s! {
    pub struct sigaction {
        pub sa_sigaction: ::sighandler_t,
        pub sa_mask: ::sigset_t,
        pub sa_flags: ::c_int,
        _restorer: *mut ::c_void,
    }

    pub struct stack_t {
        pub ss_sp: *mut ::c_void,
        pub ss_flags: ::c_int,
        pub ss_size: ::size_t
    }

    pub struct siginfo_t {
        pub si_signo: ::c_int,
        pub si_errno: ::c_int,
        pub si_code: ::c_int,
        pub _pad: [::c_int; 29],
        _align: [usize; 0],
    }

    pub struct glob64_t {
        pub gl_pathc: ::size_t,
        pub gl_pathv: *mut *mut ::c_char,
        pub gl_offs: ::size_t,
        pub gl_flags: ::c_int,

        __unused1: *mut ::c_void,
        __unused2: *mut ::c_void,
        __unused3: *mut ::c_void,
        __unused4: *mut ::c_void,
        __unused5: *mut ::c_void,
    }
}

pub const RLIMIT_RSS: ::c_int = 5;
pub const RLIMIT_NOFILE: ::c_int = 7;
pub const RLIMIT_AS: ::c_int = 9;
pub const RLIMIT_NPROC: ::c_int = 6;
pub const RLIMIT_MEMLOCK: ::c_int = 8;
pub const RLIM_INFINITY: ::rlim_t = !0;
pub const RLIMIT_RTTIME: ::c_int = 15;
pub const RLIMIT_NLIMITS: ::c_int = 16;

pub const O_APPEND: ::c_int = 1024;
pub const O_CREAT: ::c_int = 64;
pub const O_EXCL: ::c_int = 128;
pub const O_NOCTTY: ::c_int = 256;
pub const O_NONBLOCK: ::c_int = 2048;
pub const O_SYNC: ::c_int = 1052672;
pub const O_RSYNC: ::c_int = 1052672;
pub const O_DSYNC: ::c_int = 4096;

pub const MAP_ANON: ::c_int = 0x0020;
pub const MAP_ANONYMOUS: ::c_int = 0x0020;
pub const MAP_GROWSDOWN: ::c_int = 0x0100;
pub const MAP_DENYWRITE: ::c_int = 0x0800;
pub const MAP_EXECUTABLE: ::c_int = 0x01000;
pub const MAP_LOCKED: ::c_int = 0x02000;
pub const MAP_NORESERVE: ::c_int = 0x04000;
pub const MAP_POPULATE: ::c_int = 0x08000;
pub const MAP_NONBLOCK: ::c_int = 0x010000;
pub const MAP_STACK: ::c_int = 0x020000;

pub const EDEADLK: ::c_int = 35;
pub const ENAMETOOLONG: ::c_int = 36;
pub const ENOLCK: ::c_int = 37;
pub const ENOSYS: ::c_int = 38;
pub const ENOTEMPTY: ::c_int = 39;
pub const ELOOP: ::c_int = 40;
pub const ENOMSG: ::c_int = 42;
pub const EIDRM: ::c_int = 43;
pub const ECHRNG: ::c_int = 44;
pub const EL2NSYNC: ::c_int = 45;
pub const EL3HLT: ::c_int = 46;
pub const EL3RST: ::c_int = 47;
pub const ELNRNG: ::c_int = 48;
pub const EUNATCH: ::c_int = 49;
pub const ENOCSI: ::c_int = 50;
pub const EL2HLT: ::c_int = 51;
pub const EBADE: ::c_int = 52;
pub const EBADR: ::c_int = 53;
pub const EXFULL: ::c_int = 54;
pub const ENOANO: ::c_int = 55;
pub const EBADRQC: ::c_int = 56;
pub const EBADSLT: ::c_int = 57;
pub const EDEADLOCK: ::c_int = EDEADLK;
pub const EMULTIHOP: ::c_int = 72;
pub const EOVERFLOW: ::c_int = 75;
pub const ENOTUNIQ: ::c_int = 76;
pub const EBADFD: ::c_int = 77;
pub const EBADMSG: ::c_int = 74;
pub const EREMCHG: ::c_int = 78;
pub const ELIBACC: ::c_int = 79;
pub const ELIBBAD: ::c_int = 80;
pub const ELIBSCN: ::c_int = 81;
pub const ELIBMAX: ::c_int = 82;
pub const ELIBEXEC: ::c_int = 83;
pub const EILSEQ: ::c_int = 84;
pub const ERESTART: ::c_int = 85;
pub const ESTRPIPE: ::c_int = 86;
pub const EUSERS: ::c_int = 87;
pub const ENOTSOCK: ::c_int = 88;
pub const EDESTADDRREQ: ::c_int = 89;
pub const EMSGSIZE: ::c_int = 90;
pub const EPROTOTYPE: ::c_int = 91;
pub const ENOPROTOOPT: ::c_int = 92;
pub const EPROTONOSUPPORT: ::c_int = 93;
pub const ESOCKTNOSUPPORT: ::c_int = 94;
pub const EOPNOTSUPP: ::c_int = 95;
pub const EPFNOSUPPORT: ::c_int = 96;
pub const EAFNOSUPPORT: ::c_int = 97;
pub const EADDRINUSE: ::c_int = 98;
pub const EADDRNOTAVAIL: ::c_int = 99;
pub const ENETDOWN: ::c_int = 100;
pub const ENETUNREACH: ::c_int = 101;
pub const ENETRESET: ::c_int = 102;
pub const ECONNABORTED: ::c_int = 103;
pub const ECONNRESET: ::c_int = 104;
pub const ENOBUFS: ::c_int = 105;
pub const EISCONN: ::c_int = 106;
pub const ENOTCONN: ::c_int = 107;
pub const ESHUTDOWN: ::c_int = 108;
pub const ETOOMANYREFS: ::c_int = 109;
pub const ETIMEDOUT: ::c_int = 110;
pub const ECONNREFUSED: ::c_int = 111;
pub const EHOSTDOWN: ::c_int = 112;
pub const EHOSTUNREACH: ::c_int = 113;
pub const EALREADY: ::c_int = 114;
pub const EINPROGRESS: ::c_int = 115;
pub const ESTALE: ::c_int = 116;
pub const EUCLEAN: ::c_int = 117;
pub const ENOTNAM: ::c_int = 118;
pub const ENAVAIL: ::c_int = 119;
pub const EISNAM: ::c_int = 120;
pub const EREMOTEIO: ::c_int = 121;
pub const EDQUOT: ::c_int = 122;
pub const ENOMEDIUM: ::c_int = 123;
pub const EMEDIUMTYPE: ::c_int = 124;
pub const ECANCELED: ::c_int = 125;
pub const ENOKEY: ::c_int = 126;
pub const EKEYEXPIRED: ::c_int = 127;
pub const EKEYREVOKED: ::c_int = 128;
pub const EKEYREJECTED: ::c_int = 129;
pub const EOWNERDEAD: ::c_int = 130;
pub const ENOTRECOVERABLE: ::c_int = 131;
pub const EHWPOISON: ::c_int = 133;
pub const ERFKILL: ::c_int = 132;

pub const SOCK_STREAM: ::c_int = 1;
pub const SOCK_DGRAM: ::c_int = 2;

pub const SOL_SOCKET: ::c_int = 1;

pub const SO_REUSEADDR: ::c_int = 2;
pub const SO_TYPE: ::c_int = 3;
pub const SO_ERROR: ::c_int = 4;
pub const SO_DONTROUTE: ::c_int = 5;
pub const SO_BROADCAST: ::c_int = 6;
pub const SO_SNDBUF: ::c_int = 7;
pub const SO_RCVBUF: ::c_int = 8;
pub const SO_KEEPALIVE: ::c_int = 9;
pub const SO_OOBINLINE: ::c_int = 10;
pub const SO_LINGER: ::c_int = 13;
pub const SO_REUSEPORT: ::c_int = 15;
pub const SO_RCVLOWAT: ::c_int = 18;
pub const SO_SNDLOWAT: ::c_int = 19;
pub const SO_RCVTIMEO: ::c_int = 20;
pub const SO_SNDTIMEO: ::c_int = 21;
pub const SO_ACCEPTCONN: ::c_int = 30;

pub const TCP_COOKIE_TRANSACTIONS: ::c_int = 15;
pub const TCP_THIN_LINEAR_TIMEOUTS: ::c_int = 16;
pub const TCP_THIN_DUPACK: ::c_int = 17;
pub const TCP_USER_TIMEOUT: ::c_int = 18;
pub const TCP_REPAIR: ::c_int = 19;
pub const TCP_REPAIR_QUEUE: ::c_int = 20;
pub const TCP_QUEUE_SEQ: ::c_int = 21;
pub const TCP_REPAIR_OPTIONS: ::c_int = 22;
pub const TCP_FASTOPEN: ::c_int = 23;
pub const TCP_TIMESTAMP: ::c_int = 24;

pub const SA_ONSTACK: ::c_int = 0x08000000;
pub const SA_SIGINFO: ::c_int = 0x00000004;
pub const SA_NOCLDWAIT: ::c_int = 0x00000002;

pub const SIGCHLD: ::c_int = 17;
pub const SIGBUS: ::c_int = 7;
pub const SIG_SETMASK: ::c_int = 2;

pub const FALLOC_FL_KEEP_SIZE: ::c_int = 0x01;
pub const FALLOC_FL_PUNCH_HOLE: ::c_int = 0x02;

pub const FIOCLEX: ::c_ulong = 0x5451;
pub const FIONBIO: ::c_ulong = 0x5421;

pub const BUFSIZ: ::c_uint = 8192;
pub const TMP_MAX: ::c_uint = 238328;
pub const FOPEN_MAX: ::c_uint = 16;
pub const POSIX_MADV_DONTNEED: ::c_int = 4;
pub const _SC_2_C_VERSION: ::c_int = 96;
pub const RUSAGE_THREAD: ::c_int = 1;
pub const O_ACCMODE: ::c_int = 3;
pub const RUSAGE_CHILDREN: ::c_int = -1;
pub const ST_RELATIME: ::c_ulong = 4096;
pub const NI_MAXHOST: ::socklen_t = 1025;

cfg_if! {
    if #[cfg(any(target_arch = "arm", target_arch = "x86",
                 target_arch = "x86_64"))] {
        pub const PTHREAD_STACK_MIN: ::size_t = 16384;
    } else {
        pub const PTHREAD_STACK_MIN: ::size_t = 131072;
    }
}

extern {
    pub fn sysctl(name: *mut ::c_int,
                  namelen: ::c_int,
                  oldp: *mut ::c_void,
                  oldlenp: *mut ::size_t,
                  newp: *mut ::c_void,
                  newlen: ::size_t)
                  -> ::c_int;
    pub fn ioctl(fd: ::c_int, request: ::c_ulong, ...) -> ::c_int;
    pub fn backtrace(buf: *mut *mut ::c_void,
                     sz: ::c_int) -> ::c_int;
    pub fn glob64(pattern: *const ::c_char,
                  flags: ::c_int,
                  errfunc: ::dox::Option<extern "C" fn(epath: *const ::c_char,
                                                       errno: ::c_int) -> ::c_int>,
                  pglob: *mut glob64_t) -> ::c_int;
    pub fn globfree64(pglob: *mut glob64_t);
    pub fn getnameinfo(sa: *const ::sockaddr,
                       salen: ::socklen_t,
                       host: *mut ::c_char,
                       hostlen: ::socklen_t,
                       serv: *mut ::c_char,
                       sevlen: ::socklen_t,
                       flags: ::c_int) -> ::c_int;
}

cfg_if! {
    if #[cfg(any(target_arch = "x86", target_arch = "arm"))] {
        mod b32;
        pub use self::b32::*;
    } else if #[cfg(any(target_arch = "x86_64", target_arch = "aarch64"))] {
        mod b64;
        pub use self::b64::*;
    } else {
        // ...
    }
}