51 lines
1.3 KiB
Rust
51 lines
1.3 KiB
Rust
use std::env;
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use std::process::Command;
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use std::str::{self, FromStr};
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// The rustc-cfg strings below are *not* public API. Please let us know by
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// opening a GitHub issue if your build environment requires some way to enable
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// these cfgs other than by executing our build script.
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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(minor) => minor,
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None => return,
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};
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// #[track_caller] stabilized in Rust 1.46:
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// https://blog.rust-lang.org/2020/08/27/Rust-1.46.0.html#track_caller
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if minor < 46 {
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println!("cargo:rustc-cfg=no_track_caller");
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}
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}
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fn rustc_minor_version() -> Option<u32> {
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let rustc = match env::var_os("RUSTC") {
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Some(rustc) => rustc,
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None => return None,
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};
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let output = match Command::new(rustc).arg("--version").output() {
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Ok(output) => output,
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Err(_) => return None,
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};
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let version = match str::from_utf8(&output.stdout) {
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Ok(version) => version,
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Err(_) => return None,
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};
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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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let next = match pieces.next() {
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Some(next) => next,
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None => return None,
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};
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u32::from_str(next).ok()
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}
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