| use std::{ |
| env, fs, |
| path::{Path, PathBuf}, |
| process::Command, |
| 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() { |
| println!("cargo:rustc-cfg=const_fn_has_build_script"); |
| |
| let rustc = env::var_os("RUSTC").map_or_else(|| "rustc".into(), PathBuf::from); |
| let version = match Version::from_rustc(&rustc) { |
| Ok(version) => format!("{:#?}\n", version), |
| Err(e) => panic!("{}", e), |
| }; |
| |
| let out_dir = env::var_os("OUT_DIR").map(PathBuf::from).expect("OUT_DIR not set"); |
| let out_file = out_dir.join("version.rs"); |
| fs::write(out_file, version).expect("failed to write version.rs"); |
| } |
| |
| #[derive(Debug)] |
| struct Version { |
| minor: u16, |
| patch: u16, |
| nightly: bool, |
| } |
| |
| // Based on https://github.com/cuviper/autocfg/blob/1.0.1/src/version.rs |
| // |
| // Using our own parser instead of the existing crates to generate better errors. |
| impl Version { |
| // from the verbose version output |
| fn from_vv(vv: &str) -> Option<Self> { |
| // Find the release line in the verbose version output. |
| let release = vv |
| .lines() |
| .find(|line| line.starts_with("release: ")) |
| .map(|line| &line["release: ".len()..])?; |
| |
| // Split the version and channel info. |
| let mut version_channel = release.split('-'); |
| let version = version_channel.next().unwrap(); |
| let channel = version_channel.next(); |
| |
| // Split the version into semver components. |
| let mut digits = version.splitn(3, '.'); |
| let major = digits.next()?; |
| if major != "1" { |
| return None; |
| } |
| let minor = digits.next()?.parse().ok()?; |
| let patch = digits.next().unwrap_or("0").parse().ok()?; |
| |
| let nightly = channel.map_or(false, |c| c == "dev" || c == "nightly"); |
| Some(Version { minor, patch, nightly }) |
| } |
| |
| fn from_rustc(rustc: &Path) -> Result<Self, String> { |
| let output = |
| Command::new(rustc).args(&["--version", "--verbose"]).output().map_err(|e| { |
| format!("failed to run `{} --version --verbose`: {}", rustc.display(), e) |
| })?; |
| if !output.status.success() { |
| return Err("could not execute rustc".to_string()); |
| } |
| let output = str::from_utf8(&output.stdout).map_err(|e| { |
| format!("failed to parse output of `{} --version --verbose`: {}", rustc.display(), e) |
| })?; |
| |
| Self::from_vv(output).ok_or_else(|| { |
| format!("unexpected output from `{} --version --verbose`: {}", rustc.display(), output) |
| }) |
| } |
| } |