#ifdef HAVE_CONFIG_H
#include <config.h>
#endif

#include <signal.h>

#include <errno.h>

#include "../internal/syscall.h"

/*
 * kill/killpg: process- and process-group-directed signals over SYS_kill.
 *
 * kill passes its pid straight to the kernel, which interprets it exactly
 * as POSIX specifies: pid > 0 is a single process, pid == 0 the caller's
 * process group, pid == -1 every process the caller may signal, and
 * pid < -1 the process group -pid. killpg(pgrp, sig) is equivalent to
 * kill(-pgrp, sig): a negative pgrp is not a valid group id and is
 * rejected with EINVAL here (mirroring musl) rather than inverted into a
 * positive-pid send by accident.
 */

int
kill(pid_t pid, int sig)
{
    return syscall_ret(__syscall2(SYS_kill, (long)pid, sig));
}

int
killpg(pid_t pgrp, int sig)
{
    if (pgrp < 0)
    {
        errno = EINVAL;
        return -1;
    }
    return kill(-pgrp, sig);
}