51 lines
1.4 KiB
Rust
51 lines
1.4 KiB
Rust
extern crate rustc_version;
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use std::env;
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use std::io::Write;
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use std::process::{Command, Stdio};
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fn main() {
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if probe("fn main() { 0i128; }") {
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println!("cargo:rustc-cfg=has_i128");
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} else if env::var_os("CARGO_FEATURE_I128").is_some() {
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panic!("i128 support was not detected!");
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}
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match rustc_version::version_meta() {
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Ok(ref meta) if meta.semver.major >= 1 && meta.semver.minor >= 32 => {
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println!("cargo:rustc-cfg=int_to_from_bytes");
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}
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Ok(ref meta)
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if env::var_os("CARGO_FEATURE_INT_TO_FROM_BYTES").is_some()
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&& meta.channel == rustc_version::Channel::Stable =>
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{
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panic!("`int_to_from_bytes` support was not stabilizations!");
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}
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_ => {}
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}
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}
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/// Test if a code snippet can be compiled
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fn probe(code: &str) -> bool {
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let rustc = env::var_os("RUSTC").unwrap_or_else(|| "rustc".into());
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let out_dir = env::var_os("OUT_DIR").expect("environment variable OUT_DIR");
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let mut child = Command::new(rustc)
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.arg("--out-dir")
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.arg(out_dir)
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.arg("--emit=obj")
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.arg("-")
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.stdin(Stdio::piped())
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.spawn()
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.expect("rustc probe");
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child
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.stdin
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.as_mut()
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.expect("rustc stdin")
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.write_all(code.as_bytes())
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.expect("write rustc stdin");
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child.wait().expect("rustc probe").success()
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}
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