From bd90302af6e0154a99de8b152d8831fd324910a8 Mon Sep 17 00:00:00 2001
From: Niko Matsakis <niko@alum.mit.edu>
Date: Thu, 29 Mar 2018 03:45:05 -0400
Subject: [PATCH] document reason for #[inline(never)] annotation

---
 src/librustc_mir/borrow_check/nll/region_infer/mod.rs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/librustc_mir/borrow_check/nll/region_infer/mod.rs b/src/librustc_mir/borrow_check/nll/region_infer/mod.rs
index f80184a22fdc..a545a3716c90 100644
--- a/src/librustc_mir/borrow_check/nll/region_infer/mod.rs
+++ b/src/librustc_mir/borrow_check/nll/region_infer/mod.rs
@@ -556,7 +556,7 @@ impl<'tcx> RegionInferenceContext<'tcx> {
     /// indices of constraints that need to be re-evaluated when X changes.
     /// These are constraints like Y: X @ P -- so if X changed, we may
     /// need to grow Y.
-    #[inline(never)]
+    #[inline(never)] // ensure dfs is identifiable in profiles
     fn build_dependency_map(&mut self) -> IndexVec<RegionVid, Option<ConstraintIndex>> {
         let mut map = IndexVec::from_elem(None, &self.definitions);