Add regression test for rustc/rustdoc broken pipe ICEs

tests/run-make/broken-pipe-no-ice/rmake.rs

@@ -0,0 +1,50 @@
+//! Check that `rustc` and `rustdoc` does not ICE upon encountering a broken pipe due to unhandled
+//! panics from raw std `println!` usages.
+//!
+//! Regression test for <https://github.com/rust-lang/rust/issues/34376>.
+
+// FIXME(jieyouxu): should test for Windows too, but rustc currently has a hack on Windows that
+// suppresses broken pipe errors.
+//@ only-unix (related to `-Zon-broken-pipe` behavior)
+//@ ignore-cross-compile (needs to run test binary)
+
+use std::io::Read;
+use std::os::unix::process::ExitStatusExt;
+use std::process::{Command, Stdio};
+
+use run_make_support::{env_var, libc};
+
+fn check_broken_pipe_handled_gracefully(name: &str, mut cmd: Command) {
+    cmd.stdout(Stdio::piped()).stderr(Stdio::piped());
+
+    let mut child = cmd.spawn().unwrap();
+    // Close stdout
+    drop(child.stdout.take());
+    // Read stderr
+    let mut stderr = String::new();
+    child.stderr.as_mut().unwrap().read_to_string(&mut stderr).unwrap();
+    let status = child.wait().unwrap();
+
+    assert!(!status.success(), "{name}");
+
+    const PANIC_ICE_EXIT_STATUS: i32 = 101;
+    assert_ne!(status.code(), Some(101), "{name}");
+
+    // By default with `SIG_DFL`, `SIGPIPE` get `Term` action.
+    //
+    // See <https://man7.org/linux/man-pages/man7/signal.7.html>. `SIGPIPE` seems to be signal
+    // number 13 pretty consistently.
+    assert_eq!(status.signal(), Some(libc::SIGPIPE), "{name}");
+
+    assert!(stderr.is_empty(), "{name} stderr:\n{}", stderr);
+}
+
+fn main() {
+    let mut rustc = Command::new(env_var("RUSTC"));
+    rustc.arg("--print=sysroot");
+    check_broken_pipe_handled_gracefully("rustc", rustc);
+
+    let mut rustdoc = Command::new(env_var("RUSTDOC"));
+    rustdoc.arg("--version");
+    check_broken_pipe_handled_gracefully("rustdoc", rustdoc);
+}