upstream-nats-server/server/pse/freebsd.txt

/*
 * Compile and run this as a C program to get the kinfo_proc offsets
 * for your architecture.
 * While FreeBSD works hard at binary-compatibility within an ABI, various
 * we can't say for sure that these are right for _all_ use on a hardware
 * platform.  The LP64 ifdef affects the offsets considerably.
 *
 * We use these offsets in hardware-specific files for FreeBSD, to avoid a cgo
 * compilation-time dependency, allowing us to cross-compile for FreeBSD from
 * other hardware platforms, letting us distribute binaries for FreeBSD.
 */

#include <stddef.h>
#include <stdint.h>
#include <stdio.h>
#include <sys/types.h>
#include <sys/user.h>

#define SHOW_OFFSET(FIELD) printf(" KIP_OFF_%s = %zu\n", #FIELD, offsetof(struct kinfo_proc, ki_ ## FIELD))

int main(int argc, char *argv[]) {
	/* Uncomment these if you want some extra debugging aids:
	SHOW_OFFSET(pid);
	SHOW_OFFSET(ppid);
	SHOW_OFFSET(uid);
	*/
	SHOW_OFFSET(size);
	SHOW_OFFSET(rssize);
	SHOW_OFFSET(pctcpu);
}