gcc -pthread -Wall -Wextra -Werror=implicit-function-declaration pthread/pthread_getcpuclockid.c -o pthread/pthread_getcpuclockid -D_GNU_SOURCE -D_BSD_SOURCE -D_ALL_SOURCE -D_DEFAULT_SOURCE -lm -lpthread -lrt -lxnet -lsocket -latomic pthread/pthread_getcpuclockid.c: In function 'main': pthread/pthread_getcpuclockid.c:20:23: error: implicit declaration of function 'pthread_getcpuclockid'; did you mean 'pthread_getspecific'? [-Wimplicit-function-declaration] 20 | if ( (errno = pthread_getcpuclockid(pthread_self(), &clock_id)) ) | ^~~~~~~~~~~~~~~~~~~~~ | pthread_getspecific