add a check to make tidy to ensure cargo lock file is updated

src/tools/tidy/src/cargo_lock.rs

@@ -0,0 +1,43 @@
+// Copyright 2016 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+use std::path::Path;
+
+const CARGO_LOCK: &'static str = "Cargo.lock";
+
+pub fn check(path: &Path, bad: &mut bool) {
+    use std::process::Command;
+
+    super::walk(path,
+                &mut |path| super::filter_dirs(path) || path.ends_with("src/test"),
+                &mut |file| {
+        let name = file.file_name().unwrap().to_string_lossy();
+        if name == CARGO_LOCK {
+            let rel_path = file.strip_prefix(path).unwrap();
+            let ret_code = Command::new("git")
+                                        .arg("diff-index")
+                                        .arg("--quiet")
+                                        .arg("HEAD")
+                                        .arg(rel_path)
+                                        .current_dir(path)
+                                        .status()
+                                        .unwrap_or_else(|e| {
+                                            panic!("could not run git diff-index: {}", e);
+                                        });
+            if !ret_code.success() {
+                let parent_path = file.parent().unwrap().join("Cargo.toml");
+                print!("dirty lock file found at {} ", rel_path.display());
+                println!("please commit your changes or update the lock file by running:");
+                println!("\n\tcargo update --manifest-path {}", parent_path.display());
+                *bad = true;
+            }
+        }
+    });
+}

src/tools/tidy/src/main.rs

@@ -35,6 +35,7 @@ mod style;
 mod errors;
 mod features;
 mod cargo;
+mod cargo_lock;
 
 fn main() {
     let path = env::args_os().skip(1).next().expect("need an argument");
@@ -46,6 +47,7 @@ fn main() {
     errors::check(&path, &mut bad);
     cargo::check(&path, &mut bad);
     features::check(&path, &mut bad);
+    cargo_lock::check(&path, &mut bad);
 
     if bad {
         panic!("some tidy checks failed");