Sha256: 9b2b610956f9a012024360335f044a8ef5d9aa5fbc20d71ca24f8127ec721c3b
Contents?: true
Size: 1.21 KB
Versions: 25
Compression:
Stored size: 1.21 KB
Contents
use std::env::var;
use std::io::Write;
fn main() {
use_feature_or_nothing("windows_by_handle"); // https://github.com/rust-lang/rust/issues/63010
// Don't rerun this on changes other than build.rs, as we only depend on
// the rustc version.
println!("cargo:rerun-if-changed=build.rs");
}
fn use_feature_or_nothing(feature: &str) {
if has_feature(feature) {
use_feature(feature);
}
}
fn use_feature(feature: &str) {
println!("cargo:rustc-cfg={}", feature);
}
/// Test whether the rustc at `var("RUSTC")` supports the given feature.
fn has_feature(feature: &str) -> bool {
let out_dir = var("OUT_DIR").unwrap();
let rustc = var("RUSTC").unwrap();
let mut child = std::process::Command::new(rustc)
.arg("--crate-type=rlib") // Don't require `main`.
.arg("--emit=metadata") // Do as little as possible but still parse.
.arg("--out-dir")
.arg(out_dir) // Put the output somewhere inconsequential.
.arg("-") // Read from stdin.
.stdin(std::process::Stdio::piped()) // Stdin is a pipe.
.spawn()
.unwrap();
writeln!(child.stdin.take().unwrap(), "#![feature({})]", feature).unwrap();
child.wait().unwrap().success()
}
Version data entries
25 entries across 25 versions & 1 rubygems