change fn_sig query to use EarlyBinder; remove bound_fn_sig query; add EarlyBinder to fn_sig in metadata

compiler/rustc_borrowck/src/diagnostics/conflict_errors.rs

@@ -2599,7 +2599,7 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> {
                 match ty.kind() {
                     ty::FnDef(_, _) | ty::FnPtr(_) => self.annotate_fn_sig(
                         self.mir_def_id(),
-                        self.infcx.tcx.bound_fn_sig(self.mir_def_id().into()).subst_identity(),
+                        self.infcx.tcx.fn_sig(self.mir_def_id()).subst_identity(),
                     ),
                     _ => None,
                 }

compiler/rustc_borrowck/src/diagnostics/mod.rs

@@ -1136,7 +1136,7 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> {
                             && let self_ty = infcx.replace_bound_vars_with_fresh_vars(
                                 fn_call_span,
                                 LateBoundRegionConversionTime::FnCall,
-                                tcx.bound_fn_sig(method_did).subst_identity().input(0),
+                                tcx.fn_sig(method_did).subst_identity().input(0),
                             )
                             && infcx.can_eq(self.param_env, ty, self_ty).is_ok()
                         {

compiler/rustc_borrowck/src/universal_regions.rs

@@ -472,7 +472,7 @@ impl<'cx, 'tcx> UniversalRegionsBuilder<'cx, 'tcx> {
         // C-variadic fns also have a `VaList` input that's not listed in the signature
         // (as it's created inside the body itself, not passed in from outside).
         if let DefiningTy::FnDef(def_id, _) = defining_ty {
-            if self.infcx.tcx.bound_fn_sig(def_id).skip_binder().c_variadic() {
+            if self.infcx.tcx.fn_sig(def_id).skip_binder().c_variadic() {
                 let va_list_did = self.infcx.tcx.require_lang_item(
                     LangItem::VaList,
                     Some(self.infcx.tcx.def_span(self.mir_def.did)),
@@ -665,7 +665,7 @@ impl<'cx, 'tcx> UniversalRegionsBuilder<'cx, 'tcx> {
             }
 
             DefiningTy::FnDef(def_id, _) => {
-                let sig = tcx.bound_fn_sig(def_id).subst_identity();
+                let sig = tcx.fn_sig(def_id).subst_identity();
                 let sig = indices.fold_to_region_vids(tcx, sig);
                 sig.inputs_and_output()
             }

compiler/rustc_codegen_cranelift/src/main_shim.rs

@@ -46,7 +46,7 @@ pub(crate) fn maybe_create_entry_wrapper(
         is_main_fn: bool,
         sigpipe: u8,
     ) {
-        let main_ret_ty = tcx.bound_fn_sig(rust_main_def_id).subst_identity().output();
+        let main_ret_ty = tcx.fn_sig(rust_main_def_id).subst_identity().output();
         // Given that `main()` has no arguments,
         // then its return type cannot have
         // late-bound regions, since late-bound

compiler/rustc_codegen_llvm/src/attributes.rs

@@ -441,7 +441,7 @@ pub fn from_fn_attrs<'ll, 'tcx>(
         // the WebAssembly specification, which has this feature. This won't be
         // needed when LLVM enables this `multivalue` feature by default.
         if !cx.tcx.is_closure(instance.def_id()) {
-            let abi = cx.tcx.bound_fn_sig(instance.def_id()).skip_binder().abi();
+            let abi = cx.tcx.fn_sig(instance.def_id()).skip_binder().abi();
             if abi == Abi::Wasm {
                 function_features.push("+multivalue".to_string());
             }

compiler/rustc_codegen_ssa/src/base.rs

@@ -436,7 +436,7 @@ pub fn maybe_create_entry_wrapper<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>>(
             cx.type_func(&[], cx.type_int())
         };
 
-        let main_ret_ty = cx.tcx().fn_sig(rust_main_def_id).output();
+        let main_ret_ty = cx.tcx().fn_sig(rust_main_def_id).subst_identity().output();
         // Given that `main()` has no arguments,
         // then its return type cannot have
         // late-bound regions, since late-bound

compiler/rustc_codegen_ssa/src/codegen_attrs.rs

@@ -214,7 +214,7 @@ fn codegen_fn_attrs(tcx: TyCtxt<'_>, did: DefId) -> CodegenFnAttrs {
             }
         } else if attr.has_name(sym::cmse_nonsecure_entry) {
             if validate_fn_only_attr(attr.span)
-                && !matches!(tcx.bound_fn_sig(did.into()).skip_binder().abi(), abi::Abi::C { .. })
+                && !matches!(tcx.fn_sig(did).skip_binder().abi(), abi::Abi::C { .. })
             {
                 struct_span_err!(
                     tcx.sess,
@@ -234,7 +234,7 @@ fn codegen_fn_attrs(tcx: TyCtxt<'_>, did: DefId) -> CodegenFnAttrs {
         } else if attr.has_name(sym::track_caller) {
             if !tcx.is_closure(did.to_def_id())
                 && validate_fn_only_attr(attr.span)
-                && tcx.bound_fn_sig(did.into()).skip_binder().abi() != abi::Abi::Rust
+                && tcx.fn_sig(did).skip_binder().abi() != abi::Abi::Rust
             {
                 struct_span_err!(tcx.sess, attr.span, E0737, "`#[track_caller]` requires Rust ABI")
                     .emit();
@@ -266,7 +266,7 @@ fn codegen_fn_attrs(tcx: TyCtxt<'_>, did: DefId) -> CodegenFnAttrs {
             }
         } else if attr.has_name(sym::target_feature) {
             if !tcx.is_closure(did.to_def_id())
-                && tcx.bound_fn_sig(did.into()).skip_binder().unsafety() == hir::Unsafety::Normal
+                && tcx.fn_sig(did).skip_binder().unsafety() == hir::Unsafety::Normal
             {
                 if tcx.sess.target.is_like_wasm || tcx.sess.opts.actually_rustdoc {
                     // The `#[target_feature]` attribute is allowed on

compiler/rustc_const_eval/src/const_eval/fn_queries.rs

@@ -64,7 +64,7 @@ fn is_promotable_const_fn(tcx: TyCtxt<'_>, def_id: DefId) -> bool {
         && match tcx.lookup_const_stability(def_id) {
             Some(stab) => {
                 if cfg!(debug_assertions) && stab.promotable {
-                    let sig = tcx.bound_fn_sig(def_id);
+                    let sig = tcx.fn_sig(def_id);
                     assert_eq!(
                         sig.skip_binder().unsafety(),
                         hir::Unsafety::Normal,

compiler/rustc_const_eval/src/transform/check_consts/mod.rs

@@ -72,7 +72,7 @@ impl<'mir, 'tcx> ConstCx<'mir, 'tcx> {
             let ty::Closure(_, substs) = ty.kind() else { bug!("type_of closure not ty::Closure") };
             substs.as_closure().sig()
         } else {
-            self.tcx.bound_fn_sig(did).subst_identity()
+            self.tcx.fn_sig(did).subst_identity()
         }
     }
 }

compiler/rustc_hir_analysis/src/astconv/mod.rs

@@ -3140,7 +3140,7 @@ impl<'o, 'tcx> dyn AstConv<'tcx> + 'o {
             trait_ref.def_id,
         )?;
 
-        let fn_sig = tcx.bound_fn_sig(assoc.def_id).subst(
+        let fn_sig = tcx.fn_sig(assoc.def_id).subst(
             tcx,
             trait_ref.substs.extend_to(tcx, assoc.def_id, |param, _| tcx.mk_param_from_def(param)),
         );

compiler/rustc_hir_analysis/src/check/compare_impl_item.rs

@@ -249,7 +249,7 @@ fn compare_method_predicate_entailment<'tcx>(
     let unnormalized_impl_sig = infcx.replace_bound_vars_with_fresh_vars(
         impl_m_span,
         infer::HigherRankedType,
-        tcx.bound_fn_sig(impl_m.def_id).subst_identity(),
+        tcx.fn_sig(impl_m.def_id).subst_identity(),
     );
     let unnormalized_impl_fty = tcx.mk_fn_ptr(ty::Binder::dummy(unnormalized_impl_sig));
 
@@ -257,7 +257,7 @@ fn compare_method_predicate_entailment<'tcx>(
     let impl_sig = ocx.normalize(&norm_cause, param_env, unnormalized_impl_sig);
     debug!("compare_impl_method: impl_fty={:?}", impl_sig);
 
-    let trait_sig = tcx.bound_fn_sig(trait_m.def_id).subst(tcx, trait_to_placeholder_substs);
+    let trait_sig = tcx.fn_sig(trait_m.def_id).subst(tcx, trait_to_placeholder_substs);
     let trait_sig = tcx.liberate_late_bound_regions(impl_m.def_id, trait_sig);
 
     // Next, add all inputs and output as well-formed tys. Importantly,
@@ -422,8 +422,8 @@ fn extract_bad_args_for_implies_lint<'tcx>(
 
     // Map late-bound regions from trait to impl, so the names are right.
     let mapping = std::iter::zip(
-        tcx.bound_fn_sig(trait_m.def_id).subst_identity().bound_vars(),
+        tcx.fn_sig(trait_m.def_id).subst_identity().bound_vars(),
-        tcx.bound_fn_sig(impl_m.def_id).subst_identity().bound_vars(),
+        tcx.fn_sig(impl_m.def_id).subst_identity().bound_vars(),
     )
     .filter_map(|(impl_bv, trait_bv)| {
         if let ty::BoundVariableKind::Region(impl_bv) = impl_bv
@@ -540,7 +540,7 @@ fn compare_asyncness<'tcx>(
     trait_item_span: Option<Span>,
 ) -> Result<(), ErrorGuaranteed> {
     if tcx.asyncness(trait_m.def_id) == hir::IsAsync::Async {
-        match tcx.bound_fn_sig(impl_m.def_id).subst_identity().skip_binder().output().kind() {
+        match tcx.fn_sig(impl_m.def_id).subst_identity().skip_binder().output().kind() {
             ty::Alias(ty::Opaque, ..) => {
                 // allow both `async fn foo()` and `fn foo() -> impl Future`
             }
@@ -643,7 +643,7 @@ pub(super) fn collect_return_position_impl_trait_in_trait_tys<'tcx>(
         infcx.replace_bound_vars_with_fresh_vars(
             return_span,
             infer::HigherRankedType,
-            tcx.bound_fn_sig(impl_m.def_id).subst_identity(),
+            tcx.fn_sig(impl_m.def_id).subst_identity(),
         ),
     );
     impl_sig.error_reported()?;
@@ -657,7 +657,7 @@ pub(super) fn collect_return_position_impl_trait_in_trait_tys<'tcx>(
     let unnormalized_trait_sig = tcx
         .liberate_late_bound_regions(
             impl_m.def_id,
-            tcx.bound_fn_sig(trait_m.def_id).subst(tcx, trait_to_placeholder_substs),
+            tcx.fn_sig(trait_m.def_id).subst(tcx, trait_to_placeholder_substs),
         )
         .fold_with(&mut collector);
     let trait_sig = ocx.normalize(&norm_cause, param_env, unnormalized_trait_sig);
@@ -1117,7 +1117,7 @@ fn compare_self_type<'tcx>(
             ty::ImplContainer => impl_trait_ref.self_ty(),
             ty::TraitContainer => tcx.types.self_param,
         };
-        let self_arg_ty = tcx.bound_fn_sig(method.def_id).subst_identity().input(0);
+        let self_arg_ty = tcx.fn_sig(method.def_id).subst_identity().input(0);
         let param_env = ty::ParamEnv::reveal_all();
 
         let infcx = tcx.infer_ctxt().build();
@@ -1348,8 +1348,8 @@ fn compare_number_of_method_arguments<'tcx>(
     trait_m: &ty::AssocItem,
     trait_item_span: Option<Span>,
 ) -> Result<(), ErrorGuaranteed> {
-    let impl_m_fty = tcx.bound_fn_sig(impl_m.def_id);
+    let impl_m_fty = tcx.fn_sig(impl_m.def_id);
-    let trait_m_fty = tcx.bound_fn_sig(trait_m.def_id);
+    let trait_m_fty = tcx.fn_sig(trait_m.def_id);
     let trait_number_args = trait_m_fty.skip_binder().inputs().skip_binder().len();
     let impl_number_args = impl_m_fty.skip_binder().inputs().skip_binder().len();
 

compiler/rustc_hir_analysis/src/check/intrinsic.rs

@@ -58,7 +58,12 @@ fn equate_intrinsic_type<'tcx>(
         let fty = tcx.mk_fn_ptr(sig);
         let it_def_id = it.owner_id.def_id;
         let cause = ObligationCause::new(it.span, it_def_id, ObligationCauseCode::IntrinsicType);
-        require_same_types(tcx, &cause, tcx.mk_fn_ptr(tcx.bound_fn_sig(it.owner_id.to_def_id()).subst_identity()), fty);
+        require_same_types(
+            tcx,
+            &cause,
+            tcx.mk_fn_ptr(tcx.fn_sig(it.owner_id).subst_identity()),
+            fty,
+        );
     }
 }
 

compiler/rustc_hir_analysis/src/check/mod.rs

@@ -445,7 +445,7 @@ fn suggestion_signature(assoc: &ty::AssocItem, tcx: TyCtxt<'_>) -> String {
             // regions just fine, showing `fn(&MyType)`.
             fn_sig_suggestion(
                 tcx,
-                tcx.bound_fn_sig(assoc.def_id).subst_identity().skip_binder(),
+                tcx.fn_sig(assoc.def_id).subst_identity().skip_binder(),
                 assoc.ident(tcx),
                 tcx.predicates_of(assoc.def_id),
                 assoc,

compiler/rustc_hir_analysis/src/check/wfcheck.rs

@@ -386,7 +386,7 @@ fn check_gat_where_clauses(tcx: TyCtxt<'_>, associated_items: &[hir::TraitItemRe
                         // `Self::Iter<'a>` is a GAT we want to gather any potential missing bounds from.
                         let sig: ty::FnSig<'_> = tcx.liberate_late_bound_regions(
                             item_def_id.to_def_id(),
-                            tcx.bound_fn_sig(item_def_id.to_def_id()).subst_identity(),
+                            tcx.fn_sig(item_def_id).subst_identity(),
                         );
                         gather_gat_bounds(
                             tcx,
@@ -1018,7 +1018,7 @@ fn check_associated_item(
                 wfcx.register_wf_obligation(span, loc, ty.into());
             }
             ty::AssocKind::Fn => {
-                let sig = tcx.bound_fn_sig(item.def_id).subst_identity();
+                let sig = tcx.fn_sig(item.def_id).subst_identity();
                 let hir_sig = sig_if_method.expect("bad signature for method");
                 check_fn_or_method(
                     wfcx,
@@ -1203,7 +1203,7 @@ fn check_item_fn(
     decl: &hir::FnDecl<'_>,
 ) {
     enter_wf_checking_ctxt(tcx, span, def_id, |wfcx| {
-        let sig = tcx.bound_fn_sig(def_id.into()).subst_identity();
+        let sig = tcx.fn_sig(def_id).subst_identity();
         check_fn_or_method(wfcx, ident.span, sig, decl, def_id);
     })
 }
@@ -1638,7 +1638,7 @@ fn check_method_receiver<'tcx>(
 
     let span = fn_sig.decl.inputs[0].span;
 
-    let sig = tcx.bound_fn_sig(method.def_id).subst_identity();
+    let sig = tcx.fn_sig(method.def_id).subst_identity();
     let sig = tcx.liberate_late_bound_regions(method.def_id, sig);
     let sig = wfcx.normalize(span, None, sig);
 

compiler/rustc_hir_analysis/src/collect.rs

@@ -1087,7 +1087,7 @@ pub fn get_infer_ret_ty<'hir>(output: &'hir hir::FnRetTy<'hir>) -> Option<&'hir
 }
 
 #[instrument(level = "debug", skip(tcx))]
-fn fn_sig(tcx: TyCtxt<'_>, def_id: DefId) -> ty::PolyFnSig<'_> {
+fn fn_sig(tcx: TyCtxt<'_>, def_id: DefId) -> ty::EarlyBinder<ty::PolyFnSig<'_>> {
     use rustc_hir::Node::*;
     use rustc_hir::*;
 
@@ -1096,7 +1096,7 @@ fn fn_sig(tcx: TyCtxt<'_>, def_id: DefId) -> ty::PolyFnSig<'_> {
 
     let icx = ItemCtxt::new(tcx, def_id.to_def_id());
 
-    match tcx.hir().get(hir_id) {
+    let output = match tcx.hir().get(hir_id) {
         TraitItem(hir::TraitItem {
             kind: TraitItemKind::Fn(sig, TraitFn::Provided(_)),
             generics,
@@ -1169,7 +1169,8 @@ fn fn_sig(tcx: TyCtxt<'_>, def_id: DefId) -> ty::PolyFnSig<'_> {
         x => {
             bug!("unexpected sort of node in fn_sig(): {:?}", x);
         }
-    }
+    };
+    ty::EarlyBinder(output)
 }
 
 fn infer_return_ty_for_fn_sig<'tcx>(

compiler/rustc_hir_analysis/src/collect/type_of.rs

@@ -868,7 +868,7 @@ fn infer_placeholder_type<'a>(
 
             match ty.kind() {
                 ty::FnDef(def_id, _) => {
-                    self.tcx.mk_fn_ptr(self.tcx.bound_fn_sig(*def_id).subst_identity())
+                    self.tcx.mk_fn_ptr(self.tcx.fn_sig(*def_id).subst_identity())
                 }
                 // FIXME: non-capturing closures should also suggest a function pointer
                 ty::Closure(..) | ty::Generator(..) => {

compiler/rustc_hir_analysis/src/lib.rs

@@ -182,7 +182,7 @@ fn require_same_types<'tcx>(
 }
 
 fn check_main_fn_ty(tcx: TyCtxt<'_>, main_def_id: DefId) {
-    let main_fnsig = tcx.bound_fn_sig(main_def_id).subst_identity();
+    let main_fnsig = tcx.fn_sig(main_def_id).subst_identity();
     let main_span = tcx.def_span(main_def_id);
 
     fn main_fn_diagnostics_def_id(tcx: TyCtxt<'_>, def_id: DefId, sp: Span) -> LocalDefId {
@@ -449,7 +449,7 @@ fn check_start_fn_ty(tcx: TyCtxt<'_>, start_def_id: DefId) {
                     ObligationCauseCode::StartFunctionType,
                 ),
                 se_ty,
-                tcx.mk_fn_ptr(tcx.bound_fn_sig(start_def_id.into()).subst_identity()),
+                tcx.mk_fn_ptr(tcx.fn_sig(start_def_id).subst_identity()),
             );
         }
         _ => {

compiler/rustc_hir_analysis/src/variance/constraints.rs

@@ -121,7 +121,7 @@ impl<'a, 'tcx> ConstraintContext<'a, 'tcx> {
             ty::FnDef(..) => {
                 self.add_constraints_from_sig(
                     current_item,
-                    tcx.bound_fn_sig(def_id.into()).subst_identity(),
+                    tcx.fn_sig(def_id).subst_identity(),
                     self.covariant,
                 );
             }

compiler/rustc_hir_typeck/src/callee.rs

@@ -367,7 +367,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
     ) -> Ty<'tcx> {
         let (fn_sig, def_id) = match *callee_ty.kind() {
             ty::FnDef(def_id, subst) => {
-                let fn_sig = self.tcx.bound_fn_sig(def_id).subst(self.tcx, subst);
+                let fn_sig = self.tcx.fn_sig(def_id).subst(self.tcx, subst);
 
                 // Unit testing: function items annotated with
                 // `#[rustc_evaluate_where_clauses]` trigger special output

compiler/rustc_hir_typeck/src/demand.rs

@@ -299,7 +299,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
             {
                 // We special case methods, because they can influence inference through the
                 // call's arguments and we can provide a more explicit span.
-                let sig = self.tcx.bound_fn_sig(def_id).subst_identity();
+                let sig = self.tcx.fn_sig(def_id).subst_identity();
                 let def_self_ty = sig.input(0).skip_binder();
                 let rcvr_ty = self.node_ty(rcvr.hir_id);
                 // Get the evaluated type *after* calling the method call, so that the influence
@@ -613,7 +613,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                             ),
                             match self
                                 .tcx
-                                .bound_fn_sig(m.def_id)
+                                .fn_sig(m.def_id)
                                 .subst_identity()
                                 .input(0)
                                 .skip_binder()
@@ -1043,13 +1043,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         match method.kind {
             ty::AssocKind::Fn => {
                 method.fn_has_self_parameter
-                    && self
+                    && self.tcx.fn_sig(method.def_id).skip_binder().inputs().skip_binder().len()
-                        .tcx
-                        .bound_fn_sig(method.def_id)
-                        .skip_binder()
-                        .inputs()
-                        .skip_binder()
-                        .len()
                         == 1
             }
             _ => false,

compiler/rustc_hir_typeck/src/expr.rs

@@ -542,7 +542,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
 
         if let ty::FnDef(did, ..) = *ty.kind() {
             let fn_sig = ty.fn_sig(tcx);
-            if tcx.bound_fn_sig(did).skip_binder().abi() == RustIntrinsic
+            if tcx.fn_sig(did).skip_binder().abi() == RustIntrinsic
                 && tcx.item_name(did) == sym::transmute
             {
                 let from = fn_sig.inputs().skip_binder()[0];

compiler/rustc_hir_typeck/src/lib.rs

@@ -207,7 +207,7 @@ fn typeck_with_fallback<'tcx>(
             let fn_sig = if rustc_hir_analysis::collect::get_infer_ret_ty(&decl.output).is_some() {
                 fcx.astconv().ty_of_fn(id, header.unsafety, header.abi, decl, None, None)
             } else {
-                tcx.bound_fn_sig(def_id.into()).subst_identity()
+                tcx.fn_sig(def_id).subst_identity()
             };
 
             check_abi(tcx, id, span, fn_sig.abi());

compiler/rustc_hir_typeck/src/method/confirm.rs

@@ -503,7 +503,7 @@ impl<'a, 'tcx> ConfirmContext<'a, 'tcx> {
 
         debug!("method_predicates after subst = {:?}", method_predicates);
 
-        let sig = self.tcx.bound_fn_sig(def_id);
+        let sig = self.tcx.fn_sig(def_id);
 
         let sig = sig.subst(self.tcx, all_substs);
         debug!("type scheme substituted, sig={:?}", sig);

compiler/rustc_hir_typeck/src/method/mod.rs

@@ -144,7 +144,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                 None,
             )
             .map(|pick| {
-                let sig = self.tcx.bound_fn_sig(pick.item.def_id);
+                let sig = self.tcx.fn_sig(pick.item.def_id);
                 sig.skip_binder().inputs().skip_binder().len().saturating_sub(1)
             })
             .unwrap_or(0);
@@ -399,7 +399,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         // N.B., instantiate late-bound regions before normalizing the
         // function signature so that normalization does not need to deal
         // with bound regions.
-        let fn_sig = tcx.bound_fn_sig(def_id);
+        let fn_sig = tcx.fn_sig(def_id);
         let fn_sig = fn_sig.subst(self.tcx, substs);
         let fn_sig =
             self.replace_bound_vars_with_fresh_vars(obligation.cause.span, infer::FnCall, fn_sig);

compiler/rustc_hir_typeck/src/method/probe.rs

@@ -922,7 +922,7 @@ impl<'a, 'tcx> ProbeContext<'a, 'tcx> {
     ) -> bool {
         match method.kind {
             ty::AssocKind::Fn => {
-                let fty = self.tcx.bound_fn_sig(method.def_id);
+                let fty = self.tcx.fn_sig(method.def_id);
                 self.probe(|_| {
                     let substs = self.fresh_substs_for_item(self.span, method.def_id);
                     let fty = fty.subst(self.tcx, substs);
@@ -1887,7 +1887,7 @@ impl<'a, 'tcx> ProbeContext<'a, 'tcx> {
 
     #[instrument(level = "debug", skip(self))]
     fn xform_method_sig(&self, method: DefId, substs: SubstsRef<'tcx>) -> ty::FnSig<'tcx> {
-        let fn_sig = self.tcx.bound_fn_sig(method);
+        let fn_sig = self.tcx.fn_sig(method);
         debug!(?fn_sig);
 
         assert!(!substs.has_escaping_bound_vars());

compiler/rustc_hir_typeck/src/method/suggest.rs

@@ -1127,7 +1127,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                             ty::AssocKind::Const | ty::AssocKind::Type => rcvr_ty,
                             ty::AssocKind::Fn => self
                                 .tcx
-                                .bound_fn_sig(item.def_id)
+                                .fn_sig(item.def_id)
                                 .subst_identity()
                                 .inputs()
                                 .skip_binder()
@@ -1265,7 +1265,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                 && let Some(assoc) = self.associated_value(*impl_did, item_name)
                 && assoc.kind == ty::AssocKind::Fn
             {
-                let sig = self.tcx.bound_fn_sig(assoc.def_id).subst_identity();
+                let sig = self.tcx.fn_sig(assoc.def_id).subst_identity();
                 sig.inputs().skip_binder().get(0).and_then(|first| if first.peel_refs() == rcvr_ty.peel_refs() {
                     None
                 } else {
@@ -2099,7 +2099,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                     // just changing the path.
                     && pick.item.fn_has_self_parameter
                     && let Some(self_ty) =
-                        self.tcx.bound_fn_sig(pick.item.def_id).subst_identity().inputs().skip_binder().get(0)
+                        self.tcx.fn_sig(pick.item.def_id).subst_identity().inputs().skip_binder().get(0)
                     && self_ty.is_ref()
                 {
                     let suggested_path = match deref_ty.kind() {
@@ -2352,7 +2352,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                         // implement the `AsRef` trait.
                         let skip = skippable.contains(&did)
                             || (("Pin::new" == *pre) && (sym::as_ref == item_name.name))
-                            || inputs_len.map_or(false, |inputs_len| pick.item.kind == ty::AssocKind::Fn && self.tcx.bound_fn_sig(pick.item.def_id).skip_binder().skip_binder().inputs().len() != inputs_len);
+                            || inputs_len.map_or(false, |inputs_len| pick.item.kind == ty::AssocKind::Fn && self.tcx.fn_sig(pick.item.def_id).skip_binder().skip_binder().inputs().len() != inputs_len);
                         // Make sure the method is defined for the *actual* receiver: we don't
                         // want to treat `Box<Self>` as a receiver if it only works because of
                         // an autoderef to `&self`
@@ -2731,7 +2731,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
 
             // check the method arguments number
             if let Ok(pick) = probe &&
-                let fn_sig = self.tcx.bound_fn_sig(pick.item.def_id) &&
+                let fn_sig = self.tcx.fn_sig(pick.item.def_id) &&
                 let fn_args = fn_sig.skip_binder().skip_binder().inputs() &&
                 fn_args.len() == args.len() + 1 {
                 err.span_suggestion_verbose(

compiler/rustc_infer/src/infer/error_reporting/mod.rs

@@ -1345,8 +1345,8 @@ impl<'tcx> TypeErrCtxt<'_, 'tcx> {
             }
 
             (ty::FnDef(did1, substs1), ty::FnDef(did2, substs2)) => {
-                let sig1 = self.tcx.bound_fn_sig(*did1).subst(self.tcx, substs1);
+                let sig1 = self.tcx.fn_sig(*did1).subst(self.tcx, substs1);
-                let sig2 = self.tcx.bound_fn_sig(*did2).subst(self.tcx, substs2);
+                let sig2 = self.tcx.fn_sig(*did2).subst(self.tcx, substs2);
                 let mut values = self.cmp_fn_sig(&sig1, &sig2);
                 let path1 = format!(" {{{}}}", self.tcx.def_path_str_with_substs(*did1, substs1));
                 let path2 = format!(" {{{}}}", self.tcx.def_path_str_with_substs(*did2, substs2));
@@ -1357,7 +1357,7 @@ impl<'tcx> TypeErrCtxt<'_, 'tcx> {
             }
 
             (ty::FnDef(did1, substs1), ty::FnPtr(sig2)) => {
-                let sig1 = self.tcx.bound_fn_sig(*did1).subst(self.tcx, substs1);
+                let sig1 = self.tcx.fn_sig(*did1).subst(self.tcx, substs1);
                 let mut values = self.cmp_fn_sig(&sig1, sig2);
                 values.0.push_highlighted(format!(
                     " {{{}}}",
@@ -1367,7 +1367,7 @@ impl<'tcx> TypeErrCtxt<'_, 'tcx> {
             }
 
             (ty::FnPtr(sig1), ty::FnDef(did2, substs2)) => {
-                let sig2 = self.tcx.bound_fn_sig(*did2).subst(self.tcx, substs2);
+                let sig2 = self.tcx.fn_sig(*did2).subst(self.tcx, substs2);
                 let mut values = self.cmp_fn_sig(sig1, &sig2);
                 values.1.push_normal(format!(
                     " {{{}}}",

compiler/rustc_infer/src/infer/error_reporting/nice_region_error/util.rs

@@ -65,7 +65,7 @@ pub fn find_param_with_region<'tcx>(
 
     let owner_id = hir.body_owner(body_id);
     let fn_decl = hir.fn_decl_by_hir_id(owner_id).unwrap();
-    let poly_fn_sig = tcx.bound_fn_sig(id).subst_identity();
+    let poly_fn_sig = tcx.fn_sig(id).subst_identity();
 
     let fn_sig = tcx.liberate_late_bound_regions(id, poly_fn_sig);
     let body = hir.body(body_id);

compiler/rustc_lint/src/types.rs

@@ -1225,7 +1225,7 @@ impl<'a, 'tcx> ImproperCTypesVisitor<'a, 'tcx> {
 
     fn check_foreign_fn(&mut self, id: hir::HirId, decl: &hir::FnDecl<'_>) {
         let def_id = self.cx.tcx.hir().local_def_id(id);
-        let sig = self.cx.tcx.bound_fn_sig(def_id.into()).subst_identity();
+        let sig = self.cx.tcx.fn_sig(def_id).subst_identity();
         let sig = self.cx.tcx.erase_late_bound_regions(sig);
 
         for (input_ty, input_hir) in iter::zip(sig.inputs(), decl.inputs) {

compiler/rustc_metadata/src/rmeta/encoder.rs

@@ -1093,7 +1093,7 @@ fn should_encode_trait_impl_trait_tys(tcx: TyCtxt<'_>, def_id: DefId) -> bool {
     // of the trait fn to look for any RPITITs, but that's kinda doing a lot
     // of work. We can probably remove this when we refactor RPITITs to be
     // associated types.
-    tcx.bound_fn_sig(trait_item_def_id).subst_identity().skip_binder().output().walk().any(|arg| {
+    tcx.fn_sig(trait_item_def_id).subst_identity().skip_binder().output().walk().any(|arg| {
         if let ty::GenericArgKind::Type(ty) = arg.unpack()
             && let ty::Alias(ty::Projection, data) = ty.kind()
             && tcx.def_kind(data.def_id) == DefKind::ImplTraitPlaceholder
@@ -1628,7 +1628,7 @@ impl<'a, 'tcx> EncodeContext<'a, 'tcx> {
             ty::Closure(_, substs) => {
                 let constness = self.tcx.constness(def_id.to_def_id());
                 self.tables.constness.set(def_id.to_def_id().index, constness);
-                record!(self.tables.fn_sig[def_id.to_def_id()] <- substs.as_closure().sig());
+                record!(self.tables.fn_sig[def_id.to_def_id()] <- ty::EarlyBinder(substs.as_closure().sig()));
             }
 
             _ => bug!("closure that is neither generator nor closure"),

compiler/rustc_metadata/src/rmeta/mod.rs

@@ -369,7 +369,7 @@ define_tables! {
     super_predicates_of: Table<DefIndex, LazyValue<ty::GenericPredicates<'static>>>,
     type_of: Table<DefIndex, LazyValue<Ty<'static>>>,
     variances_of: Table<DefIndex, LazyArray<ty::Variance>>,
-    fn_sig: Table<DefIndex, LazyValue<ty::PolyFnSig<'static>>>,
+    fn_sig: Table<DefIndex, LazyValue<ty::EarlyBinder<ty::PolyFnSig<'static>>>>,
     codegen_fn_attrs: Table<DefIndex, LazyValue<CodegenFnAttrs>>,
     impl_trait_ref: Table<DefIndex, LazyValue<ty::EarlyBinder<ty::TraitRef<'static>>>>,
     const_param_default: Table<DefIndex, LazyValue<ty::EarlyBinder<rustc_middle::ty::Const<'static>>>>,

compiler/rustc_middle/src/query/mod.rs

@@ -814,7 +814,7 @@ rustc_queries! {
     }
 
     /// Computes the signature of the function.
-    query fn_sig(key: DefId) -> ty::PolyFnSig<'tcx> {
+    query fn_sig(key: DefId) -> ty::EarlyBinder<ty::PolyFnSig<'tcx>> {
         desc { |tcx| "computing function signature of `{}`", tcx.def_path_str(key) }
         cache_on_disk_if { key.is_local() }
         separate_provide_extern

compiler/rustc_middle/src/ty/assoc.rs

@@ -79,7 +79,7 @@ impl AssocItem {
                 // late-bound regions, and we don't want method signatures to show up
                 // `as for<'r> fn(&'r MyType)`. Pretty-printing handles late-bound
                 // regions just fine, showing `fn(&MyType)`.
-                tcx.bound_fn_sig(self.def_id).subst_identity().skip_binder().to_string()
+                tcx.fn_sig(self.def_id).subst_identity().skip_binder().to_string()
             }
             ty::AssocKind::Type => format!("type {};", self.name),
             ty::AssocKind::Const => {

compiler/rustc_middle/src/ty/instance.rs

@@ -459,7 +459,7 @@ impl<'tcx> Instance<'tcx> {
         substs: SubstsRef<'tcx>,
     ) -> Option<Instance<'tcx>> {
         debug!("resolve_for_vtable(def_id={:?}, substs={:?})", def_id, substs);
-        let fn_sig = tcx.bound_fn_sig(def_id).subst_identity();
+        let fn_sig = tcx.fn_sig(def_id).subst_identity();
         let is_vtable_shim = !fn_sig.inputs().skip_binder().is_empty()
             && fn_sig.input(0).skip_binder().is_param(0)
             && tcx.generics_of(def_id).has_self;

compiler/rustc_middle/src/ty/print/pretty.rs

@@ -675,7 +675,7 @@ pub trait PrettyPrinter<'tcx>:
                 p!(")")
             }
             ty::FnDef(def_id, substs) => {
-                let sig = self.tcx().bound_fn_sig(def_id).subst(self.tcx(), substs);
+                let sig = self.tcx().fn_sig(def_id).subst(self.tcx(), substs);
                 p!(print(sig), " {{", print_value_path(def_id, substs), "}}");
             }
             ty::FnPtr(ref bare_fn) => p!(print(bare_fn)),

compiler/rustc_middle/src/ty/sty.rs

@@ -2059,7 +2059,7 @@ impl<'tcx> Ty<'tcx> {
 
     pub fn fn_sig(self, tcx: TyCtxt<'tcx>) -> PolyFnSig<'tcx> {
         match self.kind() {
-            FnDef(def_id, substs) => tcx.bound_fn_sig(*def_id).subst(tcx, substs),
+            FnDef(def_id, substs) => tcx.fn_sig(*def_id).subst(tcx, substs),
             FnPtr(f) => *f,
             Error(_) => {
                 // ignore errors (#54954)

compiler/rustc_middle/src/ty/util.rs

@@ -643,10 +643,6 @@ impl<'tcx> TyCtxt<'tcx> {
         ty::EarlyBinder(self.collect_return_position_impl_trait_in_trait_tys(def_id))
     }
 
-    pub fn bound_fn_sig(self, def_id: DefId) -> ty::EarlyBinder<ty::PolyFnSig<'tcx>> {
-        ty::EarlyBinder(self.fn_sig(def_id))
-    }
-
     pub fn bound_explicit_item_bounds(
         self,
         def_id: DefId,
@@ -1315,10 +1311,7 @@ pub fn is_doc_notable_trait(tcx: TyCtxt<'_>, def_id: DefId) -> bool {
 
 /// Determines whether an item is an intrinsic by Abi.
 pub fn is_intrinsic(tcx: TyCtxt<'_>, def_id: DefId) -> bool {
-    matches!(
+    matches!(tcx.fn_sig(def_id).skip_binder().abi(), Abi::RustIntrinsic | Abi::PlatformIntrinsic)
-        tcx.bound_fn_sig(def_id).skip_binder().abi(),
-        Abi::RustIntrinsic | Abi::PlatformIntrinsic
-    )
 }
 
 pub fn provide(providers: &mut ty::query::Providers) {

compiler/rustc_mir_build/src/build/mod.rs

@@ -637,9 +637,7 @@ fn construct_error(
 
     let ty = tcx.ty_error();
     let num_params = match body_owner_kind {
-        hir::BodyOwnerKind::Fn => {
+        hir::BodyOwnerKind::Fn => tcx.fn_sig(def).skip_binder().inputs().skip_binder().len(),
-            tcx.bound_fn_sig(def.into()).skip_binder().inputs().skip_binder().len()
-        }
         hir::BodyOwnerKind::Closure => {
             let ty = tcx.type_of(def);
             match ty.kind() {

compiler/rustc_mir_transform/src/function_item_references.rs

@@ -79,8 +79,7 @@ impl<'tcx> FunctionItemRefChecker<'_, 'tcx> {
         for bound in bounds {
             if let Some(bound_ty) = self.is_pointer_trait(&bound.kind().skip_binder()) {
                 // Get the argument types as they appear in the function signature.
-                let arg_defs =
+                let arg_defs = self.tcx.fn_sig(def_id).subst_identity().skip_binder().inputs();
-                    self.tcx.bound_fn_sig(def_id).subst_identity().skip_binder().inputs();
                 for (arg_num, arg_def) in arg_defs.iter().enumerate() {
                     // For all types reachable from the argument type in the fn sig
                     for generic_inner_ty in arg_def.walk() {
@@ -162,7 +161,7 @@ impl<'tcx> FunctionItemRefChecker<'_, 'tcx> {
             .as_ref()
             .assert_crate_local()
             .lint_root;
-        let fn_sig = self.tcx.bound_fn_sig(fn_id).skip_binder();
+        let fn_sig = self.tcx.fn_sig(fn_id).skip_binder();
         let unsafety = fn_sig.unsafety().prefix_str();
         let abi = match fn_sig.abi() {
             Abi::Rust => String::from(""),

compiler/rustc_mir_transform/src/inline.rs

@@ -331,7 +331,7 @@ impl<'tcx> Inliner<'tcx> {
                     return None;
                 }
 
-                let fn_sig = self.tcx.bound_fn_sig(def_id).subst(self.tcx, substs);
+                let fn_sig = self.tcx.fn_sig(def_id).subst(self.tcx, substs);
                 let source_info = SourceInfo { span: fn_span, ..terminator.source_info };
 
                 return Some(CallSite { callee, fn_sig, block: bb, target, source_info });

compiler/rustc_mir_transform/src/shim.rs

@@ -152,7 +152,7 @@ fn build_drop_shim<'tcx>(tcx: TyCtxt<'tcx>, def_id: DefId, ty: Option<Ty<'tcx>>)
     } else {
         InternalSubsts::identity_for_item(tcx, def_id)
     };
-    let sig = tcx.bound_fn_sig(def_id).subst(tcx, substs);
+    let sig = tcx.fn_sig(def_id).subst(tcx, substs);
     let sig = tcx.erase_late_bound_regions(sig);
     let span = tcx.def_span(def_id);
 
@@ -363,7 +363,7 @@ impl<'tcx> CloneShimBuilder<'tcx> {
         // we must subst the self_ty because it's
         // otherwise going to be TySelf and we can't index
         // or access fields of a Place of type TySelf.
-        let sig = tcx.bound_fn_sig(def_id).subst(tcx, &[self_ty.into()]);
+        let sig = tcx.fn_sig(def_id).subst(tcx, &[self_ty.into()]);
         let sig = tcx.erase_late_bound_regions(sig);
         let span = tcx.def_span(def_id);
 
@@ -606,7 +606,7 @@ fn build_call_shim<'tcx>(
     };
 
     let def_id = instance.def_id();
-    let sig = tcx.bound_fn_sig(def_id);
+    let sig = tcx.fn_sig(def_id);
     let sig = sig.map_bound(|sig| tcx.erase_late_bound_regions(sig));
 
     assert_eq!(sig_substs.is_some(), !instance.has_polymorphic_mir_body());
@@ -799,7 +799,7 @@ pub fn build_adt_ctor(tcx: TyCtxt<'_>, ctor_id: DefId) -> Body<'_> {
 
     // Normalize the sig.
     let sig = tcx
-        .bound_fn_sig(ctor_id)
+        .fn_sig(ctor_id)
         .subst_identity()
         .no_bound_vars()
         .expect("LBR in ADT constructor signature");

compiler/rustc_monomorphize/src/collector.rs

@@ -1296,7 +1296,7 @@ impl<'v> RootCollector<'_, 'v> {
         };
 
         let start_def_id = self.tcx.require_lang_item(LangItem::Start, None);
-        let main_ret_ty = self.tcx.bound_fn_sig(main_def_id).subst_identity().output();
+        let main_ret_ty = self.tcx.fn_sig(main_def_id).subst_identity().output();
 
         // Given that `main()` has no arguments,
         // then its return type cannot have

compiler/rustc_privacy/src/lib.rs

@@ -198,7 +198,7 @@ where
                 // Something like `fn() -> Priv {my_func}` is considered a private type even if
                 // `my_func` is public, so we need to visit signatures.
                 if let ty::FnDef(..) = ty.kind() {
-                    tcx.bound_fn_sig(def_id).subst_identity().visit_with(self)?;
+                    tcx.fn_sig(def_id).subst_identity().visit_with(self)?;
                 }
                 // Inherent static methods don't have self type in substs.
                 // Something like `fn() {my_method}` type of the method

compiler/rustc_trait_selection/src/traits/object_safety.rs

@@ -395,7 +395,7 @@ fn virtual_call_violation_for_method<'tcx>(
     trait_def_id: DefId,
     method: &ty::AssocItem,
 ) -> Option<MethodViolationCode> {
-    let sig = tcx.bound_fn_sig(method.def_id).subst_identity();
+    let sig = tcx.fn_sig(method.def_id).subst_identity();
 
     // The method's first parameter must be named `self`
     if !method.fn_has_self_parameter {

compiler/rustc_traits/src/chalk/db.rs

@@ -269,7 +269,7 @@ impl<'tcx> chalk_solve::RustIrDatabase<RustInterner<'tcx>> for RustIrDatabase<'t
 
         let where_clauses = self.where_clauses_for(def_id, bound_vars);
 
-        let sig = self.interner.tcx.bound_fn_sig(def_id);
+        let sig = self.interner.tcx.fn_sig(def_id);
         let (inputs_and_output, iobinders, _) = crate::chalk::lowering::collect_bound_vars(
             self.interner,
             self.interner.tcx,

compiler/rustc_ty_utils/src/abi.rs

@@ -41,7 +41,7 @@ fn fn_sig_for_fn_abi<'tcx>(
             // We normalize the `fn_sig` again after substituting at a later point.
             let mut sig = match *ty.kind() {
                 ty::FnDef(def_id, substs) => tcx
-                    .bound_fn_sig(def_id)
+                    .fn_sig(def_id)
                     .map_bound(|fn_sig| {
                         tcx.normalize_erasing_regions(tcx.param_env(def_id), fn_sig)
                     })

compiler/rustc_ty_utils/src/implied_bounds.rs

@@ -9,12 +9,12 @@ pub fn provide(providers: &mut ty::query::Providers) {
 fn assumed_wf_types(tcx: TyCtxt<'_>, def_id: DefId) -> &ty::List<Ty<'_>> {
     match tcx.def_kind(def_id) {
         DefKind::Fn => {
-            let sig = tcx.bound_fn_sig(def_id).skip_binder();
+            let sig = tcx.fn_sig(def_id).skip_binder();
             let liberated_sig = tcx.liberate_late_bound_regions(def_id, sig);
             liberated_sig.inputs_and_output
         }
         DefKind::AssocFn => {
-            let sig = tcx.bound_fn_sig(def_id).skip_binder();
+            let sig = tcx.fn_sig(def_id).skip_binder();
             let liberated_sig = tcx.liberate_late_bound_regions(def_id, sig);
             let mut assumed_wf_types: Vec<_> =
                 tcx.assumed_wf_types(tcx.parent(def_id)).as_slice().into();

compiler/rustc_ty_utils/src/ty.rs

@@ -299,7 +299,7 @@ fn well_formed_types_in_env(tcx: TyCtxt<'_>, def_id: DefId) -> &ty::List<Predica
         // In an fn, we assume that the arguments and all their constituents are
         // well-formed.
         NodeKind::Fn => {
-            let fn_sig = tcx.bound_fn_sig(def_id).subst_identity();
+            let fn_sig = tcx.fn_sig(def_id).subst_identity();
             let fn_sig = tcx.liberate_late_bound_regions(def_id, fn_sig);
 
             inputs.extend(fn_sig.inputs().iter().flat_map(|ty| ty.walk()));

src/librustdoc/clean/inline.rs

@@ -251,7 +251,7 @@ pub(crate) fn build_external_trait(cx: &mut DocContext<'_>, did: DefId) -> clean
 }
 
 fn build_external_function<'tcx>(cx: &mut DocContext<'tcx>, did: DefId) -> Box<clean::Function> {
-    let sig = cx.tcx.bound_fn_sig(did).subst_identity();
+    let sig = cx.tcx.fn_sig(did).subst_identity();
 
     let late_bound_regions = sig.bound_vars().into_iter().filter_map(|var| match var {
         ty::BoundVariableKind::Region(ty::BrNamed(_, name)) if name != kw::UnderscoreLifetime => {

src/librustdoc/clean/mod.rs

@@ -1230,7 +1230,7 @@ pub(crate) fn clean_middle_assoc_item<'tcx>(
             }
         }
         ty::AssocKind::Fn => {
-            let sig = tcx.bound_fn_sig(assoc_item.def_id).subst_identity();
+            let sig = tcx.fn_sig(assoc_item.def_id).subst_identity();
 
             let late_bound_regions = sig.bound_vars().into_iter().filter_map(|var| match var {
                 ty::BoundVariableKind::Region(ty::BrNamed(_, name))

src/librustdoc/clean/types.rs

@@ -665,7 +665,7 @@ impl Item {
             tcx: TyCtxt<'_>,
             asyncness: hir::IsAsync,
         ) -> hir::FnHeader {
-            let sig = tcx.bound_fn_sig(def_id).skip_binder();
+            let sig = tcx.fn_sig(def_id).skip_binder();
             let constness =
                 if tcx.is_const_fn(def_id) && is_unstable_const_fn(tcx, def_id).is_none() {
                     hir::Constness::Const
@@ -677,7 +677,7 @@ impl Item {
         let header = match *self.kind {
             ItemKind::ForeignFunctionItem(_) => {
                 let def_id = self.item_id.as_def_id().unwrap();
-                let abi = tcx.bound_fn_sig(def_id).skip_binder().abi();
+                let abi = tcx.fn_sig(def_id).skip_binder().abi();
                 hir::FnHeader {
                     unsafety: if abi == Abi::RustIntrinsic {
                         intrinsic_operation_unsafety(tcx, self.item_id.as_def_id().unwrap())

src/tools/clippy/clippy_lints/src/casts/as_ptr_cast_mut.rs

@@ -17,7 +17,7 @@ pub(super) fn check(cx: &LateContext<'_>, expr: &Expr<'_>, cast_expr: &Expr<'_>,
         && let ExprKind::MethodCall(method_name, receiver, [], _) = cast_expr.peel_blocks().kind
         && method_name.ident.name == rustc_span::sym::as_ptr
         && let Some(as_ptr_did) = cx.typeck_results().type_dependent_def_id(cast_expr.peel_blocks().hir_id)
-        && let as_ptr_sig = cx.tcx.bound_fn_sig(as_ptr_did).subst_identity()
+        && let as_ptr_sig = cx.tcx.fn_sig(as_ptr_did).subst_identity()
         && let Some(first_param_ty) = as_ptr_sig.skip_binder().inputs().iter().next()
         && let ty::Ref(_, _, Mutability::Not) = first_param_ty.kind()
         && let Some(recv) = snippet_opt(cx, receiver.span)

src/tools/clippy/clippy_lints/src/default_numeric_fallback.rs

@@ -141,7 +141,7 @@ impl<'a, 'tcx> Visitor<'tcx> for NumericFallbackVisitor<'a, 'tcx> {
 
             ExprKind::MethodCall(_, receiver, args, _) => {
                 if let Some(def_id) = self.cx.typeck_results().type_dependent_def_id(expr.hir_id) {
-                    let fn_sig = self.cx.tcx.bound_fn_sig(def_id).subst_identity().skip_binder();
+                    let fn_sig = self.cx.tcx.fn_sig(def_id).subst_identity().skip_binder();
                     for (expr, bound) in iter::zip(std::iter::once(*receiver).chain(args.iter()), fn_sig.inputs()) {
                         self.ty_bounds.push((*bound).into());
                         self.visit_expr(expr);
@@ -215,7 +215,7 @@ fn fn_sig_opt<'tcx>(cx: &LateContext<'tcx>, hir_id: HirId) -> Option<PolyFnSig<'
     let node_ty = cx.typeck_results().node_type_opt(hir_id)?;
     // We can't use `Ty::fn_sig` because it automatically performs substs, this may result in FNs.
     match node_ty.kind() {
-        ty::FnDef(def_id, _) => Some(cx.tcx.bound_fn_sig(*def_id).subst_identity()),
+        ty::FnDef(def_id, _) => Some(cx.tcx.fn_sig(*def_id).subst_identity()),
         ty::FnPtr(fn_sig) => Some(*fn_sig),
         _ => None,
     }

src/tools/clippy/clippy_lints/src/dereference.rs

@@ -759,7 +759,7 @@ fn walk_parents<'tcx>(
             }) if span.ctxt() == ctxt => {
                 let output = cx
                     .tcx
-                    .erase_late_bound_regions(cx.tcx.bound_fn_sig(owner_id.to_def_id()).subst_identity().output());
+                    .erase_late_bound_regions(cx.tcx.fn_sig(owner_id).subst_identity().output());
                 Some(ty_auto_deref_stability(cx, output, precedence).position_for_result(cx))
             },
 
@@ -791,7 +791,7 @@ fn walk_parents<'tcx>(
                         } else {
                             let output = cx
                                 .tcx
-                                .erase_late_bound_regions(cx.tcx.bound_fn_sig(cx.tcx.hir().local_def_id(owner_id).into()).subst_identity().output());
+                                .erase_late_bound_regions(cx.tcx.fn_sig(cx.tcx.hir().local_def_id(owner_id)).subst_identity().output());
                             ty_auto_deref_stability(cx, output, precedence).position_for_result(cx)
                         },
                     )
@@ -858,7 +858,7 @@ fn walk_parents<'tcx>(
                             && let subs = cx
                                 .typeck_results()
                                 .node_substs_opt(parent.hir_id).map(|subs| &subs[1..]).unwrap_or_default()
-                            && let impl_ty = if cx.tcx.bound_fn_sig(id).subst_identity().skip_binder().inputs()[0].is_ref() {
+                            && let impl_ty = if cx.tcx.fn_sig(id).subst_identity().skip_binder().inputs()[0].is_ref() {
                                 // Trait methods taking `&self`
                                 sub_ty
                             } else {
@@ -879,7 +879,7 @@ fn walk_parents<'tcx>(
                         return Some(Position::MethodReceiver);
                     }
                     args.iter().position(|arg| arg.hir_id == child_id).map(|i| {
-                        let ty = cx.tcx.bound_fn_sig(id).subst_identity().skip_binder().inputs()[i + 1];
+                        let ty = cx.tcx.fn_sig(id).subst_identity().skip_binder().inputs()[i + 1];
                         // `e.hir_id == child_id` for https://github.com/rust-lang/rust-clippy/issues/9739
                         // `method.args.is_none()` for https://github.com/rust-lang/rust-clippy/issues/9782
                         if e.hir_id == child_id && method.args.is_none() && let ty::Param(param_ty) = ty.kind() {
@@ -896,7 +896,7 @@ fn walk_parents<'tcx>(
                         } else {
                             ty_auto_deref_stability(
                                 cx,
-                                cx.tcx.erase_late_bound_regions(cx.tcx.bound_fn_sig(id).subst_identity().input(i + 1)),
+                                cx.tcx.erase_late_bound_regions(cx.tcx.fn_sig(id).subst_identity().input(i + 1)),
                                 precedence,
                             )
                             .position_for_arg()
@@ -1093,7 +1093,7 @@ fn needless_borrow_impl_arg_position<'tcx>(
     let sized_trait_def_id = cx.tcx.lang_items().sized_trait();
 
     let Some(callee_def_id) = fn_def_id(cx, parent) else { return Position::Other(precedence) };
-    let fn_sig = cx.tcx.bound_fn_sig(callee_def_id).subst_identity().skip_binder();
+    let fn_sig = cx.tcx.fn_sig(callee_def_id).subst_identity().skip_binder();
     let substs_with_expr_ty = cx
         .typeck_results()
         .node_substs(if let ExprKind::Call(callee, _) = parent.kind {
@@ -1221,7 +1221,7 @@ fn has_ref_mut_self_method(cx: &LateContext<'_>, trait_def_id: DefId) -> bool {
         .in_definition_order()
         .any(|assoc_item| {
             if assoc_item.fn_has_self_parameter {
-                let self_ty = cx.tcx.bound_fn_sig(assoc_item.def_id).subst_identity().skip_binder().inputs()[0];
+                let self_ty = cx.tcx.fn_sig(assoc_item.def_id).subst_identity().skip_binder().inputs()[0];
                 matches!(self_ty.kind(), ty::Ref(_, _, Mutability::Mut))
             } else {
                 false

src/tools/clippy/clippy_lints/src/functions/not_unsafe_ptr_arg_deref.rs

@@ -58,7 +58,7 @@ fn check_raw_ptr<'tcx>(
                     },
                     hir::ExprKind::MethodCall(_, recv, args, _) => {
                         let def_id = typeck.type_dependent_def_id(e.hir_id).unwrap();
-                        if cx.tcx.bound_fn_sig(def_id).skip_binder().skip_binder().unsafety == hir::Unsafety::Unsafe {
+                        if cx.tcx.fn_sig(def_id).skip_binder().skip_binder().unsafety == hir::Unsafety::Unsafe {
                             check_arg(cx, &raw_ptrs, recv);
                             for arg in args {
                                 check_arg(cx, &raw_ptrs, arg);

src/tools/clippy/clippy_lints/src/functions/result.rs

@@ -21,7 +21,7 @@ fn result_err_ty<'tcx>(
 ) -> Option<(&'tcx hir::Ty<'tcx>, Ty<'tcx>)> {
     if !in_external_macro(cx.sess(), item_span)
         && let hir::FnRetTy::Return(hir_ty) = decl.output
-        && let ty = cx.tcx.erase_late_bound_regions(cx.tcx.bound_fn_sig(id.into()).subst_identity().output())
+        && let ty = cx.tcx.erase_late_bound_regions(cx.tcx.fn_sig(id).subst_identity().output())
         && is_type_diagnostic_item(cx, ty, sym::Result)
         && let ty::Adt(_, substs) = ty.kind()
     {

src/tools/clippy/clippy_lints/src/inherent_to_string.rs

@@ -124,7 +124,7 @@ fn show_lint(cx: &LateContext<'_>, item: &ImplItem<'_>) {
         .expect("Failed to get trait ID of `Display`!");
 
     // Get the real type of 'self'
-    let self_type = cx.tcx.bound_fn_sig(item.owner_id.to_def_id()).skip_binder().input(0);
+    let self_type = cx.tcx.fn_sig(item.owner_id).skip_binder().input(0);
     let self_type = self_type.skip_binder().peel_refs();
 
     // Emit either a warning or an error

src/tools/clippy/clippy_lints/src/iter_not_returning_iterator.rs

@@ -66,7 +66,7 @@ impl<'tcx> LateLintPass<'tcx> for IterNotReturningIterator {
 
 fn check_sig(cx: &LateContext<'_>, name: &str, sig: &FnSig<'_>, fn_id: LocalDefId) {
     if sig.decl.implicit_self.has_implicit_self() {
-        let ret_ty = cx.tcx.erase_late_bound_regions(cx.tcx.bound_fn_sig(fn_id.into()).subst_identity().output());
+        let ret_ty = cx.tcx.erase_late_bound_regions(cx.tcx.fn_sig(fn_id).subst_identity().output());
         let ret_ty = cx
             .tcx
             .try_normalize_erasing_regions(cx.param_env, ret_ty)

src/tools/clippy/clippy_lints/src/len_zero.rs

@@ -144,7 +144,7 @@ impl<'tcx> LateLintPass<'tcx> for LenZero {
             if let Some(local_id) = ty_id.as_local();
             let ty_hir_id = cx.tcx.hir().local_def_id_to_hir_id(local_id);
             if !is_lint_allowed(cx, LEN_WITHOUT_IS_EMPTY, ty_hir_id);
-            if let Some(output) = parse_len_output(cx, cx.tcx.bound_fn_sig(item.owner_id.to_def_id()).subst_identity().skip_binder());
+            if let Some(output) = parse_len_output(cx, cx.tcx.fn_sig(item.owner_id).subst_identity().skip_binder());
             then {
                 let (name, kind) = match cx.tcx.hir().find(ty_hir_id) {
                     Some(Node::ForeignItem(x)) => (x.ident.name, "extern type"),
@@ -196,7 +196,7 @@ fn check_trait_items(cx: &LateContext<'_>, visited_trait: &Item<'_>, trait_items
     fn is_named_self(cx: &LateContext<'_>, item: &TraitItemRef, name: Symbol) -> bool {
         item.ident.name == name
             && if let AssocItemKind::Fn { has_self } = item.kind {
-                has_self && { cx.tcx.bound_fn_sig(item.id.owner_id.to_def_id()).skip_binder().inputs().skip_binder().len() == 1 }
+                has_self && { cx.tcx.fn_sig(item.id.owner_id).skip_binder().inputs().skip_binder().len() == 1 }
             } else {
                 false
             }
@@ -224,7 +224,7 @@ fn check_trait_items(cx: &LateContext<'_>, visited_trait: &Item<'_>, trait_items
             .any(|i| {
                 i.kind == ty::AssocKind::Fn
                     && i.fn_has_self_parameter
-                    && cx.tcx.bound_fn_sig(i.def_id).skip_binder().inputs().skip_binder().len() == 1
+                    && cx.tcx.fn_sig(i.def_id).skip_binder().inputs().skip_binder().len() == 1
             });
 
         if !is_empty_method_found {
@@ -342,7 +342,7 @@ fn check_for_is_empty<'tcx>(
         ),
         Some(is_empty)
             if !(is_empty.fn_has_self_parameter
-                && check_is_empty_sig(cx.tcx.bound_fn_sig(is_empty.def_id).subst_identity().skip_binder(), self_kind, output)) =>
+                && check_is_empty_sig(cx.tcx.fn_sig(is_empty.def_id).subst_identity().skip_binder(), self_kind, output)) =>
         {
             (
                 format!(
@@ -473,7 +473,7 @@ fn has_is_empty(cx: &LateContext<'_>, expr: &Expr<'_>) -> bool {
     /// Gets an `AssocItem` and return true if it matches `is_empty(self)`.
     fn is_is_empty(cx: &LateContext<'_>, item: &ty::AssocItem) -> bool {
         if item.kind == ty::AssocKind::Fn {
-            let sig = cx.tcx.bound_fn_sig(item.def_id).skip_binder();
+            let sig = cx.tcx.fn_sig(item.def_id).skip_binder();
             let ty = sig.skip_binder();
             ty.inputs().len() == 1
         } else {

src/tools/clippy/clippy_lints/src/loops/needless_range_loop.rs

@@ -370,7 +370,7 @@ impl<'a, 'tcx> Visitor<'tcx> for VarVisitor<'a, 'tcx> {
             ExprKind::MethodCall(_, receiver, args, _) => {
                 let def_id = self.cx.typeck_results().type_dependent_def_id(expr.hir_id).unwrap();
                 for (ty, expr) in iter::zip(
-                    self.cx.tcx.bound_fn_sig(def_id).subst_identity().inputs().skip_binder(),
+                    self.cx.tcx.fn_sig(def_id).subst_identity().inputs().skip_binder(),
                     std::iter::once(receiver).chain(args.iter()),
                 ) {
                     self.prefer_mutable = false;

src/tools/clippy/clippy_lints/src/map_unit_fn.rs

@@ -104,7 +104,7 @@ fn is_unit_function(cx: &LateContext<'_>, expr: &hir::Expr<'_>) -> bool {
     let ty = cx.typeck_results().expr_ty(expr);
 
     if let ty::FnDef(id, _) = *ty.kind() {
-        if let Some(fn_type) = cx.tcx.bound_fn_sig(id).subst_identity().no_bound_vars() {
+        if let Some(fn_type) = cx.tcx.fn_sig(id).subst_identity().no_bound_vars() {
             return is_unit_type(fn_type.output());
         }
     }

src/tools/clippy/clippy_lints/src/methods/expect_fun_call.rs

@@ -70,7 +70,7 @@ pub(super) fn check<'tcx>(
                 if let hir::ExprKind::Path(ref p) = fun.kind {
                     match cx.qpath_res(p, fun.hir_id) {
                         hir::def::Res::Def(hir::def::DefKind::Fn | hir::def::DefKind::AssocFn, def_id) => matches!(
-                            cx.tcx.bound_fn_sig(def_id).subst_identity().output().skip_binder().kind(),
+                            cx.tcx.fn_sig(def_id).subst_identity().output().skip_binder().kind(),
                             ty::Ref(re, ..) if re.is_static(),
                         ),
                         _ => false,
@@ -84,7 +84,7 @@ pub(super) fn check<'tcx>(
                     .type_dependent_def_id(arg.hir_id)
                     .map_or(false, |method_id| {
                         matches!(
-                            cx.tcx.bound_fn_sig(method_id).subst_identity().output().skip_binder().kind(),
+                            cx.tcx.fn_sig(method_id).subst_identity().output().skip_binder().kind(),
                             ty::Ref(re, ..) if re.is_static()
                         )
                     })

src/tools/clippy/clippy_lints/src/methods/mod.rs

@@ -3352,7 +3352,7 @@ impl<'tcx> LateLintPass<'tcx> for Methods {
 
         let implements_trait = matches!(item.kind, hir::ItemKind::Impl(hir::Impl { of_trait: Some(_), .. }));
         if let hir::ImplItemKind::Fn(ref sig, id) = impl_item.kind {
-            let method_sig = cx.tcx.bound_fn_sig(impl_item.owner_id.to_def_id()).subst_identity();
+            let method_sig = cx.tcx.fn_sig(impl_item.owner_id).subst_identity();
             let method_sig = cx.tcx.erase_late_bound_regions(method_sig);
             let first_arg_ty_opt = method_sig.inputs().iter().next().copied();
             // if this impl block implements a trait, lint in trait definition instead

src/tools/clippy/clippy_lints/src/methods/needless_collect.rs

@@ -137,7 +137,7 @@ pub(super) fn check<'tcx>(
 /// Checks if the given method call matches the expected signature of `([&[mut]] self) -> bool`
 fn is_is_empty_sig(cx: &LateContext<'_>, call_id: HirId) -> bool {
     cx.typeck_results().type_dependent_def_id(call_id).map_or(false, |id| {
-        let sig = cx.tcx.bound_fn_sig(id).subst_identity().skip_binder();
+        let sig = cx.tcx.fn_sig(id).subst_identity().skip_binder();
         sig.inputs().len() == 1 && sig.output().is_bool()
     })
 }
@@ -165,7 +165,7 @@ fn iterates_same_ty<'tcx>(cx: &LateContext<'tcx>, iter_ty: Ty<'tcx>, collect_ty:
 fn is_contains_sig(cx: &LateContext<'_>, call_id: HirId, iter_expr: &Expr<'_>) -> bool {
     let typeck = cx.typeck_results();
     if let Some(id) = typeck.type_dependent_def_id(call_id)
-        && let sig = cx.tcx.bound_fn_sig(id).subst_identity()
+        && let sig = cx.tcx.fn_sig(id).subst_identity()
         && sig.skip_binder().output().is_bool()
         && let [_, search_ty] = *sig.skip_binder().inputs()
         && let ty::Ref(_, search_ty, Mutability::Not) = *cx.tcx.erase_late_bound_regions(sig.rebind(search_ty)).kind()

src/tools/clippy/clippy_lints/src/methods/unnecessary_to_owned.rs

@@ -246,7 +246,7 @@ fn check_other_call_arg<'tcx>(
     if_chain! {
         if let Some((maybe_call, maybe_arg)) = skip_addr_of_ancestors(cx, expr);
         if let Some((callee_def_id, _, recv, call_args)) = get_callee_substs_and_args(cx, maybe_call);
-        let fn_sig = cx.tcx.bound_fn_sig(callee_def_id).subst_identity().skip_binder();
+        let fn_sig = cx.tcx.fn_sig(callee_def_id).subst_identity().skip_binder();
         if let Some(i) = recv.into_iter().chain(call_args).position(|arg| arg.hir_id == maybe_arg.hir_id);
         if let Some(input) = fn_sig.inputs().get(i);
         let (input, n_refs) = peel_mid_ty_refs(*input);
@@ -386,7 +386,7 @@ fn can_change_type<'a>(cx: &LateContext<'a>, mut expr: &'a Expr<'a>, mut ty: Ty<
             Node::Expr(parent_expr) => {
                 if let Some((callee_def_id, call_substs, recv, call_args)) = get_callee_substs_and_args(cx, parent_expr)
                 {
-                    let fn_sig = cx.tcx.bound_fn_sig(callee_def_id).subst_identity().skip_binder();
+                    let fn_sig = cx.tcx.fn_sig(callee_def_id).subst_identity().skip_binder();
                     if let Some(arg_index) = recv.into_iter().chain(call_args).position(|arg| arg.hir_id == expr.hir_id)
                         && let Some(param_ty) = fn_sig.inputs().get(arg_index)
                         && let ty::Param(ParamTy { index: param_index , ..}) = param_ty.kind()

src/tools/clippy/clippy_lints/src/mut_key.rs

@@ -138,7 +138,7 @@ impl MutableKeyType {
 
     fn check_sig(&self, cx: &LateContext<'_>, item_hir_id: hir::HirId, decl: &hir::FnDecl<'_>) {
         let fn_def_id = cx.tcx.hir().local_def_id(item_hir_id);
-        let fn_sig = cx.tcx.bound_fn_sig(fn_def_id.into()).subst_identity();
+        let fn_sig = cx.tcx.fn_sig(fn_def_id).subst_identity();
         for (hir_ty, ty) in iter::zip(decl.inputs, fn_sig.inputs().skip_binder()) {
             self.check_ty_(cx, hir_ty.span, *ty);
         }

src/tools/clippy/clippy_lints/src/needless_pass_by_value.rs

@@ -147,7 +147,7 @@ impl<'tcx> LateLintPass<'tcx> for NeedlessPassByValue {
             ctx
         };
 
-        let fn_sig = cx.tcx.bound_fn_sig(fn_def_id.into()).subst_identity();
+        let fn_sig = cx.tcx.fn_sig(fn_def_id).subst_identity();
         let fn_sig = cx.tcx.erase_late_bound_regions(fn_sig);
 
         for (idx, ((input, &ty), arg)) in decl.inputs.iter().zip(fn_sig.inputs()).zip(body.params).enumerate() {

src/tools/clippy/clippy_lints/src/pass_by_ref_or_value.rs

@@ -143,7 +143,7 @@ impl<'tcx> PassByRefOrValue {
             return;
         }
 
-        let fn_sig = cx.tcx.bound_fn_sig(def_id.into()).subst_identity();
+        let fn_sig = cx.tcx.fn_sig(def_id).subst_identity();
         let fn_body = cx.enclosing_body.map(|id| cx.tcx.hir().body(id));
 
         // Gather all the lifetimes found in the output type which may affect whether

src/tools/clippy/clippy_lints/src/ptr.rs

@@ -164,7 +164,7 @@ impl<'tcx> LateLintPass<'tcx> for Ptr {
             check_mut_from_ref(cx, sig, None);
             for arg in check_fn_args(
                 cx,
-                cx.tcx.bound_fn_sig(item.owner_id.to_def_id()).subst_identity().skip_binder().inputs(),
+                cx.tcx.fn_sig(item.owner_id).subst_identity().skip_binder().inputs(),
                 sig.decl.inputs,
                 &[],
             )
@@ -217,7 +217,7 @@ impl<'tcx> LateLintPass<'tcx> for Ptr {
 
         check_mut_from_ref(cx, sig, Some(body));
         let decl = sig.decl;
-        let sig = cx.tcx.bound_fn_sig(item_id.to_def_id()).subst_identity().skip_binder();
+        let sig = cx.tcx.fn_sig(item_id).subst_identity().skip_binder();
         let lint_args: Vec<_> = check_fn_args(cx, sig.inputs(), decl.inputs, body.params)
             .filter(|arg| !is_trait_item || arg.mutability() == Mutability::Not)
             .collect();
@@ -624,7 +624,7 @@ fn check_ptr_arg_usage<'tcx>(cx: &LateContext<'tcx>, body: &'tcx Body<'_>, args:
                             return;
                         };
 
-                        match *self.cx.tcx.bound_fn_sig(id).subst_identity().skip_binder().inputs()[i].peel_refs().kind() {
+                        match *self.cx.tcx.fn_sig(id).subst_identity().skip_binder().inputs()[i].peel_refs().kind() {
                             ty::Dynamic(preds, _, _) if !matches_preds(self.cx, args.deref_ty.ty(self.cx), preds) => {
                                 set_skip_flag();
                             },

src/tools/clippy/clippy_lints/src/returns.rs

@@ -287,7 +287,7 @@ fn last_statement_borrows<'tcx>(cx: &LateContext<'tcx>, expr: &'tcx Expr<'tcx>)
         if let Some(def_id) = fn_def_id(cx, e)
             && cx
                 .tcx
-                .bound_fn_sig(def_id)
+                .fn_sig(def_id)
                 .subst_identity()
                 .skip_binder()
                 .output()

src/tools/clippy/clippy_lints/src/unit_return_expecting_ord.rs

@@ -76,7 +76,7 @@ fn get_projection_pred<'tcx>(
 fn get_args_to_check<'tcx>(cx: &LateContext<'tcx>, expr: &'tcx Expr<'tcx>) -> Vec<(usize, String)> {
     let mut args_to_check = Vec::new();
     if let Some(def_id) = cx.typeck_results().type_dependent_def_id(expr.hir_id) {
-        let fn_sig = cx.tcx.bound_fn_sig(def_id).subst_identity();
+        let fn_sig = cx.tcx.fn_sig(def_id).subst_identity();
         let generics = cx.tcx.predicates_of(def_id);
         let fn_mut_preds = get_trait_predicates_for_trait_id(cx, generics, cx.tcx.lang_items().fn_mut_trait());
         let ord_preds = get_trait_predicates_for_trait_id(cx, generics, cx.tcx.get_diagnostic_item(sym::Ord));

src/tools/clippy/clippy_lints/src/unit_types/let_unit_value.rs

@@ -156,7 +156,7 @@ fn needs_inferred_result_ty(
         },
         _ => return false,
     };
-    let sig = cx.tcx.bound_fn_sig(id).subst_identity().skip_binder();
+    let sig = cx.tcx.fn_sig(id).subst_identity().skip_binder();
     if let ty::Param(output_ty) = *sig.output().kind() {
         let args: Vec<&Expr<'_>> = if let Some(receiver) = receiver {
             std::iter::once(receiver).chain(args.iter()).collect()

src/tools/clippy/clippy_lints/src/use_self.rs

@@ -146,7 +146,7 @@ impl<'tcx> LateLintPass<'tcx> for UseSelf {
                     .associated_item(impl_item.owner_id)
                     .trait_item_def_id
                     .expect("impl method matches a trait method");
-                let trait_method_sig = cx.tcx.bound_fn_sig(trait_method).subst_identity();
+                let trait_method_sig = cx.tcx.fn_sig(trait_method).subst_identity();
                 let trait_method_sig = cx.tcx.erase_late_bound_regions(trait_method_sig);
 
                 // `impl_inputs_outputs` is an iterator over the types (`hir::Ty`) declared in the

src/tools/clippy/clippy_utils/src/eager_or_lazy.rs

@@ -79,7 +79,7 @@ fn fn_eagerness(cx: &LateContext<'_>, fn_id: DefId, name: Symbol, have_one_arg:
             && subs.types().all(|x| matches!(x.peel_refs().kind(), ty::Param(_)))
         {
             // Limit the function to either `(self) -> bool` or `(&self) -> bool`
-            match &**cx.tcx.bound_fn_sig(fn_id).subst_identity().skip_binder().inputs_and_output {
+            match &**cx.tcx.fn_sig(fn_id).subst_identity().skip_binder().inputs_and_output {
                 [arg, res] if !arg.is_mutable_ptr() && arg.peel_refs() == ty && res.is_bool() => NoChange,
                 _ => Lazy,
             }

src/tools/clippy/clippy_utils/src/lib.rs

@@ -1379,7 +1379,7 @@ pub fn get_enclosing_loop_or_multi_call_closure<'tcx>(
                                     .chain(args.iter())
                                     .position(|arg| arg.hir_id == id)?;
                                 let id = cx.typeck_results().type_dependent_def_id(e.hir_id)?;
-                                let ty = cx.tcx.bound_fn_sig(id).subst_identity().skip_binder().inputs()[i];
+                                let ty = cx.tcx.fn_sig(id).subst_identity().skip_binder().inputs()[i];
                                 ty_is_fn_once_param(cx.tcx, ty, cx.tcx.param_env(id).caller_bounds()).then_some(())
                             },
                             _ => None,
@@ -1580,14 +1580,14 @@ pub fn is_direct_expn_of(span: Span, name: &str) -> Option<Span> {
 /// Convenience function to get the return type of a function.
 pub fn return_ty<'tcx>(cx: &LateContext<'tcx>, fn_item: hir::HirId) -> Ty<'tcx> {
     let fn_def_id = cx.tcx.hir().local_def_id(fn_item);
-    let ret_ty = cx.tcx.bound_fn_sig(fn_def_id.into()).subst_identity().output();
+    let ret_ty = cx.tcx.fn_sig(fn_def_id).subst_identity().output();
     cx.tcx.erase_late_bound_regions(ret_ty)
 }
 
 /// Convenience function to get the nth argument type of a function.
 pub fn nth_arg<'tcx>(cx: &LateContext<'tcx>, fn_item: hir::HirId, nth: usize) -> Ty<'tcx> {
     let fn_def_id = cx.tcx.hir().local_def_id(fn_item);
-    let arg = cx.tcx.bound_fn_sig(fn_def_id.into()).subst_identity().input(nth);
+    let arg = cx.tcx.fn_sig(fn_def_id).subst_identity().input(nth);
     cx.tcx.erase_late_bound_regions(arg)
 }
 

src/tools/clippy/clippy_utils/src/qualify_min_const_fn.rs

@@ -55,7 +55,7 @@ pub fn is_min_const_fn<'tcx>(tcx: TyCtxt<'tcx>, body: &Body<'tcx>, msrv: &Msrv)
     // impl trait is gone in MIR, so check the return type manually
     check_ty(
         tcx,
-        tcx.bound_fn_sig(def_id).subst_identity().output().skip_binder(),
+        tcx.fn_sig(def_id).subst_identity().output().skip_binder(),
         body.local_decls.iter().next().unwrap().source_info.span,
     )?;
 

src/tools/clippy/clippy_utils/src/sugg.rs

@@ -885,7 +885,7 @@ impl<'tcx> DerefDelegate<'_, 'tcx> {
                     .cx
                     .typeck_results()
                     .type_dependent_def_id(parent_expr.hir_id)
-                    .map(|did| self.cx.tcx.bound_fn_sig(did).subst_identity().skip_binder())
+                    .map(|did| self.cx.tcx.fn_sig(did).subst_identity().skip_binder())
                 {
                     std::iter::once(receiver)
                         .chain(call_args.iter())

src/tools/clippy/clippy_utils/src/ty.rs

@@ -628,7 +628,7 @@ impl<'tcx> ExprFnSig<'tcx> {
 /// If the expression is function like, get the signature for it.
 pub fn expr_sig<'tcx>(cx: &LateContext<'tcx>, expr: &Expr<'_>) -> Option<ExprFnSig<'tcx>> {
     if let Res::Def(DefKind::Fn | DefKind::Ctor(_, CtorKind::Fn) | DefKind::AssocFn, id) = path_res(cx, expr) {
-        Some(ExprFnSig::Sig(cx.tcx.bound_fn_sig(id).subst_identity(), Some(id)))
+        Some(ExprFnSig::Sig(cx.tcx.fn_sig(id).subst_identity(), Some(id)))
     } else {
         ty_sig(cx, cx.typeck_results().expr_ty_adjusted(expr).peel_refs())
     }
@@ -646,7 +646,7 @@ pub fn ty_sig<'tcx>(cx: &LateContext<'tcx>, ty: Ty<'tcx>) -> Option<ExprFnSig<'t
                 .and_then(|id| cx.tcx.hir().fn_decl_by_hir_id(cx.tcx.hir().local_def_id_to_hir_id(id)));
             Some(ExprFnSig::Closure(decl, subs.as_closure().sig()))
         },
-        ty::FnDef(id, subs) => Some(ExprFnSig::Sig(cx.tcx.bound_fn_sig(id).subst(cx.tcx, subs), Some(id))),
+        ty::FnDef(id, subs) => Some(ExprFnSig::Sig(cx.tcx.fn_sig(id).subst(cx.tcx, subs), Some(id))),
         ty::Alias(ty::Opaque, ty::AliasTy { def_id, substs, .. }) => {
             sig_from_bounds(cx, ty, cx.tcx.item_bounds(def_id).subst(cx.tcx, substs), cx.tcx.opt_parent(def_id))
         },

src/tools/clippy/clippy_utils/src/visitors.rs

@@ -392,12 +392,12 @@ pub fn is_expr_unsafe<'tcx>(cx: &LateContext<'tcx>, e: &'tcx Expr<'_>) -> bool {
                         .cx
                         .typeck_results()
                         .type_dependent_def_id(e.hir_id)
-                        .map_or(false, |id| self.cx.tcx.bound_fn_sig(id).skip_binder().unsafety() == Unsafety::Unsafe) =>
+                        .map_or(false, |id| self.cx.tcx.fn_sig(id).skip_binder().unsafety() == Unsafety::Unsafe) =>
                 {
                     self.is_unsafe = true;
                 },
                 ExprKind::Call(func, _) => match *self.cx.typeck_results().expr_ty(func).peel_refs().kind() {
-                    ty::FnDef(id, _) if self.cx.tcx.bound_fn_sig(id).skip_binder().unsafety() == Unsafety::Unsafe => self.is_unsafe = true,
+                    ty::FnDef(id, _) if self.cx.tcx.fn_sig(id).skip_binder().unsafety() == Unsafety::Unsafe => self.is_unsafe = true,
                     ty::FnPtr(sig) if sig.unsafety() == Unsafety::Unsafe => self.is_unsafe = true,
                     _ => walk_expr(self, e),
                 },

src/tools/miri/src/eval.rs

@@ -357,7 +357,7 @@ pub fn create_ecx<'mir, 'tcx: 'mir>(
     match entry_type {
         EntryFnType::Main { .. } => {
             let start_id = tcx.lang_items().start_fn().unwrap();
-            let main_ret_ty = tcx.bound_fn_sig(entry_id).subst_identity().output();
+            let main_ret_ty = tcx.fn_sig(entry_id).subst_identity().output();
             let main_ret_ty = main_ret_ty.no_bound_vars().unwrap();
             let start_instance = ty::Instance::resolve(
                 tcx,