cc -pthread  -Wall -Wextra -Werror=implicit-function-declaration pthread/pthread_barrier_wait.c -o pthread/pthread_barrier_wait -D_GNU_SOURCE -D_BSD_SOURCE -D_ALL_SOURCE -D_DEFAULT_SOURCE -lm -lpthread -lrt -lintl -liconv
pthread/pthread_barrier_wait.c: In function ‘start’:
pthread/pthread_barrier_wait.c:14:23: error: implicit declaration of function ‘pthread_barrier_wait’; did you mean ‘pthread_cond_wait’? [-Wimplicit-function-declaration]
   14 |         if ( (errno = pthread_barrier_wait(&barrier)) &&
      |                       ^~~~~~~~~~~~~~~~~~~~
      |                       pthread_cond_wait
pthread/pthread_barrier_wait.c:15:23: error: ‘PTHREAD_BARRIER_SERIAL_THREAD’ undeclared (first use in this function)
   15 |              errno != PTHREAD_BARRIER_SERIAL_THREAD )
      |                       ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
pthread/pthread_barrier_wait.c:15:23: note: each undeclared identifier is reported only once for each function it appears in
pthread/pthread_barrier_wait.c: In function ‘main’:
pthread/pthread_barrier_wait.c:23:23: error: implicit declaration of function ‘pthread_barrierattr_init’; did you mean ‘pthread_mutexattr_init’? [-Wimplicit-function-declaration]
   23 |         if ( (errno = pthread_barrierattr_init(&attr)) )
      |                       ^~~~~~~~~~~~~~~~~~~~~~~~
      |                       pthread_mutexattr_init
pthread/pthread_barrier_wait.c:25:23: error: implicit declaration of function ‘pthread_barrier_init’; did you mean ‘pthread_attr_init’? [-Wimplicit-function-declaration]
   25 |         if ( (errno = pthread_barrier_init(&barrier, &attr, 2)) )
      |                       ^~~~~~~~~~~~~~~~~~~~
      |                       pthread_attr_init
pthread/pthread_barrier_wait.c:31:23: error: ‘PTHREAD_BARRIER_SERIAL_THREAD’ undeclared (first use in this function)
   31 |              errno != PTHREAD_BARRIER_SERIAL_THREAD )
      |                       ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~