From e72afa9573ab8cb7ca2482f53b234bb59e3040ef Mon Sep 17 00:00:00 2001
From: Wesley Wiser <wwiser@gmail.com>
Date: Sun, 21 Oct 2018 11:58:39 -0400
Subject: [PATCH] Consume optimization fuel from the MIR inliner

This makes it easier to debug mis-optimizations that occur during
inlining. Thanks to @nikomatsakis for the suggestion!
---
 src/librustc_mir/transform/inline.rs | 14 +++++++++++++-
 1 file changed, 13 insertions(+), 1 deletion(-)

diff --git a/src/librustc_mir/transform/inline.rs b/src/librustc_mir/transform/inline.rs
index 199cf5650fd..2db3bbda323 100644
--- a/src/librustc_mir/transform/inline.rs
+++ b/src/librustc_mir/transform/inline.rs
@@ -137,7 +137,7 @@ fn run_pass(&self, caller_mir: &mut Mir<'tcx>) {
 
                 let callee_mir = match self.tcx.try_optimized_mir(callsite.location.span,
                                                                   callsite.callee) {
-                    Ok(callee_mir) if self.should_inline(callsite, callee_mir) => {
+                    Ok(callee_mir) if self.consider_optimizing(callsite, callee_mir) => {
                         self.tcx.subst_and_normalize_erasing_regions(
                             &callsite.substs,
                             param_env,
@@ -198,6 +198,18 @@ fn run_pass(&self, caller_mir: &mut Mir<'tcx>) {
         }
     }
 
+    fn consider_optimizing(&self,
+                           callsite: CallSite<'tcx>,
+                           callee_mir: &Mir<'tcx>)
+                           -> bool
+    {
+        debug!("consider_optimizing({:?})", callsite);
+        self.should_inline(callsite, callee_mir)
+            && self.tcx.consider_optimizing(|| format!("Inline {:?} into {:?}",
+                                                       callee_mir.span,
+                                                       callsite))
+    }
+
     fn should_inline(&self,
                      callsite: CallSite<'tcx>,
                      callee_mir: &Mir<'tcx>)
-- 
2.44.0