Initial checkin of lldb code from internal Apple repo.
git-svn-id: https://llvm.org/svn/llvm-project/llvdb/trunk@105619 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/source/Plugins/SymbolFile/DWARF/DWARFDebugLine.cpp b/source/Plugins/SymbolFile/DWARF/DWARFDebugLine.cpp
new file mode 100644
index 0000000..2b3f39b
--- /dev/null
+++ b/source/Plugins/SymbolFile/DWARF/DWARFDebugLine.cpp
@@ -0,0 +1,1410 @@
+//===-- DWARFDebugLine.cpp --------------------------------------*- C++ -*-===//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "DWARFDebugLine.h"
+
+//#define ENABLE_DEBUG_PRINTF // DO NOT LEAVE THIS DEFINED: DEBUG ONLY!!!
+#include <assert.h>
+
+#include "lldb/Core/FileSpecList.h"
+#include "lldb/Core/Log.h"
+#include "lldb/Core/Timer.h"
+
+#include "SymbolFileDWARF.h"
+#include "LogChannelDWARF.h"
+
+using namespace lldb_private;
+using namespace std;
+
+//----------------------------------------------------------------------
+// Parse
+//
+// Parse all information in the debug_line_data into an internal
+// representation.
+//----------------------------------------------------------------------
+void
+DWARFDebugLine::Parse(const DataExtractor& debug_line_data)
+{
+ m_lineTableMap.clear();
+ dw_offset_t offset = 0;
+ LineTable::shared_ptr line_table_sp(new LineTable);
+ while (debug_line_data.ValidOffset(offset))
+ {
+ const uint32_t debug_line_offset = offset;
+
+ if (line_table_sp.get() == NULL)
+ break;
+
+ if (ParseStatementTable(debug_line_data, &offset, line_table_sp.get()))
+ {
+ // Make sure we don't don't loop infinitely
+ if (offset <= debug_line_offset)
+ break;
+ //DEBUG_PRINTF("m_lineTableMap[0x%8.8x] = line_table_sp\n", debug_line_offset);
+ m_lineTableMap[debug_line_offset] = line_table_sp;
+ line_table_sp.reset(new LineTable);
+ }
+ else
+ ++offset; // Try next byte in line table
+ }
+}
+
+void
+DWARFDebugLine::ParseIfNeeded(const DataExtractor& debug_line_data)
+{
+ if (m_lineTableMap.empty())
+ Parse(debug_line_data);
+}
+
+
+//----------------------------------------------------------------------
+// DWARFDebugLine::GetLineTable
+//----------------------------------------------------------------------
+DWARFDebugLine::LineTable::shared_ptr
+DWARFDebugLine::GetLineTable(const dw_offset_t offset) const
+{
+ DWARFDebugLine::LineTable::shared_ptr line_table_shared_ptr;
+ LineTableConstIter pos = m_lineTableMap.find(offset);
+ if (pos != m_lineTableMap.end())
+ line_table_shared_ptr = pos->second;
+ return line_table_shared_ptr;
+}
+
+
+//----------------------------------------------------------------------
+// DumpStateToFile
+//----------------------------------------------------------------------
+static void
+DumpStateToFile (dw_offset_t offset, const DWARFDebugLine::State& state, void* userData)
+{
+ Log *log = (Log *)userData;
+ if (state.row == DWARFDebugLine::State::StartParsingLineTable)
+ {
+ // If the row is zero we are being called with the prologue only
+ state.prologue->Dump (log);
+ log->PutCString ("Address Line Column File");
+ log->PutCString ("------------------ ------ ------ ------");
+ }
+ else if (state.row == DWARFDebugLine::State::DoneParsingLineTable)
+ {
+ // Done parsing line table
+ }
+ else
+ {
+ log->Printf( "0x%16.16llx %6u %6u %6u%s\n", state.address, state.line, state.column, state.file, state.end_sequence ? " END" : "");
+ }
+}
+
+//----------------------------------------------------------------------
+// DWARFDebugLine::DumpLineTableRows
+//----------------------------------------------------------------------
+bool
+DWARFDebugLine::DumpLineTableRows(Log *log, SymbolFileDWARF* dwarf2Data, dw_offset_t debug_line_offset)
+{
+ const DataExtractor& debug_line_data = dwarf2Data->get_debug_line_data();
+
+ if (debug_line_offset == DW_INVALID_OFFSET)
+ {
+ // Dump line table to a single file only
+ debug_line_offset = 0;
+ while (debug_line_data.ValidOffset(debug_line_offset))
+ debug_line_offset = DumpStatementTable (log, debug_line_data, debug_line_offset);
+ }
+ else
+ {
+ // Dump line table to a single file only
+ DumpStatementTable (log, debug_line_data, debug_line_offset);
+ }
+ return false;
+}
+
+//----------------------------------------------------------------------
+// DWARFDebugLine::DumpStatementTable
+//----------------------------------------------------------------------
+dw_offset_t
+DWARFDebugLine::DumpStatementTable(Log *log, const DataExtractor& debug_line_data, const dw_offset_t debug_line_offset)
+{
+ if (debug_line_data.ValidOffset(debug_line_offset))
+ {
+ uint32_t offset = debug_line_offset;
+ log->Printf( "----------------------------------------------------------------------\n"
+ "debug_line[0x%8.8x]\n"
+ "----------------------------------------------------------------------\n", debug_line_offset);
+
+ if (ParseStatementTable(debug_line_data, &offset, DumpStateToFile, log))
+ return offset;
+ else
+ return debug_line_offset + 1; // Skip to next byte in .debug_line section
+ }
+
+ return DW_INVALID_OFFSET;
+}
+
+
+//----------------------------------------------------------------------
+// DumpOpcodes
+//----------------------------------------------------------------------
+bool
+DWARFDebugLine::DumpOpcodes(Log *log, SymbolFileDWARF* dwarf2Data, dw_offset_t debug_line_offset, uint32_t dump_flags)
+{
+ const DataExtractor& debug_line_data = dwarf2Data->get_debug_line_data();
+
+ if (debug_line_data.GetByteSize() == 0)
+ {
+ log->Printf( "< EMPTY >\n");
+ return false;
+ }
+
+ if (debug_line_offset == DW_INVALID_OFFSET)
+ {
+ // Dump line table to a single file only
+ debug_line_offset = 0;
+ while (debug_line_data.ValidOffset(debug_line_offset))
+ debug_line_offset = DumpStatementOpcodes (log, debug_line_data, debug_line_offset, dump_flags);
+ }
+ else
+ {
+ // Dump line table to a single file only
+ DumpStatementOpcodes (log, debug_line_data, debug_line_offset, dump_flags);
+ }
+ return false;
+}
+
+//----------------------------------------------------------------------
+// DumpStatementOpcodes
+//----------------------------------------------------------------------
+dw_offset_t
+DWARFDebugLine::DumpStatementOpcodes(Log *log, const DataExtractor& debug_line_data, const dw_offset_t debug_line_offset, uint32_t flags)
+{
+ uint32_t offset = debug_line_offset;
+ if (debug_line_data.ValidOffset(offset))
+ {
+ Prologue prologue;
+
+ if (ParsePrologue(debug_line_data, &offset, &prologue))
+ {
+ log->PutCString ("----------------------------------------------------------------------");
+ log->Printf ("debug_line[0x%8.8x]", debug_line_offset);
+ log->PutCString ("----------------------------------------------------------------------\n");
+ prologue.Dump (log);
+ }
+ else
+ {
+ offset = debug_line_offset;
+ log->Printf( "0x%8.8x: skipping pad byte %2.2x", offset, debug_line_data.GetU8(&offset));
+ return offset;
+ }
+
+ Row row(prologue.default_is_stmt);
+ const dw_offset_t end_offset = debug_line_offset + prologue.total_length + sizeof(prologue.total_length);
+
+ assert(debug_line_data.ValidOffset(end_offset-1));
+
+ while (offset < end_offset)
+ {
+ const uint32_t op_offset = offset;
+ uint8_t opcode = debug_line_data.GetU8(&offset);
+ switch (opcode)
+ {
+ case 0: // Extended Opcodes always start with a zero opcode followed by
+ { // a uleb128 length so you can skip ones you don't know about
+
+ dw_offset_t ext_offset = offset;
+ dw_uleb128_t len = debug_line_data.GetULEB128(&offset);
+ dw_offset_t arg_size = len - (offset - ext_offset);
+ uint8_t sub_opcode = debug_line_data.GetU8(&offset);
+// if (verbose)
+// log->Printf( "Extended: <%u> %2.2x ", len, sub_opcode);
+
+ switch (sub_opcode)
+ {
+ case DW_LNE_end_sequence :
+ log->Printf( "0x%8.8x: DW_LNE_end_sequence", op_offset);
+ row.Dump(log);
+ row.Reset(prologue.default_is_stmt);
+ break;
+
+ case DW_LNE_set_address :
+ {
+ row.address = debug_line_data.GetMaxU64(&offset, arg_size);
+ log->Printf( "0x%8.8x: DW_LNE_set_address (0x%llx)", op_offset, row.address);
+ }
+ break;
+
+ case DW_LNE_define_file:
+ {
+ FileNameEntry fileEntry;
+ fileEntry.name = debug_line_data.GetCStr(&offset);
+ fileEntry.dir_idx = debug_line_data.GetULEB128(&offset);
+ fileEntry.mod_time = debug_line_data.GetULEB128(&offset);
+ fileEntry.length = debug_line_data.GetULEB128(&offset);
+ log->Printf( "0x%8.8x: DW_LNE_define_file('%s', dir=%i, mod_time=0x%8.8x, length=%i )",
+ op_offset,
+ fileEntry.name.c_str(),
+ fileEntry.dir_idx,
+ fileEntry.mod_time,
+ fileEntry.length);
+ prologue.file_names.push_back(fileEntry);
+ }
+ break;
+
+ default:
+ log->Printf( "0x%8.8x: DW_LNE_??? (%2.2x) - Skipping unknown upcode", op_offset, opcode);
+ // Length doesn't include the zero opcode byte or the length itself, but
+ // it does include the sub_opcode, so we have to adjust for that below
+ offset += arg_size;
+ break;
+ }
+ }
+ break;
+
+ // Standard Opcodes
+ case DW_LNS_copy:
+ log->Printf( "0x%8.8x: DW_LNS_copy", op_offset);
+ row.Dump (log);
+ break;
+
+ case DW_LNS_advance_pc:
+ {
+ dw_uleb128_t addr_offset_n = debug_line_data.GetULEB128(&offset);
+ dw_uleb128_t addr_offset = addr_offset_n * prologue.min_inst_length;
+ log->Printf( "0x%8.8x: DW_LNS_advance_pc (0x%llx)", op_offset, addr_offset);
+ row.address += addr_offset;
+ }
+ break;
+
+ case DW_LNS_advance_line:
+ {
+ dw_sleb128_t line_offset = debug_line_data.GetSLEB128(&offset);
+ log->Printf( "0x%8.8x: DW_LNS_advance_line (%i)", op_offset, line_offset);
+ row.line += line_offset;
+ }
+ break;
+
+ case DW_LNS_set_file:
+ row.file = debug_line_data.GetULEB128(&offset);
+ log->Printf( "0x%8.8x: DW_LNS_set_file (%u)", op_offset, row.file);
+ break;
+
+ case DW_LNS_set_column:
+ row.column = debug_line_data.GetULEB128(&offset);
+ log->Printf( "0x%8.8x: DW_LNS_set_column (%u)", op_offset, row.column);
+ break;
+
+ case DW_LNS_negate_stmt:
+ row.is_stmt = !row.is_stmt;
+ log->Printf( "0x%8.8x: DW_LNS_negate_stmt", op_offset);
+ break;
+
+ case DW_LNS_set_basic_block:
+ row.basic_block = true;
+ log->Printf( "0x%8.8x: DW_LNS_set_basic_block", op_offset);
+ break;
+
+ case DW_LNS_const_add_pc:
+ {
+ uint8_t adjust_opcode = 255 - prologue.opcode_base;
+ dw_addr_t addr_offset = (adjust_opcode / prologue.line_range) * prologue.min_inst_length;
+ log->Printf( "0x%8.8x: DW_LNS_const_add_pc (0x%8.8llx)", op_offset, addr_offset);
+ row.address += addr_offset;
+ }
+ break;
+
+ case DW_LNS_fixed_advance_pc:
+ {
+ uint16_t pc_offset = debug_line_data.GetU16(&offset);
+ log->Printf( "0x%8.8x: DW_LNS_fixed_advance_pc (0x%4.4x)", op_offset, pc_offset);
+ row.address += pc_offset;
+ }
+ break;
+
+ case DW_LNS_set_prologue_end:
+ row.prologue_end = true;
+ log->Printf( "0x%8.8x: DW_LNS_set_prologue_end", op_offset);
+ break;
+
+ case DW_LNS_set_epilogue_begin:
+ row.epilogue_begin = true;
+ log->Printf( "0x%8.8x: DW_LNS_set_epilogue_begin", op_offset);
+ break;
+
+ case DW_LNS_set_isa:
+ row.isa = debug_line_data.GetULEB128(&offset);
+ log->Printf( "0x%8.8x: DW_LNS_set_isa (%u)", op_offset, row.isa);
+ break;
+
+ // Special Opcodes
+ default:
+ if (opcode < prologue.opcode_base)
+ {
+ // We have an opcode that this parser doesn't know about, skip
+ // the number of ULEB128 numbers that is says to skip in the
+ // prologue's standard_opcode_lengths array
+ uint8_t n = prologue.standard_opcode_lengths[opcode-1];
+ log->Printf( "0x%8.8x: Special : Unknown skipping %u ULEB128 values.", op_offset, n);
+ while (n > 0)
+ {
+ debug_line_data.GetULEB128(&offset);
+ --n;
+ }
+ }
+ else
+ {
+ uint8_t adjust_opcode = opcode - prologue.opcode_base;
+ dw_addr_t addr_offset = (adjust_opcode / prologue.line_range) * prologue.min_inst_length;
+ int32_t line_offset = prologue.line_base + (adjust_opcode % prologue.line_range);
+ log->Printf("0x%8.8x: address += 0x%llx, line += %i\n", op_offset, (uint64_t)addr_offset, line_offset);
+ row.address += addr_offset;
+ row.line += line_offset;
+ row.Dump (log);
+ }
+ break;
+ }
+ }
+ return end_offset;
+ }
+ return DW_INVALID_OFFSET;
+}
+
+
+
+
+//----------------------------------------------------------------------
+// Parse
+//
+// Parse the entire line table contents calling callback each time a
+// new prologue is parsed and every time a new row is to be added to
+// the line table.
+//----------------------------------------------------------------------
+void
+DWARFDebugLine::Parse(const DataExtractor& debug_line_data, DWARFDebugLine::State::Callback callback, void* userData)
+{
+ uint32_t offset = 0;
+ if (debug_line_data.ValidOffset(offset))
+ {
+ if (!ParseStatementTable(debug_line_data, &offset, callback, userData))
+ ++offset; // Skip to next byte in .debug_line section
+ }
+}
+
+
+//----------------------------------------------------------------------
+// DWARFDebugLine::ParsePrologue
+//----------------------------------------------------------------------
+bool
+DWARFDebugLine::ParsePrologue(const DataExtractor& debug_line_data, dw_offset_t* offset_ptr, Prologue* prologue)
+{
+// const uint32_t prologue_offset = *offset_ptr;
+
+ //DEBUG_PRINTF("0x%8.8x: ParsePrologue()\n", *offset_ptr);
+
+ prologue->Clear();
+ uint32_t i;
+ const char * s;
+ prologue->total_length = debug_line_data.GetU32(offset_ptr);
+ prologue->version = debug_line_data.GetU16(offset_ptr);
+ if (prologue->version != 2)
+ return false;
+
+ prologue->prologue_length = debug_line_data.GetU32(offset_ptr);
+ const dw_offset_t end_prologue_offset = prologue->prologue_length + *offset_ptr;
+ prologue->min_inst_length = debug_line_data.GetU8(offset_ptr);
+ prologue->default_is_stmt = debug_line_data.GetU8(offset_ptr);
+ prologue->line_base = debug_line_data.GetU8(offset_ptr);
+ prologue->line_range = debug_line_data.GetU8(offset_ptr);
+ prologue->opcode_base = debug_line_data.GetU8(offset_ptr);
+
+ prologue->standard_opcode_lengths.reserve(prologue->opcode_base-1);
+
+ for (i=1; i<prologue->opcode_base; ++i)
+ {
+ uint8_t op_len = debug_line_data.GetU8(offset_ptr);
+ prologue->standard_opcode_lengths.push_back(op_len);
+ }
+
+ while (*offset_ptr < end_prologue_offset)
+ {
+ s = debug_line_data.GetCStr(offset_ptr);
+ if (s && s[0])
+ prologue->include_directories.push_back(s);
+ else
+ break;
+ }
+
+ while (*offset_ptr < end_prologue_offset)
+ {
+ const char* name = debug_line_data.GetCStr( offset_ptr );
+ if (name && name[0])
+ {
+ FileNameEntry fileEntry;
+ fileEntry.name = name;
+ fileEntry.dir_idx = debug_line_data.GetULEB128( offset_ptr );
+ fileEntry.mod_time = debug_line_data.GetULEB128( offset_ptr );
+ fileEntry.length = debug_line_data.GetULEB128( offset_ptr );
+ prologue->file_names.push_back(fileEntry);
+ }
+ else
+ break;
+ }
+
+ assert(*offset_ptr == end_prologue_offset);
+ return end_prologue_offset;
+}
+
+bool
+DWARFDebugLine::ParseSupportFiles(const DataExtractor& debug_line_data, const char *cu_comp_dir, dw_offset_t stmt_list, FileSpecList &support_files)
+{
+ uint32_t offset = stmt_list + 4; // Skip the total length
+ const char * s;
+ uint32_t version = debug_line_data.GetU16(&offset);
+ if (version != 2)
+ return false;
+
+ const dw_offset_t end_prologue_offset = debug_line_data.GetU32(&offset) + offset;
+ // Skip instruction length, default is stmt, line base, line range and
+ // opcode base, and all opcode lengths
+ offset += 4;
+ const uint8_t opcode_base = debug_line_data.GetU8(&offset);
+ offset += opcode_base - 1;
+ std::vector<std::string> include_directories;
+ include_directories.push_back(""); // Directory at index zero doesn't exist
+ while (offset < end_prologue_offset)
+ {
+ s = debug_line_data.GetCStr(&offset);
+ if (s && s[0])
+ include_directories.push_back(s);
+ else
+ break;
+ }
+ std::string fullpath;
+ while (offset < end_prologue_offset)
+ {
+ const char* path = debug_line_data.GetCStr( &offset );
+ if (path && path[0])
+ {
+ uint32_t dir_idx = debug_line_data.GetULEB128( &offset );
+ debug_line_data.Skip_LEB128(&offset); // Skip mod_time
+ debug_line_data.Skip_LEB128(&offset); // Skip length
+
+ if (path[0] == '/')
+ {
+ // The path starts with a directory delimiter, so we are done.
+ fullpath = path;
+ }
+ else
+ {
+ if (dir_idx > 0 && dir_idx < include_directories.size())
+ {
+ if (cu_comp_dir && include_directories[dir_idx][0] != '/')
+ {
+ fullpath = cu_comp_dir;
+
+ if (*fullpath.rbegin() != '/')
+ fullpath += '/';
+ fullpath += include_directories[dir_idx];
+
+ }
+ else
+ fullpath = include_directories[dir_idx];
+ }
+ else if (cu_comp_dir && cu_comp_dir[0])
+ {
+ fullpath = cu_comp_dir;
+ }
+
+ if (!fullpath.empty())
+ {
+ if (*fullpath.rbegin() != '/')
+ fullpath += '/';
+ }
+ fullpath += path;
+ }
+ FileSpec file_spec(fullpath.c_str());
+ support_files.Append(file_spec);
+ }
+ }
+
+ assert(offset == end_prologue_offset);
+ return end_prologue_offset;
+}
+
+//----------------------------------------------------------------------
+// ParseStatementTable
+//
+// Parse a single line table (prologue and all rows) and call the
+// callback function once for the prologue (row in state will be zero)
+// and each time a row is to be added to the line table.
+//----------------------------------------------------------------------
+bool
+DWARFDebugLine::ParseStatementTable
+(
+ const DataExtractor& debug_line_data,
+ dw_offset_t* offset_ptr,
+ DWARFDebugLine::State::Callback callback,
+ void* userData
+)
+{
+ Log *log = LogChannelDWARF::GetLogIfAll(DWARF_LOG_DEBUG_LINE);
+ Prologue::shared_ptr prologue(new Prologue());
+
+
+ const dw_offset_t debug_line_offset = *offset_ptr;
+
+ Timer scoped_timer (__PRETTY_FUNCTION__,
+ "DWARFDebugLine::ParseStatementTable (.debug_line[0x%8.8x])",
+ debug_line_offset);
+
+ if (!ParsePrologue(debug_line_data, offset_ptr, prologue.get()))
+ {
+ if (log)
+ log->Error ("failed to parse DWARF line table prologue");
+ // Restore our offset and return false to indicate failure!
+ *offset_ptr = debug_line_offset;
+ return false;
+ }
+
+ if (log)
+ prologue->Dump (log);
+
+ const dw_offset_t end_offset = debug_line_offset + prologue->total_length + sizeof(prologue->total_length);
+
+ assert(debug_line_data.ValidOffset(end_offset-1));
+
+ State state(prologue, log, callback, userData);
+
+ while (*offset_ptr < end_offset)
+ {
+ //DEBUG_PRINTF("0x%8.8x: ", *offset_ptr);
+ uint8_t opcode = debug_line_data.GetU8(offset_ptr);
+
+ if (opcode == 0)
+ {
+ // Extended Opcodes always start with a zero opcode followed by
+ // a uleb128 length so you can skip ones you don't know about
+ dw_offset_t ext_offset = *offset_ptr;
+ dw_uleb128_t len = debug_line_data.GetULEB128(offset_ptr);
+ dw_offset_t arg_size = len - (*offset_ptr - ext_offset);
+
+ //DEBUG_PRINTF("Extended: <%2u> ", len);
+ uint8_t sub_opcode = debug_line_data.GetU8(offset_ptr);
+ switch (sub_opcode)
+ {
+ case DW_LNE_end_sequence:
+ // Set the end_sequence register of the state machine to true and
+ // append a row to the matrix using the current values of the
+ // state-machine registers. Then reset the registers to the initial
+ // values specified above. Every statement program sequence must end
+ // with a DW_LNE_end_sequence instruction which creates a row whose
+ // address is that of the byte after the last target machine instruction
+ // of the sequence.
+ state.end_sequence = true;
+ state.AppendRowToMatrix(*offset_ptr);
+ state.Reset();
+ break;
+
+ case DW_LNE_set_address:
+ // Takes a single relocatable address as an operand. The size of the
+ // operand is the size appropriate to hold an address on the target
+ // machine. Set the address register to the value given by the
+ // relocatable address. All of the other statement program opcodes
+ // that affect the address register add a delta to it. This instruction
+ // stores a relocatable value into it instead.
+ state.address = debug_line_data.GetAddress(offset_ptr);
+ break;
+
+ case DW_LNE_define_file:
+ // Takes 4 arguments. The first is a null terminated string containing
+ // a source file name. The second is an unsigned LEB128 number representing
+ // the directory index of the directory in which the file was found. The
+ // third is an unsigned LEB128 number representing the time of last
+ // modification of the file. The fourth is an unsigned LEB128 number
+ // representing the length in bytes of the file. The time and length
+ // fields may contain LEB128(0) if the information is not available.
+ //
+ // The directory index represents an entry in the include_directories
+ // section of the statement program prologue. The index is LEB128(0)
+ // if the file was found in the current directory of the compilation,
+ // LEB128(1) if it was found in the first directory in the
+ // include_directories section, and so on. The directory index is
+ // ignored for file names that represent full path names.
+ //
+ // The files are numbered, starting at 1, in the order in which they
+ // appear; the names in the prologue come before names defined by
+ // the DW_LNE_define_file instruction. These numbers are used in the
+ // the file register of the state machine.
+ {
+ FileNameEntry fileEntry;
+ fileEntry.name = debug_line_data.GetCStr(offset_ptr);
+ fileEntry.dir_idx = debug_line_data.GetULEB128(offset_ptr);
+ fileEntry.mod_time = debug_line_data.GetULEB128(offset_ptr);
+ fileEntry.length = debug_line_data.GetULEB128(offset_ptr);
+ state.prologue->file_names.push_back(fileEntry);
+ }
+ break;
+
+ default:
+ // Length doesn't include the zero opcode byte or the length itself, but
+ // it does include the sub_opcode, so we have to adjust for that below
+ (*offset_ptr) += arg_size;
+ break;
+ }
+ }
+ else if (opcode < prologue->opcode_base)
+ {
+ switch (opcode)
+ {
+ // Standard Opcodes
+ case DW_LNS_copy:
+ // Takes no arguments. Append a row to the matrix using the
+ // current values of the state-machine registers. Then set
+ // the basic_block register to false.
+ state.AppendRowToMatrix(*offset_ptr);
+ break;
+
+ case DW_LNS_advance_pc:
+ // Takes a single unsigned LEB128 operand, multiplies it by the
+ // min_inst_length field of the prologue, and adds the
+ // result to the address register of the state machine.
+ state.address += debug_line_data.GetULEB128(offset_ptr) * prologue->min_inst_length;
+ break;
+
+ case DW_LNS_advance_line:
+ // Takes a single signed LEB128 operand and adds that value to
+ // the line register of the state machine.
+ state.line += debug_line_data.GetSLEB128(offset_ptr);
+ break;
+
+ case DW_LNS_set_file:
+ // Takes a single unsigned LEB128 operand and stores it in the file
+ // register of the state machine.
+ state.file = debug_line_data.GetULEB128(offset_ptr);
+ break;
+
+ case DW_LNS_set_column:
+ // Takes a single unsigned LEB128 operand and stores it in the
+ // column register of the state machine.
+ state.column = debug_line_data.GetULEB128(offset_ptr);
+ break;
+
+ case DW_LNS_negate_stmt:
+ // Takes no arguments. Set the is_stmt register of the state
+ // machine to the logical negation of its current value.
+ state.is_stmt = !state.is_stmt;
+ break;
+
+ case DW_LNS_set_basic_block:
+ // Takes no arguments. Set the basic_block register of the
+ // state machine to true
+ state.basic_block = true;
+ break;
+
+ case DW_LNS_const_add_pc:
+ // Takes no arguments. Add to the address register of the state
+ // machine the address increment value corresponding to special
+ // opcode 255. The motivation for DW_LNS_const_add_pc is this:
+ // when the statement program needs to advance the address by a
+ // small amount, it can use a single special opcode, which occupies
+ // a single byte. When it needs to advance the address by up to
+ // twice the range of the last special opcode, it can use
+ // DW_LNS_const_add_pc followed by a special opcode, for a total
+ // of two bytes. Only if it needs to advance the address by more
+ // than twice that range will it need to use both DW_LNS_advance_pc
+ // and a special opcode, requiring three or more bytes.
+ {
+ uint8_t adjust_opcode = 255 - prologue->opcode_base;
+ dw_addr_t addr_offset = (adjust_opcode / prologue->line_range) * prologue->min_inst_length;
+ state.address += addr_offset;
+ }
+ break;
+
+ case DW_LNS_fixed_advance_pc:
+ // Takes a single uhalf operand. Add to the address register of
+ // the state machine the value of the (unencoded) operand. This
+ // is the only extended opcode that takes an argument that is not
+ // a variable length number. The motivation for DW_LNS_fixed_advance_pc
+ // is this: existing assemblers cannot emit DW_LNS_advance_pc or
+ // special opcodes because they cannot encode LEB128 numbers or
+ // judge when the computation of a special opcode overflows and
+ // requires the use of DW_LNS_advance_pc. Such assemblers, however,
+ // can use DW_LNS_fixed_advance_pc instead, sacrificing compression.
+ state.address += debug_line_data.GetU16(offset_ptr);
+ break;
+
+ case DW_LNS_set_prologue_end:
+ // Takes no arguments. Set the prologue_end register of the
+ // state machine to true
+ state.prologue_end = true;
+ break;
+
+ case DW_LNS_set_epilogue_begin:
+ // Takes no arguments. Set the basic_block register of the
+ // state machine to true
+ state.epilogue_begin = true;
+ break;
+
+ case DW_LNS_set_isa:
+ // Takes a single unsigned LEB128 operand and stores it in the
+ // column register of the state machine.
+ state.isa = debug_line_data.GetULEB128(offset_ptr);
+ break;
+
+ default:
+ // Handle any unknown standard opcodes here. We know the lengths
+ // of such opcodes because they are specified in the prologue
+ // as a multiple of LEB128 operands for each opcode.
+ {
+ uint8_t i;
+ assert (opcode - 1 < prologue->standard_opcode_lengths.size());
+ const uint8_t opcode_length = prologue->standard_opcode_lengths[opcode - 1];
+ for (i=0; i<opcode_length; ++i)
+ debug_line_data.Skip_LEB128(offset_ptr);
+ }
+ break;
+ }
+ }
+ else
+ {
+ // Special Opcodes
+
+ // A special opcode value is chosen based on the amount that needs
+ // to be added to the line and address registers. The maximum line
+ // increment for a special opcode is the value of the line_base
+ // field in the header, plus the value of the line_range field,
+ // minus 1 (line base + line range - 1). If the desired line
+ // increment is greater than the maximum line increment, a standard
+ // opcode must be used instead of a special opcode. The “address
+ // advance” is calculated by dividing the desired address increment
+ // by the minimum_instruction_length field from the header. The
+ // special opcode is then calculated using the following formula:
+ //
+ // opcode = (desired line increment - line_base) + (line_range * address advance) + opcode_base
+ //
+ // If the resulting opcode is greater than 255, a standard opcode
+ // must be used instead.
+ //
+ // To decode a special opcode, subtract the opcode_base from the
+ // opcode itself to give the adjusted opcode. The amount to
+ // increment the address register is the result of the adjusted
+ // opcode divided by the line_range multiplied by the
+ // minimum_instruction_length field from the header. That is:
+ //
+ // address increment = (adjusted opcode / line_range) * minimim_instruction_length
+ //
+ // The amount to increment the line register is the line_base plus
+ // the result of the adjusted opcode modulo the line_range. That is:
+ //
+ // line increment = line_base + (adjusted opcode % line_range)
+
+ uint8_t adjust_opcode = opcode - prologue->opcode_base;
+ dw_addr_t addr_offset = (adjust_opcode / prologue->line_range) * prologue->min_inst_length;
+ int32_t line_offset = prologue->line_base + (adjust_opcode % prologue->line_range);
+ state.line += line_offset;
+ state.address += addr_offset;
+ state.AppendRowToMatrix(*offset_ptr);
+ }
+ }
+
+ state.Finalize( *offset_ptr );
+
+ return end_offset;
+}
+
+
+//----------------------------------------------------------------------
+// ParseStatementTableCallback
+//----------------------------------------------------------------------
+static void
+ParseStatementTableCallback(dw_offset_t offset, const DWARFDebugLine::State& state, void* userData)
+{
+ DWARFDebugLine::LineTable* line_table = (DWARFDebugLine::LineTable*)userData;
+ if (state.row == DWARFDebugLine::State::StartParsingLineTable)
+ {
+ // Just started parsing the line table, so lets keep a reference to
+ // the prologue using the supplied shared pointer
+ line_table->prologue = state.prologue;
+ }
+ else if (state.row == DWARFDebugLine::State::DoneParsingLineTable)
+ {
+ // Done parsing line table, nothing to do for the cleanup
+ }
+ else
+ {
+ // We have a new row, lets append it
+ line_table->AppendRow(state);
+ }
+}
+
+//----------------------------------------------------------------------
+// ParseStatementTable
+//
+// Parse a line table at offset and populate the LineTable class with
+// the prologue and all rows.
+//----------------------------------------------------------------------
+bool
+DWARFDebugLine::ParseStatementTable(const DataExtractor& debug_line_data, uint32_t* offset_ptr, LineTable* line_table)
+{
+ return ParseStatementTable(debug_line_data, offset_ptr, ParseStatementTableCallback, line_table);
+}
+
+
+inline bool
+DWARFDebugLine::Prologue::IsValid() const
+{
+ return SymbolFileDWARF::SupportedVersion(version);
+}
+
+//----------------------------------------------------------------------
+// DWARFDebugLine::Prologue::Dump
+//----------------------------------------------------------------------
+void
+DWARFDebugLine::Prologue::Dump(Log *log)
+{
+ uint32_t i;
+
+ log->Printf( "Line table prologue:");
+ log->Printf( " total_length: 0x%8.8x", total_length);
+ log->Printf( " version: %u", version);
+ log->Printf( "prologue_length: 0x%8.8x", prologue_length);
+ log->Printf( "min_inst_length: %u", min_inst_length);
+ log->Printf( "default_is_stmt: %u", default_is_stmt);
+ log->Printf( " line_base: %i", line_base);
+ log->Printf( " line_range: %u", line_range);
+ log->Printf( " opcode_base: %u", opcode_base);
+
+ for (i=0; i<standard_opcode_lengths.size(); ++i)
+ {
+ log->Printf( "standard_opcode_lengths[%s] = %u", DW_LNS_value_to_name(i+1), standard_opcode_lengths[i]);
+ }
+
+ if (!include_directories.empty())
+ {
+ for (i=0; i<include_directories.size(); ++i)
+ {
+ log->Printf( "include_directories[%3u] = '%s'", i+1, include_directories[i].c_str());
+ }
+ }
+
+ if (!file_names.empty())
+ {
+ log->PutCString (" Dir Mod Time File Len File Name");
+ log->PutCString (" ---- ---------- ---------- ---------------------------");
+ for (i=0; i<file_names.size(); ++i)
+ {
+ const FileNameEntry& fileEntry = file_names[i];
+ log->Printf ("file_names[%3u] %4u 0x%8.8x 0x%8.8x %s",
+ i+1,
+ fileEntry.dir_idx,
+ fileEntry.mod_time,
+ fileEntry.length,
+ fileEntry.name.c_str());
+ }
+ }
+}
+
+
+//----------------------------------------------------------------------
+// DWARFDebugLine::ParsePrologue::Append
+//
+// Append the contents of the prologue to the binary stream buffer
+//----------------------------------------------------------------------
+//void
+//DWARFDebugLine::Prologue::Append(BinaryStreamBuf& buff) const
+//{
+// uint32_t i;
+//
+// buff.Append32(total_length);
+// buff.Append16(version);
+// buff.Append32(prologue_length);
+// buff.Append8(min_inst_length);
+// buff.Append8(default_is_stmt);
+// buff.Append8(line_base);
+// buff.Append8(line_range);
+// buff.Append8(opcode_base);
+//
+// for (i=0; i<standard_opcode_lengths.size(); ++i)
+// buff.Append8(standard_opcode_lengths[i]);
+//
+// for (i=0; i<include_directories.size(); ++i)
+// buff.AppendCStr(include_directories[i].c_str());
+// buff.Append8(0); // Terminate the include directory section with empty string
+//
+// for (i=0; i<file_names.size(); ++i)
+// {
+// buff.AppendCStr(file_names[i].name.c_str());
+// buff.Append32_as_ULEB128(file_names[i].dir_idx);
+// buff.Append32_as_ULEB128(file_names[i].mod_time);
+// buff.Append32_as_ULEB128(file_names[i].length);
+// }
+// buff.Append8(0); // Terminate the file names section with empty string
+//}
+
+
+bool DWARFDebugLine::Prologue::GetFile(uint32_t file_idx, std::string& path, std::string& directory) const
+{
+ uint32_t idx = file_idx - 1; // File indexes are 1 based...
+ if (idx < file_names.size())
+ {
+ path = file_names[idx].name;
+ uint32_t dir_idx = file_names[idx].dir_idx - 1;
+ if (dir_idx < include_directories.size())
+ directory = include_directories[dir_idx];
+ else
+ directory.clear();
+ return true;
+ }
+ return false;
+}
+
+//----------------------------------------------------------------------
+// DWARFDebugLine::LineTable::Dump
+//----------------------------------------------------------------------
+void
+DWARFDebugLine::LineTable::Dump(Log *log) const
+{
+ if (prologue.get())
+ prologue->Dump (log);
+
+ if (!rows.empty())
+ {
+ log->PutCString ("Address Line Column File ISA Flags");
+ log->PutCString ("------------------ ------ ------ ------ --- -------------");
+ Row::const_iterator pos = rows.begin();
+ Row::const_iterator end = rows.end();
+ while (pos != end)
+ {
+ (*pos).Dump (log);
+ ++pos;
+ }
+ }
+}
+
+
+void
+DWARFDebugLine::LineTable::AppendRow(const DWARFDebugLine::Row& state)
+{
+ rows.push_back(state);
+}
+
+
+
+//----------------------------------------------------------------------
+// Compare function for the binary search in DWARFDebugLine::LineTable::LookupAddress()
+//----------------------------------------------------------------------
+static bool FindMatchingAddress (const DWARFDebugLine::Row& row1, const DWARFDebugLine::Row& row2)
+{
+ return row1.address < row2.address;
+}
+
+
+//----------------------------------------------------------------------
+// DWARFDebugLine::LineTable::LookupAddress
+//----------------------------------------------------------------------
+uint32_t
+DWARFDebugLine::LineTable::LookupAddress(dw_addr_t address, dw_addr_t cu_high_pc) const
+{
+ uint32_t index = UINT_MAX;
+ if (!rows.empty())
+ {
+ // Use the lower_bound algorithm to perform a binary search since we know
+ // that our line table data is ordered by address.
+ DWARFDebugLine::Row row;
+ row.address = address;
+ Row::const_iterator begin_pos = rows.begin();
+ Row::const_iterator end_pos = rows.end();
+ Row::const_iterator pos = lower_bound(begin_pos, end_pos, row, FindMatchingAddress);
+ if (pos == end_pos)
+ {
+ if (address < cu_high_pc)
+ return rows.size()-1;
+ }
+ else
+ {
+ // Rely on fact that we are using a std::vector and we can do
+ // pointer arithmetic to find the row index (which will be one less
+ // that what we found since it will find the first position after
+ // the current address) since std::vector iterators are just
+ // pointers to the container type.
+ index = pos - begin_pos;
+ if (pos->address > address)
+ {
+ if (index > 0)
+ --index;
+ else
+ index = UINT_MAX;
+ }
+ }
+ }
+ return index; // Failed to find address
+}
+
+
+//----------------------------------------------------------------------
+// DWARFDebugLine::Row::Row
+//----------------------------------------------------------------------
+DWARFDebugLine::Row::Row(bool default_is_stmt) :
+ address(0),
+ line(1),
+ column(0),
+ file(1),
+ is_stmt(default_is_stmt),
+ basic_block(false),
+ end_sequence(false),
+ prologue_end(false),
+ epilogue_begin(false),
+ isa(0)
+{
+}
+
+//----------------------------------------------------------------------
+// Called after a row is appended to the matrix
+//----------------------------------------------------------------------
+void
+DWARFDebugLine::Row::PostAppend()
+{
+ basic_block = false;
+ prologue_end = false;
+ epilogue_begin = false;
+}
+
+
+//----------------------------------------------------------------------
+// DWARFDebugLine::Row::Reset
+//----------------------------------------------------------------------
+void
+DWARFDebugLine::Row::Reset(bool default_is_stmt)
+{
+ address = 0;
+ line = 1;
+ column = 0;
+ file = 1;
+ is_stmt = default_is_stmt;
+ basic_block = false;
+ end_sequence = false;
+ prologue_end = false;
+ epilogue_begin = false;
+ isa = 0;
+}
+//----------------------------------------------------------------------
+// DWARFDebugLine::Row::Dump
+//----------------------------------------------------------------------
+void
+DWARFDebugLine::Row::Dump(Log *log) const
+{
+ log->Printf( "0x%16.16llx %6u %6u %6u %3u %s%s%s%s%s",
+ address,
+ line,
+ column,
+ file,
+ isa,
+ is_stmt ? " is_stmt" : "",
+ basic_block ? " basic_block" : "",
+ prologue_end ? " prologue_end" : "",
+ epilogue_begin ? " epilogue_begin" : "",
+ end_sequence ? " end_sequence" : "");
+}
+
+//----------------------------------------------------------------------
+// Compare function LineTable structures
+//----------------------------------------------------------------------
+static bool AddressLessThan (const DWARFDebugLine::Row& a, const DWARFDebugLine::Row& b)
+{
+ return a.address < b.address;
+}
+
+
+
+// Insert a row at the correct address if the addresses can be out of
+// order which can only happen when we are linking a line table that
+// may have had it's contents rearranged.
+void
+DWARFDebugLine::Row::Insert(Row::collection& state_coll, const Row& state)
+{
+ // If we don't have anything yet, or if the address of the last state in our
+ // line table is less than the current one, just append the current state
+ if (state_coll.empty() || AddressLessThan(state_coll.back(), state))
+ {
+ state_coll.push_back(state);
+ }
+ else
+ {
+ // Do a binary search for the correct entry
+ pair<Row::iterator, Row::iterator> range(equal_range(state_coll.begin(), state_coll.end(), state, AddressLessThan));
+
+ // If the addresses are equal, we can safely replace the previous entry
+ // with the current one if the one it is replacing is an end_sequence entry.
+ // We currently always place an extra end sequence when ever we exit a valid
+ // address range for a function in case the functions get rearranged by
+ // optmimizations or by order specifications. These extra end sequences will
+ // disappear by getting replaced with valid consecutive entries within a
+ // compile unit if there are no gaps.
+ if (range.first == range.second)
+ {
+ state_coll.insert(range.first, state);
+ }
+ else
+ {
+ if ((distance(range.first, range.second) == 1) && range.first->end_sequence == true)
+ {
+ *range.first = state;
+ }
+ else
+ {
+ state_coll.insert(range.second, state);
+ }
+ }
+ }
+}
+
+void
+DWARFDebugLine::Row::Dump(Log *log, const Row::collection& state_coll)
+{
+ std::for_each (state_coll.begin(), state_coll.end(), bind2nd(std::mem_fun_ref(&Row::Dump),log));
+}
+
+
+//----------------------------------------------------------------------
+// DWARFDebugLine::State::State
+//----------------------------------------------------------------------
+DWARFDebugLine::State::State(Prologue::shared_ptr& p, Log *l, DWARFDebugLine::State::Callback cb, void* userData) :
+ Row (p->default_is_stmt),
+ prologue (p),
+ log (l),
+ callback (cb),
+ callbackUserData (userData),
+ row (StartParsingLineTable)
+{
+ // Call the callback with the initial row state of zero for the prologue
+ if (callback)
+ callback(0, *this, callbackUserData);
+}
+
+//----------------------------------------------------------------------
+// DWARFDebugLine::State::Reset
+//----------------------------------------------------------------------
+void
+DWARFDebugLine::State::Reset()
+{
+ Row::Reset(prologue->default_is_stmt);
+}
+
+//----------------------------------------------------------------------
+// DWARFDebugLine::State::AppendRowToMatrix
+//----------------------------------------------------------------------
+void
+DWARFDebugLine::State::AppendRowToMatrix(dw_offset_t offset)
+{
+ // Each time we are to add an entry into the line table matrix
+ // call the callback funtion so that someone can do something with
+ // the current state of the state machine (like build a line table
+ // or dump the line table!)
+ if (log)
+ {
+ if (row == 0)
+ {
+ log->PutCString ("Address Line Column File ISA Flags");
+ log->PutCString ("------------------ ------ ------ ------ --- -------------");
+ }
+ Dump (log);
+ }
+
+ ++row; // Increase the row number before we call our callback for a real row
+ if (callback)
+ callback(offset, *this, callbackUserData);
+ PostAppend();
+}
+
+//----------------------------------------------------------------------
+// DWARFDebugLine::State::Finalize
+//----------------------------------------------------------------------
+void
+DWARFDebugLine::State::Finalize(dw_offset_t offset)
+{
+ // Call the callback with a special row state when we are done parsing a
+ // line table
+ row = DoneParsingLineTable;
+ if (callback)
+ callback(offset, *this, callbackUserData);
+}
+
+//void
+//DWARFDebugLine::AppendLineTableData
+//(
+// const DWARFDebugLine::Prologue* prologue,
+// const DWARFDebugLine::Row::collection& state_coll,
+// const uint32_t addr_size,
+// BinaryStreamBuf &debug_line_data
+//)
+//{
+// if (state_coll.empty())
+// {
+// // We have no entries, just make an empty line table
+// debug_line_data.Append8(0);
+// debug_line_data.Append8(1);
+// debug_line_data.Append8(DW_LNE_end_sequence);
+// }
+// else
+// {
+// DWARFDebugLine::Row::const_iterator pos;
+// Row::const_iterator end = state_coll.end();
+// bool default_is_stmt = prologue->default_is_stmt;
+// const DWARFDebugLine::Row reset_state(default_is_stmt);
+// const DWARFDebugLine::Row* prev_state = &reset_state;
+// const int32_t max_line_increment_for_special_opcode = prologue->MaxLineIncrementForSpecialOpcode();
+// for (pos = state_coll.begin(); pos != end; ++pos)
+// {
+// const DWARFDebugLine::Row& curr_state = *pos;
+// int32_t line_increment = 0;
+// dw_addr_t addr_offset = curr_state.address - prev_state->address;
+// dw_addr_t addr_advance = (addr_offset) / prologue->min_inst_length;
+// line_increment = (int32_t)(curr_state.line - prev_state->line);
+//
+// // If our previous state was the reset state, then let's emit the
+// // address to keep GDB's DWARF parser happy. If we don't start each
+// // sequence with a DW_LNE_set_address opcode, the line table won't
+// // get slid properly in GDB.
+//
+// if (prev_state == &reset_state)
+// {
+// debug_line_data.Append8(0); // Extended opcode
+// debug_line_data.Append32_as_ULEB128(addr_size + 1); // Length of opcode bytes
+// debug_line_data.Append8(DW_LNE_set_address);
+// debug_line_data.AppendMax64(curr_state.address, addr_size);
+// addr_advance = 0;
+// }
+//
+// if (prev_state->file != curr_state.file)
+// {
+// debug_line_data.Append8(DW_LNS_set_file);
+// debug_line_data.Append32_as_ULEB128(curr_state.file);
+// }
+//
+// if (prev_state->column != curr_state.column)
+// {
+// debug_line_data.Append8(DW_LNS_set_column);
+// debug_line_data.Append32_as_ULEB128(curr_state.column);
+// }
+//
+// // Don't do anything fancy if we are at the end of a sequence
+// // as we don't want to push any extra rows since the DW_LNE_end_sequence
+// // will push a row itself!
+// if (curr_state.end_sequence)
+// {
+// if (line_increment != 0)
+// {
+// debug_line_data.Append8(DW_LNS_advance_line);
+// debug_line_data.Append32_as_SLEB128(line_increment);
+// }
+//
+// if (addr_advance > 0)
+// {
+// debug_line_data.Append8(DW_LNS_advance_pc);
+// debug_line_data.Append32_as_ULEB128(addr_advance);
+// }
+//
+// // Now push the end sequence on!
+// debug_line_data.Append8(0);
+// debug_line_data.Append8(1);
+// debug_line_data.Append8(DW_LNE_end_sequence);
+//
+// prev_state = &reset_state;
+// }
+// else
+// {
+// if (line_increment || addr_advance)
+// {
+// if (line_increment > max_line_increment_for_special_opcode)
+// {
+// debug_line_data.Append8(DW_LNS_advance_line);
+// debug_line_data.Append32_as_SLEB128(line_increment);
+// line_increment = 0;
+// }
+//
+// uint32_t special_opcode = (line_increment >= prologue->line_base) ? ((line_increment - prologue->line_base) + (prologue->line_range * addr_advance) + prologue->opcode_base) : 256;
+// if (special_opcode > 255)
+// {
+// // Both the address and line won't fit in one special opcode
+// // check to see if just the line advance will?
+// uint32_t special_opcode_line = ((line_increment >= prologue->line_base) && (line_increment != 0)) ?
+// ((line_increment - prologue->line_base) + prologue->opcode_base) : 256;
+//
+//
+// if (special_opcode_line > 255)
+// {
+// // Nope, the line advance won't fit by itself, check the address increment by itself
+// uint32_t special_opcode_addr = addr_advance ?
+// ((0 - prologue->line_base) + (prologue->line_range * addr_advance) + prologue->opcode_base) : 256;
+//
+// if (special_opcode_addr > 255)
+// {
+// // Neither the address nor the line will fit in a
+// // special opcode, we must manually enter both then
+// // do a DW_LNS_copy to push a row (special opcode
+// // automatically imply a new row is pushed)
+// if (line_increment != 0)
+// {
+// debug_line_data.Append8(DW_LNS_advance_line);
+// debug_line_data.Append32_as_SLEB128(line_increment);
+// }
+//
+// if (addr_advance > 0)
+// {
+// debug_line_data.Append8(DW_LNS_advance_pc);
+// debug_line_data.Append32_as_ULEB128(addr_advance);
+// }
+//
+// // Now push a row onto the line table manually
+// debug_line_data.Append8(DW_LNS_copy);
+//
+// }
+// else
+// {
+// // The address increment alone will fit into a special opcode
+// // so modify our line change, then issue a special opcode
+// // for the address increment and it will push a row into the
+// // line table
+// if (line_increment != 0)
+// {
+// debug_line_data.Append8(DW_LNS_advance_line);
+// debug_line_data.Append32_as_SLEB128(line_increment);
+// }
+//
+// // Advance of line and address will fit into a single byte special opcode
+// // and this will also push a row onto the line table
+// debug_line_data.Append8(special_opcode_addr);
+// }
+// }
+// else
+// {
+// // The line change alone will fit into a special opcode
+// // so modify our address increment first, then issue a
+// // special opcode for the line change and it will push
+// // a row into the line table
+// if (addr_advance > 0)
+// {
+// debug_line_data.Append8(DW_LNS_advance_pc);
+// debug_line_data.Append32_as_ULEB128(addr_advance);
+// }
+//
+// // Advance of line and address will fit into a single byte special opcode
+// // and this will also push a row onto the line table
+// debug_line_data.Append8(special_opcode_line);
+// }
+// }
+// else
+// {
+// // Advance of line and address will fit into a single byte special opcode
+// // and this will also push a row onto the line table
+// debug_line_data.Append8(special_opcode);
+// }
+// }
+// prev_state = &curr_state;
+// }
+// }
+// }
+//}