cxx_build/
target.rs

1use std::env;
2use std::ffi::OsStr;
3use std::path::{Path, PathBuf};
4
5pub(crate) enum TargetDir {
6    Path(PathBuf),
7    Unknown,
8}
9
10pub(crate) fn find_target_dir(out_dir: &Path) -> TargetDir {
11    if let Some(target_dir) = env::var_os("CARGO_TARGET_DIR") {
12        let target_dir = PathBuf::from(target_dir);
13        if target_dir.is_absolute() {
14            return TargetDir::Path(target_dir);
15        } else {
16            return TargetDir::Unknown;
17        };
18    }
19
20    // fs::canonicalize on Windows produces UNC paths which cl.exe is unable to
21    // handle in includes.
22    // https://github.com/rust-lang/rust/issues/42869
23    // https://github.com/alexcrichton/cc-rs/issues/169
24    let mut also_try_canonical = cfg!(not(windows));
25
26    let mut dir = out_dir.to_owned();
27    loop {
28        if dir.join(".rustc_info.json").exists()
29            || dir.join("CACHEDIR.TAG").exists()
30            || dir.file_name() == Some(OsStr::new("target"))
31                && dir
32                    .parent()
33                    .is_some_and(|parent| parent.join("Cargo.toml").exists())
34        {
35            return TargetDir::Path(dir);
36        }
37        if dir.pop() {
38            continue;
39        }
40        if also_try_canonical {
41            if let Ok(canonical_dir) = out_dir.canonicalize() {
42                dir = canonical_dir;
43                also_try_canonical = false;
44                continue;
45            }
46        }
47        return TargetDir::Unknown;
48    }
49}
cxx_build/target.rs

cxx_build/
target.rs
