1 files changed, 20 insertions, 19 deletions

diff --git a/src/librustc_passes/loops.rs b/src/librustc_passes/loops.rs
index 69d6b38005c..09b3d44020d 100644
--- a/src/librustc_passes/loops.rs
+++ b/src/librustc_passes/loops.rs
@@ -1,13 +1,13 @@
 use Context::*;
 
-use rustc::hir::map::Map;
-use rustc::ty::query::Providers;
-use rustc::ty::TyCtxt;
 use rustc_errors::{struct_span_err, Applicability};
 use rustc_hir as hir;
 use rustc_hir::def_id::DefId;
 use rustc_hir::intravisit::{self, NestedVisitorMap, Visitor};
 use rustc_hir::{Destination, Movability, Node};
+use rustc_middle::hir::map::Map;
+use rustc_middle::ty::query::Providers;
+use rustc_middle::ty::TyCtxt;
 use rustc_session::Session;
 use rustc_span::Span;
 
@@ -24,15 +24,14 @@ enum Context {
 #[derive(Copy, Clone)]
 struct CheckLoopVisitor<'a, 'hir> {
     sess: &'a Session,
-    hir_map: &'a Map<'hir>,
+    hir_map: Map<'hir>,
     cx: Context,
 }
 
 fn check_mod_loops(tcx: TyCtxt<'_>, module_def_id: DefId) {
     tcx.hir().visit_item_likes_in_module(
         module_def_id,
-        &mut CheckLoopVisitor { sess: &tcx.sess, hir_map: &tcx.hir(), cx: Normal }
-            .as_deep_visitor(),
+        &mut CheckLoopVisitor { sess: &tcx.sess, hir_map: tcx.hir(), cx: Normal }.as_deep_visitor(),
     );
 }
 
@@ -43,8 +42,8 @@ pub(crate) fn provide(providers: &mut Providers<'_>) {
 impl<'a, 'hir> Visitor<'hir> for CheckLoopVisitor<'a, 'hir> {
     type Map = Map<'hir>;
 
-    fn nested_visit_map(&mut self) -> NestedVisitorMap<'_, Self::Map> {
-        NestedVisitorMap::OnlyBodies(&self.hir_map)
+    fn nested_visit_map(&mut self) -> NestedVisitorMap<Self::Map> {
+        NestedVisitorMap::OnlyBodies(self.hir_map)
     }
 
     fn visit_anon_const(&mut self, c: &'hir hir::AnonConst) {
@@ -69,7 +68,9 @@ impl<'a, 'hir> Visitor<'hir> for CheckLoopVisitor<'a, 'hir> {
                 self.with_context(LabeledBlock, |v| v.visit_block(&b));
             }
             hir::ExprKind::Break(label, ref opt_expr) => {
-                opt_expr.as_ref().map(|e| self.visit_expr(e));
+                if let Some(e) = opt_expr {
+                    self.visit_expr(e);
+                }
 
                 if self.require_label_in_labeled_block(e.span, &label, "break") {
                     // If we emitted an error about an unlabeled break in a labeled
@@ -77,32 +78,32 @@ impl<'a, 'hir> Visitor<'hir> for CheckLoopVisitor<'a, 'hir> {
                     return;
                 }
 
-                let loop_id = match label.target_id.into() {
-                    Ok(loop_id) => loop_id,
-                    Err(hir::LoopIdError::OutsideLoopScope) => hir::DUMMY_HIR_ID,
+                let loop_id = match label.target_id {
+                    Ok(loop_id) => Some(loop_id),
+                    Err(hir::LoopIdError::OutsideLoopScope) => None,
                     Err(hir::LoopIdError::UnlabeledCfInWhileCondition) => {
                         self.emit_unlabled_cf_in_while_condition(e.span, "break");
-                        hir::DUMMY_HIR_ID
+                        None
                     }
-                    Err(hir::LoopIdError::UnresolvedLabel) => hir::DUMMY_HIR_ID,
+                    Err(hir::LoopIdError::UnresolvedLabel) => None,
                 };
 
-                if loop_id != hir::DUMMY_HIR_ID {
+                if let Some(loop_id) = loop_id {
                     if let Node::Block(_) = self.hir_map.find(loop_id).unwrap() {
                         return;
                     }
                 }
 
                 if opt_expr.is_some() {
-                    let loop_kind = if loop_id == hir::DUMMY_HIR_ID {
-                        None
-                    } else {
+                    let loop_kind = if let Some(loop_id) = loop_id {
                         Some(match self.hir_map.expect_expr(loop_id).kind {
                             hir::ExprKind::Loop(_, _, source) => source,
                             ref r => {
                                 span_bug!(e.span, "break label resolved to a non-loop: {:?}", r)
                             }
                         })
+                    } else {
+                        None
                     };
                     match loop_kind {
                         None | Some(hir::LoopSource::Loop) => (),
@@ -223,7 +224,7 @@ impl<'a, 'hir> CheckLoopVisitor<'a, 'hir> {
                 return true;
             }
         }
-        return false;
+        false
     }
     fn emit_unlabled_cf_in_while_condition(&mut self, span: Span, cf_type: &str) {
         struct_span_err!(