type_name.cpp

// Copyright 2016-2023 Francesco Biscani (bluescarni@gmail.com)
//
// This file is part of the mp++ library.
//
// This Source Code Form is subject to the terms of the Mozilla
// Public License v. 2.0. If a copy of the MPL was not distributed
// with this file, You can obtain one at http://mozilla.org/MPL/2.0/.

#include <string>

#if defined(__GNUC__) || (defined(__clang__) && !defined(_MSC_VER))

// GCC demangle. This is available also for clang, both with libstdc++ and libc++.
#include <cstdlib>
#include <cxxabi.h>
#include <memory>

#endif

#include <mp++/type_name.hpp>

// NOLINTNEXTLINE(modernize-concat-nested-namespaces)
MPPP_BEGIN_NAMESPACE
namespace detail
{

std::string demangle_from_typeid(const char *s)
{
#if defined(__GNUC__) || (defined(__clang__) && !defined(_MSC_VER))
    // NOTE: wrap std::free() in a local lambda, so we avoid
    // potential ambiguities when taking the address of std::free().
    // See:
    // https://stackoverflow.com/questions/27440953/stdunique-ptr-for-c-functions-that-need-free
    // NOLINTNEXTLINE(cppcoreguidelines-no-malloc, cppcoreguidelines-owning-memory, hicpp-no-malloc)
    auto deleter = [](void *ptr) { std::free(ptr); };

    // NOTE: abi::__cxa_demangle will return a pointer allocated by std::malloc, which we will delete via std::free().
    std::unique_ptr<char, decltype(deleter)> res{::abi::__cxa_demangle(s, nullptr, nullptr, nullptr), deleter};

    // NOTE: return the original string if demangling fails.
    return res ? std::string(res.get()) : std::string(s);
#else
    // If no demangling is available, just return the mangled name.
    // NOTE: MSVC already returns the demangled name from typeid.
    return std::string(s);
#endif
}

} // namespace detail

MPPP_END_NAMESPACE