Boost::process on Windows - with MinGW?

Question

我有一个 C++17 应用程序，只使用 STL 和 boost1.71.0.该应用程序需要在Windows，Linux和BSD上运行。在Windows上，我使用MinGW-w64提供的GCC 9.2。我使用 MSYS2 附带的发行版。

我需要能够创建系统进程(从我的C++应用程序中启动外部应用程序(。

过去，我为此使用了QProcessQt库。但是，此应用程序没有任何Qt依赖项，我想防止仅针对此功能添加Qt依赖项。

寻找解决方案，我遇到了boost::process.乍一看，这似乎是QProcess的一个非常合适的替代品。

我首先使用 C++17、cmake 和 boost 创建了一个最小的应用程序：

#include <iostream>
#include <boost/process.hpp>
int main() {
int result = boost::process::system("g++ main.cpp");
return 0;
}

不幸的是，我立即遇到了编译错误：

====================[ Build | boost_process_test | Debug ]======================
C:UsersjoelAppDataLocalJetBrainsToolboxappsCLionch-0193.5233.103bincmakewinbincmake.exe --build C:UsersjoelDocumentsprojectsboost_process_testcmake-build-debug --target boost_process_test -- -j 6
Scanning dependencies of target boost_process_test
[ 50%] Building CXX object CMakeFiles/boost_process_test.dir/main.cpp.obj
In file included from C:/msys64/mingw64/include/boost/process/detail/windows/handles.hpp:11,
from C:/msys64/mingw64/include/boost/process/detail/used_handles.hpp:17,
from C:/msys64/mingw64/include/boost/process/detail/windows/async_in.hpp:20,
from C:/msys64/mingw64/include/boost/process/async.hpp:49,
from C:/msys64/mingw64/include/boost/process.hpp:23,
from C:UsersjoelDocumentsprojectsboost_process_testmain.cpp:2:
C:/msys64/mingw64/include/boost/process/detail/windows/handle_workaround.hpp:208:51: error: expected ')' before '*' token
208 | typedef ::boost::winapi::NTSTATUS_ (__kernel_entry *nt_system_query_information_p )(
|                                    ~              ^~
|                                                   )
C:/msys64/mingw64/include/boost/process/detail/windows/handle_workaround.hpp:223:51: error: expected ')' before '*' token
223 | typedef ::boost::winapi::NTSTATUS_ (__kernel_entry *nt_query_object_p )(
|                                    ~              ^~
|                                                   )
C:/msys64/mingw64/include/boost/process/detail/windows/handle_workaround.hpp: In function 'boost::winapi::NTSTATUS_ boost::process::detail::windows::workaround::nt_system_query_information(boost::process::detail::windows::workaround::SYSTEM_INFORMATION_CLASS_, void*, boost::winapi::ULONG_, boost::winapi::PULONG_)':
C:/msys64/mingw64/include/boost/process/detail/windows/handle_workaround.hpp:239:12: error: 'nt_system_query_information_p' does not name a type; did you mean 'nt_system_query_information'?
239 |     static nt_system_query_information_p f = reinterpret_cast<nt_system_query_information_p>(::boost::winapi::get_proc_address(h, "NtQuerySystemInformation"));
|            ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
|            nt_system_query_information
In file included from C:/msys64/mingw64/include/boost/process/detail/windows/handles.hpp:11,
from C:/msys64/mingw64/include/boost/process/detail/used_handles.hpp:17,
from C:/msys64/mingw64/include/boost/process/detail/windows/async_in.hpp:20,
from C:/msys64/mingw64/include/boost/process/async.hpp:49,
from C:/msys64/mingw64/include/boost/process.hpp:23,
from C:UsersjoelDocumentsprojectsboost_process_testmain.cpp:2:
C:/msys64/mingw64/include/boost/process/detail/windows/handle_workaround.hpp:241:14: error: 'f' was not declared in this scope
241 |     return (*f)(SystemInformationClass, SystemInformation, SystemInformationLength, ReturnLength);
|              ^
C:/msys64/mingw64/include/boost/process/detail/windows/handle_workaround.hpp: In function 'boost::winapi::BOOL_ boost::process::detail::windows::workaround::nt_query_object(boost::winapi::HANDLE_, boost::process::detail::windows::workaround::OBJECT_INFORMATION_CLASS_, void*, boost::winapi::ULONG_, boost::winapi::PULONG_)':
C:/msys64/mingw64/include/boost/process/detail/windows/handle_workaround.hpp:253:12: error: 'nt_query_object_p' does not name a type; did you mean 'nt_query_object'?
253 |     static nt_query_object_p f = reinterpret_cast<nt_query_object_p>(::boost::winapi::get_proc_address(h, "NtQueryObject"));
|            ^~~~~~~~~~~~~~~~~
|            nt_query_object
C:/msys64/mingw64/include/boost/process/detail/windows/handle_workaround.hpp:255:14: error: 'f' was not declared in this scope
255 |     return (*f)(Handle, ObjectInformationClass, ObjectInformation, ObjectInformationLength, ReturnLength);
|              ^
mingw32-make.exe[3]: *** [CMakeFilesboost_process_test.dirbuild.make:62: CMakeFiles/boost_process_test.dir/main.cpp.obj] Error 1
mingw32-make.exe[2]: *** [CMakeFilesMakefile2:75: CMakeFiles/boost_process_test.dir/all] Error 2
mingw32-make.exe[1]: *** [CMakeFilesMakefile2:82: CMakeFiles/boost_process_test.dir/rule] Error 2
mingw32-make.exe: *** [Makefile:117: boost_process_test] Error 2

这是我相应的CMakeLists.txt：

cmake_minimum_required(VERSION 3.15)
project(boost_process_test)
set(CMAKE_CXX_STANDARD 17)
find_package(Boost 1.71.0 REQUIRED)
add_executable(boost_process_test main.cpp)

我查阅了boost.process文档，以确定存在什么样的依赖和兼容性。不幸的是，我找不到太多关于这方面的信息。

在我开始深入实际调试之前 - 有人知道boost.process版本1.71.0是否真的在 Windows 上运行，如果是这样 - 它是否适用于 GCC/MinGW 而不仅仅是 MSVC？如果支持 MinGW/GCC - 它依赖于 posix 还是 win32api？

Answer 1

解决方案

我在 OP 提到的同一问题的boost::process存储库中遇到了这个 github 问题。这似乎是MinGW的问题。该问题中提出了一种解决方法，涉及在包含boost/process.hpp标头之前定义__kernel_entry预处理器符号。

将其应用于我的代码如下所示：

// Workaround for a boost/mingw bug.
// This must occur before the inclusion of the boost/process.hpp header.
// Taken from https://github.com/boostorg/process/issues/96
#ifndef __kernel_entry
#define __kernel_entry
#endif
#include <boost/process.hpp>
int main() {
int result = boost::process::system("g++ main.cpp");
return 0;
}

这使得编译错误消失，并导致程序二进制文件正常工作。

进一步的步骤

应用修复程序后，问题中显示的初始编译器错误不再出现。但是，该程序仍然无法正确编译和链接，因为我没有正确包含提升库。

我对工作示例的CMakeLists.txt如下所示：

cmake_minimum_required(VERSION 3.15)
project(boost_process_test)
set(CMAKE_CXX_STANDARD 17)
find_package(Boost 1.71.0 REQUIRED
COMPONENTS
filesystem
system
)
add_executable(boost_process_test main.cpp)
target_link_libraries(boost_process_test
PRIVATE
$<$<BOOL:${WIN32}>:ws2_32>
${Boost_FILESYSTEM_LIBRARY}
${Boost_SYSTEM_LIBRARY}
)

请注意指向 Windows 平台上的ws2_32库的链接。

学分

感谢来自Qt社区的@ mrjj为我指出帮助我解决这个编译问题的github问题。