【C++】【Crow】我在使用Cmake构建Crow项目时遇到的3个问题

本文最后更新于：2023年8月23日 晚上 22:51

【C++】【Crow】我在使用Cmake构建Crow项目时遇到的3个问题

目录

​ 背景：Windows

​ 前言：GCC之罪

​ 问题一：'POSIX_SEM_VALUE_MAX' was not declared in this scope

​ 问题二：fatal error: crow.h: No such file or directory

​ 问题三：Asio缺少Windows相关系统库文件链接

​ 后续

背景：Windows

我通过Vcpkg安装了Crow：

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vcpkg install crow:x64-windows-static
vcpkg install crow:x64-windows

但是在我使用Crow构建最简单的测试程序时，却不太顺利，不是想象中的即装即用。

原因是我使用了GCC😭！

看来Windows环境下还是尽可能选择MSVC编译为好。不过我经过一番研究还是成功地使用了GCC进行编译。

前言：GCC之罪

操作系统：Windows 11 22H2

编译器：GCC 13.0 x86_64-w64-mingw32

这是最新的GCC 13，其MinGW工具链来自：Github 上的x86_64-13.1.0-release-win32-seh-ucrt-rt_v11-rev1.7z

这是我的源码目录结构：

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Mode                 LastWriteTime         Length Name
----                 -------------         ------ ----
d----           2023/8/23    21:25                .vscode
d----           2023/8/23    21:31                build
d----           2023/8/23    21:13                src
-a---           2023/8/23    21:31            994 CMakelists.txt

这是src中的main.cpp：

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#include <iostream>
#include <string>
#include <crow.h>
int main() {
    crow::SimpleApp app;
    CROW_ROUTE(app, "/")
    ([]() {
        return "Hello world";
    });
    app.port(18080).multithreaded().run();
    system("pause");
    return 0;
}

这是我的CMakelist.txt：

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cmake_minimum_required(VERSION 3.17)
set(PROJECT_NAME HelloWorld) 
set(CMAKE_TOOLCHAIN_FILE "C:/C_CPP/Library/vcpkg/scripts/buildsystems/vcpkg.cmake") # set vcpkg toolchain file path
set(VCPKG_TARGET_TRIPLET "x64-windows")

project(${PROJECT_NAME}) # set project name
add_executable(${PROJECT_NAME} src/main.cpp) # add executable target named ${PROJECT_NAME}
target_compile_features(${PROJECT_NAME} PRIVATE cxx_std_20)  # enable C++20 standard
set_target_properties(${PROJECT_NAME} PROPERTIES CXX_EXTENSIONS OFF) # disable compiler extensions

# 导入Crow库
find_package(Crow CONFIG REQUIRED)
target_link_libraries(${PROJECT_NAME} Crow::Crow)

问题一：'_POSIX_SEM_VALUE_MAX' was not declared in this scope

CMake输出：

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[main] 正在生成文件夹: vscode_vcpkg_cmake_copy 
[build] 正在启动生成
[proc] 执行命令: "D:\Program Files\CMake\bin\cmake.EXE" --build d:/Code/Cpp/ExerciseCode/vscode_vcpkg_cmake_copy/build --config Debug --target all -j 22 --
[build] [ 50%] Building CXX object CMakeFiles/HelloWorld.dir/src/main.cpp.obj
[build] <command-line>: warning: ISO C++11 requires whitespace after the macro name
[build] In file included from C:/C_CPP/Tookit/mingw64_13h/lib/gcc/x86_64-w64-mingw32/13.1.0/include/c++/semaphore:37,
[build]                  from C:/C_CPP/Tookit/mingw64_13h/lib/gcc/x86_64-w64-mingw32/13.1.0/include/c++/stop_token:39,
[build]                  from C:/C_CPP/Tookit/mingw64_13h/lib/gcc/x86_64-w64-mingw32/13.1.0/include/c++/condition_variable:49,
[build]                  from C:/C_CPP/Tookit/mingw64_13h/lib/gcc/x86_64-w64-mingw32/13.1.0/include/c++/mutex:48,
[build]                  from C:/C_CPP/Library/vcpkg/installed/x64-windows/include/boost/system/detail/mutex.hpp:58,
[build]                  from C:/C_CPP/Library/vcpkg/installed/x64-windows/include/boost/system/detail/error_category_impl.hpp:101,
[build]                  from C:/C_CPP/Library/vcpkg/installed/x64-windows/include/boost/system/error_category.hpp:11,
[build]                  from C:/C_CPP/Library/vcpkg/installed/x64-windows/include/boost/system/error_code.hpp:14,
[build]                  from C:/C_CPP/Library/vcpkg/installed/x64-windows/include/boost/asio/detail/throw_error.hpp:20,
[build]                  from C:/C_CPP/Library/vcpkg/installed/x64-windows/include/boost/asio/detail/impl/win_tss_ptr.ipp:22,
[build]                  from C:/C_CPP/Library/vcpkg/installed/x64-windows/include/boost/asio/detail/win_tss_ptr.hpp:76,
[build]                  from C:/C_CPP/Library/vcpkg/installed/x64-windows/include/boost/asio/detail/tss_ptr.hpp:25,
[build]                  from C:/C_CPP/Library/vcpkg/installed/x64-windows/include/boost/asio/detail/call_stack.hpp:20,
[build]                  from C:/C_CPP/Library/vcpkg/installed/x64-windows/include/boost/asio/detail/thread_context.hpp:20,
[build]                  from C:/C_CPP/Library/vcpkg/installed/x64-windows/include/boost/asio/detail/recycling_allocator.hpp:20,
[build]                  from C:/C_CPP/Library/vcpkg/installed/x64-windows/include/boost/asio/detail/handler_alloc_helpers.hpp:21,
[build]                  from C:/C_CPP/Library/vcpkg/installed/x64-windows/include/boost/asio/detail/executor_function.hpp:19,
[build]                  from C:/C_CPP/Library/vcpkg/installed/x64-windows/include/boost/asio/execution/any_executor.hpp:24,
[build]                  from C:/C_CPP/Library/vcpkg/installed/x64-windows/include/boost/asio/execution.hpp:19,
[build]                  from C:/C_CPP/Library/vcpkg/installed/x64-windows/include/boost/asio/any_completion_executor.hpp:22,
[build]                  from C:/C_CPP/Library/vcpkg/installed/x64-windows/include/boost/asio.hpp:20,
[build]                  from C:/C_CPP/Library/vcpkg/installed/x64-windows/include/crow/socket_adaptors.h:2,
[build]                  from C:/C_CPP/Library/vcpkg/installed/x64-windows/include/crow.h:7,
[build]                  from D:\Code\Cpp\ExerciseCode\vscode_vcpkg_cmake_copy\src\main.cpp:3:
[build] C:/C_CPP/Tookit/mingw64_13h/lib/gcc/x86_64-w64-mingw32/13.1.0/include/c++/bits/semaphore_base.h:59:41: error: '_POSIX_SEM_VALUE_MAX' was not declared in this scope
[build]    59 |     static constexpr ptrdiff_t _S_max = _POSIX_SEM_VALUE_MAX;
[build]       |                                         ^~~~~~~~~~~~~~~~~~~~
[build] mingw32-make.exe[2]: *** [CMakeFiles\HelloWorld.dir\build.make:76: CMakeFiles/HelloWorld.dir/src/main.cpp.obj] Error 1
[build] mingw32-make.exe[1]: *** [CMakeFiles\Makefile2:82: CMakeFiles/HelloWorld.dir/all] Error 2
[build] mingw32-make.exe: *** [Makefile:90: all] Error 2
[proc] 命令“"D:\Program Files\CMake\bin\cmake.EXE" --build d:/Code/Cpp/ExerciseCode/vscode_vcpkg_cmake_copy/build --config Debug --target all -j 22 --”已退出，代码为 2
[driver] 生成完毕: 00:00:07.788
[build] 生成已完成，退出代码为 2
[cpptools] 生成的生成配置不包含活动生成配置。对 CMAKE_BUILD_TYPE 使用 "" 而不是 "Debug"，以确保可以找到 IntelliSense 配置

这好像是由于这个GCC的C++20实现有点BUG，将cxx_std_20 改为cxx_std_17 C++17及以下即可。 询问Claude得到回复如下：（虽然不确定是否正确）

这个错误提示在Windows环境下编译时,不能找到_POSIX_SEM_VALUE_MAX的定义。

_POSIX_SEM_VALUE_MAX是POSIX系统中的一个宏,用于定义semaphore的最大计数值。但是在Windows环境中,并没有这个定义。

很可能是C++标准库的代码原本基于POSIX平台编写,移植到Windows的时候没有适配导致的错误。

要解决这个问题,有以下几种方法:

  1. 在Windows环境下,不要直接使用_POSIX_SEM_VALUE_MAX,可以定义一个兼容值。修改C++标准库实现,根据平台宏对_POSIX_SEM_VALUE_MAX进行隔离。

  2. 在编译命令中定义_POSIX_SEM_VALUE_MAX,使其成为一个空宏。

  3. 尝试更新编译器或标准库版本,使用更兼容的实现。

  4. 根据编译器文档报告此兼容性问题。

  5. 联系原库维护者进行跨平台适配。

  6. 隔离使用非兼容接口的代码,避免污染Windows环境。

  7. 考虑用更通用的线程同步原语替换semaphore。

总之,这主要是一个跨平台兼容性问题。需要区分平台适配相关接口,或者更新编译器和库的版本来获得修复。

问题二：fatal error: crow.h: No such file or directory

CMake输出信息：

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main] 正在生成文件夹: vscode_vcpkg_cmake_copy 
[build] 正在启动生成
[proc] 执行命令: "D:\Program Files\CMake\bin\cmake.EXE" --build d:/Code/Cpp/ExerciseCode/vscode_vcpkg_cmake_copy/build --config Release --target all -j 22 --
[build] [ 50%] Building CXX object CMakeFiles/HelloWorld.dir/src/main.cpp.obj
[build] D:\Code\Cpp\ExerciseCode\vscode_vcpkg_cmake_copy\src\main.cpp:3:10: fatal error: crow.h: No such file or directory
[build]     3 | #include <crow.h>
[build]       |          ^~~~~~~~
[build] compilation terminated.
[build] mingw32-make.exe[2]: *** [CMakeFiles\HelloWorld.dir\build.make:75: CMakeFiles/HelloWorld.dir/src/main.cpp.obj] Error 1
[build] mingw32-make.exe[1]: *** [CMakeFiles\Makefile2:82: CMakeFiles/HelloWorld.dir/all] Error 2
[build] mingw32-make.exe: *** [Makefile:90: all] Error 2
[proc] 命令“"D:\Program Files\CMake\bin\cmake.EXE" --build d:/Code/Cpp/ExerciseCode/vscode_vcpkg_cmake_copy/build --config Release --target all -j 22 --”已退出，代码为 2
[driver] 生成完毕: 00:00:00.543
[build] 生成已完成，退出代码为 2

这个是有点概率出现，不太好复现，清理一下build文件夹，重启一下VSCode似乎就好了。未知原因。

问题三：Asio缺少Windows相关系统库文件链接

CMake输出信息：

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[main] 正在生成文件夹: vscode_vcpkg_cmake_copy 
[main] 缺少包含 CMake 缓存的文件夹。将重新生成缓存。
[main] 正在配置项目: vscode_vcpkg_cmake_copy 
[proc] 执行命令: "D:\Program Files\CMake\bin\cmake.EXE" --no-warn-unused-cli -DCMAKE_BUILD_TYPE:STRING=Debug -DCMAKE_EXPORT_COMPILE_COMMANDS:BOOL=TRUE -DCMAKE_C_COMPILER:FILEPATH=C:\C_CPP\Tookit\mingw64_13h\bin\gcc.exe -DCMAKE_CXX_COMPILER:FILEPATH=C:\C_CPP\Tookit\mingw64_13h\bin\g++.exe -SD:/Code/Cpp/ExerciseCode/vscode_vcpkg_cmake_copy -Bd:/Code/Cpp/ExerciseCode/vscode_vcpkg_cmake_copy/build -G "MinGW Makefiles"
[cmake] Not searching for unused variables given on the command line.
[cmake] -- The C compiler identification is GNU 13.1.0
[cmake] -- The CXX compiler identification is GNU 13.1.0
[cmake] -- Detecting C compiler ABI info
[cmake] -- Detecting C compiler ABI info - done
[cmake] -- Check for working C compiler: C:/C_CPP/Tookit/mingw64_13h/bin/gcc.exe - skipped
[cmake] -- Detecting C compile features
[cmake] -- Detecting C compile features - done
[cmake] -- Detecting CXX compiler ABI info
[cmake] -- Detecting CXX compiler ABI info - done
[cmake] -- Check for working CXX compiler: C:/C_CPP/Tookit/mingw64_13h/bin/g++.exe - skipped
[cmake] -- Detecting CXX compile features
[cmake] -- Detecting CXX compile features - done
[cmake] -- Found Boost: C:/C_CPP/Library/vcpkg/installed/x64-windows/include (found suitable version "1.82.0", minimum required is "1.64") found components: system date_time 
[cmake] -- Performing Test CMAKE_HAVE_LIBC_PTHREAD
[cmake] -- Performing Test CMAKE_HAVE_LIBC_PTHREAD - Failed
[cmake] -- Looking for pthread_create in pthreads
[cmake] -- Looking for pthread_create in pthreads - not found
[cmake] -- Looking for pthread_create in pthread
[cmake] -- Looking for pthread_create in pthread - found
[cmake] -- Found Threads: TRUE  
[cmake] -- Configuring done (7.6s)
[cmake] -- Generating done (0.0s)
[cmake] -- Build files have been written to: D:/Code/Cpp/ExerciseCode/vscode_vcpkg_cmake_copy/build
[build] 正在启动生成
[proc] 执行命令: "D:\Program Files\CMake\bin\cmake.EXE" --build d:/Code/Cpp/ExerciseCode/vscode_vcpkg_cmake_copy/build --config Debug --target all -j 22 --
[build] [ 50%] Building CXX object CMakeFiles/HelloWorld.dir/src/main.cpp.obj
[build] <command-line>: warning: ISO C++11 requires whitespace after the macro name
[build] [100%] Linking CXX executable HelloWorld.exe
[build] C:/C_CPP/Tookit/mingw64_13h/bin/../lib/gcc/x86_64-w64-mingw32/13.1.0/../../../../x86_64-w64-mingw32/bin/ld.exe: CMakeFiles\HelloWorld.dir/objects.a(main.cpp.obj): in function `boost::asio::detail::winsock_init_base::startup(boost::asio::detail::winsock_init_base::data&, unsigned char, unsigned char)':
[build] C:/C_CPP/Library/vcpkg/installed/x64-windows/include/boost/asio/detail/impl/winsock_init.ipp:39: undefined reference to `__imp_WSAStartup'
[build] C:/C_CPP/Tookit/mingw64_13h/bin/../lib/gcc/x86_64-w64-mingw32/13.1.0/../../../../x86_64-w64-mingw32/bin/ld.exe: CMakeFiles\HelloWorld.dir/objects.a(main.cpp.obj): in function `boost::asio::detail::winsock_init_base::cleanup(boost::asio::detail::winsock_init_base::data&)':
[build] C:/C_CPP/Library/vcpkg/installed/x64-windows/include/boost/asio/detail/impl/winsock_init.ipp:56: undefined reference to `__imp_WSACleanup'
[build] C:/C_CPP/Tookit/mingw64_13h/bin/../lib/gcc/x86_64-w64-mingw32/13.1.0/../../../../x86_64-w64-mingw32/bin/ld.exe: CMakeFiles\HelloWorld.dir/objects.a(main.cpp.obj): in function `boost::asio::detail::socket_ops::clear_last_error()':
[build] C:/C_CPP/Library/vcpkg/installed/x64-windows/include/boost/asio/detail/impl/socket_ops.ipp:73: undefined reference to `__imp_WSASetLastError'
[build] C:/C_CPP/Tookit/mingw64_13h/bin/../lib/gcc/x86_64-w64-mingw32/13.1.0/../../../../x86_64-w64-mingw32/bin/ld.exe: CMakeFiles\HelloWorld.dir/objects.a(main.cpp.obj): in function `boost::asio::detail::socket_ops::get_last_error(boost::system::error_code&, bool)':
[build] C:/C_CPP/Library/vcpkg/installed/x64-windows/include/boost/asio/detail/impl/socket_ops.ipp:91: undefined reference to `__imp_WSAGetLastError'
[build] C:/C_CPP/Tookit/mingw64_13h/bin/../lib/gcc/x86_64-w64-mingw32/13.1.0/../../../../x86_64-w64-mingw32/bin/ld.exe: CMakeFiles\HelloWorld.dir/objects.a(main.cpp.obj): in function `boost::asio::detail::socket_ops::complete_iocp_accept(unsigned long long, void*, unsigned long, void*, unsigned long long*, unsigned long long, boost::system::error_code&)':
[build] C:/C_CPP/Library/vcpkg/installed/x64-windows/include/boost/asio/detail/impl/socket_ops.ipp:206: undefined reference to `GetAcceptExSockaddrs'
[build] C:/C_CPP/Tookit/mingw64_13h/bin/../lib/gcc/x86_64-w64-mingw32/13.1.0/../../../../x86_64-w64-mingw32/bin/ld.exe: CMakeFiles\HelloWorld.dir/objects.a(main.cpp.obj): in function `boost::asio::detail::socket_ops::close(unsigned long long, unsigned char&, bool, boost::system::error_code&)':
[build] C:/C_CPP/Library/vcpkg/installed/x64-windows/include/boost/asio/detail/impl/socket_ops.ipp:321: undefined reference to `__imp_closesocket'
[build] C:/C_CPP/Tookit/mingw64_13h/bin/../lib/gcc/x86_64-w64-mingw32/13.1.0/../../../../x86_64-w64-mingw32/bin/ld.exe: C:/C_CPP/Library/vcpkg/installed/x64-windows/include/boost/asio/detail/impl/socket_ops.ipp:339: undefined reference to `__imp_ioctlsocket'
[build] C:/C_CPP/Tookit/mingw64_13h/bin/../lib/gcc/x86_64-w64-mingw32/13.1.0/../../../../x86_64-w64-mingw32/bin/ld.exe: C:/C_CPP/Library/vcpkg/installed/x64-windows/include/boost/asio/detail/impl/socket_ops.ipp:353: undefined reference to `__imp_closesocket'
[build] C:/C_CPP/Tookit/mingw64_13h/bin/../lib/gcc/x86_64-w64-mingw32/13.1.0/../../../../x86_64-w64-mingw32/bin/ld.exe: CMakeFiles\HelloWorld.dir/objects.a(main.cpp.obj): in function `boost::asio::detail::socket_ops::shutdown(unsigned long long, int, boost::system::error_code&)':
[build] C:/C_CPP/Library/vcpkg/installed/x64-windows/include/boost/asio/detail/impl/socket_ops.ipp:466: undefined reference to `__imp_shutdown'
[build] C:/C_CPP/Tookit/mingw64_13h/bin/../lib/gcc/x86_64-w64-mingw32/13.1.0/../../../../x86_64-w64-mingw32/bin/ld.exe: CMakeFiles\HelloWorld.dir/objects.a(main.cpp.obj): in function `boost::asio::detail::socket_ops::listen(unsigned long long, int, boost::system::error_code&)':
[build] C:/C_CPP/Library/vcpkg/installed/x64-windows/include/boost/asio/detail/impl/socket_ops.ipp:694: undefined reference to `__imp_listen'
[build] C:/C_CPP/Tookit/mingw64_13h/bin/../lib/gcc/x86_64-w64-mingw32/13.1.0/../../../../x86_64-w64-mingw32/bin/ld.exe: CMakeFiles\HelloWorld.dir/objects.a(main.cpp.obj): in function `boost::asio::detail::socket_ops::send(unsigned long long, _WSABUF const*, unsigned long long, int, boost::system::error_code&)':
[build] C:/C_CPP/Library/vcpkg/installed/x64-windows/include/boost/asio/detail/impl/socket_ops.ipp:1381: undefined reference to `__imp_WSASend'
[build] C:/C_CPP/Tookit/mingw64_13h/bin/../lib/gcc/x86_64-w64-mingw32/13.1.0/../../../../x86_64-w64-mingw32/bin/ld.exe: CMakeFiles\HelloWorld.dir/objects.a(main.cpp.obj): in function `boost::asio::detail::socket_ops::socket(int, int, int, boost::system::error_code&)':
[build] C:/C_CPP/Library/vcpkg/installed/x64-windows/include/boost/asio/detail/impl/socket_ops.ipp:1817: undefined reference to `__imp_WSASocketW'
[build] C:/C_CPP/Tookit/mingw64_13h/bin/../lib/gcc/x86_64-w64-mingw32/13.1.0/../../../../x86_64-w64-mingw32/bin/ld.exe: C:/C_CPP/Library/vcpkg/installed/x64-windows/include/boost/asio/detail/impl/socket_ops.ipp:1828: undefined reference to `__imp_setsockopt'
[build] C:/C_CPP/Tookit/mingw64_13h/bin/../lib/gcc/x86_64-w64-mingw32/13.1.0/../../../../x86_64-w64-mingw32/bin/ld.exe: CMakeFiles\HelloWorld.dir/objects.a(main.cpp.obj): in function `boost::asio::detail::socket_ops::poll_write(unsigned long long, unsigned char, int, boost::system::error_code&)':
[build] C:/C_CPP/Library/vcpkg/installed/x64-windows/include/boost/asio/detail/impl/socket_ops.ipp:2295: undefined reference to `__imp_select'
[build] C:/C_CPP/Tookit/mingw64_13h/bin/../lib/gcc/x86_64-w64-mingw32/13.1.0/../../../../x86_64-w64-mingw32/bin/ld.exe: CMakeFiles\HelloWorld.dir/objects.a(main.cpp.obj): in function `boost::asio::detail::socket_ops::inet_ntop(int, void const*, char*, unsigned long long, unsigned long, boost::system::error_code&)':
[build] C:/C_CPP/Library/vcpkg/installed/x64-windows/include/boost/asio/detail/impl/socket_ops.ipp:2497: undefined reference to `__imp_WSAAddressToStringA'
[build] C:/C_CPP/Tookit/mingw64_13h/bin/../lib/gcc/x86_64-w64-mingw32/13.1.0/../../../../x86_64-w64-mingw32/bin/ld.exe: CMakeFiles\HelloWorld.dir/objects.a(main.cpp.obj): in function `boost::asio::detail::socket_ops::inet_pton(int, char const*, void*, unsigned long*, boost::system::error_code&)':
[build] C:/C_CPP/Library/vcpkg/installed/x64-windows/include/boost/asio/detail/impl/socket_ops.ipp:2711: undefined reference to `__imp_WSAStringToAddressA'
[build] C:/C_CPP/Tookit/mingw64_13h/bin/../lib/gcc/x86_64-w64-mingw32/13.1.0/../../../../x86_64-w64-mingw32/bin/ld.exe: CMakeFiles\HelloWorld.dir/objects.a(main.cpp.obj): in function `boost::asio::detail::socket_ops::network_to_host_long(unsigned long)':
[build] C:/C_CPP/Library/vcpkg/installed/x64-windows/include/boost/asio/detail/impl/socket_ops.ipp:3932: undefined reference to `__imp_ntohl'
[build] C:/C_CPP/Tookit/mingw64_13h/bin/../lib/gcc/x86_64-w64-mingw32/13.1.0/../../../../x86_64-w64-mingw32/bin/ld.exe: CMakeFiles\HelloWorld.dir/objects.a(main.cpp.obj): in function `boost::asio::detail::socket_ops::host_to_network_long(unsigned long)':
[build] C:/C_CPP/Library/vcpkg/installed/x64-windows/include/boost/asio/detail/impl/socket_ops.ipp:3947: undefined reference to `__imp_htonl'
[build] C:/C_CPP/Tookit/mingw64_13h/bin/../lib/gcc/x86_64-w64-mingw32/13.1.0/../../../../x86_64-w64-mingw32/bin/ld.exe: CMakeFiles\HelloWorld.dir/objects.a(main.cpp.obj): in function `boost::asio::detail::socket_ops::network_to_host_short(unsigned short)':
[build] C:/C_CPP/Library/vcpkg/installed/x64-windows/include/boost/asio/detail/impl/socket_ops.ipp:3959: undefined reference to `__imp_ntohs'
[build] C:/C_CPP/Tookit/mingw64_13h/bin/../lib/gcc/x86_64-w64-mingw32/13.1.0/../../../../x86_64-w64-mingw32/bin/ld.exe: CMakeFiles\HelloWorld.dir/objects.a(main.cpp.obj): in function `boost::asio::detail::socket_ops::host_to_network_short(unsigned short)':
[build] C:/C_CPP/Library/vcpkg/installed/x64-windows/include/boost/asio/detail/impl/socket_ops.ipp:3972: undefined reference to `__imp_htons'
[build] C:/C_CPP/Tookit/mingw64_13h/bin/../lib/gcc/x86_64-w64-mingw32/13.1.0/../../../../x86_64-w64-mingw32/bin/ld.exe: CMakeFiles\HelloWorld.dir/objects.a(main.cpp.obj): in function `boost::asio::detail::win_iocp_socket_service_base::start_send_op(boost::asio::detail::win_iocp_socket_service_base::base_implementation_type&, _WSABUF*, unsigned long long, int, bool, boost::asio::detail::win_iocp_operation*)':
[build] C:/C_CPP/Library/vcpkg/installed/x64-windows/include/boost/asio/detail/impl/win_iocp_socket_service_base.ipp:400: undefined reference to `__imp_WSASend'
[build] C:/C_CPP/Tookit/mingw64_13h/bin/../lib/gcc/x86_64-w64-mingw32/13.1.0/../../../../x86_64-w64-mingw32/bin/ld.exe: C:/C_CPP/Library/vcpkg/installed/x64-windows/include/boost/asio/detail/impl/win_iocp_socket_service_base.ipp:402: undefined reference to `__imp_WSAGetLastError'
[build] C:/C_CPP/Tookit/mingw64_13h/bin/../lib/gcc/x86_64-w64-mingw32/13.1.0/../../../../x86_64-w64-mingw32/bin/ld.exe: CMakeFiles\HelloWorld.dir/objects.a(main.cpp.obj): in function `boost::asio::detail::win_iocp_socket_service_base::start_receive_op(boost::asio::detail::win_iocp_socket_service_base::base_implementation_type&, _WSABUF*, unsigned long long, int, bool, boost::asio::detail::win_iocp_operation*)':
[build] C:/C_CPP/Library/vcpkg/installed/x64-windows/include/boost/asio/detail/impl/win_iocp_socket_service_base.ipp:454: undefined reference to `__imp_WSARecv'
[build] C:/C_CPP/Tookit/mingw64_13h/bin/../lib/gcc/x86_64-w64-mingw32/13.1.0/../../../../x86_64-w64-mingw32/bin/ld.exe: C:/C_CPP/Library/vcpkg/installed/x64-windows/include/boost/asio/detail/impl/win_iocp_socket_service_base.ipp:457: undefined reference to `__imp_WSAGetLastError'
[build] C:/C_CPP/Tookit/mingw64_13h/bin/../lib/gcc/x86_64-w64-mingw32/13.1.0/../../../../x86_64-w64-mingw32/bin/ld.exe: CMakeFiles\HelloWorld.dir/objects.a(main.cpp.obj): in function `boost::asio::detail::win_iocp_socket_service_base::start_accept_op(boost::asio::detail::win_iocp_socket_service_base::base_implementation_type&, bool, boost::asio::detail::socket_holder&, int, int, int, void*, unsigned long, boost::asio::detail::win_iocp_operation*)':
[build] C:/C_CPP/Library/vcpkg/installed/x64-windows/include/boost/asio/detail/impl/win_iocp_socket_service_base.ipp:538: undefined reference to `AcceptEx'
[build] C:/C_CPP/Tookit/mingw64_13h/bin/../lib/gcc/x86_64-w64-mingw32/13.1.0/../../../../x86_64-w64-mingw32/bin/ld.exe: C:/C_CPP/Library/vcpkg/installed/x64-windows/include/boost/asio/detail/impl/win_iocp_socket_service_base.ipp:540: undefined reference to `__imp_WSAGetLastError'
[build] C:/C_CPP/Tookit/mingw64_13h/bin/../lib/gcc/x86_64-w64-mingw32/13.1.0/../../../../x86_64-w64-mingw32/bin/ld.exe: CMakeFiles\HelloWorld.dir/objects.a(main.cpp.obj): in function `boost::asio::detail::win_iocp_socket_service_base::restart_accept_op(unsigned long long, boost::asio::detail::socket_holder&, int, int, int, void*, unsigned long, long*, boost::asio::detail::win_iocp_operation*)':
[build] C:/C_CPP/Library/vcpkg/installed/x64-windows/include/boost/asio/detail/impl/win_iocp_socket_service_base.ipp:569: undefined reference to `AcceptEx'
[build] C:/C_CPP/Tookit/mingw64_13h/bin/../lib/gcc/x86_64-w64-mingw32/13.1.0/../../../../x86_64-w64-mingw32/bin/ld.exe: C:/C_CPP/Library/vcpkg/installed/x64-windows/include/boost/asio/detail/impl/win_iocp_socket_service_base.ipp:571: undefined reference to `__imp_WSAGetLastError'
[build] C:/C_CPP/Tookit/mingw64_13h/bin/../lib/gcc/x86_64-w64-mingw32/13.1.0/../../../../x86_64-w64-mingw32/bin/ld.exe: CMakeFiles\HelloWorld.dir/objects.a(main.cpp.obj): in function `int boost::asio::detail::socket_ops::call_bind<int>(int boost::asio::detail::socket_ops::msghdr::*, unsigned long long, void const*, unsigned long long)':
[build] C:/C_CPP/Library/vcpkg/installed/x64-windows/include/boost/asio/detail/impl/socket_ops.ipp:283: undefined reference to `__imp_bind'
[build] C:/C_CPP/Tookit/mingw64_13h/bin/../lib/gcc/x86_64-w64-mingw32/13.1.0/../../../../x86_64-w64-mingw32/bin/ld.exe: CMakeFiles\HelloWorld.dir/objects.a(main.cpp.obj): in function `int boost::asio::detail::socket_ops::call_setsockopt<int>(int boost::asio::detail::socket_ops::msghdr::*, unsigned long long, int, int, void const*, unsigned long long)':
[build] C:/C_CPP/Library/vcpkg/installed/x64-windows/include/boost/asio/detail/impl/socket_ops.ipp:1862: undefined reference to `__imp_setsockopt'
[build] C:/C_CPP/Tookit/mingw64_13h/bin/../lib/gcc/x86_64-w64-mingw32/13.1.0/../../../../x86_64-w64-mingw32/bin/ld.exe: CMakeFiles\HelloWorld.dir/objects.a(main.cpp.obj): in function `int boost::asio::detail::socket_ops::call_getsockopt<int>(int boost::asio::detail::socket_ops::msghdr::*, unsigned long long, int, int, void*, unsigned long long*)':
[build] C:/C_CPP/Library/vcpkg/installed/x64-windows/include/boost/asio/detail/impl/socket_ops.ipp:1949: undefined reference to `__imp_getsockopt'
[build] C:/C_CPP/Tookit/mingw64_13h/bin/../lib/gcc/x86_64-w64-mingw32/13.1.0/../../../../x86_64-w64-mingw32/bin/ld.exe: CMakeFiles\HelloWorld.dir/objects.a(main.cpp.obj): in function `int boost::asio::detail::socket_ops::call_getpeername<int>(int boost::asio::detail::socket_ops::msghdr::*, unsigned long long, void*, unsigned long long*)':
[build] C:/C_CPP/Library/vcpkg/installed/x64-windows/include/boost/asio/detail/impl/socket_ops.ipp:2054: undefined reference to `__imp_getpeername'
[build] C:/C_CPP/Tookit/mingw64_13h/bin/../lib/gcc/x86_64-w64-mingw32/13.1.0/../../../../x86_64-w64-mingw32/bin/ld.exe: CMakeFiles\HelloWorld.dir/objects.a(main.cpp.obj): in function `int boost::asio::detail::socket_ops::call_getsockname<int>(int boost::asio::detail::socket_ops::msghdr::*, unsigned long long, void*, unsigned long long*)':
[build] C:/C_CPP/Library/vcpkg/installed/x64-windows/include/boost/asio/detail/impl/socket_ops.ipp:2107: undefined reference to `__imp_getsockname'
[build] collect2.exe: error: ld returned 1 exit status
[build] mingw32-make.exe[2]: *** [CMakeFiles\HelloWorld.dir\build.make:101: HelloWorld.exe] Error 1
[build] mingw32-make.exe[1]: *** [CMakeFiles\Makefile2:82: CMakeFiles/HelloWorld.dir/all] Error 2
[build] mingw32-make.exe: *** [Makefile:90: all] Error 2
[proc] 命令“"D:\Program Files\CMake\bin\cmake.EXE" --build d:/Code/Cpp/ExerciseCode/vscode_vcpkg_cmake_copy/build --config Debug --target all -j 22 --”已退出，代码为 2
[driver] 生成完毕: 00:00:38.628
[build] 生成已完成，退出代码为 2

网上（Google、Bing、Github、StackOverFlow）难以找到答案，因为报错信息有点太了，询问Claude得到答案：

这个链接错误的原因是目标可执行文件在链接过程中无法解析 Windows sockets API 所需要的符号,包括:

  • WSAStartup, WSACleanup - Winsock 初始化和清理函数

  • WSAGetLastError, WSASetLastError - 获取和设置错误码的函数

  • AcceptEx, GetAcceptExSockaddrs - 接受连接的函数

  • closesocket, ioctlsocket 等 - 套接字操作的函数

  • ntohl, htonl, ntohs, htons - 网络字节序转换函数

  • select, WSASend, WSARecv 等 - 套接字I/O操作函数

导致这个错误的常见原因:

  1. 没有链接 Windows socket 库 ws2_32.lib,它包含上述 API 的实现。

  2. 依赖的网络库没有自动链接所需的系统库。

  3. 编译设置没有指定使用 Winsock。

  4. vcpkg动态链接设置不正确,应使用动态CRT链接。

  5. 没有根据平台预定义正确隔离连接代码。

解决方法是:

  1. 显式链接 ws2_32.lib。

  2. 确认依赖库已自动链接必要的系统库。

  3. 定义相关宏以开启Winsock支持。

  4. 使用动态链接选项并检查编译器设置。

  5. 根据Windows平台预定义隔离特定实现。

明确添加对 ws2_32.lib 的链接可以解决大部分此类问题。

于是在链接Crow库前先显式链接 ws2_32.lib库：（注意MSVC直接可以支持，无需GCC这样）

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# 导入Crow库
find_package(Crow)
target_link_libraries(${PROJECT_NAME} ws2_32)	# 显式链接 ws2_32.lib 库
target_link_libraries(${PROJECT_NAME} Crow::Crow)

运行CMake，仍然无法成功编译：

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[build] 正在启动生成
[proc] 执行命令: "D:\Program Files\CMake\bin\cmake.EXE" --build d:/Code/Cpp/ExerciseCode/vscode_vcpkg_cmake_copy/build --config Debug --target all -j 22 --
[build] [ 50%] Building CXX object CMakeFiles/HelloWorld.dir/src/main.cpp.obj
[build] <command-line>: warning: ISO C++11 requires whitespace after the macro name
[build] [100%] Linking CXX executable HelloWorld.exe
[build] C:/C_CPP/Tookit/mingw64_13h/bin/../lib/gcc/x86_64-w64-mingw32/13.1.0/../../../../x86_64-w64-mingw32/bin/ld.exe: CMakeFiles\HelloWorld.dir/objects.a(main.cpp.obj): in function `boost::asio::detail::socket_ops::complete_iocp_accept(unsigned long long, void*, unsigned long, void*, unsigned long long*, unsigned long long, boost::system::error_code&)':
[build] C:/C_CPP/Library/vcpkg/installed/x64-windows/include/boost/asio/detail/impl/socket_ops.ipp:206: undefined reference to `GetAcceptExSockaddrs'
[build] C:/C_CPP/Tookit/mingw64_13h/bin/../lib/gcc/x86_64-w64-mingw32/13.1.0/../../../../x86_64-w64-mingw32/bin/ld.exe: CMakeFiles\HelloWorld.dir/objects.a(main.cpp.obj): in function `boost::asio::detail::win_iocp_socket_service_base::start_accept_op(boost::asio::detail::win_iocp_socket_service_base::base_implementation_type&, bool, boost::asio::detail::socket_holder&, int, int, int, void*, unsigned long, boost::asio::detail::win_iocp_operation*)':
[build] C:/C_CPP/Library/vcpkg/installed/x64-windows/include/boost/asio/detail/impl/win_iocp_socket_service_base.ipp:538: undefined reference to `AcceptEx'
[build] C:/C_CPP/Tookit/mingw64_13h/bin/../lib/gcc/x86_64-w64-mingw32/13.1.0/../../../../x86_64-w64-mingw32/bin/ld.exe: CMakeFiles\HelloWorld.dir/objects.a(main.cpp.obj): in function `boost::asio::detail::win_iocp_socket_service_base::restart_accept_op(unsigned long long, boost::asio::detail::socket_holder&, int, int, int, void*, unsigned long, long*, boost::asio::detail::win_iocp_operation*)':
[build] C:/C_CPP/Library/vcpkg/installed/x64-windows/include/boost/asio/detail/impl/win_iocp_socket_service_base.ipp:569: undefined reference to `AcceptEx'
[build] collect2.exe: error: ld returned 1 exit status
[build] mingw32-make.exe[2]: *** [CMakeFiles\HelloWorld.dir\build.make:101: HelloWorld.exe] Error 1
[build] mingw32-make.exe[1]: *** [CMakeFiles\Makefile2:82: CMakeFiles/HelloWorld.dir/all] Error 2
[build] mingw32-make.exe: *** [Makefile:90: all] Error 2
[proc] 命令“"D:\Program Files\CMake\bin\cmake.EXE" --build d:/Code/Cpp/ExerciseCode/vscode_vcpkg_cmake_copy/build --config Debug --target all -j 22 --”已退出，代码为 2
[driver] 生成完毕: 00:00:39.516
[build] 生成已完成，退出代码为 2

再次询问Claude，得知：

这些 undefined reference 错误表示项目链接时无法找到 Windows 套接字编程中的 AcceptEx 和 GetAcceptExSockaddrs 这两个API函数。

在使用像 Asio 这样的 C++ 网络库开发 Windows 应用时,需要链接 mswsock.lib 库才能使用这些扩展套接字函数。

可以通过以下方式修复:

  1. 在 CMakeLists 里添加:
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target_link_libraries(myapp PRIVATE mswsock)

来显式链接 mswsock.lib。

  1. 确保网络库如 Asio 已经自动链接了依赖的系统库。

  2. 为目标添加编译宏:

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target_compile_definitions(myapp PUBLIC ASIO_WINDOWS)
  1. 如果使用 vcpkg,指定动态 CRT 链接:
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vcpkg install xxx:x64-windows-dynamic

  1. 检查项目是否已经自动链接了 Windows 平台所需的系统库。

  2. 尝试更新网络库至最新版本以获取缺失链接的修复。

综上,明确链接 mswsock.lib 或在上层网络库处理依赖,是解决大多数类似问题的办法。

这里我在链接Crow库前加上mswsock即可解决：

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find_package(Crow)
target_link_libraries(${PROJECT_NAME} ws2_32)
target_link_libraries(${PROJECT_NAME} mswsock)
target_link_libraries(${PROJECT_NAME} Crow::Crow)

再次运行CMake，完美解决：

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[main] 正在生成文件夹: vscode_vcpkg_cmake_copy 
[build] 正在启动生成
[proc] 执行命令: "D:\Program Files\CMake\bin\cmake.EXE" --build d:/Code/Cpp/ExerciseCode/vscode_vcpkg_cmake_copy/build --config Debug --target all -j 22 --
[build] [ 50%] Linking CXX executable HelloWorld.exe
[build] [100%] Built target HelloWorld
[driver] 生成完毕: 00:00:26.796
[build] 生成已完成，退出代码为 0

后续

后面我直接改用MSVC，啥问题都没有，编译时间仅为GCC的40%，同时完美支持C++20🤣 （Visual Studio Enterprise 2022 Preview - amd64，MSVC 19.38.32919.0）

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cmake_minimum_required(VERSION 3.17)
set(PROJECT_NAME HelloWorld) 
set(CMAKE_TOOLCHAIN_FILE "C:/C_CPP/Library/vcpkg/scripts/buildsystems/vcpkg.cmake") # set vcpkg toolchain file path
set(VCPKG_TARGET_TRIPLET "x64-windows")

project(${PROJECT_NAME}) # set project name
add_executable(${PROJECT_NAME} src/main.cpp) # add executable target named ${PROJECT_NAME}
target_compile_features(${PROJECT_NAME} PRIVATE cxx_std_20)  # enable C++20 standard
set_target_properties(${PROJECT_NAME} PROPERTIES CXX_EXTENSIONS OFF) # disable compiler extensions

find_package(Crow)
target_link_libraries(${PROJECT_NAME} Crow::Crow)
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[build] 正在启动生成
[proc] 执行命令: "D:\Program Files\CMake\bin\cmake.EXE" --build d:/Code/Cpp/ExerciseCode/vscode_vcpkg_cmake_copy/build --config Debug --target ALL_BUILD -j 22 --
[build] 适用于 .NET Framework MSBuild 版本 17.8.0-preview-23376-06+f413f5497
[build] 
[build]   1>Checking Build System
[build]   Building Custom Rule D:/Code/Cpp/ExerciseCode/vscode_vcpkg_cmake_copy/CMakeLists.txt
[build]   main.cpp
[build]   Please define _WIN32_WINNT or _WIN32_WINDOWS appropriately. For example:
[build]   - add -D_WIN32_WINNT=0x0601 to the compiler command line; or
[build]   - add _WIN32_WINNT=0x0601 to your project's Preprocessor Definitions.
[build]   Assuming _WIN32_WINNT=0x0601 (i.e. Windows 7 target).
[build]   HelloWorld.vcxproj -> D:\Code\Cpp\ExerciseCode\vscode_vcpkg_cmake_copy\build\Debug\HelloWorld.exe
[build]   Building Custom Rule D:/Code/Cpp/ExerciseCode/vscode_vcpkg_cmake_copy/CMakeLists.txt
[driver] 生成完毕: 00:00:10.848
[build] 生成已完成，退出代码为 0

Fuck you, GCC !

C++ > Crow
【C++】【Crow】我在使用Cmake构建Crow项目时遇到的3个问题
https://qalxry.github.io/2023/08/23/【C++】【Crow】我在使用Cmake构建Crow项目时遇到的3个问题/
作者
しずり雪
发布于
2023年8月23日
更新于
2023年8月23日
许可协议