From 4e42e774834683570b1c0ca59ce5bb1a11119fb5 Mon Sep 17 00:00:00 2001
From: David Cook <divergentdave@gmail.com>
Date: Mon, 27 Jan 2020 06:28:45 -0600
Subject: [PATCH] Add test for posix_fadvise

---
 tests/run-pass/fs.rs | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/tests/run-pass/fs.rs b/tests/run-pass/fs.rs
index 81c56e4aafc7..43f394bd3274 100644
--- a/tests/run-pass/fs.rs
+++ b/tests/run-pass/fs.rs
@@ -1,8 +1,13 @@
 // ignore-windows: File handling is not implemented yet
 // compile-flags: -Zmiri-disable-isolation
 
+#![feature(rustc_private)]
+
+extern crate libc;
+
 use std::fs::{File, remove_file};
 use std::io::{Read, Write, ErrorKind, Result};
+use std::os::unix::io::AsRawFd;
 use std::path::{PathBuf, Path};
 
 fn test_metadata(bytes: &[u8], path: &Path) -> Result<()> {
@@ -40,6 +45,16 @@ fn main() {
     file.read_to_end(&mut contents).unwrap();
     assert_eq!(bytes, contents.as_slice());
 
+    // Test calling posix_fadvise on the file.
+    unsafe {
+        libc::posix_fadvise(
+            file.as_raw_fd(),
+            0,
+            bytes.len() as i64,
+            libc::POSIX_FADV_DONTNEED,
+        );
+    }
+
     // Test that metadata of an absolute path is correct.
     test_metadata(bytes, &path).unwrap();
     // Test that metadata of a relative path is correct.