/opt/IBM/openxlC/17.1.1/bin/ibm-clang -pthread  -Wall -Wextra -Werror -Wno-error=deprecated -Wno-error=deprecated-declarations sys_socket/accept4.c -o sys_socket/accept4 -D_POSIX_C_SOURCE=202405L -lm -lpthread -lrt -latomic
sys_socket/accept4.c:5:72: error: use of undeclared identifier 'accept4'; did you mean 'naccept'?
int (*foo)(int, struct sockaddr *restrict, socklen_t *restrict, int) = accept4;
                                                                       ^~~~~~~
                                                                       naccept
/usr/include/sys/socket.h:640:9: note: 'naccept' declared here
int     accept(int, struct sockaddr *__restrict__, socklen_t *__restrict__);
        ^
/usr/include/sys/socket.h:168:25: note: expanded from macro 'accept'
#define accept          naccept
                        ^
sys_socket/accept4.c:5:7: error: incompatible function pointer types initializing 'int (*)(int, struct sockaddr *restrict, socklen_t *restrict, int)' (aka 'int (*)(int, struct sockaddr *restrict, unsigned long *restrict, int)') with an expression of type 'int (int, struct sockaddr *restrict, socklen_t *restrict)' (aka 'int (int, struct sockaddr *restrict, unsigned long *restrict)') [-Werror,-Wincompatible-function-pointer-types]
int (*foo)(int, struct sockaddr *restrict, socklen_t *restrict, int) = accept4;
      ^                                                                ~~~~~~~
2 errors generated.