1 files changed, 3 insertions, 6 deletions
diff --git a/compiler/rustc_interface/src/queries.rs b/compiler/rustc_interface/src/queries.rs
index e635ee1e0ec..2640a9575a3 100644
--- a/compiler/rustc_interface/src/queries.rs
+++ b/compiler/rustc_interface/src/queries.rs
@@ -13,7 +13,6 @@ use rustc_middle::arena::Arena;
 use rustc_middle::dep_graph::DepGraph;
 use rustc_middle::ty::{GlobalCtxt, TyCtxt};
 use rustc_query_impl::Queries as TcxQueries;
-use rustc_serialize::json;
 use rustc_session::config::{self, OutputFilenames, OutputType};
 use rustc_session::{output::find_crate_name, Session};
 use rustc_span::symbol::sym;
@@ -367,12 +366,10 @@ impl Linker {
         }
 
         if sess.opts.debugging_opts.no_link {
-            // FIXME: use a binary format to encode the `.rlink` file
-            let rlink_data = json::encode(&codegen_results).map_err(|err| {
-                sess.fatal(&format!("failed to encode rlink: {}", err));
-            })?;
+            let mut encoder = rustc_serialize::opaque::Encoder::new(Vec::new());
+            rustc_serialize::Encodable::encode(&codegen_results, &mut encoder).unwrap();
             let rlink_file = self.prepare_outputs.with_extension(config::RLINK_EXT);
-            std::fs::write(&rlink_file, rlink_data).map_err(|err| {
+            std::fs::write(&rlink_file, encoder.into_inner()).map_err(|err| {
                 sess.fatal(&format!("failed to write file {}: {}", rlink_file.display(), err));
             })?;
             return Ok(());