serde/serde_test/build.rs
David Tolnay 012ea8eb84
Keep conditional compilation cfg naming consistent with serde crate
The serde crate's build.rs uses names like `core_duration` or
`integer128`, not `has_core_duration` / `has_integer128`.
2021-01-23 14:57:12 -08:00

31 lines
941 B
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,
};
// #[track_caller] stabilized in Rust 1.46:
// https://blog.rust-lang.org/2020/08/27/Rust-1.46.0.html#track_caller
if minor >= 46 {
println!("cargo:rustc-cfg=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()
}