undefined symbol: __atomic_store ？

[纪明]

Hi all，

I have gcc 4.9.0 installed in my system. When I tried to run an
executable, I got the following error:

libMyLib.so: undefined symbol: __atomic_store

Then I tried to find this symbol in libstdc++.so with the following command:

[workspace]$ nm -DC /usr/lib64/libstdc++.so | grep atomic
000000348e07bdb0 T __gnu_cxx::__atomic_add(int volatile*, int)
000000348e05c0c0 T
std::__atomic0::atomic_flag::test_and_set(std::memory_order)
000000348e05c120 T std::__atomic0::atomic_flag::clear(std::memory_order)
000000348e05c0c0 T
std::__atomic0::atomic_flag::test_and_set(std::memory_order) volatile
000000348e05c120 T std::__atomic0::atomic_flag::clear(std::memory_order)
volatile
000000348e05c1b0 T __atomic_flag_for_address
000000348e05c180 T __atomic_flag_wait_explicit
000000348e05c170 T atomic_flag_clear_explicit
000000348e05c160 T atomic_flag_test_and_set_explicit


There is no __atomic_store indeed. Did I miss some flags when installing
gcc?


Thanks,
Ming

[Jonathan Wakely]

Post by 纪明
Hi all，
I have gcc 4.9.0 installed in my system. When I tried to run an
libMyLib.so: undefined symbol: __atomic_store
[workspace]$ nm -DC /usr/lib64/libstdc++.so | grep atomic
000000348e07bdb0 T __gnu_cxx::__atomic_add(int volatile*, int)
000000348e05c0c0 T
std::__atomic0::atomic_flag::test_and_set(std::memory_order)
000000348e05c120 T std::__atomic0::atomic_flag::clear(std::memory_order)
000000348e05c0c0 T
std::__atomic0::atomic_flag::test_and_set(std::memory_order) volatile
000000348e05c120 T std::__atomic0::atomic_flag::clear(std::memory_order)
volatile
000000348e05c1b0 T __atomic_flag_for_address
000000348e05c180 T __atomic_flag_wait_explicit
000000348e05c170 T atomic_flag_clear_explicit
000000348e05c160 T atomic_flag_test_and_set_explicit
There is no __atomic_store indeed. Did I miss some flags when installing
gcc?

You didn't say what flags you used when installing it - or even what
platform you installed it on - are we supposed to guess?

This usually means you are on a target without atomic operations, so
you need to link to GCC's libatomic.so support library.