Add `warn(unreachable_pub)` to `rustc_borrowck`.

18 files changed, 74 insertions, 68 deletions

diff --git a/compiler/rustc_borrowck/src/borrowck_errors.rs b/compiler/rustc_borrowck/src/borrowck_errors.rs
index 76e39fe94af..86f46b55bfb 100644
--- a/compiler/rustc_borrowck/src/borrowck_errors.rs
+++ b/compiler/rustc_borrowck/src/borrowck_errors.rs
@@ -9,7 +9,7 @@ use rustc_middle::ty::{self, Ty, TyCtxt};
 use rustc_span::Span;
 
 impl<'infcx, 'tcx> crate::MirBorrowckCtxt<'_, '_, 'infcx, 'tcx> {
-    pub fn dcx(&self) -> DiagCtxtHandle<'infcx> {
+    pub(crate) fn dcx(&self) -> DiagCtxtHandle<'infcx> {
         self.infcx.dcx()
     }
 
diff --git a/compiler/rustc_borrowck/src/dataflow.rs b/compiler/rustc_borrowck/src/dataflow.rs
index 77794a8525f..2795bc7162f 100644
--- a/compiler/rustc_borrowck/src/dataflow.rs
+++ b/compiler/rustc_borrowck/src/dataflow.rs
@@ -14,7 +14,7 @@ use rustc_mir_dataflow::{Analysis, AnalysisDomain, GenKill, Results, ResultsVisi
 use crate::{places_conflict, BorrowSet, PlaceConflictBias, PlaceExt, RegionInferenceContext};
 
 /// The results of the dataflow analyses used by the borrow checker.
-pub struct BorrowckResults<'a, 'mir, 'tcx> {
+pub(crate) struct BorrowckResults<'a, 'mir, 'tcx> {
     pub(crate) borrows: Results<'tcx, Borrows<'a, 'mir, 'tcx>>,
     pub(crate) uninits: Results<'tcx, MaybeUninitializedPlaces<'a, 'mir, 'tcx>>,
     pub(crate) ever_inits: Results<'tcx, EverInitializedPlaces<'a, 'mir, 'tcx>>,
@@ -22,7 +22,7 @@ pub struct BorrowckResults<'a, 'mir, 'tcx> {
 
 /// The transient state of the dataflow analyses used by the borrow checker.
 #[derive(Debug)]
-pub struct BorrowckFlowState<'a, 'mir, 'tcx> {
+pub(crate) struct BorrowckFlowState<'a, 'mir, 'tcx> {
     pub(crate) borrows: <Borrows<'a, 'mir, 'tcx> as AnalysisDomain<'tcx>>::Domain,
     pub(crate) uninits: <MaybeUninitializedPlaces<'a, 'mir, 'tcx> as AnalysisDomain<'tcx>>::Domain,
     pub(crate) ever_inits: <EverInitializedPlaces<'a, 'mir, 'tcx> as AnalysisDomain<'tcx>>::Domain,
diff --git a/compiler/rustc_borrowck/src/def_use.rs b/compiler/rustc_borrowck/src/def_use.rs
index 1f0b0981c8f..7eb9e689afe 100644
--- a/compiler/rustc_borrowck/src/def_use.rs
+++ b/compiler/rustc_borrowck/src/def_use.rs
@@ -4,13 +4,13 @@ use rustc_middle::mir::visit::{
 };
 
 #[derive(Eq, PartialEq, Clone)]
-pub enum DefUse {
+pub(crate) enum DefUse {
     Def,
     Use,
     Drop,
 }
 
-pub fn categorize(context: PlaceContext) -> Option<DefUse> {
+pub(crate) fn categorize(context: PlaceContext) -> Option<DefUse> {
     match context {
         ///////////////////////////////////////////////////////////////////////////
         // DEFS
diff --git a/compiler/rustc_borrowck/src/diagnostics/conflict_errors.rs b/compiler/rustc_borrowck/src/diagnostics/conflict_errors.rs
index 2b46e5597f7..cd35427b914 100644
--- a/compiler/rustc_borrowck/src/diagnostics/conflict_errors.rs
+++ b/compiler/rustc_borrowck/src/diagnostics/conflict_errors.rs
@@ -645,7 +645,7 @@ impl<'infcx, 'tcx> MirBorrowckCtxt<'_, '_, 'infcx, 'tcx> {
         }
     }
 
-    pub fn suggest_reborrow(
+    pub(crate) fn suggest_reborrow(
         &self,
         err: &mut Diag<'infcx>,
         span: Span,
@@ -1891,10 +1891,10 @@ impl<'infcx, 'tcx> MirBorrowckCtxt<'_, '_, 'infcx, 'tcx> {
         struct FindUselessClone<'tcx> {
             tcx: TyCtxt<'tcx>,
             typeck_results: &'tcx ty::TypeckResults<'tcx>,
-            pub clones: Vec<&'tcx hir::Expr<'tcx>>,
+            clones: Vec<&'tcx hir::Expr<'tcx>>,
         }
         impl<'tcx> FindUselessClone<'tcx> {
-            pub fn new(tcx: TyCtxt<'tcx>, def_id: LocalDefId) -> Self {
+            fn new(tcx: TyCtxt<'tcx>, def_id: LocalDefId) -> Self {
                 Self { tcx, typeck_results: tcx.typeck(def_id), clones: vec![] }
             }
         }
@@ -1916,7 +1916,7 @@ impl<'infcx, 'tcx> MirBorrowckCtxt<'_, '_, 'infcx, 'tcx> {
         let body = hir.body(body_id).value;
         expr_finder.visit_expr(body);
 
-        pub struct Holds<'tcx> {
+        struct Holds<'tcx> {
             ty: Ty<'tcx>,
         }
 
diff --git a/compiler/rustc_borrowck/src/diagnostics/mod.rs b/compiler/rustc_borrowck/src/diagnostics/mod.rs
index a2e5c7b8514..33f91d7ad30 100644
--- a/compiler/rustc_borrowck/src/diagnostics/mod.rs
+++ b/compiler/rustc_borrowck/src/diagnostics/mod.rs
@@ -58,11 +58,11 @@ pub(crate) use region_name::{RegionName, RegionNameSource};
 pub(crate) use rustc_middle::util::CallKind;
 
 pub(super) struct DescribePlaceOpt {
-    pub including_downcast: bool,
+    including_downcast: bool,
 
     /// Enable/Disable tuple fields.
     /// For example `x` tuple. if it's `true` `x.0`. Otherwise `x`
-    pub including_tuple_field: bool,
+    including_tuple_field: bool,
 }
 
 pub(super) struct IncludingTupleField(pub(super) bool);
diff --git a/compiler/rustc_borrowck/src/diagnostics/move_errors.rs b/compiler/rustc_borrowck/src/diagnostics/move_errors.rs
index 792f1548e08..42b1ffd58ad 100644
--- a/compiler/rustc_borrowck/src/diagnostics/move_errors.rs
+++ b/compiler/rustc_borrowck/src/diagnostics/move_errors.rs
@@ -16,7 +16,7 @@ use crate::prefixes::PrefixSet;
 use crate::MirBorrowckCtxt;
 
 #[derive(Debug)]
-pub enum IllegalMoveOriginKind<'tcx> {
+pub(crate) enum IllegalMoveOriginKind<'tcx> {
     /// Illegal move due to attempt to move from behind a reference.
     BorrowedContent {
         /// The place the reference refers to: if erroneous code was trying to
diff --git a/compiler/rustc_borrowck/src/diagnostics/mutability_errors.rs b/compiler/rustc_borrowck/src/diagnostics/mutability_errors.rs
index 0303b80cace..7b791928689 100644
--- a/compiler/rustc_borrowck/src/diagnostics/mutability_errors.rs
+++ b/compiler/rustc_borrowck/src/diagnostics/mutability_errors.rs
@@ -1374,7 +1374,7 @@ impl<'tcx> Visitor<'tcx> for BindingFinder {
     }
 }
 
-pub fn mut_borrow_of_mutable_ref(local_decl: &LocalDecl<'_>, local_name: Option<Symbol>) -> bool {
+fn mut_borrow_of_mutable_ref(local_decl: &LocalDecl<'_>, local_name: Option<Symbol>) -> bool {
     debug!("local_info: {:?}, ty.kind(): {:?}", local_decl.local_info, local_decl.ty.kind());
 
     match *local_decl.local_info() {
diff --git a/compiler/rustc_borrowck/src/diagnostics/outlives_suggestion.rs b/compiler/rustc_borrowck/src/diagnostics/outlives_suggestion.rs
index de0df347429..a59b7b3cde9 100644
--- a/compiler/rustc_borrowck/src/diagnostics/outlives_suggestion.rs
+++ b/compiler/rustc_borrowck/src/diagnostics/outlives_suggestion.rs
@@ -31,7 +31,7 @@ enum SuggestedConstraint {
 ///
 /// Adds a help note suggesting adding a where clause with the needed constraints.
 #[derive(Default)]
-pub struct OutlivesSuggestionBuilder {
+pub(crate) struct OutlivesSuggestionBuilder {
     /// The list of outlives constraints that need to be added. Specifically, we map each free
     /// region to all other regions that it must outlive. I will use the shorthand `fr:
     /// outlived_frs`. Not all of these regions will already have names necessarily. Some could be
diff --git a/compiler/rustc_borrowck/src/diagnostics/region_errors.rs b/compiler/rustc_borrowck/src/diagnostics/region_errors.rs
index 451e8bcb16d..ab48a09cfa4 100644
--- a/compiler/rustc_borrowck/src/diagnostics/region_errors.rs
+++ b/compiler/rustc_borrowck/src/diagnostics/region_errors.rs
@@ -72,22 +72,24 @@ impl<'tcx> ConstraintDescription for ConstraintCategory<'tcx> {
 pub(crate) struct RegionErrors<'tcx>(Vec<(RegionErrorKind<'tcx>, ErrorGuaranteed)>, TyCtxt<'tcx>);
 
 impl<'tcx> RegionErrors<'tcx> {
-    pub fn new(tcx: TyCtxt<'tcx>) -> Self {
+    pub(crate) fn new(tcx: TyCtxt<'tcx>) -> Self {
         Self(vec![], tcx)
     }
     #[track_caller]
-    pub fn push(&mut self, val: impl Into<RegionErrorKind<'tcx>>) {
+    pub(crate) fn push(&mut self, val: impl Into<RegionErrorKind<'tcx>>) {
         let val = val.into();
         let guar = self.1.sess.dcx().delayed_bug(format!("{val:?}"));
         self.0.push((val, guar));
     }
-    pub fn is_empty(&self) -> bool {
+    pub(crate) fn is_empty(&self) -> bool {
         self.0.is_empty()
     }
-    pub fn into_iter(self) -> impl Iterator<Item = (RegionErrorKind<'tcx>, ErrorGuaranteed)> {
+    pub(crate) fn into_iter(
+        self,
+    ) -> impl Iterator<Item = (RegionErrorKind<'tcx>, ErrorGuaranteed)> {
         self.0.into_iter()
     }
-    pub fn has_errors(&self) -> Option<ErrorGuaranteed> {
+    pub(crate) fn has_errors(&self) -> Option<ErrorGuaranteed> {
         self.0.get(0).map(|x| x.1)
     }
 }
@@ -141,7 +143,7 @@ pub(crate) enum RegionErrorKind<'tcx> {
 
 /// Information about the various region constraints involved in a borrow checker error.
 #[derive(Clone, Debug)]
-pub struct ErrorConstraintInfo<'tcx> {
+pub(crate) struct ErrorConstraintInfo<'tcx> {
     // fr: outlived_fr
     pub(super) fr: RegionVid,
     pub(super) fr_is_local: bool,
diff --git a/compiler/rustc_borrowck/src/lib.rs b/compiler/rustc_borrowck/src/lib.rs
index 30dd45d847c..5d54204bf80 100644
--- a/compiler/rustc_borrowck/src/lib.rs
+++ b/compiler/rustc_borrowck/src/lib.rs
@@ -12,6 +12,7 @@
 #![feature(rustdoc_internals)]
 #![feature(stmt_expr_attributes)]
 #![feature(try_blocks)]
+#![warn(unreachable_pub)]
 // tidy-alphabetical-end
 
 #[macro_use]
@@ -2444,7 +2445,7 @@ mod diags {
         }
     }
 
-    pub struct BorrowckDiags<'infcx, 'tcx> {
+    pub(crate) struct BorrowckDiags<'infcx, 'tcx> {
         /// This field keeps track of move errors that are to be reported for given move indices.
         ///
         /// There are situations where many errors can be reported for a single move out (see
@@ -2468,7 +2469,7 @@ mod diags {
     }
 
     impl<'infcx, 'tcx> BorrowckDiags<'infcx, 'tcx> {
-        pub fn new() -> Self {
+        pub(crate) fn new() -> Self {
             BorrowckDiags {
                 buffered_move_errors: BTreeMap::new(),
                 buffered_mut_errors: Default::default(),
@@ -2476,25 +2477,25 @@ mod diags {
             }
         }
 
-        pub fn buffer_error(&mut self, diag: Diag<'infcx>) {
+        pub(crate) fn buffer_error(&mut self, diag: Diag<'infcx>) {
             self.buffered_diags.push(BufferedDiag::Error(diag));
         }
 
-        pub fn buffer_non_error(&mut self, diag: Diag<'infcx, ()>) {
+        pub(crate) fn buffer_non_error(&mut self, diag: Diag<'infcx, ()>) {
             self.buffered_diags.push(BufferedDiag::NonError(diag));
         }
     }
 
     impl<'infcx, 'tcx> MirBorrowckCtxt<'_, '_, 'infcx, 'tcx> {
-        pub fn buffer_error(&mut self, diag: Diag<'infcx>) {
+        pub(crate) fn buffer_error(&mut self, diag: Diag<'infcx>) {
             self.diags.buffer_error(diag);
         }
 
-        pub fn buffer_non_error(&mut self, diag: Diag<'infcx, ()>) {
+        pub(crate) fn buffer_non_error(&mut self, diag: Diag<'infcx, ()>) {
             self.diags.buffer_non_error(diag);
         }
 
-        pub fn buffer_move_error(
+        pub(crate) fn buffer_move_error(
             &mut self,
             move_out_indices: Vec<MoveOutIndex>,
             place_and_err: (PlaceRef<'tcx>, Diag<'infcx>),
@@ -2510,16 +2511,19 @@ mod diags {
             }
         }
 
-        pub fn get_buffered_mut_error(&mut self, span: Span) -> Option<(Diag<'infcx>, usize)> {
+        pub(crate) fn get_buffered_mut_error(
+            &mut self,
+            span: Span,
+        ) -> Option<(Diag<'infcx>, usize)> {
             // FIXME(#120456) - is `swap_remove` correct?
             self.diags.buffered_mut_errors.swap_remove(&span)
         }
 
-        pub fn buffer_mut_error(&mut self, span: Span, diag: Diag<'infcx>, count: usize) {
+        pub(crate) fn buffer_mut_error(&mut self, span: Span, diag: Diag<'infcx>, count: usize) {
             self.diags.buffered_mut_errors.insert(span, (diag, count));
         }
 
-        pub fn emit_errors(&mut self) -> Option<ErrorGuaranteed> {
+        pub(crate) fn emit_errors(&mut self) -> Option<ErrorGuaranteed> {
             let mut res = None;
 
             // Buffer any move errors that we collected and de-duplicated.
@@ -2553,7 +2557,7 @@ mod diags {
             self.diags.buffered_diags.is_empty()
         }
 
-        pub fn has_move_error(
+        pub(crate) fn has_move_error(
             &self,
             move_out_indices: &[MoveOutIndex],
         ) -> Option<&(PlaceRef<'tcx>, Diag<'infcx>)> {
diff --git a/compiler/rustc_borrowck/src/prefixes.rs b/compiler/rustc_borrowck/src/prefixes.rs
index d3bfd1c418f..39d831378cd 100644
--- a/compiler/rustc_borrowck/src/prefixes.rs
+++ b/compiler/rustc_borrowck/src/prefixes.rs
@@ -8,7 +8,7 @@ use rustc_middle::mir::{PlaceRef, ProjectionElem};
 
 use super::MirBorrowckCtxt;
 
-pub trait IsPrefixOf<'tcx> {
+pub(crate) trait IsPrefixOf<'tcx> {
     fn is_prefix_of(&self, other: PlaceRef<'tcx>) -> bool;
 }
 
diff --git a/compiler/rustc_borrowck/src/region_infer/mod.rs b/compiler/rustc_borrowck/src/region_infer/mod.rs
index c8dc012de4a..6cbdd890b5e 100644
--- a/compiler/rustc_borrowck/src/region_infer/mod.rs
+++ b/compiler/rustc_borrowck/src/region_infer/mod.rs
@@ -42,9 +42,9 @@ mod graphviz;
 mod opaque_types;
 mod reverse_sccs;
 
-pub mod values;
+pub(crate) mod values;
 
-pub type ConstraintSccs = Sccs<RegionVid, ConstraintSccIndex, RegionTracker>;
+pub(crate) type ConstraintSccs = Sccs<RegionVid, ConstraintSccIndex, RegionTracker>;
 
 /// An annotation for region graph SCCs that tracks
 /// the values of its elements.
@@ -226,7 +226,7 @@ pub(crate) struct AppliedMemberConstraint {
 }
 
 #[derive(Debug)]
-pub struct RegionDefinition<'tcx> {
+pub(crate) struct RegionDefinition<'tcx> {
     /// What kind of variable is this -- a free region? existential
     /// variable? etc. (See the `NllRegionVariableOrigin` for more
     /// info.)
@@ -288,7 +288,7 @@ pub(crate) enum Cause {
 /// `InferCtxt::process_registered_region_obligations` and
 /// `InferCtxt::type_must_outlive` in `rustc_infer::infer::InferCtxt`.
 #[derive(Clone, Debug)]
-pub struct TypeTest<'tcx> {
+pub(crate) struct TypeTest<'tcx> {
     /// The type `T` that must outlive the region.
     pub generic_kind: GenericKind<'tcx>,
 
@@ -320,7 +320,7 @@ enum Trace<'tcx> {
 }
 
 #[derive(Clone, PartialEq, Eq, Debug)]
-pub enum ExtraConstraintInfo {
+pub(crate) enum ExtraConstraintInfo {
     PlaceholderFromPredicate(Span),
 }
 
@@ -2259,7 +2259,7 @@ impl<'tcx> RegionDefinition<'tcx> {
 }
 
 #[derive(Clone, Debug)]
-pub struct BlameConstraint<'tcx> {
+pub(crate) struct BlameConstraint<'tcx> {
     pub category: ConstraintCategory<'tcx>,
     pub from_closure: bool,
     pub cause: ObligationCause<'tcx>,
diff --git a/compiler/rustc_borrowck/src/region_infer/opaque_types.rs b/compiler/rustc_borrowck/src/region_infer/opaque_types.rs
index 1073ea40694..cd66acd0a8f 100644
--- a/compiler/rustc_borrowck/src/region_infer/opaque_types.rs
+++ b/compiler/rustc_borrowck/src/region_infer/opaque_types.rs
@@ -473,20 +473,20 @@ struct LazyOpaqueTyEnv<'tcx> {
 }
 
 impl<'tcx> LazyOpaqueTyEnv<'tcx> {
-    pub fn new(tcx: TyCtxt<'tcx>, def_id: LocalDefId) -> Self {
+    fn new(tcx: TyCtxt<'tcx>, def_id: LocalDefId) -> Self {
         Self { tcx, def_id, canonical_args: std::cell::OnceCell::new() }
     }
 
-    pub fn param_equal_static(&self, param_index: usize) -> bool {
+    fn param_equal_static(&self, param_index: usize) -> bool {
         self.get_canonical_args()[param_index].expect_region().is_static()
     }
 
-    pub fn params_equal(&self, param1: usize, param2: usize) -> bool {
+    fn params_equal(&self, param1: usize, param2: usize) -> bool {
         let canonical_args = self.get_canonical_args();
         canonical_args[param1] == canonical_args[param2]
     }
 
-    pub fn param_is_error(&self, param_index: usize) -> Result<(), ErrorGuaranteed> {
+    fn param_is_error(&self, param_index: usize) -> Result<(), ErrorGuaranteed> {
         self.get_canonical_args()[param_index].error_reported()
     }
 
diff --git a/compiler/rustc_borrowck/src/type_check/mod.rs b/compiler/rustc_borrowck/src/type_check/mod.rs
index a2669da1b04..bbcc2bbdc10 100644
--- a/compiler/rustc_borrowck/src/type_check/mod.rs
+++ b/compiler/rustc_borrowck/src/type_check/mod.rs
@@ -86,7 +86,7 @@ macro_rules! span_mirbug_and_err {
 
 mod canonical;
 mod constraint_conversion;
-pub mod free_region_relations;
+pub(crate) mod free_region_relations;
 mod input_output;
 pub(crate) mod liveness;
 mod relate_tys;
diff --git a/compiler/rustc_borrowck/src/type_check/relate_tys.rs b/compiler/rustc_borrowck/src/type_check/relate_tys.rs
index 8da4d80badf..35d8e2573fe 100644
--- a/compiler/rustc_borrowck/src/type_check/relate_tys.rs
+++ b/compiler/rustc_borrowck/src/type_check/relate_tys.rs
@@ -57,7 +57,7 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> {
     }
 }
 
-pub struct NllTypeRelating<'me, 'bccx, 'tcx> {
+struct NllTypeRelating<'me, 'bccx, 'tcx> {
     type_checker: &'me mut TypeChecker<'bccx, 'tcx>,
 
     /// Where (and why) is this relation taking place?
@@ -82,7 +82,7 @@ pub struct NllTypeRelating<'me, 'bccx, 'tcx> {
 }
 
 impl<'me, 'bccx, 'tcx> NllTypeRelating<'me, 'bccx, 'tcx> {
-    pub fn new(
+    fn new(
         type_checker: &'me mut TypeChecker<'bccx, 'tcx>,
         locations: Locations,
         category: ConstraintCategory<'tcx>,
diff --git a/compiler/rustc_borrowck/src/universal_regions.rs b/compiler/rustc_borrowck/src/universal_regions.rs
index 1ad80cb122a..2e41c918774 100644
--- a/compiler/rustc_borrowck/src/universal_regions.rs
+++ b/compiler/rustc_borrowck/src/universal_regions.rs
@@ -39,7 +39,7 @@ use crate::renumber::RegionCtxt;
 use crate::BorrowckInferCtxt;
 
 #[derive(Debug)]
-pub struct UniversalRegions<'tcx> {
+pub(crate) struct UniversalRegions<'tcx> {
     indices: UniversalRegionIndices<'tcx>,
 
     /// The vid assigned to `'static`
@@ -95,7 +95,7 @@ pub struct UniversalRegions<'tcx> {
 /// regions appear free in the defining type and late-bound regions
 /// appear bound in the signature.
 #[derive(Copy, Clone, Debug)]
-pub enum DefiningTy<'tcx> {
+pub(crate) enum DefiningTy<'tcx> {
     /// The MIR is a closure. The signature is found via
     /// `ClosureArgs::closure_sig_ty`.
     Closure(DefId, GenericArgsRef<'tcx>),
@@ -131,7 +131,7 @@ impl<'tcx> DefiningTy<'tcx> {
     /// not a closure or coroutine, there are no upvars, and hence it
     /// will be an empty list. The order of types in this list will
     /// match up with the upvar order in the HIR, typesystem, and MIR.
-    pub fn upvar_tys(self) -> &'tcx ty::List<Ty<'tcx>> {
+    pub(crate) fn upvar_tys(self) -> &'tcx ty::List<Ty<'tcx>> {
         match self {
             DefiningTy::Closure(_, args) => args.as_closure().upvar_tys(),
             DefiningTy::CoroutineClosure(_, args) => args.as_coroutine_closure().upvar_tys(),
@@ -145,7 +145,7 @@ impl<'tcx> DefiningTy<'tcx> {
     /// Number of implicit inputs -- notably the "environment"
     /// parameter for closures -- that appear in MIR but not in the
     /// user's code.
-    pub fn implicit_inputs(self) -> usize {
+    pub(crate) fn implicit_inputs(self) -> usize {
         match self {
             DefiningTy::Closure(..)
             | DefiningTy::CoroutineClosure(..)
@@ -154,15 +154,15 @@ impl<'tcx> DefiningTy<'tcx> {
         }
     }
 
-    pub fn is_fn_def(&self) -> bool {
+    pub(crate) fn is_fn_def(&self) -> bool {
         matches!(*self, DefiningTy::FnDef(..))
     }
 
-    pub fn is_const(&self) -> bool {
+    pub(crate) fn is_const(&self) -> bool {
         matches!(*self, DefiningTy::Const(..) | DefiningTy::InlineConst(..))
     }
 
-    pub fn def_id(&self) -> DefId {
+    pub(crate) fn def_id(&self) -> DefId {
         match *self {
             DefiningTy::Closure(def_id, ..)
             | DefiningTy::CoroutineClosure(def_id, ..)
@@ -196,7 +196,7 @@ struct UniversalRegionIndices<'tcx> {
 }
 
 #[derive(Debug, PartialEq)]
-pub enum RegionClassification {
+pub(crate) enum RegionClassification {
     /// A **global** region is one that can be named from
     /// anywhere. There is only one, `'static`.
     Global,
@@ -246,7 +246,7 @@ impl<'tcx> UniversalRegions<'tcx> {
     /// MIR -- that is, all the regions that appear in the function's
     /// signature. This will also compute the relationships that are
     /// known between those regions.
-    pub fn new(
+    pub(crate) fn new(
         infcx: &BorrowckInferCtxt<'tcx>,
         mir_def: LocalDefId,
         param_env: ty::ParamEnv<'tcx>,
@@ -263,7 +263,7 @@ impl<'tcx> UniversalRegions<'tcx> {
     /// if the `ClosureRegionRequirements` contains something like
     /// `'1: '2`, then the caller would impose the constraint that
     /// `V[1]: V[2]`.
-    pub fn closure_mapping(
+    pub(crate) fn closure_mapping(
         tcx: TyCtxt<'tcx>,
         closure_args: GenericArgsRef<'tcx>,
         expected_num_vars: usize,
@@ -289,13 +289,13 @@ impl<'tcx> UniversalRegions<'tcx> {
     }
 
     /// Returns `true` if `r` is a member of this set of universal regions.
-    pub fn is_universal_region(&self, r: RegionVid) -> bool {
+    pub(crate) fn is_universal_region(&self, r: RegionVid) -> bool {
         (FIRST_GLOBAL_INDEX..self.num_universals).contains(&r.index())
     }
 
     /// Classifies `r` as a universal region, returning `None` if this
     /// is not a member of this set of universal regions.
-    pub fn region_classification(&self, r: RegionVid) -> Option<RegionClassification> {
+    pub(crate) fn region_classification(&self, r: RegionVid) -> Option<RegionClassification> {
         let index = r.index();
         if (FIRST_GLOBAL_INDEX..self.first_extern_index).contains(&index) {
             Some(RegionClassification::Global)
@@ -310,17 +310,17 @@ impl<'tcx> UniversalRegions<'tcx> {
 
     /// Returns an iterator over all the RegionVids corresponding to
     /// universally quantified free regions.
-    pub fn universal_regions(&self) -> impl Iterator<Item = RegionVid> {
+    pub(crate) fn universal_regions(&self) -> impl Iterator<Item = RegionVid> {
         (FIRST_GLOBAL_INDEX..self.num_universals).map(RegionVid::from_usize)
     }
 
     /// Returns `true` if `r` is classified as a local region.
-    pub fn is_local_free_region(&self, r: RegionVid) -> bool {
+    pub(crate) fn is_local_free_region(&self, r: RegionVid) -> bool {
         self.region_classification(r) == Some(RegionClassification::Local)
     }
 
     /// Returns the number of universal regions created in any category.
-    pub fn len(&self) -> usize {
+    pub(crate) fn len(&self) -> usize {
         self.num_universals
     }
 
@@ -329,19 +329,19 @@ impl<'tcx> UniversalRegions<'tcx> {
     /// closure type (versus those bound in the closure
     /// signature). They are therefore the regions between which the
     /// closure may impose constraints that its creator must verify.
-    pub fn num_global_and_external_regions(&self) -> usize {
+    pub(crate) fn num_global_and_external_regions(&self) -> usize {
         self.first_local_index
     }
 
     /// Gets an iterator over all the early-bound regions that have names.
-    pub fn named_universal_regions<'s>(
+    pub(crate) fn named_universal_regions<'s>(
         &'s self,
     ) -> impl Iterator<Item = (ty::Region<'tcx>, ty::RegionVid)> + 's {
         self.indices.indices.iter().map(|(&r, &v)| (r, v))
     }
 
     /// See `UniversalRegionIndices::to_region_vid`.
-    pub fn to_region_vid(&self, r: ty::Region<'tcx>) -> RegionVid {
+    pub(crate) fn to_region_vid(&self, r: ty::Region<'tcx>) -> RegionVid {
         self.indices.to_region_vid(r)
     }
 
@@ -416,7 +416,7 @@ impl<'tcx> UniversalRegions<'tcx> {
         }
     }
 
-    pub fn tainted_by_errors(&self) -> Option<ErrorGuaranteed> {
+    pub(crate) fn tainted_by_errors(&self) -> Option<ErrorGuaranteed> {
         self.indices.tainted_by_errors.get()
     }
 }
@@ -880,7 +880,7 @@ impl<'tcx> UniversalRegionIndices<'tcx> {
     /// reference those regions from the `ParamEnv`. It is also used
     /// during initialization. Relies on the `indices` map having been
     /// fully initialized.
-    pub fn to_region_vid(&self, r: ty::Region<'tcx>) -> RegionVid {
+    fn to_region_vid(&self, r: ty::Region<'tcx>) -> RegionVid {
         if let ty::ReVar(..) = *r {
             r.as_var()
         } else if let ty::ReError(guar) = *r {
@@ -899,7 +899,7 @@ impl<'tcx> UniversalRegionIndices<'tcx> {
 
     /// Replaces all free regions in `value` with region vids, as
     /// returned by `to_region_vid`.
-    pub fn fold_to_region_vids<T>(&self, tcx: TyCtxt<'tcx>, value: T) -> T
+    fn fold_to_region_vids<T>(&self, tcx: TyCtxt<'tcx>, value: T) -> T
     where
         T: TypeFoldable<TyCtxt<'tcx>>,
     {
diff --git a/compiler/rustc_borrowck/src/util/collect_writes.rs b/compiler/rustc_borrowck/src/util/collect_writes.rs
index 93c7810b545..55f1073176a 100644
--- a/compiler/rustc_borrowck/src/util/collect_writes.rs
+++ b/compiler/rustc_borrowck/src/util/collect_writes.rs
@@ -1,7 +1,7 @@
 use rustc_middle::mir::visit::{PlaceContext, Visitor};
 use rustc_middle::mir::{Body, Local, Location};
 
-pub trait FindAssignments {
+pub(crate) trait FindAssignments {
     // Finds all statements that assign directly to local (i.e., X = ...)
     // and returns their locations.
     fn find_assignments(&self, local: Local) -> Vec<Location>;
diff --git a/compiler/rustc_borrowck/src/util/mod.rs b/compiler/rustc_borrowck/src/util/mod.rs
index 7377d4de727..5f2960b768b 100644
--- a/compiler/rustc_borrowck/src/util/mod.rs
+++ b/compiler/rustc_borrowck/src/util/mod.rs
@@ -1,3 +1,3 @@
 mod collect_writes;
 
-pub use collect_writes::FindAssignments;
+pub(crate) use collect_writes::FindAssignments;