rust ffi

ffunc.c

#include <stdio.h>
#include <netinet/in.h>
#include <sys/socket.h>

void ffunc(struct sockaddr_in s, struct sockaddr_in (*cb)(struct sockaddr_in)) {
    printf("rust -> c\n");
    printf("  family: %u\n", s.sin_family);
    printf("  port: %u\n", s.sin_port);
    printf("  addr: %u\n", s.sin_addr.s_addr);
    s.sin_family = AF_UNIX;
    s.sin_port = 100;
    s.sin_addr.s_addr = 200;
    struct sockaddr_in t = cb(s);
    printf("rust -> c\n");
    printf("  family: %u\n", t.sin_family);
    printf("  port: %u\n", t.sin_port);
    printf("  addr: %u\n", t.sin_addr.s_addr);
}

struct sockaddr_in mk_S() {
    struct sockaddr_in s;
    s.sin_family = AF_INET;
    s.sin_port = 10;
    s.sin_addr.s_addr = 20;
    return s;
}

rs.sh

gcc -c -fPIC -o ffunc.o ffunc.c
ar -r libffunc.a ffunc.o
~/src/rust-git/build/x86_64-unknown-linux-gnu/stage2/bin/rustc test.rs

test.rs

type S = {
    mut sin_family: u16,
    mut sin_port: u16,
    mut sin_addr: u32,
    mut sin_zero: (u8, u8, u8, u8, u8, u8, u8, u8)
};

#[link_args="-L."]
native mod ffunc {
    fn mk_S() -> S;
    fn ffunc(++s: S, f: *u8);
}

crust fn cb(++s: S) -> S unsafe {
    let x = s;
    io::println("c -> rust");
    io::println(#fmt("  family: %u", x.sin_family as uint));
    io::println(#fmt("  port: %u", x.sin_port as uint));
    io::println(#fmt("  addr: %u", x.sin_addr as uint));
    x.sin_family = 7 as u16;
    x.sin_port = 1000 as u16;
    x.sin_addr = 2000 as u32;
    ret x;
}

fn main(args: [str]) {
    let s = ffunc::mk_S();
    io::println("c -> rust");
    io::println(#fmt("  family: %u", s.sin_family as uint));
    io::println(#fmt("  port: %u", s.sin_port as uint));
    io::println(#fmt("  addr: %u", s.sin_addr as uint));
    ffunc::ffunc(s, cb);
}