1 use std::env;
2 use std::path::{Path, PathBuf};
3 use std::process::Command;
4 
main()5 fn main() {
6     let manifest_dir_opt = env::var_os("CARGO_MANIFEST_DIR").map(PathBuf::from);
7     let manifest_dir = manifest_dir_opt.as_deref().unwrap_or(Path::new(""));
8 
9     cc::Build::new()
10         .file(manifest_dir.join("src/cxx.cc"))
11         .cpp(true)
12         .cpp_link_stdlib(None) // linked via link-cplusplus crate
13         .std(cxxbridge_flags::STD)
14         .warnings_into_errors(cfg!(deny_warnings))
15         .compile("cxxbridge1");
16 
17     println!("cargo:rerun-if-changed=src/cxx.cc");
18     println!("cargo:rerun-if-changed=include/cxx.h");
19     println!("cargo:rustc-cfg=built_with_cargo");
20 
21     if let Some(manifest_dir) = &manifest_dir_opt {
22         let cxx_h = manifest_dir.join("include").join("cxx.h");
23         println!("cargo:HEADER={}", cxx_h.to_string_lossy());
24     }
25 
26     if let Some(rustc) = rustc_version() {
27         if rustc.minor < 60 {
28             println!("cargo:warning=The cxx crate requires a rustc version 1.60.0 or newer.");
29             println!(
30                 "cargo:warning=You appear to be building with: {}",
31                 rustc.version,
32             );
33         }
34     }
35 }
36 
37 struct RustVersion {
38     version: String,
39     minor: u32,
40 }
41 
rustc_version() -> Option<RustVersion>42 fn rustc_version() -> Option<RustVersion> {
43     let rustc = env::var_os("RUSTC")?;
44     let output = Command::new(rustc).arg("--version").output().ok()?;
45     let version = String::from_utf8(output.stdout).ok()?;
46     let mut pieces = version.split('.');
47     if pieces.next() != Some("rustc 1") {
48         return None;
49     }
50     let minor = pieces.next()?.parse().ok()?;
51     Some(RustVersion { version, minor })
52 }
53