如何使用cmake链接到boost.system

Question

我使用cmake生成的makefile来编译依赖于boost文件系统库的c ++文件。

在链接过程中，出现以下错误：

Undefined symbols:
  "boost::system::get_generic_category()", referenced from:
      __static_initialization_and_destruction_0(int, int)in FaceRecognizer.cpp.o
      __static_initialization_and_destruction_0(int, int)in FaceRecognizer.cpp.o
      __static_initialization_and_destruction_0(int, int)in FaceRecognizer.cpp.o
  "boost::system::get_system_category()", referenced from:
      __static_initialization_and_destruction_0(int, int)in FaceRecognizer.cpp.o
      __static_initialization_and_destruction_0(int, int)in FaceRecognizer.cpp.o
ld: symbol(s) not found
collect2: ld returned 1 exit status
make[2]: *** [src/ImageMarker] Error 1

来自makefile的生成此错误的操作是此行：

cd /Users/janusz/Documents/workspace/ImageMarker/Debug/src && /opt/local/bin/cmake -E cmake_link_script CMakeFiles/ImageMarker.dir/link.txt --verbose=1
/usr/bin/c++   -O3 -Wall -Wno-deprecated -g -verbose -Wl,-search_paths_first -headerpad_max_install_names -fPIC CMakeFiles/ImageMarker.dir/ImageMarker.cpp.o CMakeFiles/ImageMarker.dir/Image.cpp.o CMakeFiles/ImageMarker.dir/utils.cpp.o CMakeFiles/ImageMarker.dir/XMLWriter.cpp.o CMakeFiles/ImageMarker.dir/FaceRecognizer.cpp.o  -o ImageMarker  -L/opt/local/lib ../libTinyXml.a /opt/local/lib/libboost_filesystem-mt.dylib

进行一些谷歌搜索后，我发现该错误在boost文件系统库的Mac上似乎很常见，因为我必须链接到boost.system库，或者使我的项目依赖于boost.system库。

我如何在不对库路径进行硬编码的情况下强制cmake链接库？

这里是otool的结果：

otool -L /opt/local/lib/libboost_filesystem-mt.dylib
 /opt/local/lib/libboost_filesystem-mt.dylib:
 /opt/local/lib/libboost_filesystem-mt.dylib (compatibility version 0.0.0, current version 0.0.0)  
 /opt/local/lib/libboost_system-mt.dylib (compatibility version 0.0.0, current version 0.0.0)   
 /usr/lib/libstdc++.6.dylib (compatibility version 7.0.0, current version 7.4.0)
 /usr/lib/libgcc_s.1.dylib (compatibility version 1.0.0, current version 1.0.0)
 /usr/lib/libSystem.B.dylib (compatibility version 1.0.0, current version 111.0.0)

Answer 1

在Linux上，CMake认为boost_filesystem与boost_system链接在一起。 显然，您必须在Mac上明确地告诉它：

find_package(Boost COMPONENTS system filesystem REQUIRED)
#...
target_link_libraries(mytarget 
  ${Boost_FILESYSTEM_LIBRARY}
  ${Boost_SYSTEM_LIBRARY}
)

Answer 2

这不是发布问题的“答案”，而是对我的Ubuntu盒子的观察。

要使用Boost库，必须显式编写如下代码：

find_package(Boost COMPONENTS regex system filesystem REQUIRED)

另外，您需要通过以下方式链接：

target_link_libraries(binary
  ${Boost_FILESYSTEM_LIBRARY}
  ${Boost_SYSTEM_LIBRARY}
  ${Boost_REGEX_LIBRARY}
)

并且以下方式无效，至少对我而言：

target_link_libraries(binary regex system filesystem)

这符合Maik所说的，但不仅限于Mac。