Re: [Boost-users] libboost_date_time: undefined reference to __sync_fetch_and_add_4

Hi Tom! Tom Fogal writes:

Carsten Raas writes:

...

----------------------------------------------------------------- Shared linking: # icpc -I /opt/boost/1.38/intel/include conftest.cpp -L /opt/boost/1.38/intel/lib -lboost_date_time

/opt/boost/1.38/intel/lib/libboost_date_time.so: undefined reference to `__sync_fetch_and_add_4' ----------------------------------------------------------------- Shared linking with gcc:

# g++ -I /opt/boost/1.38/intel/include conftest.cpp \ -L /opt/boost/1.38/intel/lib -lboost_date_time

/opt/boost/1.38/intel/lib/libboost_date_time.so: undefined reference to `__sync_fetch_and_add_4' collect2: ld returned 1 exit status -----------------------------------------------------------------

This is an internal function for gcc's atomics extensions.

http://gcc.gnu.org/onlinedocs/gcc-4.3.3/gcc/Atomic-Builtins.html

Thanks for the hints! Just to make this point clear: The boost build is done completely with the Intel compiler suite (using the intel-linux toolset): ./configure --prefix=/opt/boost/1.38/intel --with-toolset=intel-linux bjam --toolset=intel-linux -prefix=/opt/boost/1.38/intel \ --build-type=complete --with-date_time install The only thing I changed was tools/build/v2/tools/intel-linux.jam to get rid of all these warnings: icpc: command line remark #10010: option '-Ob' is deprecated and will be removed in a future release. See '-help deprecated' Thus I replaced -Obx with -inline-level=x (x=0,1,2). This makes the build free of warnings.

Can you try adding -lgcc (IIRC; maybe lgcc_s?) to your link line?

I checked this, but both (-lgcc and -lgcc_s) are already in the linker call of icpc as well as in the g++ linking (visible when using the -v switch). Adding the libraries in addition (in various orders) did not help.

Looks like the more global problem is that boost_date_time is using this symbol, but was not linked against it at build time. It's a bit strange that your compiler isn't adding this implicitly though...

What is confusing for me is that the static libraries work: While icpc -I /opt/boost/1.38/intel/include \ -L /opt/boost/1.38/intel/lib conftest.cpp -lboost_date_time fails, this one works: icpc --static -I /opt/boost/1.38/intel/include \ -L /opt/boost/1.38/intel/lib conftest.cpp -lboost_date_time The same for using g++ instead of icpc (for the demo program). -Carsten