use std::{env, fs::File, io::Write, path::Path}; fn main() { println!("cargo:rerun-if-changed=build.rs"); let out_dir = env::var_os("OUT_DIR").unwrap(); let dest_path = Path::new(&out_dir).join("version.rs"); let mut w = File::create(dest_path).unwrap(); let allowed_features = [ "c2s-incoming", "c2s-outgoing", "s2s-incoming", "s2s-outgoing", "tls", "quic", "websocket", "tls-ca-roots-native", "tls-ca-roots-bundled", ]; let optional_deps = [ "rustls", "tokio-rustls", "rustls-pemfile", "quinn", "tokio-tungstenite", "futures-util", "trust-dns-resolver", "reqwest", "lazy-static", "rustls-native-certs", "webpki-roots", "env-logger", "rand", ]; let mut features = Vec::new(); let mut optional = Vec::new(); for (mut key, value) in env::vars() { //writeln!(&mut w, "{key}: {value}", ).unwrap(); if value == "1" && key.starts_with("CARGO_FEATURE_") { let mut key = key.split_off(14).replace("_", "-"); key.make_ascii_lowercase(); if allowed_features.contains(&key.as_str()) { features.push(key); } else if optional_deps.contains(&key.as_str()) { optional.push(key); } } } features.sort_by(|a, b| { allowed_features .iter() .position(|&r| r == a) .unwrap() .partial_cmp(&allowed_features.iter().position(|&r| r == b).unwrap()) .unwrap() }); optional.sort_by(|a, b| { optional_deps .iter() .position(|&r| r == a) .unwrap() .partial_cmp(&optional_deps.iter().position(|&r| r == b).unwrap()) .unwrap() }); let features = features.join(","); let optional = optional.join(","); let name = env!("CARGO_PKG_NAME"); let version = env!("CARGO_PKG_VERSION"); let target = env::var("TARGET").unwrap(); writeln!( &mut w, "{{println!( \"{name} {version} ({target}) Features: {features} Optional crates: {optional}\");}}" ) .unwrap(); }