Merge rayon-rs#1009

1009: Improve rayon-core/tests/stack_overflow_crash.rs r=cuviper a=cuviper

- Rewrite it within the regular test harness, so it doesn't crash in
  arg-parsing on broad `cargo test -- filter` commands.
- Use `std::hint::black_box` so the test even works in `--release`.


Co-authored-by: Josh Stone <cuviper@gmail.com>

Author: bors[bot]

rayon-core/Cargo.toml

@@ -33,7 +33,6 @@ libc = "0.2"
 [[test]]
 name = "stack_overflow_crash"
 path = "tests/stack_overflow_crash.rs"
-harness = false
 
 # NB: having one [[test]] manually defined means we need to declare them all
 

rayon-core/tests/stack_overflow_crash.rs

@@ -1,13 +1,14 @@
 use rayon_core::ThreadPoolBuilder;
 
 use std::env;
-use std::process::Command;
+use std::process::{Command, ExitStatus, Stdio};
 
 #[cfg(target_os = "linux")]
 use std::os::unix::process::ExitStatusExt;
 
 fn force_stack_overflow(depth: u32) {
-    let _buffer = [0u8; 1024 * 1024];
+    let mut buffer = [0u8; 1024 * 1024];
+    std::hint::black_box(&mut buffer);
     if depth > 0 {
         force_stack_overflow(depth - 1);
     }
@@ -34,49 +35,61 @@ fn overflow_code() -> Option<i32> {
 #[cfg(windows)]
 fn overflow_code() -> Option<i32> {
     use std::os::windows::process::ExitStatusExt;
-    use std::process::ExitStatus;
 
     ExitStatus::from_raw(0xc00000fd /*STATUS_STACK_OVERFLOW*/).code()
 }
 
-fn main() {
-    if env::args().len() == 1 {
-        // first check that the recursivecall actually causes a stack overflow, and does not get optimized away
-        {
-            let status = Command::new(env::current_exe().unwrap())
-                .arg("8")
-                .status()
-                .unwrap();
+#[test]
+fn stack_overflow_crash() {
+    // First check that the recursive call actually causes a stack overflow,
+    // and does not get optimized away.
+    let status = run_ignored("run_with_small_stack");
+    #[cfg(any(unix, windows))]
+    assert_eq!(status.code(), overflow_code());
+    #[cfg(target_os = "linux")]
+    assert!(matches!(
+        status.signal(),
+        Some(libc::SIGABRT | libc::SIGSEGV)
+    ));
 
-            #[cfg(any(unix, windows))]
-            assert_eq!(status.code(), overflow_code());
+    // Now run with a larger stack and verify correct operation.
+    let status = run_ignored("run_with_large_stack");
+    assert_eq!(status.code(), Some(0));
+    #[cfg(target_os = "linux")]
+    assert_eq!(status.signal(), None);
+}
 
-            #[cfg(target_os = "linux")]
-            assert!(
-                status.signal() == Some(11 /*SIGABRT*/) || status.signal() == Some(6 /*SIGSEGV*/)
-            );
-        }
+fn run_ignored(test: &str) -> ExitStatus {
+    Command::new(env::current_exe().unwrap())
+        .arg("--ignored")
+        .arg("--exact")
+        .arg(test)
+        .stdout(Stdio::null())
+        .stderr(Stdio::null())
+        .status()
+        .unwrap()
+}
 
-        // now run with a larger stack and verify correct operation
-        {
-            let status = Command::new(env::current_exe().unwrap())
-                .arg("48")
-                .status()
-                .unwrap();
-            assert_eq!(status.code(), Some(0));
-            #[cfg(target_os = "linux")]
-            assert_eq!(status.signal(), None);
-        }
-    } else {
-        let stack_size_in_mb: usize = env::args().nth(1).unwrap().parse().unwrap();
-        let pool = ThreadPoolBuilder::new()
-            .stack_size(stack_size_in_mb * 1024 * 1024)
-            .build()
-            .unwrap();
-        pool.install(|| {
-            #[cfg(unix)]
-            disable_core();
-            force_stack_overflow(32);
-        });
-    }
+#[test]
+#[ignore]
+fn run_with_small_stack() {
+    run_with_stack(8);
+}
+
+#[test]
+#[ignore]
+fn run_with_large_stack() {
+    run_with_stack(48);
+}
+
+fn run_with_stack(stack_size_in_mb: usize) {
+    let pool = ThreadPoolBuilder::new()
+        .stack_size(stack_size_in_mb * 1024 * 1024)
+        .build()
+        .unwrap();
+    pool.install(|| {
+        #[cfg(unix)]
+        disable_core();
+        force_stack_overflow(32);
+    });
 }