cmake:我必须按哪个顺序指定TARGET_LINK_LIBRARIES

cmake: In which order do I have to specify TARGET_LINK_LIBRARIES

本文关键字:TARGET 顺序 LINK LIBRARIES cmake      更新时间:2023-10-16

我一次又一次地与链接器问题作斗争,因为必须以正确的顺序指定TARGET_LINK_LIBRARIES中的所有库。但是我该如何确定此顺序呢?例:

我有以下库

libA depends on boost
libB depends on postgresql and libA (and therefore on boost)
myTarget uses libA, libB and boost directly (and through libB depends on postgresql)

由于所有必需的库仅在创建可执行文件时才链接,因此在链接myTarget(最终可执行文件)时,我必须指定所有库:

TARGET_LINK_LIBRARIES(${ApplicationName}  
libboost_program_options.a 
libboost_system.a 
libboost_filesystem.a 
libboost_date_time.a 
libboost_regex.a 
# Should include all boost libraries but strangely some libs (the ones above)
# need to be specified "by hand"???
${Boost_LIBRARIES} 
# PostgreSQL stuff
libpq.a
libsoci_core.a
libsoci_postgresql.a
libpq.so
# My libs
libB.a
libA.a
${CMAKE_THREAD_LIBS_INIT} # pthreads, needed by boost
${CMAKE_DL_LIBS} # For libdl.so etc.
) 

由于我正在链接提升静态我的CMakeList.txt还包含

SET(Boost_USE_STATIC_LIBS ON) 

但是,我仍然会收到链接错误,例如"未定义对 boost::re_detail::p erl_matcher 或 boost::d ate_time::month_formatter 的引用"

这真的很烦人,我正在更改 lib 排序,一些未定义的引用消失了,但出现了新的未定义的引用。

如何识别正确的顺序?!


编辑:

我通过分别绘制识别库之间的所有依赖项并适当排序来解决上述问题(因此添加了 libboost_log.a):

TARGET_LINK_LIBRARIES(${ApplicationName}  
libB.a
libA.a
# PostgreSQL stuff
libpq.a
libsoci_core.a
libsoci_postgresql.a
libpq.so
# Boost
libboost_program_options.a 
libboost_system.a 
libboost_log.a 
libboost_filesystem.a 
libboost_date_time.a 
libboost_regex.a 
# Should include all boost libraries but strangely some libs (the ones above)
# need to be specified "by hand"???
${Boost_LIBRARIES} 
# Lowlevel needed by boost
${CMAKE_THREAD_LIBS_INIT} # pthreads, needed by boost
${CMAKE_DL_LIBS} # For libdl.so etc.
) 

所以排序是自上而下的。顶部是可执行文件,其次是直接使用的库。接下来是进一步的依赖关系,最后必须添加低级依赖关系(由 boost 使用)。

就我而言,当我想尊重链接我的库的顺序时,我使用 cmake 命令add_dependencies。我的意思是:

find_package(Boost COMPONENTS date_time filesystem system ...)
find_package(PostgreSQL REQUIRED)
IF(Boost_FOUND AND PostgreSQL_FOUND)
  INCLUDE_DIRECTORIES(${Boost_INCLUDE_DIRS})
  INCLUDE_DIRECTORIES(${PostgreSQL_INCLUDE_DIRS})
  # ApplicationName -> your_application
  # LIB_A_TARGET -> libA
  # LIB_B_TARGET -> libB
  SET(LIB_A_ALL_DEPS ${Boost_LIBRARIES})
  SET(LIB_B_ALL_DEPS ${LIB_A_ALL_DEPS} ${PostgreSQL_LIBRARIES})
  SET(EXTRA_APP_DEPS  ) # here all your extra libs that they aren't in boost or postgre
  SET(YOUR_APP_ALL_DEPS ${LIB_A_ALL_DEPS} ${LIB_B_ALL_DEPS} ${EXTRA_APP_DEPS})
  # Here'll be all your ADD_EXECUTABLE, ADD_LIBRARY code
  TARGET_LINK_LIBRARIES(${LIB_A_TARGET} ${LIB_A_ALL_DEPS})
  ADD_DEPENDENCIES(${LIB_A_TARGET} ${LIB_A_ALL_DEPS})
  TARGET_LINK_LIBRARIES(${LIB_B_TARGET} ${LIB_B_ALL_DEPS})
  ADD_DEPENDENCIES(${LIB_B_TARGET} ${LIB_B_ALL_DEPS})
  TARGET_LINK_LIBRARIES(${ApplicationName} ${YOUR_APP_ALL_DEPS})
  ADD_DEPENDENCIES(${ApplicationName} ${YOUR_APP_ALL_DEPS})
ENDIF()

我还没有测试过这段代码,但我或多或少会这样做。我知道这个例子只是可能的 CMakeList 的一部分.txt所以我需要查看您的代码才能完全编写它。

希望对您有所帮助!