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llvm-project/lldb/source/Plugins/SymbolFile/DWARF/DWARFDebugLine.cpp

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//===-- 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 "lldb/Host/Host.h"
#include "SymbolFileDWARF.h"
#include "LogChannelDWARF.h"
using namespace lldb;
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%x)", 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;
}
if (*offset_ptr != end_prologue_offset)
{
Host::SystemLog (Host::eSystemLogWarning,
"warning: parsing line table prologue at 0x%8.8x should have ended at 0x%8.8x but it ended ad 0x%8.8x\n",
prologue_offset,
end_prologue_offset,
*offset_ptr);
}
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;
}
// We don't need to realpath files in the debug_line tables.
FileSpec file_spec(fullpath.c_str(), false);
support_files.Append(file_spec);
}
}
if (offset != end_prologue_offset)
{
Host::SystemLog (Host::eSystemLogError,
"warning: parsing line table prologue at 0x%8.8x should have ended at 0x%8.8x but it ended ad 0x%8.8x\n",
stmt_list,
end_prologue_offset,
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
)
{
LogSP 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.get());
const dw_offset_t end_offset = debug_line_offset + prologue->total_length + sizeof(prologue->total_length);
State state(prologue, log.get(), 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) * minimum_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 = UINT32_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 = UINT32_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
// optimizations 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 function 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;
// }
// }
// }
//}
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