Dump pkg version & build date & commit hash if run with --version flag

Cargo.toml

@@ -3,6 +3,8 @@ name = "rls"
 version = "0.1.0"
 authors = ["Jonathan Turner <[email protected]>"]
 
+build = "build.rs"
+
 [dependencies]
 cargo = { git = "https://github.com/rust-lang/cargo" }
 derive-new = "0.3"

build.rs

@@ -0,0 +1,55 @@
+// 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.
+
+// The original code is [rustup.rs][rustup]
+// [rustup]: https://github.com/rust-lang-nursery/rustup.rs/tree/a1c6be19add9c99f8d8868ec384aa76057fe7f70
+
+use std::env;
+use std::fs::File;
+use std::io::Write;
+use std::path::PathBuf;
+use std::process::Command;
+
+fn main() {
+    let out_dir = PathBuf::from(env::var_os("OUT_DIR").unwrap());
+
+    File::create(out_dir.join("commit-info.txt"))
+        .unwrap()
+        .write_all(commit_info().as_bytes())
+        .unwrap();
+}
+
+// Try to get hash and date of the last commit on a best effort basis. If anything goes wrong
+// (git not installed or if this is not a git repository) just return an empty string.
+fn commit_info() -> String {
+    match (commit_hash(), commit_date()) {
+        (Some(hash), Some(date)) => format!(" ({} {})", hash.trim_right(), date),
+        _ => String::new(),
+    }
+}
+
+fn commit_hash() -> Option<String> {
+    Command::new("git")
+        .args(&["rev-parse", "--short", "HEAD"])
+        .output()
+        .ok()
+        .and_then(|r| String::from_utf8(r.stdout).ok())
+}
+
+fn commit_date() -> Option<String> {
+    Command::new("git")
+        .args(&["log",
+                "-1",
+                "--date=short",
+                "--pretty=format:%cd"])
+        .output()
+        .ok()
+        .and_then(|r| String::from_utf8(r.stdout).ok())
+}

src/main.rs

@@ -51,14 +51,21 @@ type Span = span::Span<span::ZeroIndexed>;
 pub fn main() {
     env_logger::init().unwrap();
 
-    let arg_count = ::std::env::args().count();
-    if arg_count > 1 {
-        cmd::run();
-    } else {
-        let analysis = Arc::new(analysis::AnalysisHost::new(analysis::Target::Debug));
-        let vfs = Arc::new(vfs::Vfs::new());
-        let build_queue = Arc::new(build::BuildQueue::new(vfs.clone()));
-
-        server::run_server(analysis, vfs, build_queue);
+    if let Some(first_arg) = ::std::env::args().skip(1).next() {
+        match first_arg.as_str() {
+            "--version" | "-V" => println!("rls {}", version()),
+            _ => cmd::run(),
+        }
+        return;
     }
+
+    let analysis = Arc::new(analysis::AnalysisHost::new(analysis::Target::Debug));
+    let vfs = Arc::new(vfs::Vfs::new());
+    let build_queue = Arc::new(build::BuildQueue::new(vfs.clone()));
+
+    server::run_server(analysis, vfs, build_queue);
+}
+
+fn version() -> &'static str {
+    concat!(env!("CARGO_PKG_VERSION"), include_str!(concat!(env!("OUT_DIR"), "/commit-info.txt")))
 }