From 8d4afbe4136933b47082dd1efa9c1132a31dfb0d Mon Sep 17 00:00:00 2001
From: Simonas Kazlauskas <git@kazlauskas.me>
Date: Wed, 20 Feb 2019 22:27:00 +0200
Subject: Use informational target machine for metadata

Since there is nothing to optimise there...
---
 src/librustc_codegen_ssa/back/write.rs | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

(limited to 'src/librustc_codegen_ssa')

diff --git a/src/librustc_codegen_ssa/back/write.rs b/src/librustc_codegen_ssa/back/write.rs
index 859dfb99d92..55b7855ac08 100644
--- a/src/librustc_codegen_ssa/back/write.rs
+++ b/src/librustc_codegen_ssa/back/write.rs
@@ -1075,7 +1075,13 @@ fn start_executing_work<B: ExtraBackendMethods>(
         None
     };
 
-    let ol = tcx.backend_optimization_level(LOCAL_CRATE);
+    let ol = if tcx.sess.opts.debugging_opts.no_codegen
+             || !tcx.sess.opts.output_types.should_codegen() {
+        // If we know that we won’t be doing codegen, create target machines without optimisation.
+        config::OptLevel::No
+    } else {
+        tcx.backend_optimization_level(LOCAL_CRATE)
+    };
     let cgcx = CodegenContext::<B> {
         backend: backend.clone(),
         crate_types: sess.crate_types.borrow().clone(),
-- 
cgit 1.4.1-3-g733a5