rust/crates/proc-macro-api/src/process.rs
2022-05-01 10:48:58 +00:00

107 lines
3.0 KiB
Rust

//! Handle process life-time and message passing for proc-macro client
use std::{
ffi::{OsStr, OsString},
io::{self, BufRead, BufReader, Write},
process::{Child, ChildStdin, ChildStdout, Command, Stdio},
};
use paths::{AbsPath, AbsPathBuf};
use stdx::JodChild;
use crate::{
msg::{Message, Request, Response},
ProcMacroKind, ServerError,
};
#[derive(Debug)]
pub(crate) struct ProcMacroProcessSrv {
_process: Process,
stdin: ChildStdin,
stdout: BufReader<ChildStdout>,
}
impl ProcMacroProcessSrv {
pub(crate) fn run(
process_path: AbsPathBuf,
args: impl IntoIterator<Item = impl AsRef<OsStr>>,
) -> io::Result<ProcMacroProcessSrv> {
let mut process = Process::run(process_path, args)?;
let (stdin, stdout) = process.stdio().expect("couldn't access child stdio");
let srv = ProcMacroProcessSrv { _process: process, stdin, stdout };
Ok(srv)
}
pub(crate) fn find_proc_macros(
&mut self,
dylib_path: &AbsPath,
) -> Result<Result<Vec<(String, ProcMacroKind)>, String>, ServerError> {
let request = Request::ListMacros { dylib_path: dylib_path.to_path_buf().into() };
let response = self.send_task(request)?;
match response {
Response::ListMacros(it) => Ok(it),
Response::ExpandMacro { .. } => {
Err(ServerError { message: "unexpected response".to_string(), io: None })
}
}
}
pub(crate) fn send_task(&mut self, req: Request) -> Result<Response, ServerError> {
let mut buf = String::new();
send_request(&mut self.stdin, &mut self.stdout, req, &mut buf)
}
}
#[derive(Debug)]
struct Process {
child: JodChild,
}
impl Process {
fn run(
path: AbsPathBuf,
args: impl IntoIterator<Item = impl AsRef<OsStr>>,
) -> io::Result<Process> {
let args: Vec<OsString> = args.into_iter().map(|s| s.as_ref().into()).collect();
let child = JodChild(mk_child(&path, &args)?);
Ok(Process { child })
}
fn stdio(&mut self) -> Option<(ChildStdin, BufReader<ChildStdout>)> {
let stdin = self.child.stdin.take()?;
let stdout = self.child.stdout.take()?;
let read = BufReader::new(stdout);
Some((stdin, read))
}
}
fn mk_child(
path: &AbsPath,
args: impl IntoIterator<Item = impl AsRef<OsStr>>,
) -> io::Result<Child> {
Command::new(path.as_os_str())
.args(args)
.stdin(Stdio::piped())
.stdout(Stdio::piped())
.stderr(Stdio::inherit())
.spawn()
}
fn send_request(
mut writer: &mut impl Write,
mut reader: &mut impl BufRead,
req: Request,
buf: &mut String,
) -> Result<Response, ServerError> {
req.write(&mut writer)
.map_err(|err| ServerError { message: "failed to write request".into(), io: Some(err) })?;
let res = Response::read(&mut reader, buf)
.map_err(|err| ServerError { message: "failed to read response".into(), io: Some(err) })?;
res.ok_or_else(|| ServerError { message: "server exited".into(), io: None })
}