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- /*
- * 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"
- #include <AK/String.h>
- LineProgram::LineProgram(InputMemoryStream& 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 >> Bytes { &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(".");
- String directory;
- while (m_stream >> directory) {
- #ifdef DWARF_DEBUG
- dbg() << "directory: " << directory;
- #endif
- m_source_directories.append(move(directory));
- }
- m_stream.handle_error();
- m_stream.discard_or_error(1);
- ASSERT(!m_stream.handle_error());
- }
- void LineProgram::parse_source_files()
- {
- m_source_files.append({ ".", 0 });
- while (!m_stream.eof() && m_stream.peek_or_error()) {
- 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.discard_or_error(1);
- ASSERT(!m_stream.handle_error());
- }
- 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.discard_or_error(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);
- }
- }
- }
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