diff options
Diffstat (limited to 'build.rs')
-rw-r--r-- | build.rs | 82 |
1 files changed, 82 insertions, 0 deletions
diff --git a/build.rs b/build.rs new file mode 100644 index 0000000..a2c8d18 --- /dev/null +++ b/build.rs @@ -0,0 +1,82 @@ +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_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 = 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 }) + } +} |