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//===-- DIERef.cpp --------------------------------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
#include "DIERef.h"
#include "lldb/Utility/DataEncoder.h"
#include "lldb/Utility/DataExtractor.h"
#include "llvm/Support/Format.h"
#include <optional>
using namespace lldb;
using namespace lldb_private;
void llvm::format_provider<DIERef>::format(const DIERef &ref, raw_ostream &OS,
StringRef Style) {
if (ref.dwo_num())
OS << format_hex_no_prefix(*ref.dwo_num(), 8) << "/";
OS << (ref.section() == DIERef::DebugInfo ? "INFO" : "TYPE");
OS << "/" << format_hex_no_prefix(ref.die_offset(), 8);
}
constexpr uint32_t k_dwo_num_mask = 0x3FFFFFFF;
constexpr uint32_t k_dwo_num_valid_bitmask = (1u << 30);
constexpr uint32_t k_section_bitmask = (1u << 31);
std::optional<DIERef> DIERef::Decode(const DataExtractor &data,
lldb::offset_t *offset_ptr) {
const uint32_t bitfield_storage = data.GetU32(offset_ptr);
uint32_t dwo_num = bitfield_storage & k_dwo_num_mask;
bool dwo_num_valid = (bitfield_storage & (k_dwo_num_valid_bitmask)) != 0;
Section section = (Section)((bitfield_storage & (k_section_bitmask)) != 0);
// DIE offsets can't be zero and if we fail to decode something from data,
// it will return 0
dw_offset_t die_offset = data.GetU32(offset_ptr);
if (die_offset == 0)
return std::nullopt;
if (dwo_num_valid)
return DIERef(dwo_num, section, die_offset);
else
return DIERef(std::nullopt, section, die_offset);
}
void DIERef::Encode(DataEncoder &encoder) const {
uint32_t bitfield_storage = m_dwo_num;
if (m_dwo_num_valid)
bitfield_storage |= k_dwo_num_valid_bitmask;
if (m_section)
bitfield_storage |= k_section_bitmask;
encoder.AppendU32(bitfield_storage);
static_assert(sizeof(m_die_offset) == 4, "m_die_offset must be 4 bytes");
encoder.AppendU32(m_die_offset);
}
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