ladybird/Userland/Libraries/LibDebug/Dwarf/CompilationUnit.cpp
Ali Mohammad Pur da3c4e5df5 LibDebug+LibCoredump: Use ByteReader to do unaligned reads
The previous solution of "lol whats a UB" was not nice and tripped over
itself when it was run under UBSAN, fix this by doing explicit
byte-by-byte reads where needed.
2022-01-28 22:51:27 +00:00

116 lines
3.5 KiB
C++

/*
* Copyright (c) 2020, Itamar S. <itamar8910@gmail.com>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#include "CompilationUnit.h"
#include "DIE.h"
#include <AK/ByteReader.h>
namespace Debug::Dwarf {
CompilationUnit::CompilationUnit(DwarfInfo const& dwarf_info, u32 offset, CompilationUnitHeader const& header, NonnullOwnPtr<LineProgram>&& line_program)
: m_dwarf_info(dwarf_info)
, m_offset(offset)
, m_header(header)
, m_abbreviations(dwarf_info, header.abbrev_offset())
, m_line_program(move(line_program))
{
VERIFY(header.version() < 5 || header.unit_type() == CompilationUnitType::Full);
}
DIE CompilationUnit::root_die() const
{
return DIE(*this, m_offset + m_header.header_size());
}
DIE CompilationUnit::get_die_at_offset(u32 die_offset) const
{
VERIFY(die_offset >= offset() && die_offset < offset() + size());
return DIE(*this, die_offset);
}
Optional<FlatPtr> CompilationUnit::base_address() const
{
if (m_has_cached_base_address)
return m_cached_base_address;
auto die = root_die();
auto res = die.get_attribute(Attribute::LowPc);
if (res.has_value()) {
m_cached_base_address = res->as_addr();
}
m_has_cached_base_address = true;
return m_cached_base_address;
}
u64 CompilationUnit::address_table_base() const
{
if (m_has_cached_address_table_base)
return m_cached_address_table_base;
auto die = root_die();
auto res = die.get_attribute(Attribute::AddrBase);
if (res.has_value()) {
VERIFY(res->form() == AttributeDataForm::SecOffset);
m_cached_address_table_base = res->as_unsigned();
}
m_has_cached_address_table_base = true;
return m_cached_address_table_base;
}
u64 CompilationUnit::string_offsets_base() const
{
if (m_has_cached_string_offsets_base)
return m_cached_string_offsets_base;
auto die = root_die();
auto res = die.get_attribute(Attribute::StrOffsetsBase);
if (res.has_value()) {
VERIFY(res->form() == AttributeDataForm::SecOffset);
m_cached_string_offsets_base = res->as_unsigned();
}
m_has_cached_string_offsets_base = true;
return m_cached_string_offsets_base;
}
u64 CompilationUnit::range_lists_base() const
{
if (m_has_cached_range_lists_base)
return m_cached_range_lists_base;
auto die = root_die();
auto res = die.get_attribute(Attribute::RngListsBase);
if (res.has_value()) {
VERIFY(res->form() == AttributeDataForm::SecOffset);
m_cached_range_lists_base = res->as_unsigned();
}
m_has_cached_range_lists_base = true;
return m_cached_range_lists_base;
}
FlatPtr CompilationUnit::get_address(size_t index) const
{
auto base = address_table_base();
auto debug_addr_data = dwarf_info().debug_addr_data();
VERIFY(base < debug_addr_data.size());
auto addresses = debug_addr_data.slice(base);
VERIFY(index * sizeof(FlatPtr) < addresses.size());
FlatPtr value { 0 };
ByteReader::load<FlatPtr>(addresses.offset_pointer(index * sizeof(FlatPtr)), value);
return value;
}
char const* CompilationUnit::get_string(size_t index) const
{
auto base = string_offsets_base();
auto debug_str_offsets_data = dwarf_info().debug_str_offsets_data();
VERIFY(base < debug_str_offsets_data.size());
// FIXME: This assumes DWARF32
auto offsets = debug_str_offsets_data.slice(base);
VERIFY(index * sizeof(u32) < offsets.size());
auto offset = ByteReader::load32(offsets.offset_pointer(index * sizeof(u32)));
return bit_cast<char const*>(dwarf_info().debug_strings_data().offset(offset));
}
}