架构 x86_64 的未定义符号：OS X、Boost Log、CMake

Question

另一个链接问题

OS X 10.9.5 x64

正在使用 CMake 工具链构建跨平台项目。使用提升。

将所有可执行文件与 Boost Log 链接时出错（肯定找到了 BOOST_PATH，单元测试与 Boost Test 链接成功）

第一次尝试。使用 Clang

gcc -v
Apple LLVM version 6.0 (clang-600.0.56) (based on LLVM 3.5svn)
Target: x86_64-apple-darwin13.4.0
Thread model: posix

建筑提升

./bootstrap &&  ./b2 threading=multi link=static runtime-link=static install

成功完成

...updated 638 targets...

链接说明：

if( ("UNIX") AND ("${CMAKE_CXX_COMPILER_ID}" STREQUAL "Clang") )

    # using Clang
    message("UNIX configuration, Clang")
    set(CMAKE_CXX_FLAGS "-std=c++11")
    set(CMAKE_EXE_LINKER_FLAGS "-std=c++11 -Wl")

将库链接到可执行文件

add_executable(${TARGET} ${SOURCES})
if( ("UNIX") AND ("${CMAKE_CXX_COMPILER_ID}" STREQUAL "Clang") )

    # using Clang
    message("UNIX configuration, Clang")
    target_link_libraries(${TARGET}
        libhelpers.a
        libopenvpn_manager.a
        ${Boost_LOG_LIBRARY}
        ${Boost_LOG_SETUP_LIBRARY}
        ${Boost_SYSTEM_LIBRARY}
        ${Boost_FILESYSTEM_LIBRARY})

生成makefile：

cmake -DCMAKE_OSX_ARCHITECTURES=x86_64 -DCMAKE_C_COMPILER=/usr/bin/clang -DCMAKE_CXX_COMPILER=/usr/bin/clang++exit .

链接器输出（选择了一些行）：

Undefined symbols for architecture x86_64:
 "boost::detail::get_tss_data(void const*)", referenced from:
      boost::log::v2s_mt_posix::core::add_thread_attribute(boost::log::v2s_mt_posix::attribute_name const&, boost::log::v2s_mt_posix::attribute const&) in libboost_log.a(core.o)
      boost::log::v2s_mt_posix::core::remove_thread_attribute(boost::log::v2s_mt_posix::attribute_set::iter<false>) in libboost_log.a(core.o)
      boost::log::v2s_mt_posix::core::get_thread_attributes() const in libboost_log.a(core.o)
      ...
  "boost::detail::set_tss_data(void const*, boost::shared_ptr<boost::detail::tss_cleanup_function>, void*, bool)", referenced from:
      boost::thread_specific_ptr<boost::log::v2s_mt_posix::core::implementation::thread_data>::reset(boost::log::v2s_mt_posix::core::implementation::thread_data*) in libboost_log.a(core.o)

      ...
  "boost::detail::thread_data_base::~thread_data_base()", referenced from:
      boost::detail::thread_data<boost::_bi::bind_t<unsigned long, boost::_mfi::mf0<unsigned long, boost::asio::io_service>, boost::_bi::list1<boost::_bi::value<boost::asio::io_service*> > > >::~thread_data() in openvpn_test_app.cpp.o

…
ld: symbol(s) not found for architecture x86_64
clang: error: linker command failed with exit code 1 (use -v to see invocation)

第二次尝试。使用 GCC

我是如何将其设为默认的

#!/bin/bash
cd /usr/bin
rm cc gcc c++ g++
ln -s /usr/local/bin/gcc-4.9 cc
ln -s /usr/local/bin/gcc-4.9 gcc
ln -s /usr/local/bin/c++-4.9 c++
ln -s /usr/local/bin/g++-4.9 g++

gcc -v
Using built-in specs.
COLLECT_GCC=gcc
COLLECT_LTO_WRAPPER=/usr/local/Cellar/gcc/4.9.1/libexec/gcc/x86_64-apple-darwin13.2.0/4.9.1/lto-wrapper
Target: x86_64-apple-darwin13.2.0
Configured with: ../configure --build=x86_64-apple-darwin13.2.0 --prefix=/usr/local/Cellar/gcc/4.9.1 --enable-languages=c,c++,objc,obj-c++,fortran --program-suffix=-4.9 --with-gmp=/usr/local/opt/gmp --with-mpfr=/usr/local/opt/mpfr --with-mpc=/usr/local/opt/libmpc --with-cloog=/usr/local/opt/cloog --with-isl=/usr/local/opt/isl --with-system-zlib --enable-version-specific-runtime-libs --enable-libstdcxx-time=yes --enable-stage1-checking --enable-checking=release --enable-lto --disable-werror --with-pkgversion='Homebrew gcc 4.9.1' --with-bugurl=https://github.com/Homebrew/homebrew/issues --enable-plugin --disable-nls --enable-multilib
Thread model: posix
gcc version 4.9.1 (Homebrew gcc 4.9.1)

以与之前相同的方式构建 Boost

链接说明

elseif( ("UNIX") AND ("${CMAKE_CXX_COMPILER_ID}" STREQUAL "GNU") )

    # using GCC
    message("UNIX congiguration, GCC")
    set(CMAKE_CXX_FLAGS "-std=c++11 -pthread")
    set(CMAKE_EXE_LINKER_FLAGS "-std=c++11 -pthread")

将库链接到可执行文件的方式与使用 Clang 相同

target_link_libraries(${TARGET}
    libhelpers.a
    libopenvpn_manager.a
    ${Boost_LOG_LIBRARY}
    ${Boost_LOG_SETUP_LIBRARY}
    ${Boost_SYSTEM_LIBRARY}
    ${Boost_FILESYSTEM_LIBRARY})

生成生成文件

cmake -DCMAKE_OSX_ARCHITECTURES=x86_64 -DCMAKE_C_COMPILER=/usr/bin/gcc -DCMAKE_CXX_COMPILER=/usr/bin/g++ .

链接器输出：

Undefined symbols for architecture x86_64:
"boost::detail::get_tss_data(void const*)", referenced from:
      boost::log::v2s_mt_posix::core::set_thread_attributes(boost::log::v2s_mt_posix::attribute_set const&) in libboost_log.a(core.o)
boost::log::v2s_mt_posix::core::get_thread_attributes() const in libboost_log.a(core.o)
      boost::log::v2s_mt_posix::core::remove_thread_attribute(boost::log::v2s_mt_posix::attribute_set::iter<false>) in libboost_log.a(core.o)
…
ld: symbol(s) not found for architecture x86_64
collect2: error: ld returned 1 exit status

Answer 1

您缺少的符号来自 Boost.Thread，Boost.Log 在多线程配置中使用它。您需要将“线程”组件添加到 find_package 行，并将 Boost_THREAD_LIBRARY 变量添加到 target_link_libraries 行。请注意，您可能需要确保 target_link_libraries 行中库的正确顺序，以避免由符号依赖解析顺序引起的链接错误（叶依赖应最后指定）。例如：

find_package(Boost COMPONENTS log log_setup thread filesystem system)
target_link_libraries(${TARGET}
    ${Boost_LOG_SETUP_LIBRARY}
    ${Boost_LOG_LIBRARY}
    ${Boost_FILESYSTEM_LIBRARY}
    ${Boost_THREAD_LIBRARY}
    ${Boost_SYSTEM_LIBRARY}
)

根据您使用的功能，您可能需要类似地添加与 Boost.Regex 和 Boost.DateTime 的链接。

Answer 2

我没看到

find_package(Boost COMPONENTS filesystem system .... etc... )  

在您的示例中的任何位置。例如，您将需要它来定义 Boost_FILESYSTEM_LIBRARY。您可以使用 CMake 命令

message("Boost_FILESYSTEM_LIBRARY: ${Boost_FILESYSTEM_LIBRARY}")  

查看 Boost_FILESYSTEM_LIBRARY 的当前值。所有这些库名称都在 findBoost.cmake 模块中设置。