From ce73c43848aa394530693967b8a6e9343f7b99b8 Mon Sep 17 00:00:00 2001 From: veetaha Date: Sat, 21 Mar 2020 23:30:33 +0200 Subject: ra_cargo_watch: return Result<> from run_cargo(), and don't read stderr for now As stated by matklad, reading the stderr should be done alngside with stdout via select() (or I guess poll()), there is no such implementation in stdlib, since it is quite low level and platform-dependent and it also requires quite a bit of unrelated code we don't use it for now. As referenced by bjorn3, there is an implementation of the needed read2() function in rustc compiletest. The better solution will be to extract this function to a separate crate in future: https://github.com/rust-analyzer/rust-analyzer/pull/3632#discussion_r395605298 --- crates/ra_cargo_watch/src/lib.rs | 78 ++++++++++++++++++++++------------------ 1 file changed, 43 insertions(+), 35 deletions(-) (limited to 'crates/ra_cargo_watch') diff --git a/crates/ra_cargo_watch/src/lib.rs b/crates/ra_cargo_watch/src/lib.rs index deb763af9..35b0cb608 100644 --- a/crates/ra_cargo_watch/src/lib.rs +++ b/crates/ra_cargo_watch/src/lib.rs @@ -8,9 +8,10 @@ use lsp_types::{ WorkDoneProgressEnd, WorkDoneProgressReport, }; use std::{ + error, fmt, io::{BufRead, BufReader}, path::{Path, PathBuf}, - process::{Child, Command, Stdio}, + process::{Command, Stdio}, thread::JoinHandle, time::Instant, }; @@ -70,10 +71,10 @@ impl std::ops::Drop for CheckWatcher { fn drop(&mut self) { if let Some(handle) = self.handle.take() { // Take the sender out of the option - let recv = self.cmd_send.take(); + let cmd_send = self.cmd_send.take(); // Dropping the sender finishes the thread loop - drop(recv); + drop(cmd_send); // Join the thread, it should finish shortly. We don't really care // whether it panicked, so it is safe to ignore the result @@ -246,11 +247,21 @@ enum CheckEvent { End, } +#[derive(Debug)] +pub struct CargoError(String); + +impl fmt::Display for CargoError { + fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { + write!(f, "Cargo failed: {}", self.0) + } +} +impl error::Error for CargoError {} + pub fn run_cargo( args: &[String], current_dir: Option<&Path>, on_message: &mut dyn FnMut(cargo_metadata::Message) -> bool, -) -> Child { +) -> Result<(), CargoError> { let mut command = Command::new("cargo"); if let Some(current_dir) = current_dir { command.current_dir(current_dir); @@ -259,7 +270,7 @@ pub fn run_cargo( let mut child = command .args(args) .stdout(Stdio::piped()) - .stderr(Stdio::piped()) + .stderr(Stdio::null()) .stdin(Stdio::null()) .spawn() .expect("couldn't launch cargo"); @@ -273,6 +284,8 @@ pub fn run_cargo( // simply skip a line if it doesn't parse, which just ignores any // erroneus output. let stdout = BufReader::new(child.stdout.take().unwrap()); + let mut read_at_least_one_message = false; + for line in stdout.lines() { let line = match line { Ok(line) => line, @@ -291,12 +304,27 @@ pub fn run_cargo( } }; + read_at_least_one_message = true; + if !on_message(message) { break; } } - child + // It is okay to ignore the result, as it only errors if the process is already dead + let _ = child.kill(); + + let err_msg = match child.wait() { + Ok(exit_code) if !exit_code.success() && !read_at_least_one_message => { + // FIXME: Read the stderr to display the reason, see `read2()` reference in PR comment: + // https://github.com/rust-analyzer/rust-analyzer/pull/3632#discussion_r395605298 + format!("the command produced no valid metadata:\n cargo {}", args.join(" ")) + } + Err(err) => format!("io error: {:?}", err), + Ok(_) => return Ok(()), + }; + + Err(CargoError(err_msg)) } impl WatchThread { @@ -325,7 +353,7 @@ impl WatchThread { // which will break out of the loop, and continue the shutdown let _ = message_send.send(CheckEvent::Begin); - let mut child = run_cargo(&args, Some(&workspace_root), &mut |message| { + let res = run_cargo(&args, Some(&workspace_root), &mut |message| { // Skip certain kinds of messages to only spend time on what's useful match &message { Message::CompilerArtifact(artifact) if artifact.fresh => return true, @@ -334,39 +362,19 @@ impl WatchThread { _ => {} } - match message_send.send(CheckEvent::Msg(message)) { - Ok(()) => {} - Err(_err) => { - // The send channel was closed, so we want to shutdown - return false; - } - }; - - true + // if the send channel was closed, so we want to shutdown + message_send.send(CheckEvent::Msg(message)).is_ok() }); + if let Err(err) = res { + // FIXME: make the `message_send` to be `Sender>` + // to display user-caused misconfiguration errors instead of just logging them here + log::error!("Cargo watcher failed {:?}", err); + } + // We can ignore any error here, as we are already in the progress // of shutting down. let _ = message_send.send(CheckEvent::End); - - // It is okay to ignore the result, as it only errors if the process is already dead - let _ = child.kill(); - - // Again, we are resilient to errors, so we don't try to panic here - match child.wait_with_output() { - Ok(output) => match output.status.code() { - Some(0) | None => {} - Some(exit_code) => { - let output = - std::str::from_utf8(&output.stderr).unwrap_or(""); - - if !output.contains("could not compile") { - log::error!("Cargo failed with exit code {} {}", exit_code, output); - } - } - }, - Err(err) => log::error!("Cargo io error: {:?}", err), - } })) } else { None -- cgit v1.2.3