rust/build.rs
2018-05-07 22:11:26 +02:00

100 lines
3.7 KiB
Rust

//! This build script ensures that clippy is not compiled with an
//! incompatible version of rust. It will panic with a descriptive
//! error message instead.
//!
//! We specifially want to ensure that clippy is only built with a
//! rustc version that is newer or equal to the one specified in the
//! `min_version.txt` file.
//!
//! `min_version.txt` is in the repo but also in the `.gitignore` to
//! make sure that it is not updated manually by accident. Only CI
//! should update that file.
//!
//! This build script was originally taken from the Rocket web framework:
//! https://github.com/SergioBenitez/Rocket
extern crate rustc_version;
extern crate ansi_term;
use std::env;
use rustc_version::{version_meta, version_meta_for, Channel, Version, VersionMeta};
use ansi_term::Colour::Red;
fn main() {
let string = include_str!("min_version.txt");
let min_version_meta = version_meta_for(string)
.expect("Could not parse version string in min_version.txt");
let current_version_meta = version_meta()
.expect("Could not retrieve current rustc version information from ENV");
let min_version = min_version_meta.clone().semver;
let min_date_str = min_version_meta.clone().commit_date
.expect("min_version.txt does not contain a rustc commit date");
let current_version = current_version_meta.clone().semver;
let current_date_str = current_version_meta.clone().commit_date
.expect("current rustc version information does not contain a rustc commit date");
let print_version_err = |version: &Version, date: &str| {
eprintln!("> {} {}. {} {}.\n",
"Installed rustc version is:",
format!("{} ({})", version, date),
"Minimum required rustc version:",
format!("{} ({})", min_version, min_date_str));
};
if !correct_channel(&current_version_meta) {
eprintln!("\n{} {}",
Red.bold().paint("error:"),
"clippy requires a nightly version of Rust.");
print_version_err(&current_version, &*current_date_str);
eprintln!("{}{}{}",
"See the README (",
"https://github.com/rust-lang-nursery/rust-clippy#usage",
") for more information.");
panic!("Aborting compilation due to incompatible compiler.")
}
let current_date = str_to_ymd(&current_date_str).unwrap();
let min_date = str_to_ymd(&min_date_str).unwrap();
if current_date < min_date {
eprintln!("\n{} {}",
Red.bold().paint("error:"),
"clippy does not support this version of rustc nightly.");
eprintln!("> {}{}{}",
"Use `",
"rustup update",
"` or your preferred method to update Rust.");
print_version_err(&current_version, &*current_date_str);
panic!("Aborting compilation due to incompatible compiler.")
}
// Forward the profile to the main compilation
println!("cargo:rustc-env=PROFILE={}", env::var("PROFILE").unwrap());
// Don't rebuild even if nothing changed
println!("cargo:rerun-if-changed=build.rs");
}
fn correct_channel(version_meta: &VersionMeta) -> bool {
match version_meta.channel {
Channel::Stable | Channel::Beta => {
false
},
Channel::Nightly | Channel::Dev => {
true
}
}
}
/// Convert a string of %Y-%m-%d to a single u32 maintaining ordering.
fn str_to_ymd(ymd: &str) -> Option<u32> {
let ymd: Vec<u32> = ymd.split("-").filter_map(|s| s.parse::<u32>().ok()).collect();
if ymd.len() != 3 {
return None
}
let (y, m, d) = (ymd[0], ymd[1], ymd[2]);
Some((y << 9) | (m << 5) | d)
}