drone_controller/build.rs

use std::path::{Path, PathBuf};
use std::{env, time};

fn main() {
    let cargo_dir = PathBuf::from(env::var("CARGO_MANIFEST_DIR").unwrap());
    let target_dir = PathBuf::from(env::var("CARGO_BUILD_TARGET_DIR").unwrap());

    run_cbindgen(&cargo_dir, &target_dir);
}

fn run_cbindgen(cargo_dir: &Path, target_dir: &Path) {
    let out = target_dir.join("drone_controller.h");

    cbindgen::Builder::new()
        .with_crate(cargo_dir)
        .with_language(cbindgen::Language::Cxx)
        .generate()
        .expect("Unable to generate bindings")
        .write_to_file(&out);

    println!("cargo:rerun-if-changed={}", out.display());
    println!(
        "cargo:rerun-if-changed={}",
        time::SystemTime::now()
            .duration_since(time::UNIX_EPOCH)
            .unwrap()
            .as_secs()
    );
}