Boost.Log with CMake causing undefined reference error

StackOverflow https://stackoverflow.com/questions/17844085

  •  04-06-2022
  •  | 
  •  

Question

I am trying to use the new Boost.Log library in a project I am working on. The project is built with CMake. I am receiving link errors claiming that the linker has come across undefined references to Boost.Log

Linking CXX executable main
CMakeFiles/main.dir/main.cpp.o: In function `main':
main.cpp:(.text+0x30): undefined reference to `boost::log::v2s_mt_posix::trivial::logger::get()'

I have a simple hello world test that fails with these errors. If I am linking against the Boost.Log libraries what would cause it to generate an undefined reference error?

main.cpp:

#include <boost/log/trivial.hpp>
int main(int argc, char* const argv[]) {
  BOOST_LOG_TRIVIAL(info) << "Hello World";
}

CMakeLists.txt:

CMAKE_MINIMUM_REQUIRED(VERSION 2.8)
FIND_PACKAGE(Boost 1.54 COMPONENTS log REQUIRED)
FIND_PACKAGE(Threads)
INCLUDE_DIRECTORIES(${Boost_INCLUDE_DIR})
ADD_EXECUTABLE(main main.cpp)
TARGET_LINK_LIBRARIES(main ${Boost_LOG_LIBRARY} ${CMAKE_THREAD_LIBS_INIT})

Edit: verbose output from cmake and make

cmake:

-- [ /usr/share/cmake-2.8/Modules/FindBoost.cmake:476 ] _boost_TEST_VERSIONS = 1.56.0;1.56;1.55.0;1.55;1.54.0;1.54
-- [ /usr/share/cmake-2.8/Modules/FindBoost.cmake:478 ] Boost_USE_MULTITHREADED = TRUE
-- [ /usr/share/cmake-2.8/Modules/FindBoost.cmake:480 ] Boost_USE_STATIC_LIBS = 
-- [ /usr/share/cmake-2.8/Modules/FindBoost.cmake:482 ] Boost_USE_STATIC_RUNTIME = 
-- [ /usr/share/cmake-2.8/Modules/FindBoost.cmake:484 ] Boost_ADDITIONAL_VERSIONS = 
-- [ /usr/share/cmake-2.8/Modules/FindBoost.cmake:486 ] Boost_NO_SYSTEM_PATHS = 
-- [ /usr/share/cmake-2.8/Modules/FindBoost.cmake:538 ] Declared as CMake or Environmental Variables:
-- [ /usr/share/cmake-2.8/Modules/FindBoost.cmake:540 ]   BOOST_ROOT = 
-- [ /usr/share/cmake-2.8/Modules/FindBoost.cmake:542 ]   BOOST_INCLUDEDIR = 
-- [ /usr/share/cmake-2.8/Modules/FindBoost.cmake:544 ]   BOOST_LIBRARYDIR = 
-- [ /usr/share/cmake-2.8/Modules/FindBoost.cmake:546 ] _boost_TEST_VERSIONS = 1.56.0;1.56;1.55.0;1.55;1.54.0;1.54
-- [ /usr/share/cmake-2.8/Modules/FindBoost.cmake:639 ] location of version.hpp: /usr/include/boost/version.hpp
-- [ /usr/share/cmake-2.8/Modules/FindBoost.cmake:663 ] version.hpp reveals boost 1.54.0
-- [ /usr/share/cmake-2.8/Modules/FindBoost.cmake:739 ] guessed _boost_COMPILER = -gcc48
-- [ /usr/share/cmake-2.8/Modules/FindBoost.cmake:749 ] _boost_MULTITHREADED = -mt
-- [ /usr/share/cmake-2.8/Modules/FindBoost.cmake:792 ] _boost_RELEASE_ABI_TAG = -
-- [ /usr/share/cmake-2.8/Modules/FindBoost.cmake:794 ] _boost_DEBUG_ABI_TAG = -d
-- [ /usr/share/cmake-2.8/Modules/FindBoost.cmake:842 ] _boost_LIBRARY_SEARCH_DIRS = /usr/lib64;NO_DEFAULT_PATH
-- [ /usr/share/cmake-2.8/Modules/FindBoost.cmake:930 ] Searching for LOG_LIBRARY_RELEASE: boost_log-gcc48-mt-1_54;boost_log-gcc48-mt;boost_log-mt-1_54;boost_log-mt;boost_log
-- [ /usr/share/cmake-2.8/Modules/FindBoost.cmake:966 ] Searching for LOG_LIBRARY_DEBUG: boost_log-gcc48-mt-d-1_54;boost_log-gcc48-mt-d;boost_log-mt-d-1_54;boost_log-mt-d;boost_log-mt;boost_log
-- [ /usr/share/cmake-2.8/Modules/FindBoost.cmake:1017 ] Boost_FOUND = 1
-- Boost version: 1.54.0
-- Found the following Boost libraries:
--   log
-- Configuring done
-- Generating done
-- Build files have been written to: /home/durrw/boost-log-test/build

make:

/usr/bin/cmake -H/home/durrw/boost-log-test -B/home/durrw/boost-log-test/build --check-build-system CMakeFiles/Makefile.cmake 0
/usr/bin/cmake -E cmake_progress_start /home/durrw/boost-log-test/build/CMakeFiles /home/durrw/boost-log-test/build/CMakeFiles/progress.marks
make -f CMakeFiles/Makefile2 all
make[1]: Entering directory `/home/durrw/boost-log-test/build'
make -f CMakeFiles/main.dir/build.make CMakeFiles/main.dir/depend
make[2]: Entering directory `/home/durrw/boost-log-test/build'
cd /home/durrw/boost-log-test/build && /usr/bin/cmake -E cmake_depends "Unix Makefiles" /home/durrw/boost-log-test /home/durrw/boost-log-test /home/durrw/boost-log-test/build /home/durrw/boost-log-test/build /home/durrw/boost-log-test/build/CMakeFiles/main.dir/DependInfo.cmake --color=
make[2]: Leaving directory `/home/durrw/boost-log-test/build'
make -f CMakeFiles/main.dir/build.make CMakeFiles/main.dir/build
make[2]: Entering directory `/home/durrw/boost-log-test/build'
Linking CXX executable main
/usr/bin/cmake -E cmake_link_script CMakeFiles/main.dir/link.txt --verbose=1
/usr/bin/c++       CMakeFiles/main.dir/main.cpp.o  -o main -rdynamic -lboost_log -lpthread 
CMakeFiles/main.dir/main.cpp.o: In function `main':
main.cpp:(.text+0x39): undefined reference to `boost::log::v2s_mt_posix::trivial::logger::get()'
Was it helpful?

Solution

It looks like it boils down to linking to the shared version of Boost.Log.

There is a bit of detail on the issue in the docs for Boost.Log Your error message mentions the namespace boost::log::v2s_mt_posix and from the docs, this implies the linker is expecting to link to a static version of Boost.Log.

If you want to link to the shared version, it seems you need to define BOOST_LOG_DYN_LINK or BOOST_ALL_DYN_LINK, i.e. in your CMakeLists.txt add:

ADD_DEFINITIONS(-DBOOST_LOG_DYN_LINK)

If you want to link to the static version of Boost.Log, instead you need to add a CMake variable before calling FIND_PACKAGE(Boost ...):

SET(Boost_USE_STATIC_LIBS ON)
FIND_PACKAGE(Boost 1.54 COMPONENTS log REQUIRED)

For further variables which affect how CMake finds Boost, see the docs for FindBoost.

OTHER TIPS

For CMake 3.15 (and some earlier versions) the following appears to be sufficient to build Boost.Log with CMake without the original linker error:

cmake_minimum_required(VERSION 3.15)
project(boost_log_tutorial)

SET(Boost_USE_STATIC_LIBS ON)           # link statically
#ADD_DEFINITIONS(-DBOOST_LOG_DYN_LINK)  # or, link dynamically

find_package(Boost 1.69.0 COMPONENTS log REQUIRED)

add_executable(boost_log_tutorial main.cpp)
target_link_libraries(boost_log_tutorial Boost::log_setup Boost::log)

The key things seem to be linking against Boost:log_setup and Boost::log, and specifying either static or dynamic linking with SET(Boost_USE_STATIC_LIBS ON) or ADD_DEFINITIONS(-DBOOST_LOG_DYN_LINK).

It is Boost_INCLUDE_DIRS not Boost_INCLUDE_DIR.

You could try enable Boost_USE_STATIC_LIBS

Licensed under: CC-BY-SA with attribution
Not affiliated with StackOverflow
scroll top