codex/codex-rs/linux-sandbox/src/bazel_bwrap.rs

use std::ffi::OsString;
#[cfg(debug_assertions)]
use std::fs::File;
#[cfg(debug_assertions)]
use std::io::BufRead;
use std::path::Path;
use std::path::PathBuf;

#[cfg(debug_assertions)]
const BAZEL_BWRAP_ENV_VAR: &str = "CARGO_BIN_EXE_bwrap";

#[cfg(debug_assertions)]
pub(crate) fn candidate(cwd: &Path, env: impl Fn(&str) -> Option<OsString>) -> Option<PathBuf> {
    if option_env!("BAZEL_PACKAGE").is_none() || !runfiles_env_present(&env) {
        return None;
    }

    let raw = PathBuf::from(env(BAZEL_BWRAP_ENV_VAR)?);
    if raw.is_absolute() {
        return Some(raw);
    }
    resolve_runfile(raw.to_str()?, cwd, &env)
}

#[cfg(not(debug_assertions))]
pub(crate) fn candidate(_cwd: &Path, _env: impl Fn(&str) -> Option<OsString>) -> Option<PathBuf> {
    None
}

#[cfg(debug_assertions)]
fn runfiles_env_present(env: &impl Fn(&str) -> Option<OsString>) -> bool {
    env("RUNFILES_DIR").is_some()
        || env("TEST_SRCDIR").is_some()
        || env("RUNFILES_MANIFEST_FILE").is_some()
}

#[cfg(debug_assertions)]
fn resolve_runfile(
    logical_path: &str,
    cwd: &Path,
    env: &impl Fn(&str) -> Option<OsString>,
) -> Option<PathBuf> {
    let mut logical_paths = vec![logical_path.to_string()];
    if let Some(workspace) = env("TEST_WORKSPACE").and_then(|value| value.into_string().ok())
        && !workspace.is_empty()
    {
        logical_paths.push(format!("{workspace}/{logical_path}"));
    }

    for root_env in ["RUNFILES_DIR", "TEST_SRCDIR"] {
        let Some(root) = env(root_env) else {
            continue;
        };
        let root = cwd.join(root);
        for logical_path in &logical_paths {
            let candidate = root.join(logical_path);
            if candidate.exists() {
                return Some(candidate);
            }
        }
    }

    let manifest = cwd.join(env("RUNFILES_MANIFEST_FILE")?);
    let file = File::open(manifest).ok()?;
    for line in std::io::BufReader::new(file).lines().map_while(Result::ok) {
        let Some((key, value)) = line.split_once(' ') else {
            continue;
        };
        if logical_paths.iter().any(|logical_path| logical_path == key) {
            return Some(cwd.join(value));
        }
    }
    None
}