Remove Control enum in favor of ControlFlow

compiler/rustc_borrowck/src/lib.rs

@@ -17,7 +17,7 @@
 
 use std::cell::RefCell;
 use std::marker::PhantomData;
-use std::ops::Deref;
+use std::ops::{ControlFlow, Deref};
 
 use rustc_abi::FieldIdx;
 use rustc_data_structures::fx::{FxIndexMap, FxIndexSet};
@@ -1054,31 +1054,31 @@ impl<'a, 'tcx> MirBorrowckCtxt<'a, '_, 'tcx> {
                         rw,
                         (borrow_index, borrow),
                     );
-                    Control::Continue
+                    ControlFlow::Continue(())
                 }
 
                 (Read(_), BorrowKind::Shared | BorrowKind::Fake(_))
                 | (
                     Read(ReadKind::Borrow(BorrowKind::Fake(FakeBorrowKind::Shallow))),
                     BorrowKind::Mut { .. },
-                ) => Control::Continue,
+                ) => ControlFlow::Continue(()),
 
                 (Reservation(_), BorrowKind::Fake(_) | BorrowKind::Shared) => {
                     // This used to be a future compatibility warning (to be
                     // disallowed on NLL). See rust-lang/rust#56254
-                    Control::Continue
+                    ControlFlow::Continue(())
                 }
 
                 (Write(WriteKind::Move), BorrowKind::Fake(FakeBorrowKind::Shallow)) => {
                     // Handled by initialization checks.
-                    Control::Continue
+                    ControlFlow::Continue(())
                 }
 
                 (Read(kind), BorrowKind::Mut { .. }) => {
                     // Reading from mere reservations of mutable-borrows is OK.
                     if !is_active(this.dominators(), borrow, location) {
                         assert!(allow_two_phase_borrow(borrow.kind));
-                        return Control::Continue;
+                        return ControlFlow::Continue(());
                     }
 
                     error_reported = true;
@@ -1094,7 +1094,7 @@ impl<'a, 'tcx> MirBorrowckCtxt<'a, '_, 'tcx> {
                             this.buffer_error(err);
                         }
                     }
-                    Control::Break
+                    ControlFlow::Break(())
                 }
 
                 (Reservation(kind) | Activation(kind, _) | Write(kind), _) => {
@@ -1141,7 +1141,7 @@ impl<'a, 'tcx> MirBorrowckCtxt<'a, '_, 'tcx> {
                             this.report_illegal_mutation_of_borrowed(location, place_span, borrow)
                         }
                     }
-                    Control::Break
+                    ControlFlow::Break(())
                 }
             },
         );

compiler/rustc_borrowck/src/path_utils.rs

@@ -1,3 +1,5 @@
+use std::ops::ControlFlow;
+
 use rustc_abi::FieldIdx;
 use rustc_data_structures::graph::dominators::Dominators;
 use rustc_middle::mir::{BasicBlock, Body, BorrowKind, Location, Place, PlaceRef, ProjectionElem};
@@ -14,13 +16,6 @@ pub(super) fn allow_two_phase_borrow(kind: BorrowKind) -> bool {
     kind.allows_two_phase_borrow()
 }
 
-/// Control for the path borrow checking code
-#[derive(Copy, Clone, PartialEq, Eq, Debug)]
-pub(super) enum Control {
-    Continue,
-    Break,
-}
-
 /// Encapsulates the idea of iterating over every borrow that involves a particular path
 pub(super) fn each_borrow_involving_path<'tcx, F, I, S>(
     s: &mut S,
@@ -31,7 +26,7 @@ pub(super) fn each_borrow_involving_path<'tcx, F, I, S>(
     is_candidate: I,
     mut op: F,
 ) where
-    F: FnMut(&mut S, BorrowIndex, &BorrowData<'tcx>) -> Control,
+    F: FnMut(&mut S, BorrowIndex, &BorrowData<'tcx>) -> ControlFlow<()>,
     I: Fn(BorrowIndex) -> bool,
 {
     let (access, place) = access_place;
@@ -62,7 +57,7 @@ pub(super) fn each_borrow_involving_path<'tcx, F, I, S>(
                 i, borrowed, place, access
             );
             let ctrl = op(s, i, borrowed);
-            if ctrl == Control::Break {
+            if ctrl == ControlFlow::Break(()) {
                 return;
             }
         }

compiler/rustc_borrowck/src/polonius/legacy/loan_invalidations.rs

@@ -1,3 +1,5 @@
+use std::ops::ControlFlow;
+
 use rustc_data_structures::graph::dominators::Dominators;
 use rustc_middle::bug;
 use rustc_middle::mir::visit::Visitor;
@@ -379,7 +381,7 @@ impl<'a, 'tcx> LoanInvalidationsGenerator<'a, 'tcx> {
                         if !is_active(this.dominators, borrow, location) {
                             // If the borrow isn't active yet, reads don't invalidate it
                             assert!(allow_two_phase_borrow(borrow.kind));
-                            return Control::Continue;
+                            return ControlFlow::Continue(());
                         }
 
                         // Unique and mutable borrows are invalidated by reads from any
@@ -395,7 +397,7 @@ impl<'a, 'tcx> LoanInvalidationsGenerator<'a, 'tcx> {
                         this.emit_loan_invalidated_at(borrow_index, location);
                     }
                 }
-                Control::Continue
+                ControlFlow::Continue(())
             },
         );
     }