rustc_borrowck: remove ref patterns

Author: WaffleLapkin

compiler/rustc_borrowck/src/borrow_set.rs

@@ -198,7 +198,7 @@ impl<'a, 'tcx> Visitor<'tcx> for GatherBorrows<'a, 'tcx> {
         rvalue: &mir::Rvalue<'tcx>,
         location: mir::Location,
     ) {
-        if let mir::Rvalue::Ref(region, kind, ref borrowed_place) = *rvalue {
+        if let &mir::Rvalue::Ref(region, kind, borrowed_place) = rvalue {
             if borrowed_place.ignore_borrow(self.tcx, self.body, &self.locals_state_at_exit) {
                 debug!("ignoring_borrow of {:?}", borrowed_place);
                 return;
@@ -211,7 +211,7 @@ impl<'a, 'tcx> Visitor<'tcx> for GatherBorrows<'a, 'tcx> {
                 region,
                 reserve_location: location,
                 activation_location: TwoPhaseActivation::NotTwoPhase,
-                borrowed_place: *borrowed_place,
+                borrowed_place,
                 assigned_place: *assigned_place,
             };
             let (idx, _) = self.location_map.insert_full(location, borrow);
@@ -273,14 +273,14 @@ impl<'a, 'tcx> Visitor<'tcx> for GatherBorrows<'a, 'tcx> {
     }
 
     fn visit_rvalue(&mut self, rvalue: &mir::Rvalue<'tcx>, location: mir::Location) {
-        if let mir::Rvalue::Ref(region, kind, ref place) = *rvalue {
+        if let &mir::Rvalue::Ref(region, kind, place) = rvalue {
             // double-check that we already registered a BorrowData for this
 
             let borrow_data = &self.location_map[&location];
             assert_eq!(borrow_data.reserve_location, location);
             assert_eq!(borrow_data.kind, kind);
             assert_eq!(borrow_data.region, region.to_region_vid());
-            assert_eq!(borrow_data.borrowed_place, *place);
+            assert_eq!(borrow_data.borrowed_place, place);
         }
 
         self.super_rvalue(rvalue, location)

compiler/rustc_borrowck/src/dataflow.rs

@@ -358,9 +358,9 @@ impl<'tcx> rustc_mir_dataflow::GenKillAnalysis<'tcx> for Borrows<'_, 'tcx> {
         stmt: &mir::Statement<'tcx>,
         location: Location,
     ) {
-        match stmt.kind {
-            mir::StatementKind::Assign(box (lhs, ref rhs)) => {
-                if let mir::Rvalue::Ref(_, _, place) = *rhs {
+        match &stmt.kind {
+            mir::StatementKind::Assign(box (lhs, rhs)) => {
+                if let mir::Rvalue::Ref(_, _, place) = rhs {
                     if place.ignore_borrow(
                         self.tcx,
                         self.body,
@@ -377,13 +377,13 @@ impl<'tcx> rustc_mir_dataflow::GenKillAnalysis<'tcx> for Borrows<'_, 'tcx> {
 
                 // Make sure there are no remaining borrows for variables
                 // that are assigned over.
-                self.kill_borrows_on_place(trans, lhs);
+                self.kill_borrows_on_place(trans, *lhs);
             }
 
             mir::StatementKind::StorageDead(local) => {
                 // Make sure there are no remaining borrows for locals that
                 // are gone out of scope.
-                self.kill_borrows_on_place(trans, Place::from(local));
+                self.kill_borrows_on_place(trans, Place::from(*local));
             }
 
             mir::StatementKind::FakeRead(..)

compiler/rustc_borrowck/src/diagnostics/bound_region_errors.rs

@@ -243,9 +243,9 @@ impl<'tcx> TypeOpInfo<'tcx> for PredicateQuery<'tcx> {
         placeholder_region: ty::Region<'tcx>,
         error_region: Option<ty::Region<'tcx>>,
     ) -> Option<DiagnosticBuilder<'tcx, ErrorGuaranteed>> {
-        let (ref infcx, key, _) =
+        let (infcx, key, _) =
             mbcx.infcx.tcx.infer_ctxt().build_with_canonical(cause.span, &self.canonical_query);
-        let ocx = ObligationCtxt::new(infcx);
+        let ocx = ObligationCtxt::new(&infcx);
         type_op_prove_predicate_with_cause(&ocx, key, cause);
         try_extract_error_from_fulfill_cx(&ocx, placeholder_region, error_region)
     }
@@ -284,9 +284,9 @@ where
         placeholder_region: ty::Region<'tcx>,
         error_region: Option<ty::Region<'tcx>>,
     ) -> Option<DiagnosticBuilder<'tcx, ErrorGuaranteed>> {
-        let (ref infcx, key, _) =
+        let (infcx, key, _) =
             mbcx.infcx.tcx.infer_ctxt().build_with_canonical(cause.span, &self.canonical_query);
-        let ocx = ObligationCtxt::new(infcx);
+        let ocx = ObligationCtxt::new(&infcx);
 
         // FIXME(lqd): Unify and de-duplicate the following with the actual
         // `rustc_traits::type_op::type_op_normalize` query to allow the span we need in the
@@ -328,9 +328,9 @@ impl<'tcx> TypeOpInfo<'tcx> for AscribeUserTypeQuery<'tcx> {
         placeholder_region: ty::Region<'tcx>,
         error_region: Option<ty::Region<'tcx>>,
     ) -> Option<DiagnosticBuilder<'tcx, ErrorGuaranteed>> {
-        let (ref infcx, key, _) =
+        let (infcx, key, _) =
             mbcx.infcx.tcx.infer_ctxt().build_with_canonical(cause.span, &self.canonical_query);
-        let ocx = ObligationCtxt::new(infcx);
+        let ocx = ObligationCtxt::new(&infcx);
         type_op_ascribe_user_type_with_span(&ocx, key, Some(cause.span)).ok()?;
         try_extract_error_from_fulfill_cx(&ocx, placeholder_region, error_region)
     }

compiler/rustc_borrowck/src/diagnostics/conflict_errors.rs

@@ -265,7 +265,7 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> {
                 DescribePlaceOpt { including_downcast: true, including_tuple_field: true },
             );
             let note_msg = match opt_name {
-                Some(ref name) => format!("`{}`", name),
+                Some(name) => format!("`{}`", name),
                 None => "value".to_owned(),
             };
             if self.suggest_borrow_fn_like(&mut err, ty, &move_site_vec, &note_msg) {
@@ -1417,7 +1417,7 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> {
             // then just use the normal error. The closure isn't escaping
             // and `move` will not help here.
             (
-                Some(ref name),
+                Some(name),
                 BorrowExplanation::MustBeValidFor {
                     category:
                         category @ (ConstraintCategory::Return(_)
@@ -1438,7 +1438,7 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> {
                     &format!("`{}`", name),
                 ),
             (
-                ref name,
+                name,
                 BorrowExplanation::MustBeValidFor {
                     category: ConstraintCategory::Assignment,
                     from_closure: false,
@@ -1450,7 +1450,7 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> {
                     span,
                     ..
                 },
-            ) => self.report_escaping_data(borrow_span, name, upvar_span, upvar_name, span),
+            ) => self.report_escaping_data(borrow_span, &name, upvar_span, upvar_name, span),
             (Some(name), explanation) => self.report_local_value_does_not_live_long_enough(
                 location,
                 &name,
@@ -2452,7 +2452,7 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> {
         // and it'll make sense.
         let location = borrow.reserve_location;
         debug!("annotate_argument_and_return_for_borrow: location={:?}", location);
-        if let Some(&Statement { kind: StatementKind::Assign(box (ref reservation, _)), .. }) =
+        if let Some(Statement { kind: StatementKind::Assign(box (reservation, _)), .. }) =
             &self.body[location.block].statements.get(location.statement_index)
         {
             debug!("annotate_argument_and_return_for_borrow: reservation={:?}", reservation);
@@ -2480,8 +2480,8 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> {
                         // Check if our `target` was captured by a closure.
                         if let Rvalue::Aggregate(
                             box AggregateKind::Closure(def_id, substs),
-                            ref operands,
-                        ) = *rvalue
+                            operands,
+                        ) = rvalue
                         {
                             for operand in operands {
                                 let (Operand::Copy(assigned_from) | Operand::Move(assigned_from)) = operand else {
@@ -2505,7 +2505,7 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> {
                                 // into a place then we should annotate the closure in
                                 // case it ends up being assigned into the return place.
                                 annotated_closure =
-                                    self.annotate_fn_sig(def_id, substs.as_closure().sig());
+                                    self.annotate_fn_sig(*def_id, substs.as_closure().sig());
                                 debug!(
                                     "annotate_argument_and_return_for_borrow: \
                                      annotated_closure={:?} assigned_from_local={:?} \

compiler/rustc_borrowck/src/diagnostics/explain_borrow.rs

@@ -469,8 +469,8 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> {
                 } else if self.was_captured_by_trait_object(borrow) {
                     LaterUseKind::TraitCapture
                 } else if location.statement_index == block.statements.len() {
-                    if let TerminatorKind::Call { ref func, from_hir_call: true, .. } =
-                        block.terminator().kind
+                    if let TerminatorKind::Call { func, from_hir_call: true, .. } =
+                        &block.terminator().kind
                     {
                         // Just point to the function, to reduce the chance of overlapping spans.
                         let function_span = match func {
@@ -515,19 +515,16 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> {
         // will only ever have one item at any given time, but by using a vector, we can pop from
         // it which simplifies the termination logic.
         let mut queue = vec![location];
-        let mut target = if let Some(&Statement {
-            kind: StatementKind::Assign(box (ref place, _)),
-            ..
-        }) = stmt
-        {
-            if let Some(local) = place.as_local() {
-                local
+        let mut target =
+            if let Some(Statement { kind: StatementKind::Assign(box (place, _)), .. }) = stmt {
+                if let Some(local) = place.as_local() {
+                    local
+                } else {
+                    return false;
+                }
             } else {
                 return false;
-            }
-        } else {
-            return false;
-        };
+            };
 
         debug!("was_captured_by_trait: target={:?} queue={:?}", target, queue);
         while let Some(current_location) = queue.pop() {

compiler/rustc_borrowck/src/diagnostics/mod.rs

@@ -78,7 +78,7 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> {
             if let StatementKind::Assign(box (into, Rvalue::Use(from))) = &stmt.kind {
                 debug!("add_fnonce_closure_note: into={:?} from={:?}", into, from);
                 match from {
-                    Operand::Copy(ref place) | Operand::Move(ref place)
+                    Operand::Copy(place) | Operand::Move(place)
                         if target == place.local_or_deref_local() =>
                     {
                         target = into.local_or_deref_local()
@@ -101,7 +101,7 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> {
                 debug!("add_moved_or_invoked_closure_note: id={:?}", id);
                 if Some(self.infcx.tcx.parent(id)) == self.infcx.tcx.lang_items().fn_once_trait() {
                     let closure = match args.first() {
-                        Some(Operand::Copy(ref place)) | Some(Operand::Move(ref place))
+                        Some(Operand::Copy(place) | Operand::Move(place))
                             if target == place.local_or_deref_local() =>
                         {
                             place.local_or_deref_local().unwrap()
@@ -439,9 +439,9 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> {
                     if !is_terminator {
                         continue;
                     } else if let Some(Terminator {
-                        kind: TerminatorKind::Call { ref func, from_hir_call: false, .. },
+                        kind: TerminatorKind::Call { func, from_hir_call: false, .. },
                         ..
-                    }) = bbd.terminator
+                    }) = &bbd.terminator
                     {
                         if let Some(source) =
                             BorrowedContentSource::from_call(func.ty(self.body, tcx), tcx)
@@ -811,33 +811,30 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> {
         };
 
         debug!("move_spans: moved_place={:?} location={:?} stmt={:?}", moved_place, location, stmt);
-        if let StatementKind::Assign(box (_, Rvalue::Aggregate(ref kind, ref places))) = stmt.kind {
-            match **kind {
-                AggregateKind::Closure(def_id, _) | AggregateKind::Generator(def_id, _, _) => {
-                    debug!("move_spans: def_id={:?} places={:?}", def_id, places);
-                    if let Some((args_span, generator_kind, capture_kind_span, path_span)) =
-                        self.closure_span(def_id, moved_place, places)
-                    {
-                        return ClosureUse {
-                            generator_kind,
-                            args_span,
-                            capture_kind_span,
-                            path_span,
-                        };
-                    }
-                }
-                _ => {}
+        if let StatementKind::Assign(box (_, Rvalue::Aggregate(kind, places))) = &stmt.kind
+            && let AggregateKind::Closure(def_id, _) | AggregateKind::Generator(def_id, _, _) = **kind
+        {
+            debug!("move_spans: def_id={:?} places={:?}", def_id, places);
+            if let Some((args_span, generator_kind, capture_kind_span, path_span)) =
+                self.closure_span(def_id, moved_place, places)
+            {
+                return ClosureUse {
+                    generator_kind,
+                    args_span,
+                    capture_kind_span,
+                    path_span,
+                };
             }
         }
 
         // StatementKind::FakeRead only contains a def_id if they are introduced as a result
         // of pattern matching within a closure.
-        if let StatementKind::FakeRead(box (cause, ref place)) = stmt.kind {
+        if let StatementKind::FakeRead(box (cause, place)) = stmt.kind {
             match cause {
                 FakeReadCause::ForMatchedPlace(Some(closure_def_id))
                 | FakeReadCause::ForLet(Some(closure_def_id)) => {
                     debug!("move_spans: def_id={:?} place={:?}", closure_def_id, place);
-                    let places = &[Operand::Move(*place)];
+                    let places = &[Operand::Move(place)];
                     if let Some((args_span, generator_kind, capture_kind_span, path_span)) =
                         self.closure_span(closure_def_id, moved_place, places)
                     {
@@ -924,7 +921,7 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> {
         debug!("borrow_spans: use_span={:?} location={:?}", use_span, location);
 
         let target = match self.body[location.block].statements.get(location.statement_index) {
-            Some(&Statement { kind: StatementKind::Assign(box (ref place, _)), .. }) => {
+            Some(Statement { kind: StatementKind::Assign(box (place, _)), .. }) => {
                 if let Some(local) = place.as_local() {
                     local
                 } else {
@@ -940,9 +937,7 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> {
         }
 
         for stmt in &self.body[location.block].statements[location.statement_index + 1..] {
-            if let StatementKind::Assign(box (_, Rvalue::Aggregate(ref kind, ref places))) =
-                stmt.kind
-            {
+            if let StatementKind::Assign(box (_, Rvalue::Aggregate(kind, places))) = &stmt.kind {
                 let (&def_id, is_generator) = match kind {
                     box AggregateKind::Closure(def_id, _) => (def_id, false),
                     box AggregateKind::Generator(def_id, _, _) => (def_id, true),

compiler/rustc_borrowck/src/diagnostics/mutability_errors.rs

@@ -219,8 +219,8 @@ impl<'a, 'tcx> MirBorrowckCtxt<'a, 'tcx> {
             PlaceRef {
                 local,
                 projection:
-                    &[
-                        ref proj_base @ ..,
+                    [
+                        proj_base @ ..,
                         ProjectionElem::Deref,
                         ProjectionElem::Field(field, _),
                         ProjectionElem::Deref,
@@ -231,7 +231,7 @@ impl<'a, 'tcx> MirBorrowckCtxt<'a, 'tcx> {
                 if let Some(span) = get_mut_span_in_struct_field(
                     self.infcx.tcx,
                     Place::ty_from(local, proj_base, self.body, self.infcx.tcx).ty,
-                    field,
+                    *field,
                 ) {
                     err.span_suggestion_verbose(
                         span,

compiler/rustc_borrowck/src/diagnostics/region_errors.rs

@@ -921,7 +921,7 @@ impl<'a, 'tcx> MirBorrowckCtxt<'a, 'tcx> {
                 }
             }
             hir::ExprKind::Block(blk, _) => {
-                if let Some(ref expr) = blk.expr {
+                if let Some(expr) = blk.expr {
                     // only when the block is a closure
                     if let hir::ExprKind::Closure(hir::Closure {
                         capture_clause: hir::CaptureBy::Ref,

compiler/rustc_borrowck/src/diagnostics/region_name.rs

@@ -254,7 +254,7 @@ impl<'tcx> MirBorrowckCtxt<'_, 'tcx> {
             .or_else(|| self.give_name_if_anonymous_region_appears_in_impl_signature(fr))
             .or_else(|| self.give_name_if_anonymous_region_appears_in_arg_position_impl_trait(fr));
 
-        if let Some(ref value) = value {
+        if let Some(value) = &value {
             self.region_names.try_borrow_mut().unwrap().insert(fr, value.clone());
         }