mirror of
https://github.com/RGBCube/serenity
synced 2025-05-28 16:15:10 +00:00
LibDebug: Parse line number information from DWARF format
DWARF line number information, if generated, is stored in the .debug_line section of an object file. The information is encoded as instructions for a VM that is defined in the DWARF specification. By executing these instructions, we can extract the encoded line number information.
This commit is contained in:
Itamar
Andreas Kling
parent
edaa9c06d9
commit
8a886e0e96
5 changed files with 596 additions and 0 deletions
247
Libraries/LibDebug/Dwarf/LineProgram.cpp
Normal file
247
Libraries/LibDebug/Dwarf/LineProgram.cpp
Normal file
|
|
@ -0,0 +1,247 @@
|
|||
/*
|
||||
* Copyright (c) 2020, Itamar S. <itamar8910@gmail.com>
|
||||
* All rights reserved.
|
||||
*
|
||||
* Redistribution and use in source and binary forms, with or without
|
||||
* modification, are permitted provided that the following conditions are met:
|
||||
*
|
||||
* 1. Redistributions of source code must retain the above copyright notice, this
|
||||
* list of conditions and the following disclaimer.
|
||||
*
|
||||
* 2. Redistributions in binary form must reproduce the above copyright notice,
|
||||
* this list of conditions and the following disclaimer in the documentation
|
||||
* and/or other materials provided with the distribution.
|
||||
*
|
||||
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
|
||||
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
|
||||
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
|
||||
* DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
|
||||
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
|
||||
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
|
||||
* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
|
||||
* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
|
||||
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
|
||||
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
|
||||
*/
|
||||
|
||||
#include "LineProgram.h"
|
||||
|
||||
LineProgram::LineProgram(BufferStream& stream)
|
||||
: m_stream(stream)
|
||||
{
|
||||
m_unit_offset = m_stream.offset();
|
||||
parse_unit_header();
|
||||
parse_source_directories();
|
||||
parse_source_files();
|
||||
run_program();
|
||||
}
|
||||
|
||||
void LineProgram::parse_unit_header()
|
||||
{
|
||||
m_stream.read_raw((u8*)&m_unit_header, sizeof(m_unit_header));
|
||||
|
||||
ASSERT(m_unit_header.version == DWARF_VERSION);
|
||||
ASSERT(m_unit_header.opcode_base == SPECIAL_OPCODES_BASE);
|
||||
|
||||
#ifdef DWARF_DEBUG
|
||||
dbg() << "unit length: " << unit_header.length;
|
||||
#endif
|
||||
}
|
||||
|
||||
void LineProgram::parse_source_directories()
|
||||
{
|
||||
m_source_directories.append(".");
|
||||
while (m_stream.peek()) {
|
||||
String directory;
|
||||
m_stream >> directory;
|
||||
#ifdef DWARF_DEBUG
|
||||
dbg() << "directory: " << directory;
|
||||
#endif
|
||||
m_source_directories.append(move(directory));
|
||||
}
|
||||
m_stream.advance(1);
|
||||
}
|
||||
|
||||
void LineProgram::parse_source_files()
|
||||
{
|
||||
m_source_files.append({ ".", 0 });
|
||||
while (m_stream.peek()) {
|
||||
String file_name;
|
||||
m_stream >> file_name;
|
||||
size_t directory_index = 0;
|
||||
m_stream.read_LEB128_unsigned(directory_index);
|
||||
size_t _unused = 0;
|
||||
m_stream.read_LEB128_unsigned(_unused); // skip modification time
|
||||
m_stream.read_LEB128_unsigned(_unused); // skip file size
|
||||
#ifdef DWARF_DEBUG
|
||||
dbg() << "file: " << file_name << ", directory index: " << directory_index;
|
||||
#endif
|
||||
m_source_files.append({ file_name, directory_index });
|
||||
}
|
||||
m_stream.advance(1);
|
||||
ASSERT(!m_stream.handle_read_failure());
|
||||
}
|
||||
|
||||
void LineProgram::append_to_line_info()
|
||||
{
|
||||
#ifdef DWARF_DEBUG
|
||||
dbg() << "appending line info: " << (void*)address << ", " << files[file_index].name << ":" << line;
|
||||
#endif
|
||||
if (!m_is_statement)
|
||||
return;
|
||||
|
||||
String directory = m_source_directories[m_source_files[m_file_index].directory_index];
|
||||
String full_path = String::format("%s/%s", directory.characters(), m_source_files[m_file_index].name.characters());
|
||||
m_lines.append({ m_address, full_path, m_line });
|
||||
}
|
||||
|
||||
void LineProgram::reset_registers()
|
||||
{
|
||||
m_address = 0;
|
||||
m_line = 1;
|
||||
m_file_index = 1;
|
||||
m_is_statement = m_unit_header.default_is_stmt == 1;
|
||||
}
|
||||
|
||||
void LineProgram::handle_extended_opcode()
|
||||
{
|
||||
size_t length = 0;
|
||||
m_stream.read_LEB128_unsigned(length);
|
||||
|
||||
u8 sub_opcode = 0;
|
||||
m_stream >> sub_opcode;
|
||||
|
||||
switch (sub_opcode) {
|
||||
case ExtendedOpcodes::EndSequence: {
|
||||
append_to_line_info();
|
||||
reset_registers();
|
||||
break;
|
||||
}
|
||||
case ExtendedOpcodes::SetAddress: {
|
||||
ASSERT(length == sizeof(size_t) + 1);
|
||||
m_stream >> m_address;
|
||||
#ifdef DWARF_DEBUG
|
||||
dbg() << "SetAddress: " << (void*)address;
|
||||
#endif
|
||||
break;
|
||||
}
|
||||
case ExtendedOpcodes::SetDiscriminator: {
|
||||
#ifdef DWARF_DEBUG
|
||||
dbg() << "SetDiscriminator";
|
||||
#endif
|
||||
m_stream.advance(1);
|
||||
break;
|
||||
}
|
||||
default:
|
||||
#ifdef DWARF_DEBUG
|
||||
dbg() << "offset: " << (void*)m_stream.offset();
|
||||
#endif
|
||||
ASSERT_NOT_REACHED();
|
||||
}
|
||||
}
|
||||
void LineProgram::handle_standard_opcode(u8 opcode)
|
||||
{
|
||||
switch (opcode) {
|
||||
case StandardOpcodes::Copy: {
|
||||
append_to_line_info();
|
||||
break;
|
||||
}
|
||||
case StandardOpcodes::AdvancePc: {
|
||||
size_t operand = 0;
|
||||
m_stream.read_LEB128_unsigned(operand);
|
||||
size_t delta = operand * m_unit_header.min_instruction_length;
|
||||
#ifdef DWARF_DEBUG
|
||||
dbg() << "AdvnacePC by: " << delta << " to: " << (void*)(address + delta);
|
||||
#endif
|
||||
m_address += delta;
|
||||
break;
|
||||
}
|
||||
case StandardOpcodes::SetFile: {
|
||||
size_t new_file_index = 0;
|
||||
m_stream.read_LEB128_unsigned(new_file_index);
|
||||
#ifdef DWARF_DEBUG
|
||||
dbg() << "SetFile: new file index: " << new_file_index;
|
||||
#endif
|
||||
m_file_index = new_file_index;
|
||||
break;
|
||||
}
|
||||
case StandardOpcodes::SetColumn: {
|
||||
// not implemented
|
||||
#ifdef DWARF_DEBUG
|
||||
dbg() << "SetColumn";
|
||||
#endif
|
||||
size_t new_column;
|
||||
m_stream.read_LEB128_unsigned(new_column);
|
||||
|
||||
break;
|
||||
}
|
||||
case StandardOpcodes::AdvanceLine: {
|
||||
ssize_t line_delta;
|
||||
m_stream.read_LEB128_signed(line_delta);
|
||||
// dbg() << "line_delta: " << line_delta;
|
||||
ASSERT(line_delta >= 0 || m_line >= (size_t)(-line_delta));
|
||||
m_line += line_delta;
|
||||
#ifdef DWARF_DEBUG
|
||||
dbg() << "AdvanceLine: " << line;
|
||||
#endif
|
||||
break;
|
||||
}
|
||||
case StandardOpcodes::NegateStatement: {
|
||||
#ifdef DWARF_DEBUG
|
||||
dbg() << "NegateStatement";
|
||||
#endif
|
||||
m_is_statement = !m_is_statement;
|
||||
break;
|
||||
}
|
||||
case StandardOpcodes::ConstAddPc: {
|
||||
u8 adjusted_opcode = 255 - SPECIAL_OPCODES_BASE;
|
||||
ssize_t address_increment = (adjusted_opcode / m_unit_header.line_range) * m_unit_header.min_instruction_length;
|
||||
address_increment *= m_unit_header.min_instruction_length;
|
||||
#ifdef DWARF_DEBUG
|
||||
dbg() << "ConstAddPc: advance pc by: " << address_increment << " to: " << (address + address_increment);
|
||||
#endif
|
||||
m_address += address_increment;
|
||||
break;
|
||||
}
|
||||
default:
|
||||
ASSERT_NOT_REACHED();
|
||||
}
|
||||
}
|
||||
void LineProgram::handle_sepcial_opcode(u8 opcode)
|
||||
{
|
||||
u8 adjusted_opcode = opcode - SPECIAL_OPCODES_BASE;
|
||||
ssize_t address_increment = (adjusted_opcode / m_unit_header.line_range) * m_unit_header.min_instruction_length;
|
||||
ssize_t line_increment = m_unit_header.line_base + (adjusted_opcode % m_unit_header.line_range);
|
||||
|
||||
m_address += address_increment;
|
||||
m_line += line_increment;
|
||||
|
||||
#ifdef DWARF_DEBUG
|
||||
dbg() << "Special adjusted_opcode: " << adjusted_opcode << ", delta_address: " << address_increment << ", delta_line: " << line_increment;
|
||||
dbg() << "Address is now:" << (void*)m_address << ", and line is: " << source_files[m_file_index].name << ":" << line;
|
||||
#endif
|
||||
|
||||
append_to_line_info();
|
||||
}
|
||||
|
||||
void LineProgram::run_program()
|
||||
{
|
||||
reset_registers();
|
||||
|
||||
while ((size_t)m_stream.offset() < m_unit_offset + sizeof(u32) + m_unit_header.length) {
|
||||
u8 opcode = 0;
|
||||
m_stream >> opcode;
|
||||
|
||||
#ifdef DWARF_DEBUG
|
||||
dbg() << (void*)(m_stream.offset() - 1) << ": opcode: " << opcode;
|
||||
#endif
|
||||
|
||||
if (opcode == 0) {
|
||||
handle_extended_opcode();
|
||||
} else if (opcode >= 1 && opcode <= 12) {
|
||||
handle_standard_opcode(opcode);
|
||||
} else {
|
||||
handle_sepcial_opcode(opcode);
|
||||
}
|
||||
}
|
||||
}
|
||||
Loading…
Add table
Add a link
Reference in a new issue