From 3bbeac09d21f69154991131bf8a304c1ef71ab86 Mon Sep 17 00:00:00 2001
From: Eliza Weisman <eliza@buoyant.io>
Date: Wed, 17 Jan 2018 09:23:27 -0800
Subject: [PATCH] Use cargo:rerun-if-changed to avoid recompiling protos (#160)

As @seanmonstar noticed, the build script will currently re-compile all the protobufs regardless of whether or not they have changed, making the build much slower.

This PR modifies it to emit `cargo:rerun-if-changed=` for all the protobuf files, so they will only be regenerated if one of them changes.

Signed-off-by: Eliza Weisman <eliza@buoyant.io>
---
 proxy/build.rs | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/proxy/build.rs b/proxy/build.rs
index c17687940..a25b13406 100644
--- a/proxy/build.rs
+++ b/proxy/build.rs
@@ -24,4 +24,9 @@ fn build_control() {
         .enable_server(true)
         .build(server_files, dirs)
         .unwrap();
+
+    // recompile protobufs only if any of the proto files changes.
+    for file in client_files.iter().chain(server_files) {
+        println!("cargo:rerun-if-changed={}", file);
+    }
 }