use let chains in mir, resolve, target

3 files changed, 24 insertions, 27 deletions

diff --git a/compiler/rustc_mir_transform/src/promote_consts.rs b/compiler/rustc_mir_transform/src/promote_consts.rs
index 4e8f30e077b..462ddfa3dd3 100644
--- a/compiler/rustc_mir_transform/src/promote_consts.rs
+++ b/compiler/rustc_mir_transform/src/promote_consts.rs
@@ -997,12 +997,11 @@ fn promote_candidates<'tcx>(
     for candidate in candidates.into_iter().rev() {
         let Location { block, statement_index } = candidate.location;
         if let StatementKind::Assign(box (place, _)) = &body[block].statements[statement_index].kind
+            && let Some(local) = place.as_local()
         {
-            if let Some(local) = place.as_local() {
-                if temps[local] == TempState::PromotedOut {
-                    // Already promoted.
-                    continue;
-                }
+            if temps[local] == TempState::PromotedOut {
+                // Already promoted.
+                continue;
             }
         }
 
@@ -1066,11 +1065,11 @@ fn promote_candidates<'tcx>(
             _ => true,
         });
         let terminator = block.terminator_mut();
-        if let TerminatorKind::Drop { place, target, .. } = &terminator.kind {
-            if let Some(index) = place.as_local() {
-                if promoted(index) {
-                    terminator.kind = TerminatorKind::Goto { target: *target };
-                }
+        if let TerminatorKind::Drop { place, target, .. } = &terminator.kind
+            && let Some(index) = place.as_local()
+        {
+            if promoted(index) {
+                terminator.kind = TerminatorKind::Goto { target: *target };
             }
         }
     }
diff --git a/compiler/rustc_mir_transform/src/remove_noop_landing_pads.rs b/compiler/rustc_mir_transform/src/remove_noop_landing_pads.rs
index 797056ad52d..5b6d7ffb511 100644
--- a/compiler/rustc_mir_transform/src/remove_noop_landing_pads.rs
+++ b/compiler/rustc_mir_transform/src/remove_noop_landing_pads.rs
@@ -48,14 +48,13 @@ impl<'tcx> crate::MirPass<'tcx> for RemoveNoopLandingPads {
         let postorder: Vec<_> = traversal::postorder(body).map(|(bb, _)| bb).collect();
         for bb in postorder {
             debug!("  processing {:?}", bb);
-            if let Some(unwind) = body[bb].terminator_mut().unwind_mut() {
-                if let UnwindAction::Cleanup(unwind_bb) = *unwind {
-                    if nop_landing_pads.contains(unwind_bb) {
-                        debug!("    removing noop landing pad");
-                        landing_pads_removed += 1;
-                        *unwind = UnwindAction::Continue;
-                    }
-                }
+            if let Some(unwind) = body[bb].terminator_mut().unwind_mut()
+                && let UnwindAction::Cleanup(unwind_bb) = *unwind
+                && nop_landing_pads.contains(unwind_bb)
+            {
+                debug!("    removing noop landing pad");
+                landing_pads_removed += 1;
+                *unwind = UnwindAction::Continue;
             }
 
             body[bb].terminator_mut().successors_mut(|target| {
diff --git a/compiler/rustc_mir_transform/src/validate.rs b/compiler/rustc_mir_transform/src/validate.rs
index 5860072d541..98d12bf0a38 100644
--- a/compiler/rustc_mir_transform/src/validate.rs
+++ b/compiler/rustc_mir_transform/src/validate.rs
@@ -80,15 +80,14 @@ impl<'tcx> crate::MirPass<'tcx> for Validator {
             cfg_checker.fail(location, msg);
         }
 
-        if let MirPhase::Runtime(_) = body.phase {
-            if let ty::InstanceKind::Item(_) = body.source.instance {
-                if body.has_free_regions() {
-                    cfg_checker.fail(
-                        Location::START,
-                        format!("Free regions in optimized {} MIR", body.phase.name()),
-                    );
-                }
-            }
+        if let MirPhase::Runtime(_) = body.phase
+            && let ty::InstanceKind::Item(_) = body.source.instance
+            && body.has_free_regions()
+        {
+            cfg_checker.fail(
+                Location::START,
+                format!("Free regions in optimized {} MIR", body.phase.name()),
+            );
         }
     }