blob: f245ada5d37f2320abb1b35ab1aee6edea4495f8 [file] [log] [blame]
use std::env;
use std::ffi::OsString;
use std::process::Command;
fn main() {
let version = match Version::read() {
Ok(version) => version,
Err(err) => {
eprintln!("failed to parse `rustc --version`: {}", err);
return;
}
};
enable_simd_optimizations(version);
}
fn enable_simd_optimizations(version: Version) {
if env::var_os("CARGO_CFG_MEMCHR_DISABLE_AUTO_SIMD").is_some() {
return;
}
if version < (Version { major: 1, minor: 27, patch: 0 }) {
return;
}
println!("cargo:rustc-cfg=memchr_runtime_simd");
println!("cargo:rustc-cfg=memchr_runtime_sse2");
println!("cargo:rustc-cfg=memchr_runtime_sse42");
println!("cargo:rustc-cfg=memchr_runtime_avx");
}
#[derive(Clone, Copy, Debug, Eq, PartialEq, PartialOrd, Ord)]
struct Version {
major: u32,
minor: u32,
patch: u32,
}
impl Version {
fn read() -> Result<Version, String> {
let rustc = env::var_os("RUSTC").unwrap_or(OsString::from("rustc"));
let output = Command::new(&rustc)
.arg("--version")
.output()
.unwrap()
.stdout;
Version::parse(&String::from_utf8(output).unwrap())
}
fn parse(mut s: &str) -> Result<Version, String> {
if !s.starts_with("rustc ") {
return Err(format!("unrecognized version string: {}", s));
}
s = &s["rustc ".len()..];
let parts: Vec<&str> = s.split(".").collect();
if parts.len() < 3 {
return Err(format!("not enough version parts: {:?}", parts));
}
let mut num = String::new();
for c in parts[0].chars() {
if !c.is_digit(10) {
break;
}
num.push(c);
}
let major = num.parse::<u32>().map_err(|e| e.to_string())?;
num.clear();
for c in parts[1].chars() {
if !c.is_digit(10) {
break;
}
num.push(c);
}
let minor = num.parse::<u32>().map_err(|e| e.to_string())?;
num.clear();
for c in parts[2].chars() {
if !c.is_digit(10) {
break;
}
num.push(c);
}
let patch = num.parse::<u32>().map_err(|e| e.to_string())?;
Ok(Version { major, minor, patch })
}
}