1 files changed, 96 insertions, 0 deletions

diff --git a/xtask/src/not_bash.rs b/xtask/src/not_bash.rs
new file mode 100644
index 000000000..a2e47c7af
--- /dev/null
+++ b/xtask/src/not_bash.rs
@@ -0,0 +1,96 @@
+//! A bad shell -- small cross platform module for writing glue code
+use std::{
+    cell::RefCell,
+    env,
+    path::PathBuf,
+    process::{Command, Stdio},
+};
+
+use anyhow::{bail, Context, Result};
+
+macro_rules! _run {
+    ($($expr:expr),*) => {
+        run!($($expr),*; echo = true)
+    };
+    ($($expr:expr),* ; echo = $echo:expr) => {
+        $crate::not_bash::run_process(format!($($expr),*), $echo)
+    };
+}
+pub(crate) use _run as run;
+
+pub struct Pushd {
+    _p: (),
+}
+
+pub fn pushd(path: impl Into<PathBuf>) -> Pushd {
+    Env::with(|env| env.pushd(path.into()));
+    Pushd { _p: () }
+}
+
+impl Drop for Pushd {
+    fn drop(&mut self) {
+        Env::with(|env| env.popd())
+    }
+}
+
+#[doc(hidden)]
+pub fn run_process(cmd: String, echo: bool) -> Result<String> {
+    run_process_inner(&cmd, echo).with_context(|| format!("process `{}` failed", cmd))
+}
+
+fn run_process_inner(cmd: &str, echo: bool) -> Result<String> {
+    let cwd = Env::with(|env| env.cwd());
+    let mut args = shelx(cmd);
+    let binary = args.remove(0);
+
+    if echo {
+        println!("> {}", cmd)
+    }
+
+    let output = Command::new(binary)
+        .args(args)
+        .current_dir(cwd)
+        .stdin(Stdio::null())
+        .stderr(Stdio::inherit())
+        .output()?;
+    let stdout = String::from_utf8(output.stdout)?;
+
+    if echo {
+        print!("{}", stdout)
+    }
+
+    if !output.status.success() {
+        bail!("returned non-zero status: {}", output.status)
+    }
+
+    Ok(stdout)
+}
+
+// FIXME: some real shell lexing here
+fn shelx(cmd: &str) -> Vec<String> {
+    cmd.split_whitespace().map(|it| it.to_string()).collect()
+}
+
+#[derive(Default)]
+struct Env {
+    pushd_stack: Vec<PathBuf>,
+}
+
+impl Env {
+    fn with<F: FnOnce(&mut Env) -> T, T>(f: F) -> T {
+        thread_local! {
+            static ENV: RefCell<Env> = Default::default();
+        }
+        ENV.with(|it| f(&mut *it.borrow_mut()))
+    }
+
+    fn pushd(&mut self, dir: PathBuf) {
+        self.pushd_stack.push(dir)
+    }
+    fn popd(&mut self) {
+        self.pushd_stack.pop().unwrap();
+    }
+    fn cwd(&self) -> PathBuf {
+        self.pushd_stack.last().cloned().unwrap_or_else(|| env::current_dir().unwrap())
+    }
+}