如何使用 cmake 链接 boost.system

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，我收到以下错误:

<前>未定义符号:boost::system::get_generic_category()"，引用自:__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.oboost::system::get_system_category()"，引用自:__static_initialization_and_destruction_0(int, int)in FaceRecognizer.cpp.o__static_initialization_and_destruction_0(int, int)in FaceRecognizer.cpp.old:未找到符号collect2: ld 返回 1 个退出状态make[2]: *** [src/ImageMarker] 错误 1

生成此错误的 makefile 中的操作是这一行:

<前>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/选择/本地/lib/libboost_filesystem-mt.dylib

一些谷歌搜索显示，这个错误在带有 boost 文件系统库的 Mac 上似乎很常见，因为我必须链接到 boost.system 库或根据 boost.system 库创建我的项目.

如何在不硬编码库路径的情况下强制 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(兼容版本 0.0.0，当前版本 0.0.0)/opt/local/lib/libboost_system-mt.dylib(兼容版本 0.0.0，当前版本 0.0.0)/usr/lib/libstdc++.6.dylib(兼容版本 7.0.0，当前版本 7.4.0)/usr/lib/libgcc_s.1.dylib(兼容版本1.0.0，当前版本1.0.0)/usr/lib/libSystem.B.dylib(兼容版本 1.0.0，当前版本 111.0.0)

解决方案

在 linux 上，CMake 认为 boost_filesystem 与 boost_system 相关联.显然你必须在 Mac 上明确告诉它:

find_package(Boost COMPONENTS system filesystem REQUIRED)#...目标链接库(我的目标${Boost_FILESYSTEM_LIBRARY}${Boost_SYSTEM_LIBRARY})

I use a cmake generated makefile to compile a c++ file that depends on the boost filesystem library.

During the linking process I get the following error:

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

The action from the makefile that generates this error is this line:

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 

Some googling showed me that this error seems to be common on macs with the boost file system library because I have to link against a boost.system library or make my project depending on the boost.system library.

How do i force cmake to link against the library without hardcoding the library path?

Here the result from otool:

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)

解决方案

On linux CMake figures itself that boost_filesystem is linked against boost_system. Obviously you have to tell it explicitly on Mac:

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