Auto merge of #10511 - weihanglo:issue-10477, r=ehuss

Support inheriting jobserver fd for external subcommands

src/bin/cargo/main.rs

@@ -181,11 +181,12 @@ fn execute_external_subcommand(config: &Config, cmd: &str, args: &[&str]) -> Cli
  };
 
  let cargo_exe = config.cargo_exe()?;
- let err = match ProcessBuilder::new(&command)
- .env(cargo::CARGO_ENV, cargo_exe)
- .args(args)
- .exec_replace()
- {
+ let mut cmd = ProcessBuilder::new(&command);
+ cmd.env(cargo::CARGO_ENV, cargo_exe).args(args);
+ if let Some(client) = config.jobserver_from_env() {
+ cmd.inherit_jobserver(client);
+ }
+ let err = match cmd.exec_replace() {
  Ok(()) => return Ok(()),
  Err(e) => e,
  };

tests/testsuite/jobserver.rs

@@ -5,50 +5,50 @@ use std::net::TcpListener;
 use std::process::Command;
 use std::thread;
 
+use cargo_test_support::install::{assert_has_installed_exe, cargo_home};
 use cargo_test_support::{cargo_exe, project};
 
-#[cargo_test]
-fn jobserver_exists() {
- let p = project()
- .file(
- "build.rs",
- r#"
- use std::env;
+const EXE_CONTENT: &str = r#"
+use std::env;
 
- fn main() {
-  let var = env::var("CARGO_MAKEFLAGS").unwrap();
-  let arg = var.split(' ')
-  .find(|p| p.starts_with("--jobserver"))
-  .unwrap();
-  let val = &arg[arg.find('=').unwrap() + 1..];
-  validate(val);
- }
+fn main() {
+ let var = env::var("CARGO_MAKEFLAGS").unwrap();
+ let arg = var.split(' ')
+ .find(|p| p.starts_with("--jobserver"))
+ .unwrap();
+ let val = &arg[arg.find('=').unwrap() + 1..];
+ validate(val);
+}
 
- #[cfg(unix)]
- fn validate(s: &str) {
-  use std::fs::File;
-  use std::io::*;
-  use std::os::unix::prelude::*;
-
-  let fds = s.split(',').collect::<Vec<_>>();
-  println!("{}", s);
-  assert_eq!(fds.len(), 2);
-  unsafe {
-  let mut read = File::from_raw_fd(fds[0].parse().unwrap());
-  let mut write = File::from_raw_fd(fds[1].parse().unwrap());
-
-  let mut buf = [0];
-  assert_eq!(read.read(&mut buf).unwrap(), 1);
-  assert_eq!(write.write(&buf).unwrap(), 1);
-  }
- }
+#[cfg(unix)]
+fn validate(s: &str) {
+ use std::fs::File;
+ use std::io::*;
+ use std::os::unix::prelude::*;
+
+ let fds = s.split(',').collect::<Vec<_>>();
+ println!("{}", s);
+ assert_eq!(fds.len(), 2);
+ unsafe {
+ let mut read = File::from_raw_fd(fds[0].parse().unwrap());
+ let mut write = File::from_raw_fd(fds[1].parse().unwrap());
+
+ let mut buf = [0];
+ assert_eq!(read.read(&mut buf).unwrap(), 1);
+ assert_eq!(write.write(&buf).unwrap(), 1);
+ }
+}
 
- #[cfg(windows)]
- fn validate(_: &str) {
- // a little too complicated for a test...
- }
- "#,
- )
+#[cfg(windows)]
+fn validate(_: &str) {
+ // a little too complicated for a test...
+}
+"#;
+
+#[cargo_test]
+fn jobserver_exists() {
+ let p = project()
+ .file("build.rs", EXE_CONTENT)
  .file("src/lib.rs", "")
  .build();
 
@@ -58,6 +58,45 @@ fn jobserver_exists() {
  p.cargo("build -j2").run();
 }
 
+#[cargo_test]
+fn external_subcommand_inherits_jobserver() {
+ let make = if cfg!(windows) {
+ "mingw32-make"
+ } else {
+ "make"
+ };
+ if Command::new(make).arg("--version").output().is_err() {
+ return;
+ }
+
+ let name = "cargo-jobserver-check";
+ let p = project()
+ .file(
+ "Cargo.toml",
+ &format!(
+ r#"
+ [package]
+ name = "{name}"
+ version = "0.0.1"
+ "#
+ ),
+ )
+ .file("src/main.rs", EXE_CONTENT)
+ .file(
+ "Makefile",
+ "\
+all:
+\t+$(CARGO) jobserver-check
+",
+ )
+ .build();
+
+ p.cargo("install --path .").run();
+ assert_has_installed_exe(cargo_home(), name);
+
+ p.process(make).env("CARGO", cargo_exe()).arg("-j2").run();
+}
+
 #[cargo_test]
 fn makes_jobserver_used() {
  let make = if cfg!(windows) {