713             case DW_LNS_set_prologue_end:
 714                 // Takes no arguments. Set the prologue_end register of the
 715                 // state machine to true
 716                 state.prologue_end = true;
 717                 break;
 718
 719             case DW_LNS_set_epilogue_begin:
 720                 // Takes no arguments. Set the basic_block register of the
 721                 // state machine to true
 722                 state.epilogue_begin = true;
 723                 break;
 724
 725             case DW_LNS_set_isa:
 726                 // Takes a single unsigned LEB128 operand and stores it in the
 727                 // column register of the state machine.
 728                 state.isa = debug_line_data.GetULEB128(offset_ptr);
 729                 break;
 730
 731             default:
 732                 // Handle any unknown standard opcodes here. We know the lengths
 733                 // of such opcodes because they are specified in the prologue
 734                 // as a multiple of LEB128 operands for each opcode.
 735                 {
 736                     uint8_t i;
 737                     assert (static_cast<size_t>(opcode - 1) < prologue->standard_opcode_lengths.size());
 738                     const uint8_t opcode_length = prologue->standard_opcode_lengths[opcode - 1];
 739                     for (i=0; i<opcode_length; ++i)
 740                         debug_line_data.Skip_LEB128(offset_ptr);
 741                 }
 742                 break;
 743             }
 744         }
 745         else
 746         {
 747             // Special Opcodes
 748
 749             // A special opcode value is chosen based on the amount that needs
 750             // to be added to the line and address registers. The maximum line
 751             // increment for a special opcode is the value of the line_base
 752             // field in the header, plus the value of the line_range field,
 753             // minus 1 (line base + line range - 1). If the desired line
 754             // increment is greater than the maximum line increment, a standard
 755             // opcode must be used instead of a special opcode. The "address
 756             // advance" is calculated by dividing the desired address increment
 757             // by the minimum_instruction_length field from the header. The
 758             // special opcode is then calculated using the following formula:
 759             //
 760             //  opcode = (desired line increment - line_base) + (line_range * address advance) + opcode_base
 761             //
 762             // If the resulting opcode is greater than 255, a standard opcode
 763             // must be used instead.
 764             //
 765             // To decode a special opcode, subtract the opcode_base from the
 766             // opcode itself to give the adjusted opcode. The amount to
 767             // increment the address register is the result of the adjusted
 768             // opcode divided by the line_range multiplied by the
 769             // minimum_instruction_length field from the header. That is:
 770             //
 771             //  address increment = (adjusted opcode / line_range) * minimum_instruction_length
 772             //
 773             // The amount to increment the line register is the line_base plus
 774             // the result of the adjusted opcode modulo the line_range. That is:
 775             //
 776             // line increment = line_base + (adjusted opcode % line_range)
 777
 778             uint8_t adjust_opcode = opcode - prologue->opcode_base;
 779             dw_addr_t addr_offset = (adjust_opcode / prologue->line_range) * prologue->min_inst_length;
 780             int32_t line_offset = prologue->line_base + (adjust_opcode % prologue->line_range);
 781             state.line += line_offset;
 782             state.address += addr_offset;
 783             state.AppendRowToMatrix(*offset_ptr);
 784         }
 785     }
 786
 787     state.Finalize( *offset_ptr );
 788
 789     return end_offset;
 790 }
 791
 792
 793 //----------------------------------------------------------------------
 794 // ParseStatementTableCallback
 795 //----------------------------------------------------------------------
 796 static void
 797 ParseStatementTableCallback(dw_offset_t offset, const DWARFDebugLine::State& state, void* userData)
 798 {
 799     DWARFDebugLine::LineTable* line_table = (DWARFDebugLine::LineTable*)userData;
 800     if (state.row == DWARFDebugLine::State::StartParsingLineTable)
 801     {
 802         // Just started parsing the line table, so lets keep a reference to
 803         // the prologue using the supplied shared pointer
 804         line_table->prologue = state.prologue;
 805     }
 806     else if (state.row == DWARFDebugLine::State::DoneParsingLineTable)
 807     {
 808         // Done parsing line table, nothing to do for the cleanup
 809     }
 810     else
 811     {
 812         // We have a new row, lets append it
 813         line_table->AppendRow(state);
 814     }
 815 }
 816
 817 //----------------------------------------------------------------------
 818 // ParseStatementTable
 819 //
 820 // Parse a line table at offset and populate the LineTable class with
 821 // the prologue and all rows.
 822 //----------------------------------------------------------------------
 823 bool
 824 DWARFDebugLine::ParseStatementTable(const DWARFDataExtractor& debug_line_data, lldb::offset_t *offset_ptr, LineTable* line_table)
 825 {
 826     return ParseStatementTable(debug_line_data, offset_ptr, ParseStatementTableCallback, line_table);
 827 }
 828
 829
 830 inline bool
 831 DWARFDebugLine::Prologue::IsValid() const
 832 {
 833     return SymbolFileDWARF::SupportedVersion(version);
 834 }
 835
 836 //----------------------------------------------------------------------
 837 // DWARFDebugLine::Prologue::Dump
 838 //----------------------------------------------------------------------
 839 void
 840 DWARFDebugLine::Prologue::Dump(Log *log)
 841 {
 842     uint32_t i;
 843
 844     log->Printf( "Line table prologue:");
 845     log->Printf( "   total_length: 0x%8.8x", total_length);
 846     log->Printf( "        version: %u", version);
 847     log->Printf( "prologue_length: 0x%8.8x", prologue_length);
 848     log->Printf( "min_inst_length: %u", min_inst_length);
 849     log->Printf( "default_is_stmt: %u", default_is_stmt);
 850     log->Printf( "      line_base: %i", line_base);
 851     log->Printf( "     line_range: %u", line_range);
 852     log->Printf( "    opcode_base: %u", opcode_base);
 853
 854     for (i=0; i<standard_opcode_lengths.size(); ++i)
 855     {
 856         log->Printf( "standard_opcode_lengths[%s] = %u", DW_LNS_value_to_name(i+1), standard_opcode_lengths[i]);
 857     }
 858
 859     if (!include_directories.empty())
 860     {
 861         for (i=0; i<include_directories.size(); ++i)
 862         {
 863             log->Printf( "include_directories[%3u] = '%s'", i+1, include_directories[i]);
 864         }
 865     }
 866
 867     if (!file_names.empty())
 868     {
 869         log->PutCString ("                Dir  Mod Time   File Len   File Name");
 870         log->PutCString ("                ---- ---------- ---------- ---------------------------");
 871         for (i=0; i<file_names.size(); ++i)
 872         {
 873             const FileNameEntry& fileEntry = file_names[i];
 874             log->Printf ("file_names[%3u] %4u 0x%8.8x 0x%8.8x %s",
 875                 i+1,
 876                 fileEntry.dir_idx,
 877                 fileEntry.mod_time,
 878                 fileEntry.length,
 879                 fileEntry.name);
 880         }
 881     }
 882 }
 883
 884
 885 //----------------------------------------------------------------------
 886 // DWARFDebugLine::ParsePrologue::Append
 887 //
 888 // Append the contents of the prologue to the binary stream buffer
 889 //----------------------------------------------------------------------
 890 //void
 891 //DWARFDebugLine::Prologue::Append(BinaryStreamBuf& buff) const
 892 //{
 893 //  uint32_t i;
 894 //
 895 //  buff.Append32(total_length);
 896 //  buff.Append16(version);
 897 //  buff.Append32(prologue_length);
 898 //  buff.Append8(min_inst_length);
 899 //  buff.Append8(default_is_stmt);
 900 //  buff.Append8(line_base);
 901 //  buff.Append8(line_range);
 902 //  buff.Append8(opcode_base);
 903 //
 904 //  for (i=0; i<standard_opcode_lengths.size(); ++i)
 905 //      buff.Append8(standard_opcode_lengths[i]);
 906 //
 907 //  for (i=0; i<include_directories.size(); ++i)
 908 //      buff.AppendCStr(include_directories[i].c_str());
 909 //  buff.Append8(0);    // Terminate the include directory section with empty string
 910 //
 911 //  for (i=0; i<file_names.size(); ++i)
 912 //  {
 913 //      buff.AppendCStr(file_names[i].name.c_str());
 914 //      buff.Append32_as_ULEB128(file_names[i].dir_idx);
 915 //      buff.Append32_as_ULEB128(file_names[i].mod_time);
 916 //      buff.Append32_as_ULEB128(file_names[i].length);
 917 //  }
 918 //  buff.Append8(0);    // Terminate the file names section with empty string
 919 //}
 920
 921
 922 bool DWARFDebugLine::Prologue::GetFile(uint32_t file_idx, const char *comp_dir, FileSpec &file) const
 923 {
 924     uint32_t idx = file_idx - 1;    // File indexes are 1 based...
 925     if (idx < file_names.size())
 926     {
 927         file.SetFile(file_names[idx].name, false);
 928         if (file.IsRelative())
 929         {
 930             if (file_names[idx].dir_idx > 0)
 931             {
 932                 const uint32_t dir_idx = file_names[idx].dir_idx - 1;
 933                 if (dir_idx < include_directories.size())
 934                 {
 935                     file.PrependPathComponent(include_directories[dir_idx]);
 936                     if (!file.IsRelative())
 937                         return true;
 938                 }
 939             }
 940
 941             if (comp_dir && comp_dir[0])
 942                 file.PrependPathComponent(comp_dir);
 943         }
 944         return true;
 945     }
 946     return false;
 947 }
 948
 949 //----------------------------------------------------------------------
 950 // DWARFDebugLine::LineTable::Dump
 951 //----------------------------------------------------------------------
 952 void
 953 DWARFDebugLine::LineTable::Dump(Log *log) const
 954 {
 955     if (prologue.get())
 956         prologue->Dump (log);
 957
 958     if (!rows.empty())
 959     {
 960         log->PutCString ("Address            Line   Column File   ISA Flags");
 961         log->PutCString ("------------------ ------ ------ ------ --- -------------");
 962         Row::const_iterator pos = rows.begin();
 963         Row::const_iterator end = rows.end();
 964         while (pos != end)
 965         {
 966             (*pos).Dump (log);
 967             ++pos;
 968         }
 969     }
 970 }
 971
 972
 973 void
 974 DWARFDebugLine::LineTable::AppendRow(const DWARFDebugLine::Row& state)
 975 {
 976     rows.push_back(state);
 977 }
 978
 979
 980
 981 //----------------------------------------------------------------------
 982 // Compare function for the binary search in DWARFDebugLine::LineTable::LookupAddress()
 983 //----------------------------------------------------------------------
 984 static bool FindMatchingAddress (const DWARFDebugLine::Row& row1, const DWARFDebugLine::Row& row2)
 985 {
 986     return row1.address < row2.address;
 987 }
 988
 989
 990 //----------------------------------------------------------------------
 991 // DWARFDebugLine::LineTable::LookupAddress
 992 //----------------------------------------------------------------------
 993 uint32_t
 994 DWARFDebugLine::LineTable::LookupAddress(dw_addr_t address, dw_addr_t cu_high_pc) const
 995 {
 996     uint32_t index = UINT32_MAX;
 997     if (!rows.empty())
 998     {
 999         // Use the lower_bound algorithm to perform a binary search since we know
1000         // that our line table data is ordered by address.
1001         DWARFDebugLine::Row row;
1002         row.address = address;
1003         Row::const_iterator begin_pos = rows.begin();
1004         Row::const_iterator end_pos = rows.end();
1005         Row::const_iterator pos = lower_bound(begin_pos, end_pos, row, FindMatchingAddress);
1006         if (pos == end_pos)
1007         {
1008             if (address < cu_high_pc)
1009                 return rows.size()-1;
1010         }
1011         else
1012         {
1013             // Rely on fact that we are using a std::vector and we can do
1014             // pointer arithmetic to find the row index (which will be one less
1015             // that what we found since it will find the first position after
1016             // the current address) since std::vector iterators are just
1017             // pointers to the container type.
1018             index = pos - begin_pos;
1019             if (pos->address > address)
1020             {
1021                 if (index > 0)
1022                     --index;
1023                 else
1024                     index = UINT32_MAX;
1025             }
1026         }
1027     }
1028     return index;   // Failed to find address
1029 }
1030
1031
1032 //----------------------------------------------------------------------
1033 // DWARFDebugLine::Row::Row
1034 //----------------------------------------------------------------------
1035 DWARFDebugLine::Row::Row(bool default_is_stmt) :
1036     address(0),
1037     line(1),
1038     column(0),
1039     file(1),
1040     is_stmt(default_is_stmt),
1041     basic_block(false),
1042     end_sequence(false),
1043     prologue_end(false),
1044     epilogue_begin(false),
1045     isa(0)
1046 {
1047 }
1048
1049 //----------------------------------------------------------------------
1050 // Called after a row is appended to the matrix
1051 //----------------------------------------------------------------------
1052 void
1053 DWARFDebugLine::Row::PostAppend()
1054 {
1055     basic_block = false;
1056     prologue_end = false;
1057     epilogue_begin = false;
1058 }
1059
1060
1061 //----------------------------------------------------------------------
1062 // DWARFDebugLine::Row::Reset
1063 //----------------------------------------------------------------------
1064 void
1065 DWARFDebugLine::Row::Reset(bool default_is_stmt)
1066 {
1067     address = 0;
1068     line = 1;
1069     column = 0;
1070     file = 1;
1071     is_stmt = default_is_stmt;
1072     basic_block = false;
1073     end_sequence = false;
1074     prologue_end = false;
1075     epilogue_begin = false;
1076     isa = 0;
1077 }
1078 //----------------------------------------------------------------------
1079 // DWARFDebugLine::Row::Dump
1080 //----------------------------------------------------------------------
1081 void
1082 DWARFDebugLine::Row::Dump(Log *log) const
1083 {
1084     log->Printf( "0x%16.16" PRIx64 " %6u %6u %6u %3u %s%s%s%s%s",
1085                 address,
1086                 line,
1087                 column,
1088                 file,
1089                 isa,
1090                 is_stmt ? " is_stmt" : "",
1091                 basic_block ? " basic_block" : "",
1092                 prologue_end ? " prologue_end" : "",
1093                 epilogue_begin ? " epilogue_begin" : "",
1094                 end_sequence ? " end_sequence" : "");
1095 }
1096
1097 //----------------------------------------------------------------------
1098 // Compare function LineTable structures
1099 //----------------------------------------------------------------------
1100 static bool AddressLessThan (const DWARFDebugLine::Row& a, const DWARFDebugLine::Row& b)
1101 {
1102     return a.address < b.address;
1103 }
1104
1105
1106
1107 // Insert a row at the correct address if the addresses can be out of
1108 // order which can only happen when we are linking a line table that
1109 // may have had it's contents rearranged.
1110 void
1111 DWARFDebugLine::Row::Insert(Row::collection& state_coll, const Row& state)
1112 {
1113     // If we don't have anything yet, or if the address of the last state in our
1114     // line table is less than the current one, just append the current state
1115     if (state_coll.empty() || AddressLessThan(state_coll.back(), state))
1116     {
1117         state_coll.push_back(state);
1118     }
1119     else
1120     {
1121         // Do a binary search for the correct entry
1122         pair<Row::iterator, Row::iterator> range(equal_range(state_coll.begin(), state_coll.end(), state, AddressLessThan));
1123
1124         // If the addresses are equal, we can safely replace the previous entry
1125         // with the current one if the one it is replacing is an end_sequence entry.
1126         // We currently always place an extra end sequence when ever we exit a valid
1127         // address range for a function in case the functions get rearranged by
1128         // optimizations or by order specifications. These extra end sequences will
1129         // disappear by getting replaced with valid consecutive entries within a
1130         // compile unit if there are no gaps.
1131         if (range.first == range.second)
1132         {
1133             state_coll.insert(range.first, state);
1134         }
1135         else
1136         {
1137             if ((distance(range.first, range.second) == 1) && range.first->end_sequence == true)
1138             {
1139                 *range.first = state;
1140             }
1141             else
1142             {
1143                 state_coll.insert(range.second, state);
1144             }
1145         }
1146     }
1147 }
1148
1149 void
1150 DWARFDebugLine::Row::Dump(Log *log, const Row::collection& state_coll)
1151 {
1152     std::for_each (state_coll.begin(), state_coll.end(), bind2nd(std::mem_fun_ref(&Row::Dump),log));
1153 }
1154
1155
1156 //----------------------------------------------------------------------
1157 // DWARFDebugLine::State::State
1158 //----------------------------------------------------------------------
1159 DWARFDebugLine::State::State(Prologue::shared_ptr& p, Log *l, DWARFDebugLine::State::Callback cb, void* userData) :
1160     Row (p->default_is_stmt),
1161     prologue (p),
1162     log (l),
1163     callback (cb),
1164     callbackUserData (userData),
1165     row (StartParsingLineTable)
1166 {
1167     // Call the callback with the initial row state of zero for the prologue
1168     if (callback)
1169         callback(0, *this, callbackUserData);
1170 }
1171
1172 //----------------------------------------------------------------------
1173 // DWARFDebugLine::State::Reset
1174 //----------------------------------------------------------------------
1175 void
1176 DWARFDebugLine::State::Reset()
1177 {
1178     Row::Reset(prologue->default_is_stmt);
1179 }
1180
1181 //----------------------------------------------------------------------
1182 // DWARFDebugLine::State::AppendRowToMatrix
1183 //----------------------------------------------------------------------
1184 void
1185 DWARFDebugLine::State::AppendRowToMatrix(dw_offset_t offset)
1186 {
1187     // Each time we are to add an entry into the line table matrix
1188     // call the callback function so that someone can do something with
1189     // the current state of the state machine (like build a line table
1190     // or dump the line table!)
1191     if (log)
1192     {
1193         if (row == 0)
1194         {
1195             log->PutCString ("Address            Line   Column File   ISA Flags");
1196             log->PutCString ("------------------ ------ ------ ------ --- -------------");
1197         }
1198         Dump (log);
1199     }
1200
1201     ++row;  // Increase the row number before we call our callback for a real row
1202     if (callback)
1203         callback(offset, *this, callbackUserData);
1204     PostAppend();
1205 }
1206
1207 //----------------------------------------------------------------------
1208 // DWARFDebugLine::State::Finalize
1209 //----------------------------------------------------------------------
1210 void
1211 DWARFDebugLine::State::Finalize(dw_offset_t offset)
1212 {
1213     // Call the callback with a special row state when we are done parsing a
1214     // line table
1215     row = DoneParsingLineTable;
1216     if (callback)
1217         callback(offset, *this, callbackUserData);
1218 }
1219
1220 //void
1221 //DWARFDebugLine::AppendLineTableData
1222 //(
1223 //  const DWARFDebugLine::Prologue* prologue,
1224 //  const DWARFDebugLine::Row::collection& state_coll,
1225 //  const uint32_t addr_size,
1226 //  BinaryStreamBuf &debug_line_data
1227 //)
1228 //{
1229 //  if (state_coll.empty())
1230 //  {
1231 //      // We have no entries, just make an empty line table
1232 //      debug_line_data.Append8(0);
1233 //      debug_line_data.Append8(1);
1234 //      debug_line_data.Append8(DW_LNE_end_sequence);
1235 //  }
1236 //  else
1237 //  {
1238 //      DWARFDebugLine::Row::const_iterator pos;
1239 //      Row::const_iterator end = state_coll.end();
1240 //      bool default_is_stmt = prologue->default_is_stmt;
1241 //      const DWARFDebugLine::Row reset_state(default_is_stmt);
1242 //      const DWARFDebugLine::Row* prev_state = &reset_state;
1243 //      const int32_t max_line_increment_for_special_opcode = prologue->MaxLineIncrementForSpecialOpcode();
1244 //      for (pos = state_coll.begin(); pos != end; ++pos)
1245 //      {
1246 //          const DWARFDebugLine::Row& curr_state = *pos;
1247 //          int32_t line_increment  = 0;
1248 //          dw_addr_t addr_offset   = curr_state.address - prev_state->address;
1249 //          dw_addr_t addr_advance  = (addr_offset) / prologue->min_inst_length;
1250 //          line_increment = (int32_t)(curr_state.line - prev_state->line);
1251 //
1252 //          // If our previous state was the reset state, then let's emit the
1253 //          // address to keep GDB's DWARF parser happy. If we don't start each
1254 //          // sequence with a DW_LNE_set_address opcode, the line table won't
1255 //          // get slid properly in GDB.
1256 //
1257 //          if (prev_state == &reset_state)
1258 //          {
1259 //              debug_line_data.Append8(0); // Extended opcode
1260 //              debug_line_data.Append32_as_ULEB128(addr_size + 1); // Length of opcode bytes
1261 //              debug_line_data.Append8(DW_LNE_set_address);
1262 //              debug_line_data.AppendMax64(curr_state.address, addr_size);
1263 //              addr_advance = 0;
1264 //          }
1265 //
1266 //          if (prev_state->file != curr_state.file)
1267 //          {
1268 //              debug_line_data.Append8(DW_LNS_set_file);
1269 //              debug_line_data.Append32_as_ULEB128(curr_state.file);
1270 //          }
1271 //
1272 //          if (prev_state->column != curr_state.column)
1273 //          {
1274 //              debug_line_data.Append8(DW_LNS_set_column);
1275 //              debug_line_data.Append32_as_ULEB128(curr_state.column);
1276 //          }
1277 //
1278 //          // Don't do anything fancy if we are at the end of a sequence
1279 //          // as we don't want to push any extra rows since the DW_LNE_end_sequence
1280 //          // will push a row itself!
1281 //          if (curr_state.end_sequence)
1282 //          {
1283 //              if (line_increment != 0)
1284 //              {
1285 //                  debug_line_data.Append8(DW_LNS_advance_line);
1286 //                  debug_line_data.Append32_as_SLEB128(line_increment);
1287 //              }
1288 //
1289 //              if (addr_advance > 0)
1290 //              {
1291 //                  debug_line_data.Append8(DW_LNS_advance_pc);
1292 //                  debug_line_data.Append32_as_ULEB128(addr_advance);
1293 //              }
1294 //
1295 //              // Now push the end sequence on!
1296 //              debug_line_data.Append8(0);
1297 //              debug_line_data.Append8(1);
1298 //              debug_line_data.Append8(DW_LNE_end_sequence);
1299 //
1300 //              prev_state = &reset_state;
1301 //          }
1302 //          else
1303 //          {
1304 //              if (line_increment || addr_advance)
1305 //              {
1306 //                  if (line_increment > max_line_increment_for_special_opcode)
1307 //                  {
1308 //                      debug_line_data.Append8(DW_LNS_advance_line);
1309 //                      debug_line_data.Append32_as_SLEB128(line_increment);
1310 //                      line_increment = 0;
1311 //                  }
1312 //
1313 //                  uint32_t special_opcode = (line_increment >= prologue->line_base) ? ((line_increment - prologue->line_base) + (prologue->line_range * addr_advance) + prologue->opcode_base) : 256;
1314 //                  if (special_opcode > 255)
1315 //                  {
1316 //                      // Both the address and line won't fit in one special opcode
1317 //                      // check to see if just the line advance will?
1318 //                      uint32_t special_opcode_line = ((line_increment >= prologue->line_base) && (line_increment != 0)) ?
1319 //                              ((line_increment - prologue->line_base) + prologue->opcode_base) : 256;
1320 //
1321 //
1322 //                      if (special_opcode_line > 255)
1323 //                      {
1324 //                          // Nope, the line advance won't fit by itself, check the address increment by itself
1325 //                          uint32_t special_opcode_addr = addr_advance ?
1326 //                              ((0 - prologue->line_base) + (prologue->line_range * addr_advance) + prologue->opcode_base) : 256;
1327 //
1328 //                          if (special_opcode_addr > 255)
1329 //                          {
1330 //                              // Neither the address nor the line will fit in a
1331 //                              // special opcode, we must manually enter both then
1332 //                              // do a DW_LNS_copy to push a row (special opcode
1333 //                              // automatically imply a new row is pushed)
1334 //                              if (line_increment != 0)
1335 //                              {
1336 //                                  debug_line_data.Append8(DW_LNS_advance_line);
1337 //                                  debug_line_data.Append32_as_SLEB128(line_increment);
1338 //                              }
1339 //
1340 //                              if (addr_advance > 0)
1341 //                              {
1342 //                                  debug_line_data.Append8(DW_LNS_advance_pc);
1343 //                                  debug_line_data.Append32_as_ULEB128(addr_advance);
1344 //                              }
1345 //
1346 //                              // Now push a row onto the line table manually
1347 //                              debug_line_data.Append8(DW_LNS_copy);
1348 //
1349 //                          }
1350 //                          else
1351 //                          {
1352 //                              // The address increment alone will fit into a special opcode
1353 //                              // so modify our line change, then issue a special opcode
1354 //                              // for the address increment and it will push a row into the
1355 //                              // line table
1356 //                              if (line_increment != 0)
1357 //                              {
1358 //                                  debug_line_data.Append8(DW_LNS_advance_line);
1359 //                                  debug_line_data.Append32_as_SLEB128(line_increment);
1360 //                              }
1361 //
1362 //                              // Advance of line and address will fit into a single byte special opcode
1363 //                              // and this will also push a row onto the line table
1364 //                              debug_line_data.Append8(special_opcode_addr);
1365 //                          }
1366 //                      }
1367 //                      else
1368 //                      {
1369 //                          // The line change alone will fit into a special opcode
1370 //                          // so modify our address increment first, then issue a
1371 //                          // special opcode for the line change and it will push
1372 //                          // a row into the line table
1373 //                          if (addr_advance > 0)
1374 //                          {
1375 //                              debug_line_data.Append8(DW_LNS_advance_pc);
1376 //                              debug_line_data.Append32_as_ULEB128(addr_advance);
1377 //                          }
1378 //
1379 //                          // Advance of line and address will fit into a single byte special opcode
1380 //                          // and this will also push a row onto the line table
1381 //                          debug_line_data.Append8(special_opcode_line);
1382 //                      }
1383 //                  }
1384 //                  else
1385 //                  {
1386 //                      // Advance of line and address will fit into a single byte special opcode
1387 //                      // and this will also push a row onto the line table
1388 //                      debug_line_data.Append8(special_opcode);
1389 //                  }
1390 //              }
1391 //              prev_state = &curr_state;
1392 //          }
1393 //      }
1394 //  }
1395 //}