rust/tests/ui/foreign/foreign-fn-linkname.rs
2023-09-27 18:05:14 +10:00

32 lines
658 B
Rust

// run-pass
// ignore-wasm32-bare no libc to test ffi with
// ignore-sgx no libc
// Ensure no false positive on "unused extern crate" lint
#![deny(unused_extern_crates)]
#![feature(rustc_private)]
extern crate libc;
use std::ffi::CString;
mod mlibc {
use libc::{c_char, size_t};
extern "C" {
#[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);
}