use std::env;
use std::fs::File;
use std::io::Write;
use std::path::Path;
fn main() {
println!("cargo:rerun-if-env-changed=HAZPTR_SCAN_THRESHOLD");
let out_dir = env::var("OUT_DIR").expect("no out directory");
let dest = Path::new(&out_dir).join("build_constants.rs");
let mut file = File::create(&dest).expect("could not create file");
let scan: u32 = option_env!("HAZPTR_SCAN_THRESHOLD")
.map_or(Ok(100), str::parse)
.expect("failed to parse env variable HAZPTR_SCAN_THRESHOLD");
if scan == 0 {
panic!("invalid HAZPTR_SCAN_THRESHOLD value (0)");
}
write!(&mut file, "const SCAN_THRESHOLD: u32 = {};", scan).expect("could not write to file");
}