serde/serde_test/build.rs

34 lines
1.1 KiB
Rust

use std::env;
use std::process::Command;
use std::str;
// The rustc-cfg strings below are *not* public API. Please let us know by
// opening a GitHub issue if your build environment requires some way to enable
// these cfgs other than by executing our build script.
fn main() {
let minor = match rustc_minor_version() {
Some(minor) => minor,
None => return,
};
// Check ability to use #[track_caller]:
// https://doc.rust-lang.org/reference/attributes/codegen.html#the-track_caller-attribute
//
// Perhaps sometime it will be possible to replace by built-in `version` attribute:
// https://github.com/rust-lang/rust/issues/64796
if minor >= 46 {
println!("cargo:rustc-cfg=has_track_caller");
}
}
fn rustc_minor_version() -> Option<u32> {
let rustc = env::var_os("RUSTC")?;
let output = Command::new(rustc).arg("--version").output().ok()?;
let version = str::from_utf8(&output.stdout).ok()?;
let mut pieces = version.split('.');
if pieces.next() != Some("rustc 1") {
return None;
}
pieces.next()?.parse().ok()
}