Auto merge of #2738 - RalfJung:rustup, r=RalfJung

Rustup

14 files changed, 158 insertions, 68 deletions

diff --git a/compiler/rustc_hir_analysis/src/astconv/mod.rs b/compiler/rustc_hir_analysis/src/astconv/mod.rs
index 71f26eb60c9..c29a3afd7fb 100644
--- a/compiler/rustc_hir_analysis/src/astconv/mod.rs
+++ b/compiler/rustc_hir_analysis/src/astconv/mod.rs
@@ -26,11 +26,9 @@ use rustc_hir::intravisit::{walk_generics, Visitor as _};
 use rustc_hir::{GenericArg, GenericArgs, OpaqueTyOrigin};
 use rustc_middle::middle::stability::AllowUnstable;
 use rustc_middle::ty::subst::{self, GenericArgKind, InternalSubsts, SubstsRef};
-use rustc_middle::ty::DynKind;
 use rustc_middle::ty::GenericParamDefKind;
-use rustc_middle::ty::{
-    self, Const, DefIdTree, EarlyBinder, IsSuggestable, Ty, TyCtxt, TypeVisitable,
-};
+use rustc_middle::ty::{self, Const, DefIdTree, IsSuggestable, Ty, TyCtxt, TypeVisitable};
+use rustc_middle::ty::{DynKind, EarlyBinder};
 use rustc_session::lint::builtin::{AMBIGUOUS_ASSOCIATED_ITEMS, BARE_TRAIT_OBJECTS};
 use rustc_span::edition::Edition;
 use rustc_span::lev_distance::find_best_match_for_name;
@@ -490,7 +488,8 @@ impl<'o, 'tcx> dyn AstConv<'tcx> + 'o {
                             self.astconv
                                 .normalize_ty(
                                     self.span,
-                                    EarlyBinder(tcx.at(self.span).type_of(param.def_id))
+                                    tcx.at(self.span)
+                                        .bound_type_of(param.def_id)
                                         .subst(tcx, substs),
                                 )
                                 .into()
@@ -1255,10 +1254,7 @@ impl<'o, 'tcx> dyn AstConv<'tcx> + 'o {
         item_segment: &hir::PathSegment<'_>,
     ) -> Ty<'tcx> {
         let substs = self.ast_path_substs_for_ty(span, did, item_segment);
-        self.normalize_ty(
-            span,
-            EarlyBinder(self.tcx().at(span).type_of(did)).subst(self.tcx(), substs),
-        )
+        self.normalize_ty(span, self.tcx().at(span).bound_type_of(did).subst(self.tcx(), substs))
     }
 
     fn conv_object_ty_poly_trait_ref(
@@ -2240,7 +2236,7 @@ impl<'o, 'tcx> dyn AstConv<'tcx> + 'o {
                     ),
                     "s",
                 ),
-                [only] => (format!("{only}"), ""),
+                [only] => (only.to_string(), ""),
                 [] => unreachable!(),
             };
             let last_span = *arg_spans.last().unwrap();
diff --git a/compiler/rustc_hir_analysis/src/check/check.rs b/compiler/rustc_hir_analysis/src/check/check.rs
index aa01feb3a1e..a714663741b 100644
--- a/compiler/rustc_hir_analysis/src/check/check.rs
+++ b/compiler/rustc_hir_analysis/src/check/check.rs
@@ -99,18 +99,17 @@ fn check_union_fields(tcx: TyCtxt<'_>, span: Span, item_def_id: LocalDefId) -> b
             ty: Ty<'tcx>,
             tcx: TyCtxt<'tcx>,
             param_env: ty::ParamEnv<'tcx>,
-            span: Span,
         ) -> bool {
             // We don't just accept all !needs_drop fields, due to semver concerns.
             match ty.kind() {
                 ty::Ref(..) => true, // references never drop (even mutable refs, which are non-Copy and hence fail the later check)
                 ty::Tuple(tys) => {
                     // allow tuples of allowed types
-                    tys.iter().all(|ty| allowed_union_field(ty, tcx, param_env, span))
+                    tys.iter().all(|ty| allowed_union_field(ty, tcx, param_env))
                 }
                 ty::Array(elem, _len) => {
                     // Like `Copy`, we do *not* special-case length 0.
-                    allowed_union_field(*elem, tcx, param_env, span)
+                    allowed_union_field(*elem, tcx, param_env)
                 }
                 _ => {
                     // Fallback case: allow `ManuallyDrop` and things that are `Copy`.
@@ -124,7 +123,7 @@ fn check_union_fields(tcx: TyCtxt<'_>, span: Span, item_def_id: LocalDefId) -> b
         for field in &def.non_enum_variant().fields {
             let field_ty = field.ty(tcx, substs);
 
-            if !allowed_union_field(field_ty, tcx, param_env, span) {
+            if !allowed_union_field(field_ty, tcx, param_env) {
                 let (field_span, ty_span) = match tcx.hir().get_if_local(field.did) {
                     // We are currently checking the type this field came from, so it must be local.
                     Some(Node::Field(field)) => (field.span, field.ty.span),
@@ -163,7 +162,7 @@ fn check_union_fields(tcx: TyCtxt<'_>, span: Span, item_def_id: LocalDefId) -> b
 }
 
 /// Check that a `static` is inhabited.
-fn check_static_inhabited<'tcx>(tcx: TyCtxt<'tcx>, def_id: LocalDefId) {
+fn check_static_inhabited(tcx: TyCtxt<'_>, def_id: LocalDefId) {
     // Make sure statics are inhabited.
     // Other parts of the compiler assume that there are no uninhabited places. In principle it
     // would be enough to check this for `extern` statics, as statics with an initializer will
@@ -213,7 +212,7 @@ fn check_static_inhabited<'tcx>(tcx: TyCtxt<'tcx>, def_id: LocalDefId) {
 
 /// Checks that an opaque type does not contain cycles and does not use `Self` or `T::Foo`
 /// projections that would result in "inheriting lifetimes".
-fn check_opaque<'tcx>(tcx: TyCtxt<'tcx>, id: hir::ItemId) {
+fn check_opaque(tcx: TyCtxt<'_>, id: hir::ItemId) {
     let item = tcx.hir().item(id);
     let hir::ItemKind::OpaqueTy(hir::OpaqueTy { origin, .. }) = item.kind else {
         tcx.sess.delay_span_bug(tcx.hir().span(id.hir_id()), "expected opaque item");
@@ -246,8 +245,8 @@ fn check_opaque<'tcx>(tcx: TyCtxt<'tcx>, id: hir::ItemId) {
 /// Checks that an opaque type does not use `Self` or `T::Foo` projections that would result
 /// in "inheriting lifetimes".
 #[instrument(level = "debug", skip(tcx, span))]
-pub(super) fn check_opaque_for_inheriting_lifetimes<'tcx>(
-    tcx: TyCtxt<'tcx>,
+pub(super) fn check_opaque_for_inheriting_lifetimes(
+    tcx: TyCtxt<'_>,
     def_id: LocalDefId,
     span: Span,
 ) {
@@ -497,7 +496,7 @@ fn is_enum_of_nonnullable_ptr<'tcx>(
     matches!(field.ty(tcx, substs).kind(), ty::FnPtr(..) | ty::Ref(..))
 }
 
-fn check_static_linkage<'tcx>(tcx: TyCtxt<'tcx>, def_id: LocalDefId) {
+fn check_static_linkage(tcx: TyCtxt<'_>, def_id: LocalDefId) {
     if tcx.codegen_fn_attrs(def_id).import_linkage.is_some() {
         if match tcx.type_of(def_id).kind() {
             ty::RawPtr(_) => false,
@@ -509,7 +508,7 @@ fn check_static_linkage<'tcx>(tcx: TyCtxt<'tcx>, def_id: LocalDefId) {
     }
 }
 
-fn check_item_type<'tcx>(tcx: TyCtxt<'tcx>, id: hir::ItemId) {
+fn check_item_type(tcx: TyCtxt<'_>, id: hir::ItemId) {
     debug!(
         "check_item_type(it.def_id={:?}, it.name={})",
         id.owner_id,
@@ -1161,7 +1160,7 @@ pub(super) fn check_transparent<'tcx>(tcx: TyCtxt<'tcx>, adt: ty::AdtDef<'tcx>)
 }
 
 #[allow(trivial_numeric_casts)]
-fn check_enum<'tcx>(tcx: TyCtxt<'tcx>, def_id: LocalDefId) {
+fn check_enum(tcx: TyCtxt<'_>, def_id: LocalDefId) {
     let def = tcx.adt_def(def_id);
     def.destructor(tcx); // force the destructor to be evaluated
 
diff --git a/compiler/rustc_hir_analysis/src/check/compare_method.rs b/compiler/rustc_hir_analysis/src/check/compare_method.rs
index 6b9ce9a4599..c6bda9b4641 100644
--- a/compiler/rustc_hir_analysis/src/check/compare_method.rs
+++ b/compiler/rustc_hir_analysis/src/check/compare_method.rs
@@ -71,8 +71,14 @@ pub(crate) fn compare_impl_method<'tcx>(
         return;
     }
 
-    if let Err(_) = compare_predicate_entailment(tcx, impl_m, impl_m_span, trait_m, impl_trait_ref)
-    {
+    if let Err(_) = compare_predicate_entailment(
+        tcx,
+        impl_m,
+        impl_m_span,
+        trait_m,
+        impl_trait_ref,
+        CheckImpliedWfMode::Check,
+    ) {
         return;
     }
 }
@@ -150,6 +156,7 @@ fn compare_predicate_entailment<'tcx>(
     impl_m_span: Span,
     trait_m: &ty::AssocItem,
     impl_trait_ref: ty::TraitRef<'tcx>,
+    check_implied_wf: CheckImpliedWfMode,
 ) -> Result<(), ErrorGuaranteed> {
     let trait_to_impl_substs = impl_trait_ref.substs;
 
@@ -255,15 +262,15 @@ fn compare_predicate_entailment<'tcx>(
 
     let mut wf_tys = FxIndexSet::default();
 
-    let impl_sig = infcx.replace_bound_vars_with_fresh_vars(
+    let unnormalized_impl_sig = infcx.replace_bound_vars_with_fresh_vars(
         impl_m_span,
         infer::HigherRankedType,
         tcx.fn_sig(impl_m.def_id),
     );
+    let unnormalized_impl_fty = tcx.mk_fn_ptr(ty::Binder::dummy(unnormalized_impl_sig));
 
     let norm_cause = ObligationCause::misc(impl_m_span, impl_m_hir_id);
-    let impl_sig = ocx.normalize(&norm_cause, param_env, impl_sig);
-    let impl_fty = tcx.mk_fn_ptr(ty::Binder::dummy(impl_sig));
+    let impl_fty = ocx.normalize(&norm_cause, param_env, unnormalized_impl_fty);
     debug!("compare_impl_method: impl_fty={:?}", impl_fty);
 
     let trait_sig = tcx.bound_fn_sig(trait_m.def_id).subst(tcx, trait_to_placeholder_substs);
@@ -304,29 +311,108 @@ fn compare_predicate_entailment<'tcx>(
         return Err(emitted);
     }
 
+    if check_implied_wf == CheckImpliedWfMode::Check {
+        // We need to check that the impl's args are well-formed given
+        // the hybrid param-env (impl + trait method where-clauses).
+        ocx.register_obligation(traits::Obligation::new(
+            infcx.tcx,
+            ObligationCause::dummy(),
+            param_env,
+            ty::Binder::dummy(ty::PredicateKind::WellFormed(unnormalized_impl_fty.into())),
+        ));
+    }
+    let emit_implied_wf_lint = || {
+        infcx.tcx.struct_span_lint_hir(
+            rustc_session::lint::builtin::IMPLIED_BOUNDS_ENTAILMENT,
+            impl_m_hir_id,
+            infcx.tcx.def_span(impl_m.def_id),
+            "impl method assumes more implied bounds than the corresponding trait method",
+            |lint| lint,
+        );
+    };
+
     // Check that all obligations are satisfied by the implementation's
     // version.
     let errors = ocx.select_all_or_error();
     if !errors.is_empty() {
-        let reported = infcx.err_ctxt().report_fulfillment_errors(&errors, None);
-        return Err(reported);
+        match check_implied_wf {
+            CheckImpliedWfMode::Check => {
+                return compare_predicate_entailment(
+                    tcx,
+                    impl_m,
+                    impl_m_span,
+                    trait_m,
+                    impl_trait_ref,
+                    CheckImpliedWfMode::Skip,
+                )
+                .map(|()| {
+                    // If the skip-mode was successful, emit a lint.
+                    emit_implied_wf_lint();
+                });
+            }
+            CheckImpliedWfMode::Skip => {
+                let reported = infcx.err_ctxt().report_fulfillment_errors(&errors, None);
+                return Err(reported);
+            }
+        }
     }
 
     // Finally, resolve all regions. This catches wily misuses of
     // lifetime parameters.
-    let outlives_environment = OutlivesEnvironment::with_bounds(
+    let outlives_env = OutlivesEnvironment::with_bounds(
         param_env,
         Some(infcx),
-        infcx.implied_bounds_tys(param_env, impl_m_hir_id, wf_tys),
+        infcx.implied_bounds_tys(param_env, impl_m_hir_id, wf_tys.clone()),
     );
-    infcx.check_region_obligations_and_report_errors(
-        impl_m.def_id.expect_local(),
-        &outlives_environment,
+    infcx.process_registered_region_obligations(
+        outlives_env.region_bound_pairs(),
+        outlives_env.param_env,
     );
+    let errors = infcx.resolve_regions(&outlives_env);
+    if !errors.is_empty() {
+        // FIXME(compiler-errors): This can be simplified when IMPLIED_BOUNDS_ENTAILMENT
+        // becomes a hard error (i.e. ideally we'd just call `resolve_regions_and_report_errors`
+        match check_implied_wf {
+            CheckImpliedWfMode::Check => {
+                return compare_predicate_entailment(
+                    tcx,
+                    impl_m,
+                    impl_m_span,
+                    trait_m,
+                    impl_trait_ref,
+                    CheckImpliedWfMode::Skip,
+                )
+                .map(|()| {
+                    // If the skip-mode was successful, emit a lint.
+                    emit_implied_wf_lint();
+                });
+            }
+            CheckImpliedWfMode::Skip => {
+                if infcx.tainted_by_errors().is_none() {
+                    infcx.err_ctxt().report_region_errors(impl_m.def_id.expect_local(), &errors);
+                }
+                return Err(tcx
+                    .sess
+                    .delay_span_bug(rustc_span::DUMMY_SP, "error should have been emitted"));
+            }
+        }
+    }
 
     Ok(())
 }
 
+#[derive(Debug, PartialEq, Eq)]
+enum CheckImpliedWfMode {
+    /// Checks implied well-formedness of the impl method. If it fails, we will
+    /// re-check with `Skip`, and emit a lint if it succeeds.
+    Check,
+    /// Skips checking implied well-formedness of the impl method, but will emit
+    /// a lint if the `compare_predicate_entailment` succeeded. This means that
+    /// the reason that we had failed earlier during `Check` was due to the impl
+    /// having stronger requirements than the trait.
+    Skip,
+}
+
 fn compare_asyncness<'tcx>(
     tcx: TyCtxt<'tcx>,
     impl_m: &ty::AssocItem,
@@ -405,6 +491,7 @@ pub fn collect_trait_impl_trait_tys<'tcx>(
             tcx.fn_sig(impl_m.def_id),
         ),
     );
+    impl_sig.error_reported()?;
     let impl_return_ty = impl_sig.output();
 
     // Normalize the trait signature with liberated bound vars, passing it through
@@ -419,6 +506,7 @@ pub fn collect_trait_impl_trait_tys<'tcx>(
         )
         .fold_with(&mut collector);
     let trait_sig = ocx.normalize(&norm_cause, param_env, unnormalized_trait_sig);
+    trait_sig.error_reported()?;
     let trait_return_ty = trait_sig.output();
 
     let wf_tys = FxIndexSet::from_iter(
@@ -1429,8 +1517,8 @@ fn compare_generic_param_kinds<'tcx>(
 }
 
 /// Use `tcx.compare_assoc_const_impl_item_with_trait_item` instead
-pub(crate) fn raw_compare_const_impl<'tcx>(
-    tcx: TyCtxt<'tcx>,
+pub(crate) fn raw_compare_const_impl(
+    tcx: TyCtxt<'_>,
     (impl_const_item_def, trait_const_item_def): (LocalDefId, DefId),
 ) -> Result<(), ErrorGuaranteed> {
     let impl_const_item = tcx.associated_item(impl_const_item_def);
diff --git a/compiler/rustc_hir_analysis/src/check/intrinsic.rs b/compiler/rustc_hir_analysis/src/check/intrinsic.rs
index 69e54b41d4c..598dc2dca5c 100644
--- a/compiler/rustc_hir_analysis/src/check/intrinsic.rs
+++ b/compiler/rustc_hir_analysis/src/check/intrinsic.rs
@@ -75,7 +75,7 @@ pub fn intrinsic_operation_unsafety(tcx: TyCtxt<'_>, intrinsic_id: DefId) -> hir
         sym::abort
         | sym::assert_inhabited
         | sym::assert_zero_valid
-        | sym::assert_uninit_valid
+        | sym::assert_mem_uninitialized_valid
         | sym::size_of
         | sym::min_align_of
         | sym::needs_drop
@@ -193,9 +193,9 @@ pub fn check_intrinsic_type(tcx: TyCtxt<'_>, it: &hir::ForeignItem<'_>) {
             }
             sym::rustc_peek => (1, vec![param(0)], param(0)),
             sym::caller_location => (0, vec![], tcx.caller_location_ty()),
-            sym::assert_inhabited | sym::assert_zero_valid | sym::assert_uninit_valid => {
-                (1, Vec::new(), tcx.mk_unit())
-            }
+            sym::assert_inhabited
+            | sym::assert_zero_valid
+            | sym::assert_mem_uninitialized_valid => (1, Vec::new(), tcx.mk_unit()),
             sym::forget => (1, vec![param(0)], tcx.mk_unit()),
             sym::transmute => (2, vec![param(0)], param(1)),
             sym::prefetch_read_data
diff --git a/compiler/rustc_hir_analysis/src/check/mod.rs b/compiler/rustc_hir_analysis/src/check/mod.rs
index 57f0cae12bb..ed2aed293a7 100644
--- a/compiler/rustc_hir_analysis/src/check/mod.rs
+++ b/compiler/rustc_hir_analysis/src/check/mod.rs
@@ -115,10 +115,10 @@ fn adt_destructor(tcx: TyCtxt<'_>, def_id: DefId) -> Option<ty::Destructor> {
 
 /// Given a `DefId` for an opaque type in return position, find its parent item's return
 /// expressions.
-fn get_owner_return_paths<'tcx>(
-    tcx: TyCtxt<'tcx>,
+fn get_owner_return_paths(
+    tcx: TyCtxt<'_>,
     def_id: LocalDefId,
-) -> Option<(LocalDefId, ReturnsVisitor<'tcx>)> {
+) -> Option<(LocalDefId, ReturnsVisitor<'_>)> {
     let hir_id = tcx.hir().local_def_id_to_hir_id(def_id);
     let parent_id = tcx.hir().get_parent_item(hir_id).def_id;
     tcx.hir().find_by_def_id(parent_id).and_then(|node| node.body_id()).map(|body_id| {
diff --git a/compiler/rustc_hir_analysis/src/check/wfcheck.rs b/compiler/rustc_hir_analysis/src/check/wfcheck.rs
index 94d333c336e..aedc736b023 100644
--- a/compiler/rustc_hir_analysis/src/check/wfcheck.rs
+++ b/compiler/rustc_hir_analysis/src/check/wfcheck.rs
@@ -1673,7 +1673,7 @@ fn check_method_receiver<'tcx>(
     }
 }
 
-fn e0307<'tcx>(tcx: TyCtxt<'tcx>, span: Span, receiver_ty: Ty<'_>) {
+fn e0307(tcx: TyCtxt<'_>, span: Span, receiver_ty: Ty<'_>) {
     struct_span_err!(
         tcx.sess.diagnostic(),
         span,
diff --git a/compiler/rustc_hir_analysis/src/coherence/builtin.rs b/compiler/rustc_hir_analysis/src/coherence/builtin.rs
index 193ecdb1678..2790d91572b 100644
--- a/compiler/rustc_hir_analysis/src/coherence/builtin.rs
+++ b/compiler/rustc_hir_analysis/src/coherence/builtin.rs
@@ -171,7 +171,7 @@ fn visit_implementation_of_copy(tcx: TyCtxt<'_>, impl_did: LocalDefId) {
     }
 }
 
-fn visit_implementation_of_coerce_unsized<'tcx>(tcx: TyCtxt<'tcx>, impl_did: LocalDefId) {
+fn visit_implementation_of_coerce_unsized(tcx: TyCtxt<'_>, impl_did: LocalDefId) {
     debug!("visit_implementation_of_coerce_unsized: impl_did={:?}", impl_did);
 
     // Just compute this for the side-effects, in particular reporting
@@ -181,7 +181,7 @@ fn visit_implementation_of_coerce_unsized<'tcx>(tcx: TyCtxt<'tcx>, impl_did: Loc
     tcx.at(span).coerce_unsized_info(impl_did);
 }
 
-fn visit_implementation_of_dispatch_from_dyn<'tcx>(tcx: TyCtxt<'tcx>, impl_did: LocalDefId) {
+fn visit_implementation_of_dispatch_from_dyn(tcx: TyCtxt<'_>, impl_did: LocalDefId) {
     debug!("visit_implementation_of_dispatch_from_dyn: impl_did={:?}", impl_did);
 
     let impl_hir_id = tcx.hir().local_def_id_to_hir_id(impl_did);
diff --git a/compiler/rustc_hir_analysis/src/coherence/inherent_impls_overlap.rs b/compiler/rustc_hir_analysis/src/coherence/inherent_impls_overlap.rs
index 972769eb197..a9331af4eab 100644
--- a/compiler/rustc_hir_analysis/src/coherence/inherent_impls_overlap.rs
+++ b/compiler/rustc_hir_analysis/src/coherence/inherent_impls_overlap.rs
@@ -198,10 +198,10 @@ impl<'tcx> InherentOverlapChecker<'tcx> {
             // entire graph when there are many connected regions.
 
             rustc_index::newtype_index! {
-                pub struct RegionId {
-                    ENCODABLE = custom
-                }
+                #[custom_encodable]
+                pub struct RegionId {}
             }
+
             struct ConnectedRegion {
                 idents: SmallVec<[Symbol; 8]>,
                 impl_blocks: FxHashSet<usize>,
diff --git a/compiler/rustc_hir_analysis/src/coherence/orphan.rs b/compiler/rustc_hir_analysis/src/coherence/orphan.rs
index cc5114dba5e..c6d4aeefc80 100644
--- a/compiler/rustc_hir_analysis/src/coherence/orphan.rs
+++ b/compiler/rustc_hir_analysis/src/coherence/orphan.rs
@@ -184,11 +184,19 @@ fn emit_orphan_check_error<'tcx>(
                     ty::Adt(def, _) => tcx.mk_adt(*def, ty::List::empty()),
                     _ => ty,
                 };
-                let this = "this".to_string();
-                let (ty, postfix) = match &ty.kind() {
-                    ty::Slice(_) => (this, " because slices are always foreign"),
-                    ty::Array(..) => (this, " because arrays are always foreign"),
-                    ty::Tuple(..) => (this, " because tuples are always foreign"),
+                let msg = |ty: &str, postfix: &str| {
+                    format!("{ty} is not defined in the current crate{postfix}")
+                };
+                let this = |name: &str| msg("this", &format!(" because {name} are always foreign"));
+                let msg = match &ty.kind() {
+                    ty::Slice(_) => this("slices"),
+                    ty::Array(..) => this("arrays"),
+                    ty::Tuple(..) => this("tuples"),
+                    ty::Alias(ty::Opaque, ..) => {
+                        "type alias impl trait is treated as if it were foreign, \
+                        because its hidden type could be from a foreign crate"
+                            .to_string()
+                    }
                     ty::RawPtr(ptr_ty) => {
                         emit_newtype_suggestion_for_raw_ptr(
                             full_impl_span,
@@ -198,12 +206,11 @@ fn emit_orphan_check_error<'tcx>(
                             &mut err,
                         );
 
-                        (format!("`{}`", ty), " because raw pointers are always foreign")
+                        msg(&format!("`{ty}`"), " because raw pointers are always foreign")
                     }
-                    _ => (format!("`{}`", ty), ""),
+                    _ => msg(&format!("`{ty}`"), ""),
                 };
 
-                let msg = format!("{} is not defined in the current crate{}", ty, postfix);
                 if is_target_ty {
                     // Point at `D<A>` in `impl<A, B> for C<B> in D<A>`
                     err.span_label(self_ty_span, &msg);
diff --git a/compiler/rustc_hir_analysis/src/collect.rs b/compiler/rustc_hir_analysis/src/collect.rs
index 0c4649cea14..b7d599f57fd 100644
--- a/compiler/rustc_hir_analysis/src/collect.rs
+++ b/compiler/rustc_hir_analysis/src/collect.rs
@@ -839,7 +839,7 @@ fn convert_variant(
     )
 }
 
-fn adt_def<'tcx>(tcx: TyCtxt<'tcx>, def_id: DefId) -> ty::AdtDef<'tcx> {
+fn adt_def(tcx: TyCtxt<'_>, def_id: DefId) -> ty::AdtDef<'_> {
     use rustc_hir::*;
 
     let def_id = def_id.expect_local();
diff --git a/compiler/rustc_hir_analysis/src/collect/lifetimes.rs b/compiler/rustc_hir_analysis/src/collect/lifetimes.rs
index b4ad3467e7d..b63a8ef698d 100644
--- a/compiler/rustc_hir_analysis/src/collect/lifetimes.rs
+++ b/compiler/rustc_hir_analysis/src/collect/lifetimes.rs
@@ -276,7 +276,7 @@ fn resolve_lifetimes(tcx: TyCtxt<'_>, local_def_id: hir::OwnerId) -> ResolveLife
     rl
 }
 
-fn late_region_as_bound_region<'tcx>(tcx: TyCtxt<'tcx>, region: &Region) -> ty::BoundVariableKind {
+fn late_region_as_bound_region(tcx: TyCtxt<'_>, region: &Region) -> ty::BoundVariableKind {
     match region {
         Region::LateBound(_, _, def_id) => {
             let name = tcx.hir().name(tcx.hir().local_def_id_to_hir_id(def_id.expect_local()));
@@ -1018,7 +1018,7 @@ impl<'a, 'tcx> Visitor<'tcx> for LifetimeContext<'a, 'tcx> {
     }
 }
 
-fn object_lifetime_default<'tcx>(tcx: TyCtxt<'tcx>, param_def_id: DefId) -> ObjectLifetimeDefault {
+fn object_lifetime_default(tcx: TyCtxt<'_>, param_def_id: DefId) -> ObjectLifetimeDefault {
     debug_assert_eq!(tcx.def_kind(param_def_id), DefKind::TyParam);
     let param_def_id = param_def_id.expect_local();
     let parent_def_id = tcx.local_parent(param_def_id);
diff --git a/compiler/rustc_hir_analysis/src/collect/predicates_of.rs b/compiler/rustc_hir_analysis/src/collect/predicates_of.rs
index 79d75231e5d..0943350e2d4 100644
--- a/compiler/rustc_hir_analysis/src/collect/predicates_of.rs
+++ b/compiler/rustc_hir_analysis/src/collect/predicates_of.rs
@@ -318,10 +318,10 @@ fn gather_explicit_predicates_of(tcx: TyCtxt<'_>, def_id: DefId) -> ty::GenericP
     }
 }
 
-fn const_evaluatable_predicates_of<'tcx>(
-    tcx: TyCtxt<'tcx>,
+fn const_evaluatable_predicates_of(
+    tcx: TyCtxt<'_>,
     def_id: LocalDefId,
-) -> FxIndexSet<(ty::Predicate<'tcx>, Span)> {
+) -> FxIndexSet<(ty::Predicate<'_>, Span)> {
     struct ConstCollector<'tcx> {
         tcx: TyCtxt<'tcx>,
         preds: FxIndexSet<(ty::Predicate<'tcx>, Span)>,
diff --git a/compiler/rustc_hir_analysis/src/impl_wf_check/min_specialization.rs b/compiler/rustc_hir_analysis/src/impl_wf_check/min_specialization.rs
index fd8e8ed7ba6..b60fc276178 100644
--- a/compiler/rustc_hir_analysis/src/impl_wf_check/min_specialization.rs
+++ b/compiler/rustc_hir_analysis/src/impl_wf_check/min_specialization.rs
@@ -157,11 +157,11 @@ fn check_constness(tcx: TyCtxt<'_>, impl1_def_id: LocalDefId, impl2_node: Node,
 /// ```
 ///
 /// Would return `S1 = [C]` and `S2 = [Vec<C>, C]`.
-fn get_impl_substs<'tcx>(
-    tcx: TyCtxt<'tcx>,
+fn get_impl_substs(
+    tcx: TyCtxt<'_>,
     impl1_def_id: LocalDefId,
     impl2_node: Node,
-) -> Option<(SubstsRef<'tcx>, SubstsRef<'tcx>)> {
+) -> Option<(SubstsRef<'_>, SubstsRef<'_>)> {
     let infcx = &tcx.infer_ctxt().build();
     let ocx = ObligationCtxt::new(infcx);
     let param_env = tcx.param_env(impl1_def_id);
diff --git a/compiler/rustc_hir_analysis/src/outlives/implicit_infer.rs b/compiler/rustc_hir_analysis/src/outlives/implicit_infer.rs
index af8d7e85158..a46f2a94cd2 100644
--- a/compiler/rustc_hir_analysis/src/outlives/implicit_infer.rs
+++ b/compiler/rustc_hir_analysis/src/outlives/implicit_infer.rs
@@ -13,9 +13,9 @@ use super::utils::*;
 /// `global_inferred_outlives`: this is initially the empty map that
 ///     was generated by walking the items in the crate. This will
 ///     now be filled with inferred predicates.
-pub(super) fn infer_predicates<'tcx>(
-    tcx: TyCtxt<'tcx>,
-) -> FxHashMap<DefId, ty::EarlyBinder<RequiredPredicates<'tcx>>> {
+pub(super) fn infer_predicates(
+    tcx: TyCtxt<'_>,
+) -> FxHashMap<DefId, ty::EarlyBinder<RequiredPredicates<'_>>> {
     debug!("infer_predicates");
 
     let mut explicit_map = ExplicitPredicatesMap::new();