libc {
  GLIBC_2.0 {
    __pthread_once;
    _pthread_cleanup_pop;
    _pthread_cleanup_pop_restore;
    _pthread_cleanup_push;
    _pthread_cleanup_push_defer;
    pthread_attr_destroy;
    pthread_attr_getdetachstate;
    pthread_attr_getinheritsched;
    pthread_attr_getschedparam;
    pthread_attr_getschedpolicy;
    pthread_attr_getscope;
    pthread_attr_init;
    pthread_attr_setdetachstate;
    pthread_attr_setinheritsched;
    pthread_attr_setschedparam;
    pthread_attr_setschedpolicy;
    pthread_attr_setscope;
    pthread_cond_broadcast;
    pthread_cond_destroy;
    pthread_cond_init;
    pthread_cond_signal;
    pthread_cond_timedwait;
    pthread_cond_wait;
    pthread_condattr_destroy;
    pthread_condattr_init;
    pthread_equal;
    pthread_exit;
    pthread_getschedparam;
    pthread_kill;
    pthread_mutex_destroy;
    pthread_mutex_init;
    pthread_mutex_lock;
    pthread_mutex_unlock;
    pthread_once;
    pthread_self;
    pthread_setcancelstate;
    pthread_setcanceltype;
    pthread_setschedparam;
    pthread_sigmask;
  }
  GLIBC_2.1 {
    pthread_attr_init;
  }
  GLIBC_2.2.3 {
    pthread_getattr_np;
  }
  GLIBC_2.3.2 {
    __register_atfork;
    pthread_cond_broadcast;
    pthread_cond_destroy;
    pthread_cond_init;
    pthread_cond_signal;
    pthread_cond_timedwait;
    pthread_cond_wait;
  }
  GLIBC_2.3.3 {
    __pthread_cleanup_routine;
    __pthread_unwind_next;
    pthread_attr_setaffinity_np;
    pthread_getaffinity_np;
  }
  GLIBC_2.3.4 {
    pthread_attr_setaffinity_np;
  }
  GLIBC_2.4 {
    pthread_mutex_consistent_np;
  }
  GLIBC_2.12 {
    pthread_mutex_consistent;
  }
  # C11 thread symbols.
  GLIBC_2.28 {
    thrd_current;
    thrd_equal;
    thrd_sleep;
    thrd_yield;
  }
  GLIBC_2.32 {
    pthread_attr_getsigmask_np;
    pthread_attr_setaffinity_np;
    pthread_attr_setsigmask_np;
    pthread_getaffinity_np;
    pthread_getattr_np;
    pthread_sigmask;
  }
  GLIBC_2.34 {
    __pthread_cleanup_routine;
    __pthread_once;
    pthread_kill;
    pthread_mutex_consistent;
    pthread_once;
  }
  GLIBC_PRIVATE {
    __futex_abstimed_wait64;
    __futex_abstimed_wait_cancelable64;
    __libc_alloca_cutoff;
    __libc_cleanup_pop_restore;
    __libc_cleanup_push_defer;
    __libc_dl_error_tsd;
    __libc_pthread_init;
    __lll_clocklock_elision;
    __lll_lock_elision;
    __lll_lock_wait;
    __lll_lock_wait_private;
    __lll_trylock_elision;
    __lll_unlock_elision;
    __nptl_deallocate_tsd;
    __nptl_nthreads;
    __pthread_attr_copy;
    __pthread_attr_destroy;
    __pthread_attr_init;
    __pthread_attr_setaffinity_np;
    __pthread_attr_setsigmask_internal;
    __pthread_cleanup_pop;
    __pthread_cleanup_push;
    __pthread_cleanup_upto;
    __pthread_cond_destroy; # Used by the C11 threads.
    __pthread_cond_init; # Used by the C11 threads.
    __pthread_exit;
    __pthread_force_elision;
    __pthread_getattr_default_np;
    __pthread_keys;
    __pthread_setcancelstate;
    __pthread_unwind;
  }
}

libpthread {
  GLIBC_2.0 {
    _Exit;
    _IO_flockfile;
    _IO_ftrylockfile;
    _IO_funlockfile;
    __errno_location;
    __h_errno_location;
    __pthread_atfork;
    __pthread_getspecific;
    __pthread_key_create;
    __pthread_mutex_destroy;
    __pthread_mutex_init;
    __pthread_mutex_lock;
    __pthread_mutex_trylock;
    __pthread_mutex_unlock;
    __pthread_mutexattr_destroy;
    __pthread_mutexattr_init;
    __pthread_mutexattr_settype;
    __pthread_setspecific;
    _exit;
    flockfile;
    ftrylockfile;
    funlockfile;
    pthread_atfork;
    pthread_cancel;
    pthread_cond_broadcast;
    pthread_cond_signal;
    pthread_cond_timedwait;
    pthread_cond_wait;
    pthread_create;
    pthread_detach;
    pthread_getspecific;
    pthread_join;
    pthread_key_create;
    pthread_key_delete;
    pthread_kill_other_threads_np;
    pthread_mutex_destroy;
    pthread_mutex_init;
    pthread_mutex_lock;
    pthread_mutex_trylock;
    pthread_mutex_unlock;
    pthread_mutexattr_destroy;
    pthread_mutexattr_getkind_np;
    pthread_mutexattr_init;
    pthread_mutexattr_setkind_np;
    pthread_setcanceltype;
    pthread_setspecific;
    pthread_sigmask;
    pthread_testcancel;
    sem_destroy;
    sem_getvalue;
    sem_init;
    sem_post;
    sem_trywait;
    sem_wait;
  }

  GLIBC_2.1 {
    pthread_attr_getguardsize;
    pthread_attr_getstackaddr;
    pthread_attr_getstacksize;
    pthread_attr_setguardsize;
    pthread_attr_setstackaddr;
    pthread_attr_setstacksize;
    pthread_create;
    pthread_getconcurrency;
    pthread_mutexattr_gettype;
    pthread_mutexattr_settype;
    pthread_rwlock_destroy;
    pthread_rwlock_init;
    pthread_rwlock_rdlock;
    pthread_rwlock_tryrdlock;
    pthread_rwlock_trywrlock;
    pthread_rwlock_unlock;
    pthread_rwlock_wrlock;
    pthread_rwlockattr_destroy;
    pthread_rwlockattr_getkind_np;
    pthread_rwlockattr_getpshared;
    pthread_rwlockattr_init;
    pthread_rwlockattr_setkind_np;
    pthread_rwlockattr_setpshared;
    pthread_setconcurrency;
    sem_destroy;
    sem_getvalue;
    sem_init;
    sem_post;
    sem_trywait;
    sem_wait;
  }

  GLIBC_2.1.1 {
    sem_close;
    sem_open;
    sem_unlink;
  }

  GLIBC_2.1.2 {
    __libpthread_version_placeholder;
  }

  GLIBC_2.2 {
    __pthread_rwlock_destroy;
    __pthread_rwlock_init;
    __pthread_rwlock_rdlock;
    __pthread_rwlock_tryrdlock;
    __pthread_rwlock_trywrlock;
    __pthread_rwlock_unlock;
    __pthread_rwlock_wrlock;
    __res_state;
    pthread_attr_getstack;
    pthread_attr_setstack;
    pthread_barrier_destroy;
    pthread_barrier_init;
    pthread_barrier_wait;
    pthread_barrierattr_destroy;
    pthread_barrierattr_init;
    pthread_barrierattr_setpshared;
    pthread_condattr_getpshared;
    pthread_condattr_setpshared;
    pthread_getcpuclockid;
    pthread_mutex_timedlock;
    pthread_mutexattr_getpshared;
    pthread_mutexattr_setpshared;
    pthread_rwlock_timedrdlock;
    pthread_rwlock_timedwrlock;
    pthread_spin_destroy;
    pthread_spin_init;
    pthread_spin_lock;
    pthread_spin_trylock;
    pthread_spin_unlock;
    pthread_yield;
    sem_timedwait;
  }

  GLIBC_2.2.3 {
    __libpthread_version_placeholder;
  }

  GLIBC_2.2.6 {
    __libpthread_version_placeholder;
  }

  GLIBC_2.3.2 {
    pthread_cond_broadcast;
    pthread_cond_init;
    pthread_cond_signal;
    pthread_cond_timedwait;
    pthread_cond_wait;
  }

  GLIBC_2.3.3 {
    __pthread_register_cancel;
    __pthread_register_cancel_defer;
    __pthread_unregister_cancel;
    __pthread_unregister_cancel_restore;
    pthread_attr_getaffinity_np;
    pthread_barrierattr_getpshared;
    pthread_condattr_getclock;
    pthread_condattr_setclock;
    pthread_setaffinity_np;
    pthread_timedjoin_np;
    pthread_tryjoin_np;
  }

  GLIBC_2.3.4 {
    pthread_attr_getaffinity_np;
    pthread_getaffinity_np;
    pthread_setaffinity_np;
    pthread_setschedprio;
  }

  GLIBC_2.4 {
    pthread_mutex_getprioceiling;
    pthread_mutex_setprioceiling;
    pthread_mutexattr_getprioceiling;
    pthread_mutexattr_getprotocol;
    pthread_mutexattr_getrobust_np;
    pthread_mutexattr_setprioceiling;
    pthread_mutexattr_setprotocol;
    pthread_mutexattr_setrobust_np;
  };

  GLIBC_2.11 {
    pthread_sigqueue;
  };

  GLIBC_2.12 {
    pthread_getname_np;
    pthread_mutexattr_getrobust;
    pthread_mutexattr_setrobust;
    pthread_setname_np;
  };

  GLIBC_2.18 {
    pthread_getattr_default_np;
    pthread_setattr_default_np;
  }

  # C11 thread symbols.
  GLIBC_2.28 {
    call_once;
    cnd_broadcast;
    cnd_destroy;
    cnd_init;
    cnd_signal;
    cnd_timedwait;
    cnd_wait;
    mtx_destroy;
    mtx_init;
    mtx_lock;
    mtx_timedlock;
    mtx_trylock;
    mtx_unlock;
    thrd_create;
    thrd_detach;
    thrd_exit;
    thrd_join;
    tss_create;
    tss_delete;
    tss_get;
    tss_set;
  }

  GLIBC_2.30 {
    pthread_cond_clockwait;
    pthread_mutex_clocklock;
    pthread_rwlock_clockrdlock;
    pthread_rwlock_clockwrlock;
    sem_clockwait;
  }

  GLIBC_2.31 {
    pthread_clockjoin_np;
  }

  GLIBC_PRIVATE {
    __libpthread_freeres;
    __pthread_barrier_init;
    __pthread_barrier_wait;
    __pthread_clock_gettime;
    __pthread_clock_settime;
    __pthread_get_minstack;
    __pthread_initialize_minimal;
  }
}