36 lines
849 B
Rust
36 lines
849 B
Rust
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use std::env;
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use std::process::Command;
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use std::str;
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fn main() {
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println!("cargo:rerun-if-changed=build.rs");
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let minor = match rustc_minor_version() {
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Some(n) => n,
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None => return,
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};
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if minor >= 27 {
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println!("cargo:rustc-cfg=crc32fast_stdarchx86");
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}
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}
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fn rustc_minor_version() -> Option<u32> {
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macro_rules! otry {
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($e:expr) => {
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match $e {
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Some(e) => e,
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None => return None,
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}
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};
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}
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let rustc = otry!(env::var_os("RUSTC"));
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let output = otry!(Command::new(rustc).arg("--version").output().ok());
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let version = otry!(str::from_utf8(&output.stdout).ok());
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let mut pieces = version.split('.');
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if pieces.next() != Some("rustc 1") {
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return None;
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}
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otry!(pieces.next()).parse().ok()
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}
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