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|
use std::env;
use std::process::Command;
use std::str::{self, FromStr};
// 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() {
let compiler = match rustc_version() {
Some(compiler) => compiler,
None => return,
};
if compiler.minor < 36 {
println!("cargo:rustc-cfg=syn_omit_await_from_token_macro");
}
if !compiler.nightly {
println!("cargo:rustc-cfg=syn_disable_nightly_tests");
}
}
struct Compiler {
minor: u32,
nightly: bool,
}
fn rustc_version() -> Option<Compiler> {
let rustc = match env::var_os("RUSTC") {
Some(rustc) => rustc,
None => return None,
};
let output = match Command::new(rustc).arg("--version").output() {
Ok(output) => output,
Err(_) => return None,
};
let version = match str::from_utf8(&output.stdout) {
Ok(version) => version,
Err(_) => return None,
};
let mut pieces = version.split('.');
if pieces.next() != Some("rustc 1") {
return None;
}
let next = match pieces.next() {
Some(next) => next,
None => return None,
};
let minor = match u32::from_str(next) {
Ok(minor) => minor,
Err(_) => return None,
};
Some(Compiler {
minor,
nightly: version.contains("nightly"),
})
}
|
