ceph/src/boost/libs/dll/include/boost/dll/detail/windows/path_from_handle.hpp

   1 // Copyright 2014 Renato Tegon Forti, Antony Polukhin.
   2 // Copyright 2015 Antony Polukhin.
   3 //
   4 // Distributed under the Boost Software License, Version 1.0.
   5 // (See accompanying file LICENSE_1_0.txt
   6 // or copy at http://www.boost.org/LICENSE_1_0.txt)
   7
   8 #ifndef BOOST_DLL_DETAIL_WINDOWS_PATH_FROM_HANDLE_HPP
   9 #define BOOST_DLL_DETAIL_WINDOWS_PATH_FROM_HANDLE_HPP
  10
  11 #include <boost/config.hpp>
  12 #include <boost/dll/detail/system_error.hpp>
  13 #include <boost/detail/winapi/dll.hpp>
  14 #include <boost/detail/winapi/get_last_error.hpp>
  15 #include <boost/filesystem/path.hpp>
  16
  17 #ifdef BOOST_HAS_PRAGMA_ONCE
  18 # pragma once
  19 #endif
  20
  21 namespace boost { namespace dll { namespace detail {
  22
  23     static inline boost::system::error_code last_error_code() BOOST_NOEXCEPT {
  24         boost::detail::winapi::DWORD_ err = boost::detail::winapi::GetLastError();
  25         return boost::system::error_code(
  26             err,
  27             boost::system::system_category()
  28         );
  29     }
  30
  31     inline boost::filesystem::path path_from_handle(boost::detail::winapi::HMODULE_ handle, boost::system::error_code &ec) {
  32         BOOST_STATIC_CONSTANT(boost::detail::winapi::DWORD_, ERROR_INSUFFICIENT_BUFFER_ = 0x7A);
  33         BOOST_STATIC_CONSTANT(boost::detail::winapi::DWORD_, DEFAULT_PATH_SIZE_ = 260);
  34
  35         // If `handle` parameter is NULL, GetModuleFileName retrieves the path of the
  36         // executable file of the current process.
  37         boost::detail::winapi::WCHAR_ path_hldr[DEFAULT_PATH_SIZE_];
  38         boost::detail::winapi::GetModuleFileNameW(handle, path_hldr, DEFAULT_PATH_SIZE_);
  39         ec = last_error_code();
  40         if (!ec) {
  41             return boost::filesystem::path(path_hldr);
  42         }
  43
  44         for (unsigned i = 2; i < 1025 && static_cast<boost::detail::winapi::DWORD_>(ec.value()) == ERROR_INSUFFICIENT_BUFFER_; i *= 2) {
  45             std::wstring p(DEFAULT_PATH_SIZE_ * i, L'\0');
  46             const std::size_t size = boost::detail::winapi::GetModuleFileNameW(handle, &p[0], DEFAULT_PATH_SIZE_ * i);
  47             ec = last_error_code();
  48
  49             if (!ec) {
  50                 p.resize(size);
  51                 return boost::filesystem::path(p);
  52             }
  53         }
  54
  55         // Error other than ERROR_INSUFFICIENT_BUFFER_ occurred or failed to allocate buffer big enough
  56         return boost::filesystem::path();
  57     }
  58
  59 }}} // namespace boost::dll::detail
  60
  61 #endif // BOOST_DLL_DETAIL_WINDOWS_PATH_FROM_HANDLE_HPP
  62