use std::process::Command;
use std::{env, process};
fn main() {
let version = match rustc_version() {
Some(version) => version,
None => return,
};
if version.minor < 45 {
eprintln!("Turbolift requires rust 1.45 or above.");
process::exit(1);
}
println!("cargo:rerun-if-changed=build.rs");
println!("cargo:rustc-cfg=procmacro2_semver_exempt");
println!("cargo:rustc-cfg=span_locations");
println!("cargo:rustc-cfg=use_proc_macro");
println!("cargo:rustc-cfg=hygiene");
if version.nightly {
println!("cargo:rustc-cfg=super_unstable");
println!("cargo:rustc-cfg=proc_macro_span");
println!("cargo:rustc-cfg=wrap_proc_macro");
}
}
struct RustcVersion {
minor: u32,
nightly: bool,
}
fn rustc_version() -> Option<RustcVersion> {
let rustc = env::var_os("RUSTC")?;
let output = Command::new(rustc).arg("--version").output().ok()?;
let version = std::str::from_utf8(&output.stdout).ok()?;
let nightly = version.contains("nightly") || version.contains("dev");
let mut pieces = version.split('.');
if pieces.next() != Some("rustc 1") {
return None;
}
let minor = pieces.next()?.parse().ok()?;
Some(RustcVersion { minor, nightly })
}