rust/tests/run-pass/foreign-fn-linkname.rs

40 lines
1.1 KiB
Rust

// Copyright 2012 The Rust Project Developers. See the COPYRIGHT
// file at the top-level directory of this distribution and at
// http://rust-lang.org/COPYRIGHT.
//
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
// option. This file may not be copied, modified, or distributed
// except according to those terms.
//ignore-windows: Uses POSIX APIs
#![feature(libc)]
#![allow(unused_extern_crates)] // rustc bug https://github.com/rust-lang/rust/issues/56098
extern crate libc;
use std::ffi::CString;
mod mlibc {
use libc::{c_char, size_t};
extern {
#[link_name = "strlen"]
pub fn my_strlen(str: *const c_char) -> size_t;
}
}
fn strlen(str: String) -> usize {
// C string is terminated with a zero
let s = CString::new(str).unwrap();
unsafe {
mlibc::my_strlen(s.as_ptr()) as usize
}
}
pub fn main() {
let len = strlen("Rust".to_string());
assert_eq!(len, 4);
}