1 //! Handle process life-time and message passing for proc-macro client
4 convert::{TryFrom, TryInto},
5 ffi::{OsStr, OsString},
6 io::{self, BufRead, BufReader, Write},
8 process::{Child, Command, Stdio},
12 use crossbeam_channel::{bounded, Receiver, Sender};
15 msg::{ErrorCode, Message, Request, Response, ResponseError},
16 rpc::{ListMacrosResult, ListMacrosTask, ProcMacroKind},
19 #[derive(Debug, Default)]
20 pub(crate) struct ProcMacroProcessSrv {
21 inner: Weak<Sender<Task>>,
25 pub(crate) struct ProcMacroProcessThread {
26 // XXX: drop order is significant
27 sender: Arc<Sender<Task>>,
28 handle: jod_thread::JoinHandle<()>,
31 impl ProcMacroProcessSrv {
33 process_path: PathBuf,
34 args: impl IntoIterator<Item = impl AsRef<OsStr>>,
35 ) -> io::Result<(ProcMacroProcessThread, ProcMacroProcessSrv)> {
36 let process = Process::run(process_path, args)?;
38 let (task_tx, task_rx) = bounded(0);
39 let handle = jod_thread::spawn(move || {
40 client_loop(task_rx, process);
43 let task_tx = Arc::new(task_tx);
44 let srv = ProcMacroProcessSrv { inner: Arc::downgrade(&task_tx) };
45 let thread = ProcMacroProcessThread { handle, sender: task_tx };
50 pub(crate) fn find_proc_macros(
53 ) -> Result<Vec<(String, ProcMacroKind)>, tt::ExpansionError> {
54 let task = ListMacrosTask { lib: dylib_path.to_path_buf() };
56 let result: ListMacrosResult = self.send_task(Request::ListMacro(task))?;
60 pub(crate) fn send_task<R>(&self, req: Request) -> Result<R, tt::ExpansionError>
62 R: TryFrom<Response, Error = &'static str>,
64 let (result_tx, result_rx) = bounded(0);
65 let sender = match self.inner.upgrade() {
66 None => return Err(tt::ExpansionError::Unknown("proc macro process is closed".into())),
70 .send(Task { req, result_tx })
71 .map_err(|_| tt::ExpansionError::Unknown("proc macro server crashed".into()))?;
75 .map_err(|_| tt::ExpansionError::Unknown("proc macro server crashed".into()))?;
78 Some(Response::Error(err)) => {
79 return Err(tt::ExpansionError::ExpansionError(err.message));
81 Some(res) => Ok(res.try_into().map_err(|err| {
82 tt::ExpansionError::Unknown(format!("Fail to get response, reason : {:#?} ", err))
84 None => Err(tt::ExpansionError::Unknown("Empty result".into())),
89 fn client_loop(task_rx: Receiver<Task>, mut process: Process) {
90 let (mut stdin, mut stdout) = process.stdio().expect("couldn't access child stdio");
92 for Task { req, result_tx } in task_rx {
93 match send_request(&mut stdin, &mut stdout, req) {
94 Ok(res) => result_tx.send(res).unwrap(),
97 "proc macro server crashed, server process state: {:?}",
98 process.child.try_wait()
100 let res = Response::Error(ResponseError {
101 code: ErrorCode::ServerErrorEnd,
102 message: "proc macro server crashed".into(),
104 result_tx.send(res.into()).unwrap();
114 result_tx: Sender<Option<Response>>,
121 impl Drop for Process {
123 let _ = self.child.kill();
130 args: impl IntoIterator<Item = impl AsRef<OsStr>>,
131 ) -> io::Result<Process> {
132 let args: Vec<OsString> = args.into_iter().map(|s| s.as_ref().into()).collect();
133 let child = mk_child(&path, &args)?;
134 Ok(Process { child })
137 fn stdio(&mut self) -> Option<(impl Write, impl BufRead)> {
138 let stdin = self.child.stdin.take()?;
139 let stdout = self.child.stdout.take()?;
140 let read = BufReader::new(stdout);
146 fn mk_child(path: &Path, args: impl IntoIterator<Item = impl AsRef<OsStr>>) -> io::Result<Child> {
149 .stdin(Stdio::piped())
150 .stdout(Stdio::piped())
151 .stderr(Stdio::inherit())
156 mut writer: &mut impl Write,
157 mut reader: &mut impl BufRead,
159 ) -> io::Result<Option<Response>> {
160 req.write(&mut writer)?;
161 Ok(Response::read(&mut reader)?)