boost/dll/detail/windows/path_from_handle.hpp
// Copyright 2014 Renato Tegon Forti, Antony Polukhin.
// Copyright 2015 Antony Polukhin.
//
// Distributed under the Boost Software License, Version 1.0.
// (See accompanying file LICENSE_1_0.txt
// or copy at http://www.boost.org/LICENSE_1_0.txt)
#ifndef BOOST_DLL_DETAIL_WINDOWS_PATH_FROM_HANDLE_HPP
#define BOOST_DLL_DETAIL_WINDOWS_PATH_FROM_HANDLE_HPP
#include <boost/config.hpp>
#include <boost/dll/detail/system_error.hpp>
#include <boost/detail/winapi/dll.hpp>
#include <boost/detail/winapi/get_last_error.hpp>
#include <boost/filesystem/path.hpp>
#ifdef BOOST_HAS_PRAGMA_ONCE
# pragma once
#endif
namespace boost { namespace dll { namespace detail {
static inline boost::system::error_code last_error_code() BOOST_NOEXCEPT {
boost::detail::winapi::DWORD_ err = boost::detail::winapi::GetLastError();
return boost::system::error_code(
err,
boost::system::system_category()
);
}
inline boost::filesystem::path path_from_handle(boost::detail::winapi::HMODULE_ handle, boost::system::error_code &ec) {
BOOST_STATIC_CONSTANT(boost::detail::winapi::DWORD_, ERROR_INSUFFICIENT_BUFFER_ = 0x7A);
BOOST_STATIC_CONSTANT(boost::detail::winapi::DWORD_, DEFAULT_PATH_SIZE_ = 260);
// If `handle` parameter is NULL, GetModuleFileName retrieves the path of the
// executable file of the current process.
boost::detail::winapi::WCHAR_ path_hldr[DEFAULT_PATH_SIZE_];
boost::detail::winapi::GetModuleFileNameW(handle, path_hldr, DEFAULT_PATH_SIZE_);
ec = last_error_code();
if (!ec) {
return boost::filesystem::path(path_hldr);
}
for (unsigned i = 2; i < 1025 && static_cast<boost::detail::winapi::DWORD_>(ec.value()) == ERROR_INSUFFICIENT_BUFFER_; i *= 2) {
std::wstring p(DEFAULT_PATH_SIZE_ * i, L'\0');
const std::size_t size = boost::detail::winapi::GetModuleFileNameW(handle, &p[0], DEFAULT_PATH_SIZE_ * i);
ec = last_error_code();
if (!ec) {
p.resize(size);
return boost::filesystem::path(p);
}
}
// Error other than ERROR_INSUFFICIENT_BUFFER_ occurred or failed to allocate buffer big enough
return boost::filesystem::path();
}
}}} // namespace boost::dll::detail
#endif // BOOST_DLL_DETAIL_WINDOWS_PATH_FROM_HANDLE_HPP