| use std::env; |
| use std::ffi::OsString; |
| use std::io::{self, Write}; |
| use std::process::Command; |
| |
| fn main() { |
| let version = match Version::read() { |
| Ok(version) => version, |
| Err(err) => { |
| writeln!( |
| &mut io::stderr(), |
| "failed to parse `rustc --version`: {}", |
| err |
| ).unwrap(); |
| return; |
| } |
| }; |
| enable_i128(version); |
| } |
| |
| fn enable_i128(version: Version) { |
| if version < (Version { major: 1, minor: 26, patch: 0 }) { |
| return; |
| } |
| |
| println!("cargo:rustc-cfg=byteorder_i128"); |
| } |
| |
| #[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 = try!(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 = try!(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 = try!(num.parse::<u32>().map_err(|e| e.to_string())); |
| |
| Ok(Version { major: major, minor: minor, patch: patch }) |
| } |
| } |