refactor(rustc_middle): Substs -> GenericArg

clippy_lints/src/assertions_on_result_states.rs

@@ -47,7 +47,7 @@ impl<'tcx> LateLintPass<'tcx> for AssertionsOnResultStates {
             && let result_type_with_refs = cx.typeck_results().expr_ty(recv)
             && let result_type = result_type_with_refs.peel_refs()
             && is_type_diagnostic_item(cx, result_type, sym::Result)
-            && let ty::Adt(_, substs) = result_type.kind()
+            && let ty::Adt(_, args) = result_type.kind()
         {
             if !is_copy(cx, result_type) {
                 if result_type_with_refs != result_type {
@@ -61,7 +61,7 @@ impl<'tcx> LateLintPass<'tcx> for AssertionsOnResultStates {
             let semicolon = if is_expr_final_block_expr(cx.tcx, e) {";"} else {""};
             let mut app = Applicability::MachineApplicable;
             match method_segment.ident.as_str() {
-                "is_ok" if type_suitable_to_unwrap(cx, substs.type_at(1)) => {
+                "is_ok" if type_suitable_to_unwrap(cx, args.type_at(1)) => {
                     span_lint_and_sugg(
                         cx,
                         ASSERTIONS_ON_RESULT_STATES,
@@ -75,7 +75,7 @@ impl<'tcx> LateLintPass<'tcx> for AssertionsOnResultStates {
                         app,
                     );
                 }
-                "is_err" if type_suitable_to_unwrap(cx, substs.type_at(0)) => {
+                "is_err" if type_suitable_to_unwrap(cx, args.type_at(0)) => {
                     span_lint_and_sugg(
                         cx,
                         ASSERTIONS_ON_RESULT_STATES,

clippy_lints/src/bool_assert_comparison.rs

@@ -61,7 +61,7 @@ fn is_impl_not_trait_with_bool_out<'tcx>(cx: &LateContext<'tcx>, ty: Ty<'tcx>) -
             )
         })
         .map_or(false, |assoc_item| {
-            let proj = Ty::new_projection(cx.tcx,assoc_item.def_id, cx.tcx.mk_substs_trait(ty, []));
+            let proj = Ty::new_projection(cx.tcx,assoc_item.def_id, cx.tcx.mk_args_trait(ty, []));
             let nty = cx.tcx.normalize_erasing_regions(cx.param_env, proj);
 
             nty.is_bool()

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.fn_sig(as_ptr_did).subst_identity()
+        && let as_ptr_sig = cx.tcx.fn_sig(as_ptr_did).instantiate_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)

clippy_lints/src/casts/cast_ptr_alignment.rs

@@ -66,7 +66,7 @@ fn is_used_as_unaligned(cx: &LateContext<'_>, e: &Expr<'_>) -> bool {
             if matches!(name.ident.as_str(), "read_unaligned" | "write_unaligned")
                 && let Some(def_id) = cx.typeck_results().type_dependent_def_id(parent.hir_id)
                 && let Some(def_id) = cx.tcx.impl_of_method(def_id)
-                && cx.tcx.type_of(def_id).subst_identity().is_unsafe_ptr()
+                && cx.tcx.type_of(def_id).instantiate_identity().is_unsafe_ptr()
             {
                 true
             } else {

clippy_lints/src/copy_iterator.rs

@@ -43,7 +43,7 @@ impl<'tcx> LateLintPass<'tcx> for CopyIterator {
                 of_trait: Some(ref trait_ref),
                 ..
             }) = item.kind;
-            let ty = cx.tcx.type_of(item.owner_id).subst_identity();
+            let ty = cx.tcx.type_of(item.owner_id).instantiate_identity();
             if is_copy(cx, ty);
             if let Some(trait_id) = trait_ref.trait_def_id();
             if cx.tcx.is_diagnostic_item(sym::Iterator, trait_id);

clippy_lints/src/default.rs

@@ -150,7 +150,7 @@ impl<'tcx> LateLintPass<'tcx> for Default {
                     .fields
                     .iter()
                     .all(|field| {
-                        is_copy(cx, cx.tcx.type_of(field.did).subst_identity())
+                        is_copy(cx, cx.tcx.type_of(field.did).instantiate_identity())
                     });
                 if !has_drop(cx, binding_type) || all_fields_are_copy;
                 then {
@@ -219,11 +219,11 @@ impl<'tcx> LateLintPass<'tcx> for Default {
 
                 // give correct suggestion if generics are involved (see #6944)
                 let binding_type = if_chain! {
-                    if let ty::Adt(adt_def, substs) = binding_type.kind();
+                    if let ty::Adt(adt_def, args) = binding_type.kind();
-                    if !substs.is_empty();
+                    if !args.is_empty();
                     then {
                         let adt_def_ty_name = cx.tcx.item_name(adt_def.did());
-                        let generic_args = substs.iter().collect::<Vec<_>>();
+                        let generic_args = args.iter().collect::<Vec<_>>();
                         let tys_str = generic_args
                             .iter()
                             .map(ToString::to_string)

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.fn_sig(def_id).subst_identity().skip_binder();
+                    let fn_sig = self.cx.tcx.fn_sig(def_id).instantiate_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);
@@ -167,7 +167,7 @@ impl<'a, 'tcx> Visitor<'tcx> for NumericFallbackVisitor<'a, 'tcx> {
                                     .iter()
                                     .find_map(|f_def| {
                                         if f_def.ident(self.cx.tcx) == field.ident
-                                            { Some(self.cx.tcx.type_of(f_def.did).subst_identity()) }
+                                            { Some(self.cx.tcx.type_of(f_def.did).instantiate_identity()) }
                                         else { None }
                                     });
                             self.ty_bounds.push(bound.into());
@@ -213,9 +213,9 @@ impl<'a, 'tcx> Visitor<'tcx> for NumericFallbackVisitor<'a, 'tcx> {
 
 fn fn_sig_opt<'tcx>(cx: &LateContext<'tcx>, hir_id: HirId) -> Option<PolyFnSig<'tcx>> {
     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.
+    // We can't use `Ty::fn_sig` because it automatically performs args, this may result in FNs.
     match node_ty.kind() {
-        ty::FnDef(def_id, _) => Some(cx.tcx.fn_sig(*def_id).subst_identity()),
+        ty::FnDef(def_id, _) => Some(cx.tcx.fn_sig(*def_id).instantiate_identity()),
         ty::FnPtr(fn_sig) => Some(*fn_sig),
         _ => None,
     }

clippy_lints/src/dereference.rs

@@ -739,7 +739,7 @@ fn walk_parents<'tcx>(
                 span,
                 ..
             }) if span.ctxt() == ctxt => {
-                let ty = cx.tcx.type_of(owner_id.def_id).subst_identity();
+                let ty = cx.tcx.type_of(owner_id.def_id).instantiate_identity();
                 Some(ty_auto_deref_stability(cx.tcx, cx.param_env, ty, precedence).position_for_result(cx))
             },
 
@@ -763,7 +763,7 @@ fn walk_parents<'tcx>(
             }) if span.ctxt() == ctxt => {
                 let output = cx
                     .tcx
-                    .erase_late_bound_regions(cx.tcx.fn_sig(owner_id).subst_identity().output());
+                    .erase_late_bound_regions(cx.tcx.fn_sig(owner_id).instantiate_identity().output());
                 Some(ty_auto_deref_stability(cx.tcx, cx.param_env, output, precedence).position_for_result(cx))
             },
 
@@ -785,7 +785,7 @@ fn walk_parents<'tcx>(
                             cx.tcx,
                             // Use the param_env of the target type.
                             cx.tcx.param_env(adt.did()),
-                            cx.tcx.type_of(field_def.did).subst_identity(),
+                            cx.tcx.type_of(field_def.did).instantiate_identity(),
                             precedence,
                         )
                         .position_for_arg()
@@ -808,7 +808,7 @@ fn walk_parents<'tcx>(
                         } else {
                             let output = cx
                                 .tcx
-                                .erase_late_bound_regions(cx.tcx.fn_sig(owner_id).subst_identity().output());
+                                .erase_late_bound_regions(cx.tcx.fn_sig(owner_id).instantiate_identity().output());
                             ty_auto_deref_stability(cx.tcx, cx.param_env, output, precedence).position_for_result(cx)
                         },
                     )
@@ -879,9 +879,9 @@ fn walk_parents<'tcx>(
                             && let ty::Ref(_, sub_ty, _) = *arg_ty.kind()
                             && let subs = cx
                                 .typeck_results()
-                                .node_substs_opt(parent.hir_id).map(|subs| &subs[1..]).unwrap_or_default()
+                                .node_args_opt(parent.hir_id).map(|subs| &subs[1..]).unwrap_or_default()
                             && let impl_ty = if cx.tcx.fn_sig(fn_id)
-                                .subst_identity()
+                                .instantiate_identity()
                                 .skip_binder()
                                 .inputs()[0].is_ref()
                             {
@@ -905,7 +905,7 @@ fn walk_parents<'tcx>(
                         return Some(Position::MethodReceiver);
                     }
                     args.iter().position(|arg| arg.hir_id == child_id).map(|i| {
-                        let ty = cx.tcx.fn_sig(fn_id).subst_identity().input(i + 1);
+                        let ty = cx.tcx.fn_sig(fn_id).instantiate_identity().input(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
@@ -1124,10 +1124,10 @@ 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.fn_sig(callee_def_id).subst_identity().skip_binder();
+    let fn_sig = cx.tcx.fn_sig(callee_def_id).instantiate_identity().skip_binder();
-    let substs_with_expr_ty = cx
+    let args_with_expr_ty = cx
         .typeck_results()
-        .node_substs(if let ExprKind::Call(callee, _) = parent.kind {
+        .node_args(if let ExprKind::Call(callee, _) = parent.kind {
             callee.hir_id
         } else {
             parent.hir_id
@@ -1181,9 +1181,9 @@ fn needless_borrow_impl_arg_position<'tcx>(
         return Position::Other(precedence);
     }
 
-    // `substs_with_referent_ty` can be constructed outside of `check_referent` because the same
+    // `args_with_referent_ty` can be constructed outside of `check_referent` because the same
     // elements are modified each time `check_referent` is called.
-    let mut substs_with_referent_ty = substs_with_expr_ty.to_vec();
+    let mut args_with_referent_ty = args_with_expr_ty.to_vec();
 
     let mut check_reference_and_referent = |reference, referent| {
         let referent_ty = cx.typeck_results().expr_ty(referent);
@@ -1207,7 +1207,7 @@ fn needless_borrow_impl_arg_position<'tcx>(
             fn_sig,
             arg_index,
             &projection_predicates,
-            &mut substs_with_referent_ty,
+            &mut args_with_referent_ty,
         ) {
             return false;
         }
@@ -1216,14 +1216,14 @@ fn needless_borrow_impl_arg_position<'tcx>(
             if let ClauseKind::Trait(trait_predicate) = predicate.kind().skip_binder()
                 && cx.tcx.is_diagnostic_item(sym::IntoIterator, trait_predicate.trait_ref.def_id)
                 && let ty::Param(param_ty) = trait_predicate.self_ty().kind()
-                && let GenericArgKind::Type(ty) = substs_with_referent_ty[param_ty.index as usize].unpack()
+                && let GenericArgKind::Type(ty) = args_with_referent_ty[param_ty.index as usize].unpack()
                 && ty.is_array()
                 && !msrv.meets(msrvs::ARRAY_INTO_ITERATOR)
             {
                 return false;
             }
 
-            let predicate = EarlyBinder::bind(predicate).subst(cx.tcx, &substs_with_referent_ty);
+            let predicate = EarlyBinder::bind(predicate).instantiate(cx.tcx, &args_with_referent_ty);
             let obligation = Obligation::new(cx.tcx, ObligationCause::dummy(), cx.param_env, predicate);
             let infcx = cx.tcx.infer_ctxt().build();
             infcx.predicate_must_hold_modulo_regions(&obligation)
@@ -1252,7 +1252,7 @@ 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.fn_sig(assoc_item.def_id).subst_identity().skip_binder().inputs()[0];
+                let self_ty = cx.tcx.fn_sig(assoc_item.def_id).instantiate_identity().skip_binder().inputs()[0];
                 matches!(self_ty.kind(), ty::Ref(_, _, Mutability::Mut))
             } else {
                 false
@@ -1323,7 +1323,7 @@ fn referent_used_exactly_once<'tcx>(
     }
 }
 
-// Iteratively replaces `param_ty` with `new_ty` in `substs`, and similarly for each resulting
+// Iteratively replaces `param_ty` with `new_ty` in `args`, and similarly for each resulting
 // projected type that is a type parameter. Returns `false` if replacing the types would have an
 // effect on the function signature beyond substituting `new_ty` for `param_ty`.
 // See: https://github.com/rust-lang/rust-clippy/pull/9136#discussion_r927212757
@@ -1334,11 +1334,11 @@ fn replace_types<'tcx>(
     fn_sig: FnSig<'tcx>,
     arg_index: usize,
     projection_predicates: &[ProjectionPredicate<'tcx>],
-    substs: &mut [ty::GenericArg<'tcx>],
+    args: &mut [ty::GenericArg<'tcx>],
 ) -> bool {
-    let mut replaced = BitSet::new_empty(substs.len());
+    let mut replaced = BitSet::new_empty(args.len());
 
-    let mut deque = VecDeque::with_capacity(substs.len());
+    let mut deque = VecDeque::with_capacity(args.len());
     deque.push_back((param_ty, new_ty));
 
     while let Some((param_ty, new_ty)) = deque.pop_front() {
@@ -1352,7 +1352,7 @@ fn replace_types<'tcx>(
             return false;
         }
 
-        substs[param_ty.index as usize] = ty::GenericArg::from(new_ty);
+        args[param_ty.index as usize] = ty::GenericArg::from(new_ty);
 
         // The `replaced.insert(...)` check provides some protection against infinite loops.
         if replaced.insert(param_ty.index) {
@@ -1367,7 +1367,7 @@ fn replace_types<'tcx>(
                     ));
 
                     if let Ok(projected_ty) = cx.tcx.try_normalize_erasing_regions(cx.param_env, projection)
-                        && substs[term_param_ty.index as usize] != ty::GenericArg::from(projected_ty)
+                        && args[term_param_ty.index as usize] != ty::GenericArg::from(projected_ty)
                     {
                         deque.push_back((*term_param_ty, projected_ty));
                     }
@@ -1442,7 +1442,7 @@ fn ty_auto_deref_stability<'tcx>(
             ty::Adt(..) if ty.has_placeholders() || ty.has_opaque_types() => {
                 Position::ReborrowStable(precedence).into()
             },
-            ty::Adt(_, substs) if substs.has_non_region_param() => {
+            ty::Adt(_, args) if args.has_non_region_param() => {
                 TyPosition::new_deref_stable_for_result(precedence, ty)
             },
             ty::Bool

clippy_lints/src/derivable_impls.rs

@@ -10,7 +10,7 @@ use rustc_hir::{
 };
 use rustc_lint::{LateContext, LateLintPass};
 use rustc_middle::ty::adjustment::{Adjust, PointerCoercion};
-use rustc_middle::ty::{self, Adt, AdtDef, SubstsRef, Ty, TypeckResults};
+use rustc_middle::ty::{self, Adt, AdtDef, GenericArgsRef, Ty, TypeckResults};
 use rustc_session::{declare_tool_lint, impl_lint_pass};
 use rustc_span::sym;
 
@@ -80,7 +80,7 @@ fn is_path_self(e: &Expr<'_>) -> bool {
 fn contains_trait_object(ty: Ty<'_>) -> bool {
     match ty.kind() {
         ty::Ref(_, ty, _) => contains_trait_object(*ty),
-        ty::Adt(def, substs) => def.is_box() && substs[0].as_type().map_or(false, contains_trait_object),
+        ty::Adt(def, args) => def.is_box() && args[0].as_type().map_or(false, contains_trait_object),
         ty::Dynamic(..) => true,
         _ => false,
     }
@@ -92,18 +92,18 @@ fn check_struct<'tcx>(
     self_ty: &hir::Ty<'_>,
     func_expr: &Expr<'_>,
     adt_def: AdtDef<'_>,
-    substs: SubstsRef<'_>,
+    ty_args: GenericArgsRef<'_>,
     typeck_results: &'tcx TypeckResults<'tcx>,
 ) {
     if let TyKind::Path(QPath::Resolved(_, p)) = self_ty.kind {
         if let Some(PathSegment { args, .. }) = p.segments.last() {
             let args = args.map(|a| a.args).unwrap_or(&[]);
 
-            // substs contains the generic parameters of the type declaration, while args contains the arguments
+            // ty_args contains the generic parameters of the type declaration, while args contains the arguments
             // used at instantiation time. If both len are not equal, it means that some parameters were not
             // provided (which means that the default values were used); in this case we will not risk
             // suggesting too broad a rewrite. We won't either if any argument is a type or a const.
-            if substs.len() != args.len() || args.iter().any(|arg| !matches!(arg, GenericArg::Lifetime(_))) {
+            if ty_args.len() != args.len() || args.iter().any(|arg| !matches!(arg, GenericArg::Lifetime(_))) {
                 return;
             }
         }
@@ -214,7 +214,7 @@ impl<'tcx> LateLintPass<'tcx> for DerivableImpls {
             if let Some(Node::ImplItem(impl_item)) = cx.tcx.hir().find(impl_item_hir);
             if let ImplItemKind::Fn(_, b) = &impl_item.kind;
             if let Body { value: func_expr, .. } = cx.tcx.hir().body(*b);
-            if let &Adt(adt_def, substs) = cx.tcx.type_of(item.owner_id).subst_identity().kind();
+            if let &Adt(adt_def, args) = cx.tcx.type_of(item.owner_id).instantiate_identity().kind();
             if let attrs = cx.tcx.hir().attrs(item.hir_id());
             if !attrs.iter().any(|attr| attr.doc_str().is_some());
             if let child_attrs = cx.tcx.hir().attrs(impl_item_hir);
@@ -222,7 +222,7 @@ impl<'tcx> LateLintPass<'tcx> for DerivableImpls {
 
             then {
                 if adt_def.is_struct() {
-                    check_struct(cx, item, self_ty, func_expr, adt_def, substs, cx.tcx.typeck_body(*b));
+                    check_struct(cx, item, self_ty, func_expr, adt_def, args, cx.tcx.typeck_body(*b));
                 } else if adt_def.is_enum() && self.msrv.meets(msrvs::DEFAULT_ENUM_ATTRIBUTE) {
                     check_enum(cx, item, func_expr, adt_def);
                 }

clippy_lints/src/derive.rs

@@ -211,7 +211,7 @@ impl<'tcx> LateLintPass<'tcx> for Derive {
             ..
         }) = item.kind
         {
-            let ty = cx.tcx.type_of(item.owner_id).subst_identity();
+            let ty = cx.tcx.type_of(item.owner_id).instantiate_identity();
             let is_automatically_derived = cx.tcx.has_attr(item.owner_id, sym::automatically_derived);
 
             check_hash_peq(cx, item.span, trait_ref, ty, is_automatically_derived);
@@ -252,7 +252,7 @@ fn check_hash_peq<'tcx>(
 
                 // Only care about `impl PartialEq<Foo> for Foo`
                 // For `impl PartialEq<B> for A, input_types is [A, B]
-                if trait_ref.subst_identity().substs.type_at(1) == ty {
+                if trait_ref.instantiate_identity().args.type_at(1) == ty {
                     span_lint_and_then(
                         cx,
                         DERIVED_HASH_WITH_MANUAL_EQ,
@@ -300,7 +300,7 @@ fn check_ord_partial_ord<'tcx>(
 
                 // Only care about `impl PartialOrd<Foo> for Foo`
                 // For `impl PartialOrd<B> for A, input_types is [A, B]
-                if trait_ref.subst_identity().substs.type_at(1) == ty {
+                if trait_ref.instantiate_identity().args.type_at(1) == ty {
                     let mess = if partial_ord_is_automatically_derived {
                         "you are implementing `Ord` explicitly but have derived `PartialOrd`"
                     } else {
@@ -347,7 +347,7 @@ fn check_copy_clone<'tcx>(cx: &LateContext<'tcx>, item: &Item<'_>, trait_ref: &h
             let has_copy_impl = cx.tcx.all_local_trait_impls(()).get(&copy_id).map_or(false, |impls| {
                 impls
                     .iter()
-                    .any(|&id| matches!(cx.tcx.type_of(id).subst_identity().kind(), ty::Adt(adt, _) if ty_adt.did() == adt.did()))
+                    .any(|&id| matches!(cx.tcx.type_of(id).instantiate_identity().kind(), ty::Adt(adt, _) if ty_adt.did() == adt.did()))
             });
             if !has_copy_impl {
                 return;
@@ -464,7 +464,7 @@ impl<'tcx> Visitor<'tcx> for UnsafeVisitor<'_, 'tcx> {
 /// Implementation of the `DERIVE_PARTIAL_EQ_WITHOUT_EQ` lint.
 fn check_partial_eq_without_eq<'tcx>(cx: &LateContext<'tcx>, span: Span, trait_ref: &hir::TraitRef<'_>, ty: Ty<'tcx>) {
     if_chain! {
-        if let ty::Adt(adt, substs) = ty.kind();
+        if let ty::Adt(adt, args) = ty.kind();
         if cx.tcx.visibility(adt.did()).is_public();
         if let Some(eq_trait_def_id) = cx.tcx.get_diagnostic_item(sym::Eq);
         if let Some(def_id) = trait_ref.trait_def_id();
@@ -474,7 +474,7 @@ fn check_partial_eq_without_eq<'tcx>(cx: &LateContext<'tcx>, span: Span, trait_r
         // If all of our fields implement `Eq`, we can implement `Eq` too
         if adt
             .all_fields()
-            .map(|f| f.ty(cx.tcx, substs))
+            .map(|f| f.ty(cx.tcx, args))
             .all(|ty| implements_trait_with_env(cx.tcx, param_env, ty, eq_trait_def_id, []));
         then {
             span_lint_and_sugg(

clippy_lints/src/empty_enum.rs

@@ -49,7 +49,7 @@ impl<'tcx> LateLintPass<'tcx> for EmptyEnum {
         }
 
         if let ItemKind::Enum(..) = item.kind {
-            let ty = cx.tcx.type_of(item.owner_id).subst_identity();
+            let ty = cx.tcx.type_of(item.owner_id).instantiate_identity();
             let adt = ty.ty_adt_def().expect("already checked whether this is an enum");
             if adt.variants().is_empty() {
                 span_lint_and_help(

clippy_lints/src/enum_clike.rs

@@ -45,7 +45,7 @@ impl<'tcx> LateLintPass<'tcx> for UnportableVariant {
             for var in def.variants {
                 if let Some(anon_const) = &var.disr_expr {
                     let def_id = cx.tcx.hir().body_owner_def_id(anon_const.body);
-                    let mut ty = cx.tcx.type_of(def_id.to_def_id()).subst_identity();
+                    let mut ty = cx.tcx.type_of(def_id.to_def_id()).instantiate_identity();
                     let constant = cx
                         .tcx
                         .const_eval_poly(def_id.to_def_id())

clippy_lints/src/eta_reduction.rs

@@ -11,7 +11,7 @@ use rustc_hir::{Closure, Expr, ExprKind, Param, PatKind, Unsafety};
 use rustc_lint::{LateContext, LateLintPass};
 use rustc_middle::ty::adjustment::{Adjust, Adjustment, AutoBorrow};
 use rustc_middle::ty::binding::BindingMode;
-use rustc_middle::ty::{self, EarlyBinder, SubstsRef, Ty, TypeVisitableExt};
+use rustc_middle::ty::{self, EarlyBinder, GenericArgsRef, Ty, TypeVisitableExt};
 use rustc_session::{declare_lint_pass, declare_tool_lint};
 use rustc_span::symbol::sym;
 
@@ -108,18 +108,18 @@ impl<'tcx> LateLintPass<'tcx> for EtaReduction {
             if check_inputs(cx, body.params, None, args);
             let callee_ty = cx.typeck_results().expr_ty_adjusted(callee);
             let call_ty = cx.typeck_results().type_dependent_def_id(body.value.hir_id)
-                .map_or(callee_ty, |id| cx.tcx.type_of(id).subst_identity());
+                .map_or(callee_ty, |id| cx.tcx.type_of(id).instantiate_identity());
             if check_sig(cx, closure_ty, call_ty);
-            let substs = cx.typeck_results().node_substs(callee.hir_id);
+            let args = cx.typeck_results().node_args(callee.hir_id);
             // This fixes some false positives that I don't entirely understand
-            if substs.is_empty() || !cx.typeck_results().expr_ty(expr).has_late_bound_regions();
+            if args.is_empty() || !cx.typeck_results().expr_ty(expr).has_late_bound_regions();
             // A type param function ref like `T::f` is not 'static, however
             // it is if cast like `T::f as fn()`. This seems like a rustc bug.
-            if !substs.types().any(|t| matches!(t.kind(), ty::Param(_)));
+            if !args.types().any(|t| matches!(t.kind(), ty::Param(_)));
             let callee_ty_unadjusted = cx.typeck_results().expr_ty(callee).peel_refs();
             if !is_type_diagnostic_item(cx, callee_ty_unadjusted, sym::Arc);
             if !is_type_diagnostic_item(cx, callee_ty_unadjusted, sym::Rc);
-            if let ty::Closure(_, substs) = *closure_ty.kind();
+            if let ty::Closure(_, args) = *closure_ty.kind();
             // Don't lint if this is an inclusive range expression.
             // They desugar to a call to `RangeInclusiveNew` which would have odd suggestions. (#10684)
             if !matches!(higher::Range::hir(body.value), Some(higher::Range {
@@ -131,7 +131,7 @@ impl<'tcx> LateLintPass<'tcx> for EtaReduction {
                 span_lint_and_then(cx, REDUNDANT_CLOSURE, expr.span, "redundant closure", |diag| {
                     if let Some(mut snippet) = snippet_opt(cx, callee.span) {
                         if let Some(fn_mut_id) = cx.tcx.lang_items().fn_mut_trait()
-                            && let args = cx.tcx.erase_late_bound_regions(substs.as_closure().sig()).inputs()
+                            && let args = cx.tcx.erase_late_bound_regions(args.as_closure().sig()).inputs()
                             && implements_trait(
                                    cx,
                                    callee_ty.peel_refs(),
@@ -160,12 +160,12 @@ impl<'tcx> LateLintPass<'tcx> for EtaReduction {
             if let ExprKind::MethodCall(path, receiver, args, _) = body.value.kind;
             if check_inputs(cx, body.params, Some(receiver), args);
             let method_def_id = cx.typeck_results().type_dependent_def_id(body.value.hir_id).unwrap();
-            let substs = cx.typeck_results().node_substs(body.value.hir_id);
+            let args = cx.typeck_results().node_args(body.value.hir_id);
-            let call_ty = cx.tcx.type_of(method_def_id).subst(cx.tcx, substs);
+            let call_ty = cx.tcx.type_of(method_def_id).instantiate(cx.tcx, args);
             if check_sig(cx, closure_ty, call_ty);
             then {
                 span_lint_and_then(cx, REDUNDANT_CLOSURE_FOR_METHOD_CALLS, expr.span, "redundant closure", |diag| {
-                    let name = get_ufcs_type_name(cx, method_def_id, substs);
+                    let name = get_ufcs_type_name(cx, method_def_id, args);
                     diag.span_suggestion(
                         expr.span,
                         "replace the closure with the method itself",
@@ -228,14 +228,14 @@ fn check_sig<'tcx>(cx: &LateContext<'tcx>, closure_ty: Ty<'tcx>, call_ty: Ty<'tc
     if !closure_ty.has_late_bound_regions() {
         return true;
     }
-    let ty::Closure(_, substs) = closure_ty.kind() else {
+    let ty::Closure(_, args) = closure_ty.kind() else {
         return false;
     };
-    let closure_sig = cx.tcx.signature_unclosure(substs.as_closure().sig(), Unsafety::Normal);
+    let closure_sig = cx.tcx.signature_unclosure(args.as_closure().sig(), Unsafety::Normal);
     cx.tcx.erase_late_bound_regions(closure_sig) == cx.tcx.erase_late_bound_regions(call_sig)
 }
 
-fn get_ufcs_type_name<'tcx>(cx: &LateContext<'tcx>, method_def_id: DefId, substs: SubstsRef<'tcx>) -> String {
+fn get_ufcs_type_name<'tcx>(cx: &LateContext<'tcx>, method_def_id: DefId, args: GenericArgsRef<'tcx>) -> String {
     let assoc_item = cx.tcx.associated_item(method_def_id);
     let def_id = assoc_item.container_id(cx.tcx);
     match assoc_item.container {
@@ -251,7 +251,7 @@ fn get_ufcs_type_name<'tcx>(cx: &LateContext<'tcx>, method_def_id: DefId, substs
                 | ty::Ref(..)
                 | ty::Slice(_)
                 | ty::Tuple(_) => {
-                    format!("<{}>", EarlyBinder::bind(ty).subst(cx.tcx, substs))
+                    format!("<{}>", EarlyBinder::bind(ty).instantiate(cx.tcx, args))
                 },
                 _ => ty.to_string(),
             }

clippy_lints/src/from_over_into.rs

@@ -76,9 +76,9 @@ impl<'tcx> LateLintPass<'tcx> for FromOverInto {
             && let Some(into_trait_seg) = hir_trait_ref.path.segments.last()
             // `impl Into<target_ty> for self_ty`
             && let Some(GenericArgs { args: [GenericArg::Type(target_ty)], .. }) = into_trait_seg.args
-            && let Some(middle_trait_ref) = cx.tcx.impl_trait_ref(item.owner_id).map(ty::EarlyBinder::subst_identity)
+            && let Some(middle_trait_ref) = cx.tcx.impl_trait_ref(item.owner_id).map(ty::EarlyBinder::instantiate_identity)
             && cx.tcx.is_diagnostic_item(sym::Into, middle_trait_ref.def_id)
-            && !matches!(middle_trait_ref.substs.type_at(1).kind(), ty::Alias(ty::Opaque, _))
+            && !matches!(middle_trait_ref.args.type_at(1).kind(), ty::Alias(ty::Opaque, _))
         {
             span_lint_and_then(
                 cx,

clippy_lints/src/functions/must_use.rs

@@ -198,14 +198,14 @@ fn is_mutable_ty<'tcx>(cx: &LateContext<'tcx>, ty: Ty<'tcx>, tys: &mut DefIdSet)
     match *ty.kind() {
         // primitive types are never mutable
         ty::Bool | ty::Char | ty::Int(_) | ty::Uint(_) | ty::Float(_) | ty::Str => false,
-        ty::Adt(adt, substs) => {
+        ty::Adt(adt, args) => {
             tys.insert(adt.did()) && !ty.is_freeze(cx.tcx, cx.param_env)
                 || KNOWN_WRAPPER_TYS
                     .iter()
                     .any(|&sym| cx.tcx.is_diagnostic_item(sym, adt.did()))
-                    && substs.types().any(|ty| is_mutable_ty(cx, ty, tys))
+                    && args.types().any(|ty| is_mutable_ty(cx, ty, tys))
         },
-        ty::Tuple(substs) => substs.iter().any(|ty| is_mutable_ty(cx, ty, tys)),
+        ty::Tuple(args) => args.iter().any(|ty| is_mutable_ty(cx, ty, tys)),
         ty::Array(ty, _) | ty::Slice(ty) => is_mutable_ty(cx, ty, tys),
         ty::RawPtr(ty::TypeAndMut { ty, mutbl }) | ty::Ref(_, ty, mutbl) => {
             mutbl == hir::Mutability::Mut || is_mutable_ty(cx, ty, tys)

clippy_lints/src/functions/result.rs

@@ -21,11 +21,11 @@ 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.fn_sig(id).subst_identity().output())
+        && let ty = cx.tcx.erase_late_bound_regions(cx.tcx.fn_sig(id).instantiate_identity().output())
         && is_type_diagnostic_item(cx, ty, sym::Result)
-        && let ty::Adt(_, substs) = ty.kind()
+        && let ty::Adt(_, args) = ty.kind()
     {
-        let err_ty = substs.type_at(1);
+        let err_ty = args.type_at(1);
         Some((hir_ty, err_ty))
     } else {
         None

clippy_lints/src/future_not_send.rs

@@ -63,10 +63,10 @@ impl<'tcx> LateLintPass<'tcx> for FutureNotSend {
             return;
         }
         let ret_ty = return_ty(cx, cx.tcx.hir().local_def_id_to_hir_id(fn_def_id).expect_owner());
-        if let ty::Alias(ty::Opaque, AliasTy { def_id, substs, .. }) = *ret_ty.kind() {
+        if let ty::Alias(ty::Opaque, AliasTy { def_id, args, .. }) = *ret_ty.kind() {
             let preds = cx.tcx.explicit_item_bounds(def_id);
             let mut is_future = false;
-            for (p, _span) in preds.subst_iter_copied(cx.tcx, substs) {
+            for (p, _span) in preds.arg_iter_copied(cx.tcx, args) {
                 if let Some(trait_pred) = p.as_trait_clause() {
                     if Some(trait_pred.skip_binder().trait_ref.def_id) == cx.tcx.lang_items().future_trait() {
                         is_future = true;

clippy_lints/src/implicit_saturating_sub.rs

@@ -102,7 +102,7 @@ impl<'tcx> LateLintPass<'tcx> for ImplicitSaturatingSub {
                             if let Some(const_id) = cx.typeck_results().type_dependent_def_id(cond_num_val.hir_id);
                             if let Some(impl_id) = cx.tcx.impl_of_method(const_id);
                             if let None = cx.tcx.impl_trait_ref(impl_id); // An inherent impl
-                            if cx.tcx.type_of(impl_id).subst_identity().is_integral();
+                            if cx.tcx.type_of(impl_id).instantiate_identity().is_integral();
                             then {
                                 print_lint_and_sugg(cx, var_name, expr)
                             }
@@ -115,7 +115,7 @@ impl<'tcx> LateLintPass<'tcx> for ImplicitSaturatingSub {
                             if let Some(func_id) = cx.typeck_results().type_dependent_def_id(func.hir_id);
                             if let Some(impl_id) = cx.tcx.impl_of_method(func_id);
                             if let None = cx.tcx.impl_trait_ref(impl_id); // An inherent impl
-                            if cx.tcx.type_of(impl_id).subst_identity().is_integral();
+                            if cx.tcx.type_of(impl_id).instantiate_identity().is_integral();
                             then {
                                 print_lint_and_sugg(cx, var_name, expr)
                             }

clippy_lints/src/inherent_impl.rs

@@ -66,7 +66,7 @@ impl<'tcx> LateLintPass<'tcx> for MultipleInherentImpl {
             )
         }) {
             for impl_id in impl_ids.iter().map(|id| id.expect_local()) {
-                let impl_ty = cx.tcx.type_of(impl_id).subst_identity();
+                let impl_ty = cx.tcx.type_of(impl_id).instantiate_identity();
                 match type_map.entry(impl_ty) {
                     Entry::Vacant(e) => {
                         // Store the id for the first impl block of this type. The span is retrieved lazily.

clippy_lints/src/iter_not_returning_iterator.rs

@@ -68,7 +68,7 @@ fn check_sig(cx: &LateContext<'_>, name: &str, sig: &FnSig<'_>, fn_id: LocalDefI
     if sig.decl.implicit_self.has_implicit_self() {
         let ret_ty = cx
             .tcx
-            .erase_late_bound_regions(cx.tcx.fn_sig(fn_id).subst_identity().output());
+            .erase_late_bound_regions(cx.tcx.fn_sig(fn_id).instantiate_identity().output());
         let ret_ty = cx
             .tcx
             .try_normalize_erasing_regions(cx.param_env, ret_ty)

clippy_lints/src/large_enum_variant.rs

@@ -83,7 +83,7 @@ impl<'tcx> LateLintPass<'tcx> for LargeEnumVariant {
             return;
         }
         if let ItemKind::Enum(ref def, _) = item.kind {
-            let ty = cx.tcx.type_of(item.owner_id).subst_identity();
+            let ty = cx.tcx.type_of(item.owner_id).instantiate_identity();
             let Adt(adt, subst) = ty.kind() else {
                 panic!("already checked whether this is an enum")
             };
@@ -169,8 +169,8 @@ impl<'tcx> LateLintPass<'tcx> for LargeEnumVariant {
 }
 
 fn maybe_copy<'tcx>(cx: &LateContext<'tcx>, ty: Ty<'tcx>) -> bool {
-    if let Adt(_def, substs) = ty.kind()
+    if let Adt(_def, args) = ty.kind()
-        && substs.types().next().is_some()
+        && args.types().next().is_some()
         && let Some(copy_trait) = cx.tcx.lang_items().copy_trait()
     {
         return cx.tcx.non_blanket_impls_for_ty(copy_trait, ty).next().is_some();

clippy_lints/src/len_zero.rs

@@ -145,7 +145,7 @@ 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.fn_sig(item.owner_id).subst_identity().skip_binder());
+            if let Some(output) = parse_len_output(cx, cx.tcx.fn_sig(item.owner_id).instantiate_identity().skip_binder());
             then {
                 let (name, kind) = match cx.tcx.hir().find(ty_hir_id) {
                     Some(Node::ForeignItem(x)) => (x.ident.name, "extern type"),
@@ -425,7 +425,7 @@ fn check_for_is_empty(
             if !(is_empty.fn_has_self_parameter
                 && check_is_empty_sig(
                     cx,
-                    cx.tcx.fn_sig(is_empty.def_id).subst_identity().skip_binder(),
+                    cx.tcx.fn_sig(is_empty.def_id).instantiate_identity().skip_binder(),
                     self_kind,
                     output,
                 )) =>

clippy_lints/src/let_underscore.rs

@@ -5,7 +5,7 @@ use clippy_utils::{is_must_use_func_call, paths};
 use rustc_hir::{Local, PatKind};
 use rustc_lint::{LateContext, LateLintPass};
 use rustc_middle::lint::in_external_macro;
-use rustc_middle::ty::subst::GenericArgKind;
+use rustc_middle::ty::GenericArgKind;
 use rustc_middle::ty::IsSuggestable;
 use rustc_session::{declare_lint_pass, declare_tool_lint};
 use rustc_span::{BytePos, Span};

clippy_lints/src/loops/explicit_iter_loop.rs

@@ -125,7 +125,7 @@ fn is_ref_iterable<'tcx>(
         }
 
         let res_ty = cx.tcx.erase_regions(EarlyBinder::bind(req_res_ty)
-            .subst(cx.tcx, typeck.node_substs(call_expr.hir_id)));
+            .instantiate(cx.tcx, typeck.node_args(call_expr.hir_id)));
         let mutbl = if let ty::Ref(_, _, mutbl) = *req_self_ty.kind() {
             Some(mutbl)
         } else {

clippy_lints/src/loops/missing_spin_loop.rs

@@ -35,7 +35,7 @@ pub(super) fn check<'tcx>(cx: &LateContext<'tcx>, cond: &'tcx Expr<'_>, body: &'
         if let ExprKind::Block(Block { stmts: [], expr: None, ..}, _) = body.kind;
         if let ExprKind::MethodCall(method, callee, ..) = unpack_cond(cond).kind;
         if [sym::load, sym::compare_exchange, sym::compare_exchange_weak].contains(&method.ident.name);
-        if let ty::Adt(def, _substs) = cx.typeck_results().expr_ty(callee).kind();
+        if let ty::Adt(def, _args) = cx.typeck_results().expr_ty(callee).kind();
         if cx.tcx.is_diagnostic_item(sym::AtomicBool, def.did());
         then {
             span_lint_and_sugg(

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.fn_sig(def_id).subst_identity().inputs().skip_binder(),
+                    self.cx.tcx.fn_sig(def_id).instantiate_identity().inputs().skip_binder(),
                     std::iter::once(receiver).chain(args.iter()),
                 ) {
                     self.prefer_mutable = false;

clippy_lints/src/manual_bits.rs

@@ -110,7 +110,7 @@ fn get_size_of_ty<'tcx>(cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>) -> Option<
         if let Some(def_id) = cx.qpath_res(count_func_qpath, count_func.hir_id).opt_def_id();
         if cx.tcx.is_diagnostic_item(sym::mem_size_of, def_id);
         then {
-            cx.typeck_results().node_substs(count_func.hir_id).types().next().map(|resolved_ty| (*real_ty, resolved_ty))
+            cx.typeck_results().node_args(count_func.hir_id).types().next().map(|resolved_ty| (*real_ty, resolved_ty))
         } else {
             None
         }

clippy_lints/src/manual_slice_size_calculation.rs

@@ -92,7 +92,7 @@ fn simplify_half<'tcx>(
         && let ExprKind::Path(ref func_qpath) = func.kind
         && let Some(def_id) = cx.qpath_res(func_qpath, func.hir_id).opt_def_id()
         && cx.tcx.is_diagnostic_item(sym::mem_size_of, def_id)
-        && let Some(ty2) = cx.typeck_results().node_substs(func.hir_id).types().next()
+        && let Some(ty2) = cx.typeck_results().node_args(func.hir_id).types().next()
         // T1 == T2?
         && *ty1 == ty2
     {

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.fn_sig(id).subst_identity().no_bound_vars() {
+        if let Some(fn_type) = cx.tcx.fn_sig(id).instantiate_identity().no_bound_vars() {
             return is_unit_type(fn_type.output());
         }
     }

clippy_lints/src/matches/match_as_ref.rs

@@ -27,10 +27,10 @@ pub(crate) fn check(cx: &LateContext<'_>, ex: &Expr<'_>, arms: &[Arm<'_>], expr:
             let input_ty = cx.typeck_results().expr_ty(ex);
 
             let cast = if_chain! {
-                if let ty::Adt(_, substs) = input_ty.kind();
+                if let ty::Adt(_, args) = input_ty.kind();
-                let input_ty = substs.type_at(0);
+                let input_ty = args.type_at(0);
-                if let ty::Adt(_, substs) = output_ty.kind();
+                if let ty::Adt(_, args) = output_ty.kind();
-                let output_ty = substs.type_at(0);
+                let output_ty = args.type_at(0);
                 if let ty::Ref(_, output_ty, _) = *output_ty.kind();
                 if input_ty != output_ty;
                 then {

clippy_lints/src/matches/redundant_pattern_match.rs

@@ -12,7 +12,7 @@ use rustc_hir::def::{DefKind, Res};
 use rustc_hir::LangItem::{self, OptionNone, OptionSome, PollPending, PollReady, ResultErr, ResultOk};
 use rustc_hir::{Arm, Expr, ExprKind, Node, Pat, PatKind, QPath, UnOp};
 use rustc_lint::LateContext;
-use rustc_middle::ty::{self, subst::GenericArgKind, Ty};
+use rustc_middle::ty::{self, GenericArgKind, Ty};
 use rustc_span::{sym, Symbol};
 
 pub(super) fn check<'tcx>(cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>) {

clippy_lints/src/matches/rest_pat_in_fully_bound_struct.rs

@@ -10,7 +10,7 @@ pub(crate) fn check(cx: &LateContext<'_>, pat: &Pat<'_>) {
         if !pat.span.from_expansion();
         if let PatKind::Struct(QPath::Resolved(_, path), fields, true) = pat.kind;
         if let Some(def_id) = path.res.opt_def_id();
-        let ty = cx.tcx.type_of(def_id).subst_identity();
+        let ty = cx.tcx.type_of(def_id).instantiate_identity();
         if let ty::Adt(def, _) = ty.kind();
         if def.is_struct() || def.is_union();
         if fields.len() == def.non_enum_variant().fields.len();

clippy_lints/src/matches/significant_drop_in_scrutinee.rs

@@ -6,7 +6,7 @@ use rustc_errors::{Applicability, Diagnostic};
 use rustc_hir::intravisit::{walk_expr, Visitor};
 use rustc_hir::{Arm, Expr, ExprKind, MatchSource};
 use rustc_lint::{LateContext, LintContext};
-use rustc_middle::ty::subst::GenericArgKind;
+use rustc_middle::ty::GenericArgKind;
 use rustc_middle::ty::{Ty, TypeAndMut};
 use rustc_span::Span;
 

clippy_lints/src/methods/bytes_count_to_len.rs

@@ -17,7 +17,7 @@ pub(super) fn check<'tcx>(
     if_chain! {
         if let Some(bytes_id) = cx.typeck_results().type_dependent_def_id(count_recv.hir_id);
         if let Some(impl_id) = cx.tcx.impl_of_method(bytes_id);
-        if cx.tcx.type_of(impl_id).subst_identity().is_str();
+        if cx.tcx.type_of(impl_id).instantiate_identity().is_str();
         let ty = cx.typeck_results().expr_ty(bytes_recv).peel_refs();
         if ty.is_str() || is_type_lang_item(cx, ty, hir::LangItem::String);
         then {

clippy_lints/src/methods/case_sensitive_file_extension_comparisons.rs

@@ -30,7 +30,7 @@ pub(super) fn check<'tcx>(
     if_chain! {
         if let Some(method_id) = cx.typeck_results().type_dependent_def_id(expr.hir_id);
         if let Some(impl_id) = cx.tcx.impl_of_method(method_id);
-        if cx.tcx.type_of(impl_id).subst_identity().is_str();
+        if cx.tcx.type_of(impl_id).instantiate_identity().is_str();
         if let ExprKind::Lit(Spanned { node: LitKind::Str(ext_literal, ..), ..}) = arg.kind;
         if (2..=6).contains(&ext_literal.as_str().len());
         let ext_str = ext_literal.as_str();

clippy_lints/src/methods/err_expect.rs

@@ -47,7 +47,7 @@ pub(super) fn check(
 /// Given a `Result<T, E>` type, return its data (`T`).
 fn get_data_type<'a>(cx: &LateContext<'_>, ty: Ty<'a>) -> Option<Ty<'a>> {
     match ty.kind() {
-        ty::Adt(_, substs) if is_type_diagnostic_item(cx, ty, sym::Result) => substs.types().next(),
+        ty::Adt(_, args) if is_type_diagnostic_item(cx, ty, sym::Result) => args.types().next(),
         _ => None,
     }
 }

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.fn_sig(def_id).subst_identity().output().skip_binder().kind(),
+                            cx.tcx.fn_sig(def_id).instantiate_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.fn_sig(method_id).subst_identity().output().skip_binder().kind(),
+                            cx.tcx.fn_sig(method_id).instantiate_identity().output().skip_binder().kind(),
                             ty::Ref(re, ..) if re.is_static()
                         )
                     })

clippy_lints/src/methods/flat_map_option.rs

@@ -15,7 +15,7 @@ pub(super) fn check<'tcx>(cx: &LateContext<'tcx>, expr: &'tcx hir::Expr<'_>, arg
     }
     let arg_ty = cx.typeck_results().expr_ty_adjusted(arg);
     let sig = match arg_ty.kind() {
-        ty::Closure(_, substs) => substs.as_closure().sig(),
+        ty::Closure(_, args) => args.as_closure().sig(),
         _ if arg_ty.is_fn() => arg_ty.fn_sig(cx.tcx),
         _ => return,
     };

clippy_lints/src/methods/get_first.rs

@@ -19,7 +19,7 @@ pub(super) fn check<'tcx>(
     if_chain! {
         if let Some(method_id) = cx.typeck_results().type_dependent_def_id(expr.hir_id);
         if let Some(impl_id) = cx.tcx.impl_of_method(method_id);
-        if cx.tcx.type_of(impl_id).subst_identity().is_slice();
+        if cx.tcx.type_of(impl_id).instantiate_identity().is_slice();
         if let Some(_) = is_slice_of_primitives(cx, recv);
         if let hir::ExprKind::Lit(Spanned { node: LitKind::Int(0, _), .. }) = arg.kind;
         then {

clippy_lints/src/methods/implicit_clone.rs

@@ -54,7 +54,7 @@ pub fn is_clone_like(cx: &LateContext<'_>, method_name: &str, method_def_id: hir
             .tcx
             .impl_of_method(method_def_id)
             .filter(|&impl_did| {
-                cx.tcx.type_of(impl_did).subst_identity().is_slice() && cx.tcx.impl_trait_ref(impl_did).is_none()
+                cx.tcx.type_of(impl_did).instantiate_identity().is_slice() && cx.tcx.impl_trait_ref(impl_did).is_none()
             })
             .is_some(),
         _ => false,

clippy_lints/src/methods/inefficient_to_string.rs

@@ -23,9 +23,9 @@ pub fn check(
         if args.is_empty() && method_name == sym::to_string;
         if let Some(to_string_meth_did) = cx.typeck_results().type_dependent_def_id(expr.hir_id);
         if match_def_path(cx, to_string_meth_did, &paths::TO_STRING_METHOD);
-        if let Some(substs) = cx.typeck_results().node_substs_opt(expr.hir_id);
+        if let Some(args) = cx.typeck_results().node_args_opt(expr.hir_id);
         let arg_ty = cx.typeck_results().expr_ty_adjusted(receiver);
-        let self_ty = substs.type_at(0);
+        let self_ty = args.type_at(0);
         let (deref_self_ty, deref_count) = walk_ptrs_ty_depth(self_ty);
         if deref_count >= 1;
         if specializes_tostring(cx, deref_self_ty);
@@ -64,8 +64,8 @@ fn specializes_tostring(cx: &LateContext<'_>, ty: Ty<'_>) -> bool {
         return true;
     }
 
-    if let ty::Adt(adt, substs) = ty.kind() {
+    if let ty::Adt(adt, args) = ty.kind() {
-        cx.tcx.is_diagnostic_item(sym::Cow, adt.did()) && substs.type_at(1).is_str()
+        cx.tcx.is_diagnostic_item(sym::Cow, adt.did()) && args.type_at(1).is_str()
     } else {
         false
     }

clippy_lints/src/methods/manual_ok_or.rs

@@ -21,7 +21,7 @@ pub(super) fn check<'tcx>(
     if_chain! {
         if let Some(method_id) = cx.typeck_results().type_dependent_def_id(expr.hir_id);
         if let Some(impl_id) = cx.tcx.impl_of_method(method_id);
-        if is_type_diagnostic_item(cx, cx.tcx.type_of(impl_id).subst_identity(), sym::Option);
+        if is_type_diagnostic_item(cx, cx.tcx.type_of(impl_id).instantiate_identity(), sym::Option);
         if let ExprKind::Call(err_path, [err_arg]) = or_expr.kind;
         if is_res_lang_ctor(cx, path_res(cx, err_path), ResultErr);
         if is_ok_wrapping(cx, map_expr);

clippy_lints/src/methods/map_clone.rs

@@ -19,7 +19,7 @@ pub(super) fn check(cx: &LateContext<'_>, e: &hir::Expr<'_>, recv: &hir::Expr<'_
     if_chain! {
         if let Some(method_id) = cx.typeck_results().type_dependent_def_id(e.hir_id);
         if cx.tcx.impl_of_method(method_id)
-            .map_or(false, |id| is_type_diagnostic_item(cx, cx.tcx.type_of(id).subst_identity(), sym::Option))
+            .map_or(false, |id| is_type_diagnostic_item(cx, cx.tcx.type_of(id).instantiate_identity(), sym::Option))
             || is_diag_trait_item(cx, method_id, sym::Iterator);
         if let hir::ExprKind::Closure(&hir::Closure{ body, .. }) = arg.kind;
         then {

clippy_lints/src/methods/map_collect_result_unit.rs

@@ -15,8 +15,8 @@ pub(super) fn check(cx: &LateContext<'_>, expr: &hir::Expr<'_>, iter: &hir::Expr
     let collect_ret_ty = cx.typeck_results().expr_ty(expr);
     if_chain! {
         if is_type_diagnostic_item(cx, collect_ret_ty, sym::Result);
-        if let ty::Adt(_, substs) = collect_ret_ty.kind();
+        if let ty::Adt(_, args) = collect_ret_ty.kind();
-        if let Some(result_t) = substs.types().next();
+        if let Some(result_t) = args.types().next();
         if result_t.is_unit();
         // get parts for snippet
         then {

clippy_lints/src/methods/map_err_ignore.rs

@@ -9,7 +9,7 @@ use super::MAP_ERR_IGNORE;
 pub(super) fn check(cx: &LateContext<'_>, e: &Expr<'_>, arg: &Expr<'_>) {
     if let Some(method_id) = cx.typeck_results().type_dependent_def_id(e.hir_id)
         && let Some(impl_id) = cx.tcx.impl_of_method(method_id)
-        && is_type_diagnostic_item(cx, cx.tcx.type_of(impl_id).subst_identity(), sym::Result)
+        && is_type_diagnostic_item(cx, cx.tcx.type_of(impl_id).instantiate_identity(), sym::Result)
         && let ExprKind::Closure(&Closure {
             capture_clause: CaptureBy::Ref,
             body,

clippy_lints/src/methods/map_flatten.rs

@@ -59,7 +59,7 @@ fn is_map_to_option(cx: &LateContext<'_>, map_arg: &Expr<'_>) -> bool {
     match map_closure_ty.kind() {
         ty::Closure(_, _) | ty::FnDef(_, _) | ty::FnPtr(_) => {
             let map_closure_sig = match map_closure_ty.kind() {
-                ty::Closure(_, substs) => substs.as_closure().sig(),
+                ty::Closure(_, args) => args.as_closure().sig(),
                 _ => map_closure_ty.fn_sig(cx.tcx),
             };
             let map_closure_return_ty = cx.tcx.erase_late_bound_regions(map_closure_sig.output());

clippy_lints/src/methods/mod.rs

@@ -3508,11 +3508,11 @@ impl<'tcx> LateLintPass<'tcx> for Methods {
         let name = impl_item.ident.name.as_str();
         let parent = cx.tcx.hir().get_parent_item(impl_item.hir_id()).def_id;
         let item = cx.tcx.hir().expect_item(parent);
-        let self_ty = cx.tcx.type_of(item.owner_id).subst_identity();
+        let self_ty = cx.tcx.type_of(item.owner_id).instantiate_identity();
 
         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.fn_sig(impl_item.owner_id).subst_identity();
+            let method_sig = cx.tcx.fn_sig(impl_item.owner_id).instantiate_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
@@ -4113,8 +4113,8 @@ impl SelfKind {
             } else if ty.is_box() {
                 ty.boxed_ty() == parent_ty
             } else if is_type_diagnostic_item(cx, ty, sym::Rc) || is_type_diagnostic_item(cx, ty, sym::Arc) {
-                if let ty::Adt(_, substs) = ty.kind() {
+                if let ty::Adt(_, args) = ty.kind() {
-                    substs.types().next().map_or(false, |t| t == parent_ty)
+                    args.types().next().map_or(false, |t| t == parent_ty)
                 } else {
                     false
                 }

clippy_lints/src/methods/mut_mutex_lock.rs

@@ -15,7 +15,7 @@ pub(super) fn check<'tcx>(cx: &LateContext<'tcx>, ex: &'tcx Expr<'tcx>, recv: &'
         if let ty::Ref(_, _, Mutability::Mut) = cx.typeck_results().expr_ty(recv).kind();
         if let Some(method_id) = cx.typeck_results().type_dependent_def_id(ex.hir_id);
         if let Some(impl_id) = cx.tcx.impl_of_method(method_id);
-        if is_type_diagnostic_item(cx, cx.tcx.type_of(impl_id).subst_identity(), sym::Mutex);
+        if is_type_diagnostic_item(cx, cx.tcx.type_of(impl_id).instantiate_identity(), sym::Mutex);
         then {
             span_lint_and_sugg(
                 cx,

clippy_lints/src/methods/needless_collect.rs

@@ -163,7 +163,7 @@ fn check_collect_into_intoiterator<'tcx>(
             // that contains `collect_expr`
             let inputs = cx
                 .tcx
-                .liberate_late_bound_regions(id, cx.tcx.fn_sig(id).subst_identity())
+                .liberate_late_bound_regions(id, cx.tcx.fn_sig(id).instantiate_identity())
                 .inputs();
 
             // map IntoIterator generic bounds to their signature
@@ -201,7 +201,7 @@ fn check_collect_into_intoiterator<'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.fn_sig(id).subst_identity().skip_binder();
+        let sig = cx.tcx.fn_sig(id).instantiate_identity().skip_binder();
         sig.inputs().len() == 1 && sig.output().is_bool()
     })
 }
@@ -215,7 +215,7 @@ fn iterates_same_ty<'tcx>(cx: &LateContext<'tcx>, iter_ty: Ty<'tcx>, collect_ty:
         && let Some(into_iter_item_proj) = make_projection(cx.tcx, into_iter_trait, item, [collect_ty])
         && let Ok(into_iter_item_ty) = cx.tcx.try_normalize_erasing_regions(
             cx.param_env,
-            Ty::new_projection(cx.tcx,into_iter_item_proj.def_id, into_iter_item_proj.substs)
+            Ty::new_projection(cx.tcx,into_iter_item_proj.def_id, into_iter_item_proj.args)
         )
     {
         iter_item_ty == into_iter_item_ty
@@ -229,7 +229,7 @@ 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.fn_sig(id).subst_identity()
+        && let sig = cx.tcx.fn_sig(id).instantiate_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()
@@ -237,11 +237,11 @@ fn is_contains_sig(cx: &LateContext<'_>, call_id: HirId, iter_expr: &Expr<'_>) -
         && let Some(iter_item) = cx.tcx
             .associated_items(iter_trait)
             .find_by_name_and_kind(cx.tcx, Ident::with_dummy_span(Symbol::intern("Item")), AssocKind::Type, iter_trait)
-        && let substs = cx.tcx.mk_substs(&[GenericArg::from(typeck.expr_ty_adjusted(iter_expr))])
+        && let args = cx.tcx.mk_args(&[GenericArg::from(typeck.expr_ty_adjusted(iter_expr))])
-        && let proj_ty = Ty::new_projection(cx.tcx,iter_item.def_id, substs)
+        && let proj_ty = Ty::new_projection(cx.tcx,iter_item.def_id, args)
         && let Ok(item_ty) = cx.tcx.try_normalize_erasing_regions(cx.param_env, proj_ty)
     {
-        item_ty == EarlyBinder::bind(search_ty).subst(cx.tcx, cx.typeck_results().node_substs(call_id))
+        item_ty == EarlyBinder::bind(search_ty).instantiate(cx.tcx, cx.typeck_results().node_args(call_id))
     } else {
         false
     }

clippy_lints/src/methods/ok_expect.rs

@@ -33,7 +33,7 @@ pub(super) fn check(cx: &LateContext<'_>, expr: &hir::Expr<'_>, recv: &hir::Expr
 /// Given a `Result<T, E>` type, return its error type (`E`).
 fn get_error_type<'a>(cx: &LateContext<'_>, ty: Ty<'a>) -> Option<Ty<'a>> {
     match ty.kind() {
-        ty::Adt(_, substs) if is_type_diagnostic_item(cx, ty, sym::Result) => substs.types().nth(1),
+        ty::Adt(_, args) if is_type_diagnostic_item(cx, ty, sym::Result) => args.types().nth(1),
         _ => None,
     }
 }

clippy_lints/src/methods/open_options.rs

@@ -11,7 +11,7 @@ use super::NONSENSICAL_OPEN_OPTIONS;
 pub(super) fn check<'tcx>(cx: &LateContext<'tcx>, e: &'tcx Expr<'_>, recv: &'tcx Expr<'_>) {
     if let Some(method_id) = cx.typeck_results().type_dependent_def_id(e.hir_id)
         && let Some(impl_id) = cx.tcx.impl_of_method(method_id)
-        && match_type(cx, cx.tcx.type_of(impl_id).subst_identity(), &paths::OPEN_OPTIONS)
+        && match_type(cx, cx.tcx.type_of(impl_id).instantiate_identity(), &paths::OPEN_OPTIONS)
     {
         let mut options = Vec::new();
         get_open_options(cx, recv, &mut options);

clippy_lints/src/methods/path_buf_push_overwrite.rs

@@ -14,7 +14,7 @@ pub(super) fn check<'tcx>(cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>, arg: &'t
     if_chain! {
         if let Some(method_id) = cx.typeck_results().type_dependent_def_id(expr.hir_id);
         if let Some(impl_id) = cx.tcx.impl_of_method(method_id);
-        if is_type_diagnostic_item(cx, cx.tcx.type_of(impl_id).subst_identity(), sym::PathBuf);
+        if is_type_diagnostic_item(cx, cx.tcx.type_of(impl_id).instantiate_identity(), sym::PathBuf);
         if let ExprKind::Lit(lit) = arg.kind;
         if let LitKind::Str(ref path_lit, _) = lit.node;
         if let pushed_path = Path::new(path_lit.as_str());

clippy_lints/src/methods/stable_sort_primitive.rs

@@ -10,7 +10,7 @@ use super::STABLE_SORT_PRIMITIVE;
 pub(super) fn check<'tcx>(cx: &LateContext<'tcx>, e: &'tcx Expr<'_>, recv: &'tcx Expr<'_>) {
     if let Some(method_id) = cx.typeck_results().type_dependent_def_id(e.hir_id)
         && let Some(impl_id) = cx.tcx.impl_of_method(method_id)
-        && cx.tcx.type_of(impl_id).subst_identity().is_slice()
+        && cx.tcx.type_of(impl_id).instantiate_identity().is_slice()
         && let Some(slice_type) = is_slice_of_primitives(cx, recv)
     {
         span_lint_and_then(

clippy_lints/src/methods/suspicious_splitn.rs

@@ -13,7 +13,7 @@ pub(super) fn check(cx: &LateContext<'_>, method_name: &str, expr: &Expr<'_>, se
         if let Some(call_id) = cx.typeck_results().type_dependent_def_id(expr.hir_id);
         if let Some(impl_id) = cx.tcx.impl_of_method(call_id);
         if cx.tcx.impl_trait_ref(impl_id).is_none();
-        let self_ty = cx.tcx.type_of(impl_id).subst_identity();
+        let self_ty = cx.tcx.type_of(impl_id).instantiate_identity();
         if self_ty.is_slice() || self_ty.is_str();
         then {
             // Ignore empty slice and string literals when used with a literal count.

clippy_lints/src/methods/unnecessary_sort_by.rs

@@ -6,7 +6,7 @@ use if_chain::if_chain;
 use rustc_errors::Applicability;
 use rustc_hir::{Closure, Expr, ExprKind, Mutability, Param, Pat, PatKind, Path, PathSegment, QPath};
 use rustc_lint::LateContext;
-use rustc_middle::ty::{self, subst::GenericArgKind};
+use rustc_middle::ty::{self, GenericArgKind};
 use rustc_span::sym;
 use rustc_span::symbol::Ident;
 use std::iter;
@@ -118,7 +118,7 @@ fn detect_lint(cx: &LateContext<'_>, expr: &Expr<'_>, recv: &Expr<'_>, arg: &Exp
     if_chain! {
         if let Some(method_id) = cx.typeck_results().type_dependent_def_id(expr.hir_id);
         if let Some(impl_id) = cx.tcx.impl_of_method(method_id);
-        if cx.tcx.type_of(impl_id).subst_identity().is_slice();
+        if cx.tcx.type_of(impl_id).instantiate_identity().is_slice();
         if let ExprKind::Closure(&Closure { body, .. }) = arg.kind;
         if let closure_body = cx.tcx.hir().body(body);
         if let &[

clippy_lints/src/methods/unnecessary_to_owned.rs

@@ -13,7 +13,7 @@ use rustc_infer::infer::TyCtxtInferExt;
 use rustc_lint::LateContext;
 use rustc_middle::mir::Mutability;
 use rustc_middle::ty::adjustment::{Adjust, Adjustment, OverloadedDeref};
-use rustc_middle::ty::subst::{GenericArg, GenericArgKind, SubstsRef};
+use rustc_middle::ty::{GenericArg, GenericArgKind, GenericArgsRef};
 use rustc_middle::ty::{self, ClauseKind, EarlyBinder, ParamTy, ProjectionPredicate, TraitPredicate, Ty};
 use rustc_span::{sym, Symbol};
 use rustc_trait_selection::traits::{query::evaluate_obligation::InferCtxtExt as _, Obligation, ObligationCause};
@@ -250,8 +250,8 @@ fn check_other_call_arg<'tcx>(
 ) -> bool {
     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);
+        if let Some((callee_def_id, _, recv, call_args)) = get_callee_generic_args_and_args(cx, maybe_call);
-        let fn_sig = cx.tcx.fn_sig(callee_def_id).subst_identity().skip_binder();
+        let fn_sig = cx.tcx.fn_sig(callee_def_id).instantiate_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);
@@ -315,26 +315,26 @@ fn skip_addr_of_ancestors<'tcx>(
 }
 
 /// Checks whether an expression is a function or method call and, if so, returns its `DefId`,
-/// `Substs`, and arguments.
+/// `GenericArgs`, and arguments.
-fn get_callee_substs_and_args<'tcx>(
+fn get_callee_generic_args_and_args<'tcx>(
     cx: &LateContext<'tcx>,
     expr: &'tcx Expr<'tcx>,
-) -> Option<(DefId, SubstsRef<'tcx>, Option<&'tcx Expr<'tcx>>, &'tcx [Expr<'tcx>])> {
+) -> Option<(DefId, GenericArgsRef<'tcx>, Option<&'tcx Expr<'tcx>>, &'tcx [Expr<'tcx>])> {
     if_chain! {
         if let ExprKind::Call(callee, args) = expr.kind;
         let callee_ty = cx.typeck_results().expr_ty(callee);
         if let ty::FnDef(callee_def_id, _) = callee_ty.kind();
         then {
-            let substs = cx.typeck_results().node_substs(callee.hir_id);
+            let generic_args = cx.typeck_results().node_args(callee.hir_id);
-            return Some((*callee_def_id, substs, None, args));
+            return Some((*callee_def_id, generic_args, None, args));
         }
     }
     if_chain! {
         if let ExprKind::MethodCall(_, recv, args, _) = expr.kind;
         if let Some(method_def_id) = cx.typeck_results().type_dependent_def_id(expr.hir_id);
         then {
-            let substs = cx.typeck_results().node_substs(expr.hir_id);
+            let generic_args = cx.typeck_results().node_args(expr.hir_id);
-            return Some((method_def_id, substs, Some(recv), args));
+            return Some((method_def_id, generic_args, Some(recv), args));
         }
     }
     None
@@ -388,17 +388,17 @@ 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)
+                if let Some((callee_def_id, call_generic_args, recv, call_args)) = get_callee_generic_args_and_args(cx, parent_expr)
                 {
-                    // FIXME: the `subst_identity()` below seems incorrect, since we eventually
+                    // FIXME: the `instantiate_identity()` below seems incorrect, since we eventually
                     // call `tcx.try_subst_and_normalize_erasing_regions` further down
                     // (i.e., we are explicitly not in the identity context).
-                    let fn_sig = cx.tcx.fn_sig(callee_def_id).subst_identity().skip_binder();
+                    let fn_sig = cx.tcx.fn_sig(callee_def_id).instantiate_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()
                         // https://github.com/rust-lang/rust-clippy/issues/9504 and https://github.com/rust-lang/rust-clippy/issues/10021
-                        && (*param_index as usize) < call_substs.len()
+                        && (*param_index as usize) < call_generic_args.len()
                     {
                         if fn_sig
                             .inputs()
@@ -422,8 +422,8 @@ fn can_change_type<'a>(cx: &LateContext<'a>, mut expr: &'a Expr<'a>, mut ty: Ty<
                             }
                         });
 
-                        let new_subst = cx.tcx.mk_substs_from_iter(
+                        let new_subst = cx.tcx.mk_args_from_iter(
-                            call_substs.iter()
+                            call_generic_args.iter()
                                 .enumerate()
                                 .map(|(i, t)|
                                      if i == (*param_index as usize) {
@@ -433,7 +433,7 @@ fn can_change_type<'a>(cx: &LateContext<'a>, mut expr: &'a Expr<'a>, mut ty: Ty<
                                      }));
 
                         if trait_predicates.any(|predicate| {
-                            let predicate = EarlyBinder::bind(predicate).subst(cx.tcx, new_subst);
+                            let predicate = EarlyBinder::bind(predicate).instantiate(cx.tcx, new_subst);
                             let obligation = Obligation::new(cx.tcx, ObligationCause::dummy(), cx.param_env, predicate);
                             !cx.tcx.infer_ctxt().build().predicate_must_hold_modulo_regions(&obligation)
                         }) {
@@ -500,8 +500,8 @@ fn is_to_string_on_string_like<'a>(
         return false;
     }
 
-    if let Some(substs) = cx.typeck_results().node_substs_opt(call_expr.hir_id)
+    if let Some(args) = cx.typeck_results().node_args_opt(call_expr.hir_id)
-        && let [generic_arg] = substs.as_slice()
+        && let [generic_arg] = args.as_slice()
         && let GenericArgKind::Type(ty) = generic_arg.unpack()
         && let Some(deref_trait_id) = cx.tcx.get_diagnostic_item(sym::Deref)
         && let Some(as_ref_trait_id) = cx.tcx.get_diagnostic_item(sym::AsRef)

clippy_lints/src/methods/utils.rs

@@ -143,7 +143,7 @@ impl<'cx, 'tcx> Visitor<'tcx> for CloneOrCopyVisitor<'cx, 'tcx> {
                         if_chain! {
                             if args.iter().all(|arg| !self.is_binding(arg));
                             if let Some(method_def_id) = self.cx.typeck_results().type_dependent_def_id(parent.hir_id);
-                            let method_ty = self.cx.tcx.type_of(method_def_id).subst_identity();
+                            let method_ty = self.cx.tcx.type_of(method_def_id).instantiate_identity();
                             let self_ty = method_ty.fn_sig(self.cx.tcx).input(0).skip_binder();
                             if matches!(self_ty.kind(), ty::Ref(_, _, Mutability::Not));
                             then {

clippy_lints/src/methods/vec_resize_to_zero.rs

@@ -20,7 +20,7 @@ pub(super) fn check<'tcx>(
     if_chain! {
         if let Some(method_id) = cx.typeck_results().type_dependent_def_id(expr.hir_id);
         if let Some(impl_id) = cx.tcx.impl_of_method(method_id);
-        if is_type_diagnostic_item(cx, cx.tcx.type_of(impl_id).subst_identity(), sym::Vec);
+        if is_type_diagnostic_item(cx, cx.tcx.type_of(impl_id).instantiate_identity(), sym::Vec);
         if let ExprKind::Lit(Spanned { node: LitKind::Int(0, _), .. }) = count_arg.kind;
         if let ExprKind::Lit(Spanned { node: LitKind::Int(..), .. }) = default_arg.kind;
         then {

clippy_lints/src/mut_key.rs

@@ -139,7 +139,7 @@ impl MutableKeyType {
     }
 
     fn check_sig(&self, cx: &LateContext<'_>, fn_def_id: LocalDefId, decl: &hir::FnDecl<'_>) {
-        let fn_sig = cx.tcx.fn_sig(fn_def_id).subst_identity();
+        let fn_sig = cx.tcx.fn_sig(fn_def_id).instantiate_identity();
         for (hir_ty, ty) in iter::zip(decl.inputs, fn_sig.inputs().skip_binder()) {
             self.check_ty_(cx, hir_ty.span, *ty);
         }
@@ -150,7 +150,7 @@ impl MutableKeyType {
     // generics (because the compiler cannot ensure immutability for unknown types).
     fn check_ty_<'tcx>(&self, cx: &LateContext<'tcx>, span: Span, ty: Ty<'tcx>) {
         let ty = ty.peel_refs();
-        if let Adt(def, substs) = ty.kind() {
+        if let Adt(def, args) = ty.kind() {
             let is_keyed_type = [sym::HashMap, sym::BTreeMap, sym::HashSet, sym::BTreeSet]
                 .iter()
                 .any(|diag_item| cx.tcx.is_diagnostic_item(*diag_item, def.did()));
@@ -158,7 +158,7 @@ impl MutableKeyType {
                 return;
             }
 
-            let subst_ty = substs.type_at(0);
+            let subst_ty = args.type_at(0);
             // Determines if a type contains interior mutability which would affect its implementation of
             // [`Hash`] or [`Ord`].
             if is_interior_mut_ty(cx, subst_ty)

clippy_lints/src/mut_reference.rs

@@ -51,8 +51,8 @@ impl<'tcx> LateLintPass<'tcx> for UnnecessaryMutPassed {
             },
             ExprKind::MethodCall(path, receiver, arguments, _) => {
                 let def_id = cx.typeck_results().type_dependent_def_id(e.hir_id).unwrap();
-                let substs = cx.typeck_results().node_substs(e.hir_id);
+                let args = cx.typeck_results().node_args(e.hir_id);
-                let method_type = cx.tcx.type_of(def_id).subst(cx.tcx, substs);
+                let method_type = cx.tcx.type_of(def_id).instantiate(cx.tcx, args);
                 check_arguments(
                     cx,
                     std::iter::once(receiver).chain(arguments.iter()).collect(),

clippy_lints/src/needless_pass_by_value.rs

@@ -140,7 +140,7 @@ impl<'tcx> LateLintPass<'tcx> for NeedlessPassByValue {
             ctx
         };
 
-        let fn_sig = cx.tcx.fn_sig(fn_def_id).subst_identity();
+        let fn_sig = cx.tcx.fn_sig(fn_def_id).instantiate_identity();
         let fn_sig = cx.tcx.liberate_late_bound_regions(fn_def_id.to_def_id(), fn_sig);
 
         for (idx, ((input, &ty), arg)) in decl.inputs.iter().zip(fn_sig.inputs()).zip(body.params).enumerate() {
@@ -170,7 +170,7 @@ impl<'tcx> LateLintPass<'tcx> for NeedlessPassByValue {
                     !preds.is_empty() && {
                         let ty_empty_region = Ty::new_imm_ref(cx.tcx,cx.tcx.lifetimes.re_erased, ty);
                         preds.iter().all(|t| {
-                            let ty_params = t.trait_ref.substs.iter().skip(1).collect::<Vec<_>>();
+                            let ty_params = t.trait_ref.args.iter().skip(1).collect::<Vec<_>>();
                             implements_trait(cx, ty_empty_region, t.def_id(), &ty_params)
                         })
                     },

clippy_lints/src/new_without_default.rs

@@ -98,14 +98,14 @@ impl<'tcx> LateLintPass<'tcx> for NewWithoutDefault {
                             if name == sym::new;
                             if cx.effective_visibilities.is_reachable(impl_item.owner_id.def_id);
                             let self_def_id = cx.tcx.hir().get_parent_item(id.into());
-                            let self_ty = cx.tcx.type_of(self_def_id).subst_identity();
+                            let self_ty = cx.tcx.type_of(self_def_id).instantiate_identity();
                             if self_ty == return_ty(cx, id);
                             if let Some(default_trait_id) = cx.tcx.get_diagnostic_item(sym::Default);
                             then {
                                 if self.impling_types.is_none() {
                                     let mut impls = HirIdSet::default();
                                     cx.tcx.for_each_impl(default_trait_id, |d| {
-                                        let ty = cx.tcx.type_of(d).subst_identity();
+                                        let ty = cx.tcx.type_of(d).instantiate_identity();
                                         if let Some(ty_def) = ty.ty_adt_def() {
                                             if let Some(local_def_id) = ty_def.did().as_local() {
                                                 impls.insert(cx.tcx.hir().local_def_id_to_hir_id(local_def_id));
@@ -119,7 +119,7 @@ impl<'tcx> LateLintPass<'tcx> for NewWithoutDefault {
                                 // generics
                                 if_chain! {
                                     if let Some(ref impling_types) = self.impling_types;
-                                    let self_def = cx.tcx.type_of(self_def_id).subst_identity();
+                                    let self_def = cx.tcx.type_of(self_def_id).instantiate_identity();
                                     if let Some(self_def) = self_def.ty_adt_def();
                                     if let Some(self_local_did) = self_def.did().as_local();
                                     let self_id = cx.tcx.hir().local_def_id_to_hir_id(self_local_did);

clippy_lints/src/non_copy_const.rs

@@ -158,7 +158,7 @@ fn is_value_unfrozen_raw<'tcx>(
                 val.unwrap_branch().iter().any(|field| inner(cx, *field, ty))
             },
             ty::Adt(def, _) if def.is_union() => false,
-            ty::Adt(def, substs) if def.is_enum() => {
+            ty::Adt(def, args) if def.is_enum() => {
                 let (&variant_index, fields) = val.unwrap_branch().split_first().unwrap();
                 let variant_index =
                     VariantIdx::from_u32(variant_index.unwrap_leaf().try_to_u32().ok().unwrap());
@@ -166,10 +166,10 @@ fn is_value_unfrozen_raw<'tcx>(
                     def.variants()[variant_index]
                         .fields
                         .iter()
-                        .map(|field| field.ty(cx.tcx, substs))).any(|(field, ty)| inner(cx, field, ty))
+                        .map(|field| field.ty(cx.tcx, args))).any(|(field, ty)| inner(cx, field, ty))
             }
-            ty::Adt(def, substs) => {
+            ty::Adt(def, args) => {
-                val.unwrap_branch().iter().zip(def.non_enum_variant().fields.iter().map(|field| field.ty(cx.tcx, substs))).any(|(field, ty)| inner(cx, *field, ty))
+                val.unwrap_branch().iter().zip(def.non_enum_variant().fields.iter().map(|field| field.ty(cx.tcx, args))).any(|(field, ty)| inner(cx, *field, ty))
             }
             ty::Tuple(tys) => val.unwrap_branch().iter().zip(tys).any(|(field, ty)| inner(cx, *field, ty)),
             _ => false,
@@ -206,8 +206,8 @@ fn is_value_unfrozen_raw<'tcx>(
 
 fn is_value_unfrozen_poly<'tcx>(cx: &LateContext<'tcx>, body_id: BodyId, ty: Ty<'tcx>) -> bool {
     let def_id = body_id.hir_id.owner.to_def_id();
-    let substs = ty::InternalSubsts::identity_for_item(cx.tcx, def_id);
+    let args = ty::GenericArgs::identity_for_item(cx.tcx, def_id);
-    let instance = ty::Instance::new(def_id, substs);
+    let instance = ty::Instance::new(def_id, args);
     let cid = rustc_middle::mir::interpret::GlobalId { instance, promoted: None };
     let param_env = cx.tcx.param_env(def_id).with_reveal_all_normalized(cx.tcx);
     let result = cx.tcx.const_eval_global_id_for_typeck(param_env, cid, None);
@@ -215,9 +215,9 @@ fn is_value_unfrozen_poly<'tcx>(cx: &LateContext<'tcx>, body_id: BodyId, ty: Ty<
 }
 
 fn is_value_unfrozen_expr<'tcx>(cx: &LateContext<'tcx>, hir_id: HirId, def_id: DefId, ty: Ty<'tcx>) -> bool {
-    let substs = cx.typeck_results().node_substs(hir_id);
+    let args = cx.typeck_results().node_args(hir_id);
 
-    let result = const_eval_resolve(cx.tcx, cx.param_env, ty::UnevaluatedConst::new(def_id, substs), None);
+    let result = const_eval_resolve(cx.tcx, cx.param_env, ty::UnevaluatedConst::new(def_id, args), None);
     is_value_unfrozen_raw(cx, result, ty)
 }
 
@@ -228,7 +228,7 @@ pub fn const_eval_resolve<'tcx>(
     ct: ty::UnevaluatedConst<'tcx>,
     span: Option<Span>,
 ) -> EvalToValTreeResult<'tcx> {
-    match ty::Instance::resolve(tcx, param_env, ct.def, ct.substs) {
+    match ty::Instance::resolve(tcx, param_env, ct.def, ct.args) {
         Ok(Some(instance)) => {
             let cid = GlobalId { instance, promoted: None };
             tcx.const_eval_global_id_for_typeck(param_env, cid, span)
@@ -347,7 +347,7 @@ impl<'tcx> LateLintPass<'tcx> for NonCopyConst {
                                 // and, in that case, the definition is *not* generic.
                                 cx.tcx.normalize_erasing_regions(
                                     cx.tcx.param_env(of_trait_def_id),
-                                    cx.tcx.type_of(of_assoc_item).subst_identity(),
+                                    cx.tcx.type_of(of_assoc_item).instantiate_identity(),
                                 ),
                             ))
                             .is_err();

clippy_lints/src/non_send_fields_in_send_ty.rs

@@ -7,7 +7,7 @@ use rustc_hir::def_id::DefId;
 use rustc_hir::{FieldDef, Item, ItemKind, Node};
 use rustc_lint::{LateContext, LateLintPass};
 use rustc_middle::lint::in_external_macro;
-use rustc_middle::ty::{self, subst::GenericArgKind, Ty};
+use rustc_middle::ty::{self, GenericArgKind, Ty};
 use rustc_session::{declare_tool_lint, impl_lint_pass};
 use rustc_span::sym;
 
@@ -90,8 +90,8 @@ impl<'tcx> LateLintPass<'tcx> for NonSendFieldInSendTy {
             if send_trait == trait_id;
             if hir_impl.polarity == ImplPolarity::Positive;
             if let Some(ty_trait_ref) = cx.tcx.impl_trait_ref(item.owner_id);
-            if let self_ty = ty_trait_ref.subst_identity().self_ty();
+            if let self_ty = ty_trait_ref.instantiate_identity().self_ty();
-            if let ty::Adt(adt_def, impl_trait_substs) = self_ty.kind();
+            if let ty::Adt(adt_def, impl_trait_args) = self_ty.kind();
             then {
                 let mut non_send_fields = Vec::new();
 
@@ -104,7 +104,7 @@ impl<'tcx> LateLintPass<'tcx> for NonSendFieldInSendTy {
                                 .as_local()
                                 .map(|local_def_id| hir_map.local_def_id_to_hir_id(local_def_id));
                             if !is_lint_allowed(cx, NON_SEND_FIELDS_IN_SEND_TY, field_hir_id);
-                            if let field_ty = field.ty(cx.tcx, impl_trait_substs);
+                            if let field_ty = field.ty(cx.tcx, impl_trait_args);
                             if !ty_allowed_in_send(cx, field_ty, send_trait);
                             if let Node::Field(field_def) = hir_map.get(field_hir_id);
                             then {
@@ -206,10 +206,10 @@ fn ty_allowed_with_raw_pointer_heuristic<'tcx>(cx: &LateContext<'tcx>, ty: Ty<'t
             .iter()
             .all(|ty| ty_allowed_with_raw_pointer_heuristic(cx, ty, send_trait)),
         ty::Array(ty, _) | ty::Slice(ty) => ty_allowed_with_raw_pointer_heuristic(cx, *ty, send_trait),
-        ty::Adt(_, substs) => {
+        ty::Adt(_, args) => {
             if contains_pointer_like(cx, ty) {
                 // descends only if ADT contains any raw pointers
-                substs.iter().all(|generic_arg| match generic_arg.unpack() {
+                args.iter().all(|generic_arg| match generic_arg.unpack() {
                     GenericArgKind::Type(ty) => ty_allowed_with_raw_pointer_heuristic(cx, ty, send_trait),
                     // Lifetimes and const generics are not solid part of ADT and ignored
                     GenericArgKind::Lifetime(_) | GenericArgKind::Const(_) => true,
@@ -224,7 +224,7 @@ fn ty_allowed_with_raw_pointer_heuristic<'tcx>(cx: &LateContext<'tcx>, ty: Ty<'t
     }
 }
 
-/// Checks if the type contains any pointer-like types in substs (including nested ones)
+/// Checks if the type contains any pointer-like types in args (including nested ones)
 fn contains_pointer_like<'tcx>(cx: &LateContext<'tcx>, target_ty: Ty<'tcx>) -> bool {
     for ty_node in target_ty.walk() {
         if let GenericArgKind::Type(inner_ty) = ty_node.unpack() {

clippy_lints/src/only_used_in_recursion.rs

@@ -7,7 +7,7 @@ use rustc_hir::def_id::DefId;
 use rustc_hir::hir_id::HirIdMap;
 use rustc_hir::{Body, Expr, ExprKind, HirId, ImplItem, ImplItemKind, Node, PatKind, TraitItem, TraitItemKind};
 use rustc_lint::{LateContext, LateLintPass};
-use rustc_middle::ty::subst::{EarlyBinder, GenericArgKind, SubstsRef};
+use rustc_middle::ty::{EarlyBinder, GenericArgKind, GenericArgsRef};
 use rustc_middle::ty::{self, ConstKind};
 use rustc_session::{declare_tool_lint, impl_lint_pass};
 use rustc_span::symbol::{kw, Ident};
@@ -90,7 +90,7 @@ impl_lint_pass!(OnlyUsedInRecursion => [ONLY_USED_IN_RECURSION]);
 enum FnKind {
     Fn,
     TraitFn,
-    // This is a hack. Ideally we would store a `SubstsRef<'tcx>` type here, but a lint pass must be `'static`.
+    // This is a hack. Ideally we would store a `GenericArgsRef<'tcx>` type here, but a lint pass must be `'static`.
     // Substitutions are, however, interned. This allows us to store the pointer as a `usize` when comparing for
     // equality.
     ImplTraitFn(usize),
@@ -244,12 +244,12 @@ impl<'tcx> LateLintPass<'tcx> for OnlyUsedInRecursion {
             })) => {
                 #[allow(trivial_casts)]
                 if let Some(Node::Item(item)) = get_parent_node(cx.tcx, owner_id.into())
-                    && let Some(trait_ref) = cx.tcx.impl_trait_ref(item.owner_id).map(EarlyBinder::subst_identity)
+                    && let Some(trait_ref) = cx.tcx.impl_trait_ref(item.owner_id).map(EarlyBinder::instantiate_identity)
                     && let Some(trait_item_id) = cx.tcx.associated_item(owner_id).trait_item_def_id
                 {
                     (
                         trait_item_id,
-                        FnKind::ImplTraitFn(cx.tcx.erase_regions(trait_ref.substs) as *const _ as usize),
+                        FnKind::ImplTraitFn(cx.tcx.erase_regions(trait_ref.args) as *const _ as usize),
                         usize::from(sig.decl.implicit_self.has_implicit_self()),
                     )
                 } else {
@@ -289,7 +289,7 @@ impl<'tcx> LateLintPass<'tcx> for OnlyUsedInRecursion {
                         ExprKind::Call(callee, args)
                             if path_def_id(cx, callee).map_or(false, |id| {
                                 id == param.fn_id
-                                    && has_matching_substs(param.fn_kind, typeck.node_substs(callee.hir_id))
+                                    && has_matching_args(param.fn_kind, typeck.node_args(callee.hir_id))
                             }) =>
                         {
                             if let Some(idx) = args.iter().position(|arg| arg.hir_id == child_id) {
@@ -300,7 +300,7 @@ impl<'tcx> LateLintPass<'tcx> for OnlyUsedInRecursion {
                         ExprKind::MethodCall(_, receiver, args, _)
                             if typeck.type_dependent_def_id(parent.hir_id).map_or(false, |id| {
                                 id == param.fn_id
-                                    && has_matching_substs(param.fn_kind, typeck.node_substs(parent.hir_id))
+                                    && has_matching_args(param.fn_kind, typeck.node_args(parent.hir_id))
                             }) =>
                         {
                             if let Some(idx) = iter::once(receiver).chain(args).position(|arg| arg.hir_id == child_id) {
@@ -381,15 +381,15 @@ impl<'tcx> LateLintPass<'tcx> for OnlyUsedInRecursion {
     }
 }
 
-fn has_matching_substs(kind: FnKind, substs: SubstsRef<'_>) -> bool {
+fn has_matching_args(kind: FnKind, args: GenericArgsRef<'_>) -> bool {
     match kind {
         FnKind::Fn => true,
-        FnKind::TraitFn => substs.iter().enumerate().all(|(idx, subst)| match subst.unpack() {
+        FnKind::TraitFn => args.iter().enumerate().all(|(idx, subst)| match subst.unpack() {
             GenericArgKind::Lifetime(_) => true,
             GenericArgKind::Type(ty) => matches!(*ty.kind(), ty::Param(ty) if ty.index as usize == idx),
             GenericArgKind::Const(c) => matches!(c.kind(), ConstKind::Param(c) if c.index as usize == idx),
         }),
         #[allow(trivial_casts)]
-        FnKind::ImplTraitFn(expected_substs) => substs as *const _ as usize == expected_substs,
+        FnKind::ImplTraitFn(expected_args) => args as *const _ as usize == expected_args,
     }
 }

clippy_lints/src/pass_by_ref_or_value.rs

@@ -143,7 +143,7 @@ impl<'tcx> PassByRefOrValue {
             return;
         }
 
-        let fn_sig = cx.tcx.fn_sig(def_id).subst_identity();
+        let fn_sig = cx.tcx.fn_sig(def_id).instantiate_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

clippy_lints/src/ptr.rs

@@ -166,7 +166,7 @@ impl<'tcx> LateLintPass<'tcx> for Ptr {
             check_mut_from_ref(cx, sig, None);
             for arg in check_fn_args(
                 cx,
-                cx.tcx.fn_sig(item.owner_id).subst_identity().skip_binder().inputs(),
+                cx.tcx.fn_sig(item.owner_id).instantiate_identity().skip_binder().inputs(),
                 sig.decl.inputs,
                 &sig.decl.output,
                 &[],
@@ -220,7 +220,7 @@ impl<'tcx> LateLintPass<'tcx> for Ptr {
 
         check_mut_from_ref(cx, sig, Some(body));
         let decl = sig.decl;
-        let sig = cx.tcx.fn_sig(item_id).subst_identity().skip_binder();
+        let sig = cx.tcx.fn_sig(item_id).instantiate_identity().skip_binder();
         let lint_args: Vec<_> = check_fn_args(cx, sig.inputs(), decl.inputs, &decl.output, body.params)
             .filter(|arg| !is_trait_item || arg.mutability() == Mutability::Not)
             .collect();
@@ -423,7 +423,7 @@ fn check_fn_args<'cx, 'tcx: 'cx>(
         .enumerate()
         .filter_map(move |(i, (ty, hir_ty))| {
             if let ty::Ref(_, ty, mutability) = *ty.kind()
-                && let  ty::Adt(adt, substs) = *ty.kind()
+                && let  ty::Adt(adt, args) = *ty.kind()
                 && let TyKind::Ref(lt, ref ty) = hir_ty.kind
                 && let TyKind::Path(QPath::Resolved(None, path)) = ty.ty.kind
                 // Check that the name as typed matches the actual name of the type.
@@ -443,7 +443,7 @@ fn check_fn_args<'cx, 'tcx: 'cx>(
                                     } else {
                                         None
                                     }),
-                                substs.type_at(0),
+                                args.type_at(0),
                             ),
                         ),
                         _ if Some(adt.did()) == cx.tcx.lang_items().string() => (
@@ -496,7 +496,7 @@ fn check_fn_args<'cx, 'tcx: 'cx>(
                                 }
 
                                 let ty_name =
-                                    snippet_opt(cx, ty.span()).unwrap_or_else(|| substs.type_at(1).to_string());
+                                    snippet_opt(cx, ty.span()).unwrap_or_else(|| args.type_at(1).to_string());
 
                                 span_lint_hir_and_then(
                                     cx,
@@ -659,7 +659,7 @@ fn check_ptr_arg_usage<'tcx>(cx: &LateContext<'tcx>, body: &'tcx Body<'_>, args:
                             return;
                         };
 
-                        match *self.cx.tcx.fn_sig(id).subst_identity().skip_binder().inputs()[i]
+                        match *self.cx.tcx.fn_sig(id).instantiate_identity().skip_binder().inputs()[i]
                             .peel_refs()
                             .kind()
                         {
@@ -725,7 +725,7 @@ fn matches_preds<'tcx>(
     let infcx = cx.tcx.infer_ctxt().build();
     preds.iter().all(|&p| match cx.tcx.erase_late_bound_regions(p) {
         ExistentialPredicate::Trait(p) => infcx
-            .type_implements_trait(p.def_id, [ty.into()].into_iter().chain(p.substs.iter()), cx.param_env)
+            .type_implements_trait(p.def_id, [ty.into()].into_iter().chain(p.args.iter()), cx.param_env)
             .must_apply_modulo_regions(),
         ExistentialPredicate::Projection(p) => infcx.predicate_must_hold_modulo_regions(&Obligation::new(
             cx.tcx,

clippy_lints/src/redundant_slicing.rs

@@ -9,7 +9,7 @@ use rustc_hir::{BorrowKind, Expr, ExprKind, LangItem, Mutability};
 use rustc_lint::{LateContext, LateLintPass, Lint};
 use rustc_middle::ty::Ty;
 use rustc_middle::ty::adjustment::{Adjust, AutoBorrow, AutoBorrowMutability};
-use rustc_middle::ty::subst::GenericArg;
+use rustc_middle::ty::GenericArg;
 use rustc_session::{declare_lint_pass, declare_tool_lint};
 
 declare_clippy_lint! {
@@ -135,7 +135,7 @@ impl<'tcx> LateLintPass<'tcx> for RedundantSlicing {
                 } else if let Some(target_id) = cx.tcx.lang_items().deref_target() {
                     if let Ok(deref_ty) = cx.tcx.try_normalize_erasing_regions(
                         cx.param_env,
-                        Ty::new_projection(cx.tcx,target_id, cx.tcx.mk_substs(&[GenericArg::from(indexed_ty)])),
+                        Ty::new_projection(cx.tcx,target_id, cx.tcx.mk_args(&[GenericArg::from(indexed_ty)])),
                     ) {
                         if deref_ty == expr_ty {
                             let snip = snippet_with_context(cx, indexed.span, ctxt, "..", &mut app).0;

clippy_lints/src/returns.rs

@@ -9,7 +9,7 @@ use rustc_hir::intravisit::FnKind;
 use rustc_hir::{Block, Body, Expr, ExprKind, FnDecl, LangItem, MatchSource, PatKind, QPath, StmtKind};
 use rustc_lint::{LateContext, LateLintPass, LintContext};
 use rustc_middle::lint::in_external_macro;
-use rustc_middle::ty::{self, subst::GenericArgKind, Ty};
+use rustc_middle::ty::{self, GenericArgKind, Ty};
 use rustc_session::{declare_lint_pass, declare_tool_lint};
 use rustc_span::def_id::LocalDefId;
 use rustc_span::source_map::Span;
@@ -333,7 +333,7 @@ fn last_statement_borrows<'tcx>(cx: &LateContext<'tcx>, expr: &'tcx Expr<'tcx>)
             && cx
                 .tcx
                 .fn_sig(def_id)
-                .subst_identity()
+                .instantiate_identity()
                 .skip_binder()
                 .output()
                 .walk()

clippy_lints/src/self_named_constructors.rs

@@ -53,7 +53,7 @@ impl<'tcx> LateLintPass<'tcx> for SelfNamedConstructors {
 
         let parent = cx.tcx.hir().get_parent_item(impl_item.hir_id()).def_id;
         let item = cx.tcx.hir().expect_item(parent);
-        let self_ty = cx.tcx.type_of(item.owner_id).subst_identity();
+        let self_ty = cx.tcx.type_of(item.owner_id).instantiate_identity();
         let ret_ty = return_ty(cx, impl_item.owner_id);
 
         // Do not check trait impls

clippy_lints/src/significant_drop_tightening.rs

@@ -10,7 +10,7 @@ use rustc_hir::{
     intravisit::{walk_expr, Visitor},
 };
 use rustc_lint::{LateContext, LateLintPass, LintContext};
-use rustc_middle::ty::{subst::GenericArgKind, Ty, TypeAndMut};
+use rustc_middle::ty::{GenericArgKind, Ty, TypeAndMut};
 use rustc_session::{declare_tool_lint, impl_lint_pass};
 use rustc_span::{symbol::Ident, Span, DUMMY_SP};
 use std::borrow::Cow;

clippy_lints/src/size_of_in_element_count.rs

@@ -47,7 +47,7 @@ fn get_size_of_ty<'tcx>(cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>, inverted:
                 if let Some(def_id) = cx.qpath_res(count_func_qpath, count_func.hir_id).opt_def_id();
                 if matches!(cx.tcx.get_diagnostic_name(def_id), Some(sym::mem_size_of | sym::mem_size_of_val));
                 then {
-                    cx.typeck_results().node_substs(count_func.hir_id).types().next()
+                    cx.typeck_results().node_args(count_func.hir_id).types().next()
                 } else {
                     None
                 }
@@ -101,7 +101,7 @@ fn get_pointee_ty_and_count_expr<'tcx>(
         if FUNCTIONS.iter().any(|func_path| match_def_path(cx, def_id, func_path));
 
         // Get the pointee type
-        if let Some(pointee_ty) = cx.typeck_results().node_substs(func.hir_id).types().next();
+        if let Some(pointee_ty) = cx.typeck_results().node_args(func.hir_id).types().next();
         then {
             return Some((pointee_ty, count));
         }

clippy_lints/src/transmute/transmute_undefined_repr.rs

@@ -3,7 +3,7 @@ use clippy_utils::diagnostics::span_lint_and_then;
 use clippy_utils::ty::is_c_void;
 use rustc_hir::Expr;
 use rustc_lint::LateContext;
-use rustc_middle::ty::SubstsRef;
+use rustc_middle::ty::GenericArgsRef;
 use rustc_middle::ty::{self, IntTy, Ty, TypeAndMut, UintTy};
 
 #[expect(clippy::too_many_lines)]
@@ -268,12 +268,12 @@ fn reduce_ty<'tcx>(cx: &LateContext<'tcx>, mut ty: Ty<'tcx>) -> ReducedTy<'tcx>
                 }
                 ReducedTy::UnorderedFields(ty)
             },
-            ty::Adt(def, substs) if def.is_struct() => {
+            ty::Adt(def, args) if def.is_struct() => {
                 let mut iter = def
                     .non_enum_variant()
                     .fields
                     .iter()
-                    .map(|f| cx.tcx.type_of(f.did).subst(cx.tcx, substs));
+                    .map(|f| cx.tcx.type_of(f.did).instantiate(cx.tcx, args));
                 let Some(sized_ty) = iter.find(|&ty| !is_zero_sized_ty(cx, ty)) else {
                     return ReducedTy::TypeErasure { raw_ptr_only: false };
                 };
@@ -322,7 +322,7 @@ fn is_size_pair(ty: Ty<'_>) -> bool {
     }
 }
 
-fn same_except_params<'tcx>(subs1: SubstsRef<'tcx>, subs2: SubstsRef<'tcx>) -> bool {
+fn same_except_params<'tcx>(subs1: GenericArgsRef<'tcx>, subs2: GenericArgsRef<'tcx>) -> bool {
     // TODO: check const parameters as well. Currently this will consider `Array<5>` the same as
     // `Array<6>`
     for (ty1, ty2) in subs1.types().zip(subs2.types()).filter(|(ty1, ty2)| ty1 != ty2) {

clippy_lints/src/transmute/unsound_collection_transmute.rs

@@ -10,7 +10,7 @@ use rustc_span::symbol::sym;
 /// Returns `true` if it's triggered, otherwise returns `false`.
 pub(super) fn check<'tcx>(cx: &LateContext<'tcx>, e: &'tcx Expr<'_>, from_ty: Ty<'tcx>, to_ty: Ty<'tcx>) -> bool {
     match (&from_ty.kind(), &to_ty.kind()) {
-        (ty::Adt(from_adt, from_substs), ty::Adt(to_adt, to_substs)) => {
+        (ty::Adt(from_adt, from_args), ty::Adt(to_adt, to_args)) => {
             if from_adt.did() != to_adt.did() {
                 return false;
             }
@@ -28,9 +28,9 @@ pub(super) fn check<'tcx>(cx: &LateContext<'tcx>, e: &'tcx Expr<'_>, from_ty: Ty
             ) {
                 return false;
             }
-            if from_substs
+            if from_args
                 .types()
-                .zip(to_substs.types())
+                .zip(to_args.types())
                 .any(|(from_ty, to_ty)| is_layout_incompatible(cx, from_ty, to_ty))
             {
                 span_lint(

clippy_lints/src/uninit_vec.rs

@@ -88,7 +88,7 @@ fn handle_uninit_vec_pair<'tcx>(
         if let Some((set_len_self, call_span)) = extract_set_len_self(cx, maybe_set_len);
         if vec.location.eq_expr(cx, set_len_self);
         if let ty::Ref(_, vec_ty, _) = cx.typeck_results().expr_ty_adjusted(set_len_self).kind();
-        if let ty::Adt(_, substs) = vec_ty.kind();
+        if let ty::Adt(_, args) = vec_ty.kind();
         // `#[allow(...)]` attribute can be set on enclosing unsafe block of `set_len()`
         if !is_lint_allowed(cx, UNINIT_VEC, maybe_set_len.hir_id);
         then {
@@ -96,7 +96,7 @@ fn handle_uninit_vec_pair<'tcx>(
                 // with_capacity / reserve -> set_len
 
                 // Check T of Vec<T>
-                if !is_uninit_value_valid_for_ty(cx, substs.type_at(0)) {
+                if !is_uninit_value_valid_for_ty(cx, args.type_at(0)) {
                     // FIXME: #7698, false positive of the internal lints
                     #[expect(clippy::collapsible_span_lint_calls)]
                     span_lint_and_then(

clippy_lints/src/unit_return_expecting_ord.rs

@@ -65,7 +65,7 @@ fn get_projection_pred<'tcx>(
     generics.predicates.iter().find_map(|(proj_pred, _)| {
         if let ClauseKind::Projection(pred) = proj_pred.kind().skip_binder() {
             let projection_pred = cx.tcx.erase_late_bound_regions(proj_pred.kind().rebind(pred));
-            if projection_pred.projection_ty.substs == trait_pred.trait_ref.substs {
+            if projection_pred.projection_ty.args == trait_pred.trait_ref.args {
                 return Some(projection_pred);
             }
         }
@@ -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.fn_sig(def_id).subst_identity();
+        let fn_sig = cx.tcx.fn_sig(def_id).instantiate_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));
@@ -120,8 +120,8 @@ fn get_args_to_check<'tcx>(cx: &LateContext<'tcx>, expr: &'tcx Expr<'tcx>) -> Ve
 fn check_arg<'tcx>(cx: &LateContext<'tcx>, arg: &'tcx Expr<'tcx>) -> Option<(Span, Option<Span>)> {
     if_chain! {
         if let ExprKind::Closure(&Closure { body, fn_decl_span, .. }) = arg.kind;
-        if let ty::Closure(_def_id, substs) = &cx.typeck_results().node_type(arg.hir_id).kind();
+        if let ty::Closure(_def_id, args) = &cx.typeck_results().node_type(arg.hir_id).kind();
-        let ret_ty = substs.as_closure().sig().output();
+        let ret_ty = args.as_closure().sig().output();
         let ty = cx.tcx.erase_late_bound_regions(ret_ty);
         if ty.is_unit();
         then {

clippy_lints/src/unit_types/let_unit_value.rs

@@ -161,7 +161,7 @@ fn needs_inferred_result_ty(
         },
         _ => return false,
     };
-    let sig = cx.tcx.fn_sig(id).subst_identity().skip_binder();
+    let sig = cx.tcx.fn_sig(id).instantiate_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()

clippy_lints/src/unnamed_address.rs

@@ -97,7 +97,7 @@ impl LateLintPass<'_> for UnnamedAddress {
             if let ExprKind::Path(ref func_qpath) = func.kind;
             if let Some(def_id) = cx.qpath_res(func_qpath, func.hir_id).opt_def_id();
             if match_def_path(cx, def_id, &paths::PTR_EQ);
-            let ty_param = cx.typeck_results().node_substs(func.hir_id).type_at(0);
+            let ty_param = cx.typeck_results().node_args(func.hir_id).type_at(0);
             if ty_param.is_trait();
             then {
                 span_lint_and_help(

clippy_lints/src/use_self.rs

@@ -145,7 +145,7 @@ impl<'tcx> LateLintPass<'tcx> for UseSelf {
             then {
                 // `self_ty` is the semantic self type of `impl <trait> for <type>`. This cannot be
                 // `Self`.
-                let self_ty = impl_trait_ref.subst_identity().self_ty();
+                let self_ty = impl_trait_ref.instantiate_identity().self_ty();
 
                 // `trait_method_sig` is the signature of the function, how it is declared in the
                 // trait, not in the impl of the trait.
@@ -154,7 +154,7 @@ 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.fn_sig(trait_method).subst_identity();
+                let trait_method_sig = cx.tcx.fn_sig(trait_method).instantiate_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
@@ -226,7 +226,7 @@ impl<'tcx> LateLintPass<'tcx> for UseSelf {
             } else {
                 hir_ty_to_ty(cx.tcx, hir_ty)
             };
-            if same_type_and_consts(ty, cx.tcx.type_of(impl_id).subst_identity());
+            if same_type_and_consts(ty, cx.tcx.type_of(impl_id).instantiate_identity());
             then {
                 span_lint(cx, hir_ty.span);
             }
@@ -238,7 +238,7 @@ impl<'tcx> LateLintPass<'tcx> for UseSelf {
             if !expr.span.from_expansion();
             if self.msrv.meets(msrvs::TYPE_ALIAS_ENUM_VARIANTS);
             if let Some(&StackItem::Check { impl_id, .. }) = self.stack.last();
-            if cx.typeck_results().expr_ty(expr) == cx.tcx.type_of(impl_id).subst_identity();
+            if cx.typeck_results().expr_ty(expr) == cx.tcx.type_of(impl_id).instantiate_identity();
             then {} else { return; }
         }
         match expr.kind {
@@ -262,7 +262,7 @@ impl<'tcx> LateLintPass<'tcx> for UseSelf {
             if let PatKind::Path(QPath::Resolved(_, path))
                  | PatKind::TupleStruct(QPath::Resolved(_, path), _, _)
                  | PatKind::Struct(QPath::Resolved(_, path), _, _) = pat.kind;
-            if cx.typeck_results().pat_ty(pat) == cx.tcx.type_of(impl_id).subst_identity();
+            if cx.typeck_results().pat_ty(pat) == cx.tcx.type_of(impl_id).instantiate_identity();
             then {
                 check_path(cx, path);
             }

clippy_lints/src/useless_conversion.rs

@@ -227,8 +227,8 @@ impl<'tcx> LateLintPass<'tcx> for UselessConversion {
                     let a = cx.typeck_results().expr_ty(e);
                     let b = cx.typeck_results().expr_ty(recv);
                     if is_type_diagnostic_item(cx, a, sym::Result);
-                    if let ty::Adt(_, substs) = a.kind();
+                    if let ty::Adt(_, args) = a.kind();
-                    if let Some(a_type) = substs.types().next();
+                    if let Some(a_type) = args.types().next();
                     if same_type_and_consts(a_type, b);
 
                     then {
@@ -255,8 +255,8 @@ impl<'tcx> LateLintPass<'tcx> for UselessConversion {
                         if_chain! {
                             if match_def_path(cx, def_id, &paths::TRY_FROM);
                             if is_type_diagnostic_item(cx, a, sym::Result);
-                            if let ty::Adt(_, substs) = a.kind();
+                            if let ty::Adt(_, args) = a.kind();
-                            if let Some(a_type) = substs.types().next();
+                            if let Some(a_type) = args.types().next();
                             if same_type_and_consts(a_type, b);
 
                             then {

clippy_lints/src/utils/internal_lints/interning_defined_symbol.rs

@@ -78,7 +78,7 @@ impl<'tcx> LateLintPass<'tcx> for InterningDefinedSymbol {
                 for item in cx.tcx.module_children(def_id) {
                     if_chain! {
                         if let Res::Def(DefKind::Const, item_def_id) = item.res;
-                        let ty = cx.tcx.type_of(item_def_id).subst_identity();
+                        let ty = cx.tcx.type_of(item_def_id).instantiate_identity();
                         if match_type(cx, ty, &paths::SYMBOL);
                         if let Ok(ConstValue::Scalar(value)) = cx.tcx.const_eval_poly(item_def_id);
                         if let Ok(value) = value.to_u32();

clippy_lints/src/utils/internal_lints/msrv_attr_impl.rs

@@ -7,7 +7,7 @@ use rustc_errors::Applicability;
 use rustc_hir as hir;
 use rustc_hir_analysis::hir_ty_to_ty;
 use rustc_lint::{LateContext, LateLintPass, LintContext};
-use rustc_middle::ty::{self, subst::GenericArgKind};
+use rustc_middle::ty::{self, GenericArgKind};
 use rustc_session::{declare_lint_pass, declare_tool_lint};
 
 declare_clippy_lint! {
@@ -39,7 +39,7 @@ impl LateLintPass<'_> for MsrvAttrImpl {
             if self_ty_def.all_fields().any(|f| {
                 cx.tcx
                     .type_of(f.did)
-                    .subst_identity()
+                    .instantiate_identity()
                     .walk()
                     .filter(|t| matches!(t.unpack(), GenericArgKind::Type(_)))
                     .any(|t| match_type(cx, t.expect_ty(), &paths::MSRV))

clippy_lints/src/utils/internal_lints/unnecessary_def_path.rs

@@ -229,11 +229,11 @@ fn path_to_matched_type(cx: &LateContext<'_>, expr: &hir::Expr<'_>) -> Option<Ve
             Res::Def(DefKind::Static(_), def_id) => read_mir_alloc_def_path(
                 cx,
                 cx.tcx.eval_static_initializer(def_id).ok()?.inner(),
-                cx.tcx.type_of(def_id).subst_identity(),
+                cx.tcx.type_of(def_id).instantiate_identity(),
             ),
             Res::Def(DefKind::Const, def_id) => match cx.tcx.const_eval_poly(def_id).ok()? {
                 ConstValue::ByRef { alloc, offset } if offset.bytes() == 0 => {
-                    read_mir_alloc_def_path(cx, alloc.inner(), cx.tcx.type_of(def_id).subst_identity())
+                    read_mir_alloc_def_path(cx, alloc.inner(), cx.tcx.type_of(def_id).instantiate_identity())
                 },
                 _ => None,
             },

clippy_lints/src/vec.rs

@@ -230,8 +230,8 @@ fn size_of(cx: &LateContext<'_>, expr: &Expr<'_>) -> u64 {
 
 /// Returns the item type of the vector (i.e., the `T` in `Vec<T>`).
 fn vec_type(ty: Ty<'_>) -> Ty<'_> {
-    if let ty::Adt(_, substs) = ty.kind() {
+    if let ty::Adt(_, args) = ty.kind() {
-        substs.type_at(0)
+        args.type_at(0)
     } else {
         panic!("The type of `vec!` is a not a struct?");
     }

clippy_lints/src/zero_sized_map_values.rs

@@ -51,8 +51,8 @@ impl LateLintPass<'_> for ZeroSizedMapValues {
             if !in_trait_impl(cx, hir_ty.hir_id);
             let ty = ty_from_hir_ty(cx, hir_ty);
             if is_type_diagnostic_item(cx, ty, sym::HashMap) || is_type_diagnostic_item(cx, ty, sym::BTreeMap);
-            if let Adt(_, substs) = ty.kind();
+            if let Adt(_, args) = ty.kind();
-            let ty = substs.type_at(1);
+            let ty = args.type_at(1);
             // Fixes https://github.com/rust-lang/rust-clippy/issues/7447 because of
             // https://github.com/rust-lang/rust/blob/master/compiler/rustc_middle/src/ty/sty.rs#L968
             if !ty.has_escaping_bound_vars();

clippy_utils/src/consts.rs

@@ -12,7 +12,7 @@ use rustc_lint::LateContext;
 use rustc_middle::mir;
 use rustc_middle::mir::interpret::Scalar;
 use rustc_middle::ty::{self, EarlyBinder, FloatTy, ScalarInt, Ty, TyCtxt};
-use rustc_middle::ty::{List, SubstsRef};
+use rustc_middle::ty::{List, GenericArgsRef};
 use rustc_middle::{bug, span_bug};
 use rustc_span::symbol::{Ident, Symbol};
 use rustc_span::SyntaxContext;
@@ -327,7 +327,7 @@ pub struct ConstEvalLateContext<'a, 'tcx> {
     typeck_results: &'a ty::TypeckResults<'tcx>,
     param_env: ty::ParamEnv<'tcx>,
     source: ConstantSource,
-    substs: SubstsRef<'tcx>,
+    args: GenericArgsRef<'tcx>,
 }
 
 impl<'a, 'tcx> ConstEvalLateContext<'a, 'tcx> {
@@ -337,7 +337,7 @@ impl<'a, 'tcx> ConstEvalLateContext<'a, 'tcx> {
             typeck_results,
             param_env: lcx.param_env,
             source: ConstantSource::Local,
-            substs: List::empty(),
+            args: List::empty(),
         }
     }
 
@@ -473,16 +473,16 @@ impl<'a, 'tcx> ConstEvalLateContext<'a, 'tcx> {
                     return None;
                 }
 
-                let substs = self.typeck_results.node_substs(id);
+                let args = self.typeck_results.node_args(id);
-                let substs = if self.substs.is_empty() {
+                let args = if self.args.is_empty() {
-                    substs
+                    args
                 } else {
-                    EarlyBinder::bind(substs).subst(self.lcx.tcx, self.substs)
+                    EarlyBinder::bind(args).instantiate(self.lcx.tcx, self.args)
                 };
                 let result = self
                     .lcx
                     .tcx
-                    .const_eval_resolve(self.param_env, mir::UnevaluatedConst::new(def_id, substs), None)
+                    .const_eval_resolve(self.param_env, mir::UnevaluatedConst::new(def_id, args), None)
                     .ok()
                     .map(|val| rustc_middle::mir::ConstantKind::from_value(val, ty))?;
                 let result = miri_to_const(self.lcx, result)?;

clippy_utils/src/eager_or_lazy.rs

@@ -51,7 +51,7 @@ fn fn_eagerness(cx: &LateContext<'_>, fn_id: DefId, name: Symbol, have_one_arg:
     let name = name.as_str();
 
     let ty = match cx.tcx.impl_of_method(fn_id) {
-        Some(id) => cx.tcx.type_of(id).subst_identity(),
+        Some(id) => cx.tcx.type_of(id).instantiate_identity(),
         None => return Lazy,
     };
 
@@ -72,7 +72,7 @@ fn fn_eagerness(cx: &LateContext<'_>, fn_id: DefId, name: Symbol, have_one_arg:
             .variants()
             .iter()
             .flat_map(|v| v.fields.iter())
-            .any(|x| matches!(cx.tcx.type_of(x.did).subst_identity().peel_refs().kind(), ty::Param(_)))
+            .any(|x| matches!(cx.tcx.type_of(x.did).instantiate_identity().peel_refs().kind(), ty::Param(_)))
             && all_predicates_of(cx.tcx, fn_id).all(|(pred, _)| match pred.kind().skip_binder() {
                 ty::ClauseKind::Trait(pred) => cx.tcx.trait_def(pred.trait_ref.def_id).is_marker,
                 _ => true,
@@ -80,7 +80,7 @@ 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.fn_sig(fn_id).subst_identity().skip_binder().inputs_and_output {
+            match &**cx.tcx.fn_sig(fn_id).instantiate_identity().skip_binder().inputs_and_output {
                 [arg, res] if !arg.is_mutable_ptr() && arg.peel_refs() == ty && res.is_bool() => NoChange,
                 _ => Lazy,
             }

clippy_utils/src/lib.rs

@@ -305,7 +305,7 @@ pub fn match_trait_method(cx: &LateContext<'_>, expr: &Expr<'_>, path: &[&str])
 /// Checks if a method is defined in an impl of a diagnostic item
 pub fn is_diag_item_method(cx: &LateContext<'_>, def_id: DefId, diag_item: Symbol) -> bool {
     if let Some(impl_did) = cx.tcx.impl_of_method(def_id) {
-        if let Some(adt) = cx.tcx.type_of(impl_did).subst_identity().ty_adt_def() {
+        if let Some(adt) = cx.tcx.type_of(impl_did).instantiate_identity().ty_adt_def() {
             return cx.tcx.is_diagnostic_item(diag_item, adt.did());
         }
     }
@@ -812,7 +812,7 @@ fn is_default_equivalent_ctor(cx: &LateContext<'_>, def_id: DefId, path: &QPath<
     if let QPath::TypeRelative(_, method) = path {
         if method.ident.name == sym::new {
             if let Some(impl_did) = cx.tcx.impl_of_method(def_id) {
-                if let Some(adt) = cx.tcx.type_of(impl_did).subst_identity().ty_adt_def() {
+                if let Some(adt) = cx.tcx.type_of(impl_did).instantiate_identity().ty_adt_def() {
                     return std_types_symbols.iter().any(|&symbol| {
                         cx.tcx.is_diagnostic_item(symbol, adt.did()) || Some(adt.did()) == cx.tcx.lang_items().string()
                     });
@@ -1377,7 +1377,7 @@ 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.fn_sig(id).subst_identity().skip_binder().inputs()[i];
+                                let ty = cx.tcx.fn_sig(id).instantiate_identity().skip_binder().inputs()[i];
                                 ty_is_fn_once_param(cx.tcx, ty, cx.tcx.param_env(id).caller_bounds()).then_some(())
                             },
                             _ => None,
@@ -1639,13 +1639,13 @@ 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_def_id: hir::OwnerId) -> Ty<'tcx> {
-    let ret_ty = cx.tcx.fn_sig(fn_def_id).subst_identity().output();
+    let ret_ty = cx.tcx.fn_sig(fn_def_id).instantiate_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_def_id: hir::OwnerId, nth: usize) -> Ty<'tcx> {
-    let arg = cx.tcx.fn_sig(fn_def_id).subst_identity().input(nth);
+    let arg = cx.tcx.fn_sig(fn_def_id).instantiate_identity().input(nth);
     cx.tcx.erase_late_bound_regions(arg)
 }
 

clippy_utils/src/qualify_min_const_fn.rs

@@ -15,7 +15,7 @@ use rustc_middle::mir::{
     Terminator, TerminatorKind,
 };
 use rustc_middle::traits::{ImplSource, ObligationCause};
-use rustc_middle::ty::subst::GenericArgKind;
+use rustc_middle::ty::GenericArgKind;
 use rustc_middle::ty::{self, adjustment::PointerCoercion, Ty, TyCtxt};
 use rustc_middle::ty::{BoundConstness, TraitRef};
 use rustc_semver::RustcVersion;
@@ -35,7 +35,7 @@ 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.fn_sig(def_id).subst_identity().output().skip_binder(),
+        tcx.fn_sig(def_id).instantiate_identity().output().skip_binder(),
         body.local_decls.iter().next().unwrap().source_info.span,
     )?;
 

clippy_utils/src/sugg.rs

@@ -877,7 +877,7 @@ impl<'tcx> DerefDelegate<'_, 'tcx> {
                     .cx
                     .typeck_results()
                     .type_dependent_def_id(parent_expr.hir_id)
-                    .map(|did| self.cx.tcx.fn_sig(did).subst_identity().skip_binder())
+                    .map(|did| self.cx.tcx.fn_sig(did).instantiate_identity().skip_binder())
                 {
                     std::iter::once(receiver)
                         .chain(call_args.iter())

clippy_utils/src/ty.rs

@@ -17,7 +17,7 @@ use rustc_lint::LateContext;
 use rustc_middle::mir::interpret::{ConstValue, Scalar};
 use rustc_middle::ty::{
     self, layout::ValidityRequirement, AdtDef, AliasTy, AssocKind, Binder, BoundRegion, FnSig, IntTy, List, ParamEnv,
-    Region, RegionKind, SubstsRef, Ty, TyCtxt, TypeSuperVisitable, TypeVisitable, TypeVisitableExt, TypeVisitor,
+    Region, RegionKind, GenericArgsRef, Ty, TyCtxt, TypeSuperVisitable, TypeVisitable, TypeVisitableExt, TypeVisitor,
     UintTy, VariantDef, VariantDiscr,
 };
 use rustc_middle::ty::{GenericArg, GenericArgKind};
@@ -90,14 +90,14 @@ pub fn contains_ty_adt_constructor_opaque<'tcx>(cx: &LateContext<'tcx>, ty: Ty<'
                         return false;
                     }
 
-                    for (predicate, _span) in cx.tcx.explicit_item_bounds(def_id).subst_identity_iter_copied() {
+                    for (predicate, _span) in cx.tcx.explicit_item_bounds(def_id).instantiate_identity_iter_copied() {
                         match predicate.kind().skip_binder() {
                             // For `impl Trait<U>`, it will register a predicate of `T: Trait<U>`, so we go through
                             // and check substitutions to find `U`.
                             ty::ClauseKind::Trait(trait_predicate) => {
                                 if trait_predicate
                                     .trait_ref
-                                    .substs
+                                    .args
                                     .types()
                                     .skip(1) // Skip the implicit `Self` generic parameter
                                     .any(|ty| contains_ty_adt_constructor_opaque_inner(cx, ty, needle, seen))
@@ -237,7 +237,7 @@ pub fn implements_trait_with_env<'tcx>(
         kind: TypeVariableOriginKind::MiscVariable,
         span: DUMMY_SP,
     };
-    let ty_params = tcx.mk_substs_from_iter(
+    let ty_params = tcx.mk_args_from_iter(
         ty_params
             .into_iter()
             .map(|arg| arg.unwrap_or_else(|| infcx.next_ty_var(orig).into())),
@@ -265,7 +265,7 @@ pub fn is_must_use_ty<'tcx>(cx: &LateContext<'tcx>, ty: Ty<'tcx>) -> bool {
             // because we don't want to lint functions returning empty arrays
             is_must_use_ty(cx, *ty)
         },
-        ty::Tuple(substs) => substs.iter().any(|ty| is_must_use_ty(cx, ty)),
+        ty::Tuple(args) => args.iter().any(|ty| is_must_use_ty(cx, ty)),
         ty::Alias(ty::Opaque, ty::AliasTy { def_id, .. }) => {
             for (predicate, _) in cx.tcx.explicit_item_bounds(def_id).skip_binder() {
                 if let ty::ClauseKind::Trait(trait_predicate) = predicate.kind().skip_binder() {
@@ -314,11 +314,11 @@ fn is_normalizable_helper<'tcx>(
     let cause = rustc_middle::traits::ObligationCause::dummy();
     let result = if infcx.at(&cause, param_env).query_normalize(ty).is_ok() {
         match ty.kind() {
-            ty::Adt(def, substs) => def.variants().iter().all(|variant| {
+            ty::Adt(def, args) => def.variants().iter().all(|variant| {
                 variant
                     .fields
                     .iter()
-                    .all(|field| is_normalizable_helper(cx, param_env, field.ty(cx.tcx, substs), cache))
+                    .all(|field| is_normalizable_helper(cx, param_env, field.ty(cx.tcx, args), cache))
             }),
             _ => ty.walk().all(|generic_arg| match generic_arg.unpack() {
                 GenericArgKind::Type(inner_ty) if inner_ty != ty => {
@@ -517,14 +517,14 @@ pub fn walk_ptrs_ty_depth(ty: Ty<'_>) -> (Ty<'_>, usize) {
 /// otherwise returns `false`
 pub fn same_type_and_consts<'tcx>(a: Ty<'tcx>, b: Ty<'tcx>) -> bool {
     match (&a.kind(), &b.kind()) {
-        (&ty::Adt(did_a, substs_a), &ty::Adt(did_b, substs_b)) => {
+        (&ty::Adt(did_a, args_a), &ty::Adt(did_b, args_b)) => {
             if did_a != did_b {
                 return false;
             }
 
-            substs_a
+            args_a
                 .iter()
-                .zip(substs_b.iter())
+                .zip(args_b.iter())
                 .all(|(arg_a, arg_b)| match (arg_a.unpack(), arg_b.unpack()) {
                     (GenericArgKind::Const(inner_a), GenericArgKind::Const(inner_b)) => inner_a == inner_b,
                     (GenericArgKind::Type(type_a), GenericArgKind::Type(type_b)) => {
@@ -643,7 +643,7 @@ 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.fn_sig(id).subst_identity(), Some(id)))
+        Some(ExprFnSig::Sig(cx.tcx.fn_sig(id).instantiate_identity(), Some(id)))
     } else {
         ty_sig(cx, cx.typeck_results().expr_ty_adjusted(expr).peel_refs())
     }
@@ -661,11 +661,11 @@ 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.fn_sig(id).subst(cx.tcx, subs), Some(id))),
+        ty::FnDef(id, subs) => Some(ExprFnSig::Sig(cx.tcx.fn_sig(id).instantiate(cx.tcx, subs), Some(id))),
-        ty::Alias(ty::Opaque, ty::AliasTy { def_id, substs, .. }) => sig_from_bounds(
+        ty::Alias(ty::Opaque, ty::AliasTy { def_id, args, .. }) => sig_from_bounds(
             cx,
             ty,
-            cx.tcx.item_bounds(def_id).subst_iter(cx.tcx, substs),
+            cx.tcx.item_bounds(def_id).arg_iter(cx.tcx, args),
             cx.tcx.opt_parent(def_id),
         ),
         ty::FnPtr(sig) => Some(ExprFnSig::Sig(sig, None)),
@@ -681,7 +681,7 @@ pub fn ty_sig<'tcx>(cx: &LateContext<'tcx>, ty: Ty<'tcx>) -> Option<ExprFnSig<'t
                         .projection_bounds()
                         .find(|p| lang_items.fn_once_output().map_or(false, |id| id == p.item_def_id()))
                         .map(|p| p.map_bound(|p| p.term.ty().unwrap()));
-                    Some(ExprFnSig::Trait(bound.map_bound(|b| b.substs.type_at(0)), output, None))
+                    Some(ExprFnSig::Trait(bound.map_bound(|b| b.args.type_at(0)), output, None))
                 },
                 _ => None,
             }
@@ -713,7 +713,7 @@ fn sig_from_bounds<'tcx>(
                     || lang_items.fn_once_trait() == Some(p.def_id()))
                     && p.self_ty() == ty =>
             {
-                let i = pred.kind().rebind(p.trait_ref.substs.type_at(1));
+                let i = pred.kind().rebind(p.trait_ref.args.type_at(1));
                 if inputs.map_or(false, |inputs| i != inputs) {
                     // Multiple different fn trait impls. Is this even allowed?
                     return None;
@@ -744,7 +744,7 @@ fn sig_for_projection<'tcx>(cx: &LateContext<'tcx>, ty: AliasTy<'tcx>) -> Option
     for (pred, _) in cx
         .tcx
         .explicit_item_bounds(ty.def_id)
-        .subst_iter_copied(cx.tcx, ty.substs)
+        .arg_iter_copied(cx.tcx, ty.args)
     {
         match pred.kind().skip_binder() {
             ty::ClauseKind::Trait(p)
@@ -752,7 +752,7 @@ fn sig_for_projection<'tcx>(cx: &LateContext<'tcx>, ty: AliasTy<'tcx>) -> Option
                     || lang_items.fn_mut_trait() == Some(p.def_id())
                     || lang_items.fn_once_trait() == Some(p.def_id())) =>
             {
-                let i = pred.kind().rebind(p.trait_ref.substs.type_at(1));
+                let i = pred.kind().rebind(p.trait_ref.args.type_at(1));
 
                 if inputs.map_or(false, |inputs| inputs != i) {
                     // Multiple different fn trait impls. Is this even allowed?
@@ -793,7 +793,7 @@ impl core::ops::Add<u32> for EnumValue {
 #[expect(clippy::cast_possible_truncation, clippy::cast_possible_wrap)]
 pub fn read_explicit_enum_value(tcx: TyCtxt<'_>, id: DefId) -> Option<EnumValue> {
     if let Ok(ConstValue::Scalar(Scalar::Int(value))) = tcx.const_eval_poly(id) {
-        match tcx.type_of(id).subst_identity().kind() {
+        match tcx.type_of(id).instantiate_identity().kind() {
             ty::Int(_) => Some(EnumValue::Signed(match value.size().bytes() {
                 1 => i128::from(value.assert_bits(Size::from_bytes(1)) as u8 as i8),
                 2 => i128::from(value.assert_bits(Size::from_bytes(2)) as u16 as i16),
@@ -927,7 +927,7 @@ pub fn adt_and_variant_of_res<'tcx>(cx: &LateContext<'tcx>, res: Res) -> Option<
             Some((adt, adt.variant_with_id(var_id)))
         },
         Res::SelfCtor(id) => {
-            let adt = cx.tcx.type_of(id).subst_identity().ty_adt_def().unwrap();
+            let adt = cx.tcx.type_of(id).instantiate_identity().ty_adt_def().unwrap();
             Some((adt, adt.non_enum_variant()))
         },
         _ => None,
@@ -1025,13 +1025,13 @@ pub fn make_projection<'tcx>(
     tcx: TyCtxt<'tcx>,
     container_id: DefId,
     assoc_ty: Symbol,
-    substs: impl IntoIterator<Item = impl Into<GenericArg<'tcx>>>,
+    args: impl IntoIterator<Item = impl Into<GenericArg<'tcx>>>,
 ) -> Option<AliasTy<'tcx>> {
     fn helper<'tcx>(
         tcx: TyCtxt<'tcx>,
         container_id: DefId,
         assoc_ty: Symbol,
-        substs: SubstsRef<'tcx>,
+        args: GenericArgsRef<'tcx>,
     ) -> Option<AliasTy<'tcx>> {
         let Some(assoc_item) = tcx
             .associated_items(container_id)
@@ -1052,18 +1052,18 @@ pub fn make_projection<'tcx>(
                 .map(|x| &x.kind);
 
             debug_assert!(
-                generic_count == substs.len(),
+                generic_count == args.len(),
-                "wrong number of substs for `{:?}`: found `{}` expected `{generic_count}`.\n\
+                "wrong number of args for `{:?}`: found `{}` expected `{generic_count}`.\n\
                     note: the expected parameters are: {:#?}\n\
-                    the given arguments are: `{substs:#?}`",
+                    the given arguments are: `{args:#?}`",
                 assoc_item.def_id,
-                substs.len(),
+                args.len(),
                 params.map(ty::GenericParamDefKind::descr).collect::<Vec<_>>(),
             );
 
             if let Some((idx, (param, arg))) = params
                 .clone()
-                .zip(substs.iter().map(GenericArg::unpack))
+                .zip(args.iter().map(GenericArg::unpack))
                 .enumerate()
                 .find(|(_, (param, arg))| {
                     !matches!(
@@ -1078,20 +1078,20 @@ pub fn make_projection<'tcx>(
                     false,
                     "mismatched subst type at index {idx}: expected a {}, found `{arg:?}`\n\
                         note: the expected parameters are {:#?}\n\
-                        the given arguments are {substs:#?}",
+                        the given arguments are {args:#?}",
                     param.descr(),
                     params.map(ty::GenericParamDefKind::descr).collect::<Vec<_>>()
                 );
             }
         }
 
-        Some(tcx.mk_alias_ty(assoc_item.def_id, substs))
+        Some(tcx.mk_alias_ty(assoc_item.def_id, args))
     }
     helper(
         tcx,
         container_id,
         assoc_ty,
-        tcx.mk_substs_from_iter(substs.into_iter().map(Into::into)),
+        tcx.mk_args_from_iter(args.into_iter().map(Into::into)),
     )
 }
 
@@ -1106,25 +1106,25 @@ pub fn make_normalized_projection<'tcx>(
     param_env: ParamEnv<'tcx>,
     container_id: DefId,
     assoc_ty: Symbol,
-    substs: impl IntoIterator<Item = impl Into<GenericArg<'tcx>>>,
+    args: impl IntoIterator<Item = impl Into<GenericArg<'tcx>>>,
 ) -> Option<Ty<'tcx>> {
     fn helper<'tcx>(tcx: TyCtxt<'tcx>, param_env: ParamEnv<'tcx>, ty: AliasTy<'tcx>) -> Option<Ty<'tcx>> {
         #[cfg(debug_assertions)]
         if let Some((i, subst)) = ty
-            .substs
+            .args
             .iter()
             .enumerate()
             .find(|(_, subst)| subst.has_late_bound_regions())
         {
             debug_assert!(
                 false,
-                "substs contain late-bound region at index `{i}` which can't be normalized.\n\
+                "args contain late-bound region at index `{i}` which can't be normalized.\n\
                     use `TyCtxt::erase_late_bound_regions`\n\
                     note: subst is `{subst:#?}`",
             );
             return None;
         }
-        match tcx.try_normalize_erasing_regions(param_env, Ty::new_projection(tcx,ty.def_id, ty.substs)) {
+        match tcx.try_normalize_erasing_regions(param_env, Ty::new_projection(tcx,ty.def_id, ty.args)) {
             Ok(ty) => Some(ty),
             Err(e) => {
                 debug_assert!(false, "failed to normalize type `{ty}`: {e:#?}");
@@ -1132,7 +1132,7 @@ pub fn make_normalized_projection<'tcx>(
             },
         }
     }
-    helper(tcx, param_env, make_projection(tcx, container_id, assoc_ty, substs)?)
+    helper(tcx, param_env, make_projection(tcx, container_id, assoc_ty, args)?)
 }
 
 /// Check if given type has inner mutability such as [`std::cell::Cell`] or [`std::cell::RefCell`]
@@ -1147,7 +1147,7 @@ pub fn is_interior_mut_ty<'tcx>(cx: &LateContext<'tcx>, ty: Ty<'tcx>) -> bool {
                 && is_interior_mut_ty(cx, inner_ty)
         },
         ty::Tuple(fields) => fields.iter().any(|ty| is_interior_mut_ty(cx, ty)),
-        ty::Adt(def, substs) => {
+        ty::Adt(def, args) => {
             // Special case for collections in `std` who's impl of `Hash` or `Ord` delegates to
             // that of their type parameters.  Note: we don't include `HashSet` and `HashMap`
             // because they have no impl for `Hash` or `Ord`.
@@ -1168,7 +1168,7 @@ pub fn is_interior_mut_ty<'tcx>(cx: &LateContext<'tcx>, ty: Ty<'tcx>) -> bool {
             let is_box = Some(def_id) == cx.tcx.lang_items().owned_box();
             if is_std_collection || is_box {
                 // The type is mutable if any of its type parameters are
-                substs.types().any(|ty| is_interior_mut_ty(cx, ty))
+                args.types().any(|ty| is_interior_mut_ty(cx, ty))
             } else {
                 !ty.has_escaping_bound_vars()
                     && cx.tcx.layout_of(cx.param_env.and(ty)).is_ok()
@@ -1184,19 +1184,19 @@ pub fn make_normalized_projection_with_regions<'tcx>(
     param_env: ParamEnv<'tcx>,
     container_id: DefId,
     assoc_ty: Symbol,
-    substs: impl IntoIterator<Item = impl Into<GenericArg<'tcx>>>,
+    args: impl IntoIterator<Item = impl Into<GenericArg<'tcx>>>,
 ) -> Option<Ty<'tcx>> {
     fn helper<'tcx>(tcx: TyCtxt<'tcx>, param_env: ParamEnv<'tcx>, ty: AliasTy<'tcx>) -> Option<Ty<'tcx>> {
         #[cfg(debug_assertions)]
         if let Some((i, subst)) = ty
-            .substs
+            .args
             .iter()
             .enumerate()
             .find(|(_, subst)| subst.has_late_bound_regions())
         {
             debug_assert!(
                 false,
-                "substs contain late-bound region at index `{i}` which can't be normalized.\n\
+                "args contain late-bound region at index `{i}` which can't be normalized.\n\
                     use `TyCtxt::erase_late_bound_regions`\n\
                     note: subst is `{subst:#?}`",
             );
@@ -1207,7 +1207,7 @@ pub fn make_normalized_projection_with_regions<'tcx>(
             .infer_ctxt()
             .build()
             .at(&cause, param_env)
-            .query_normalize(Ty::new_projection(tcx,ty.def_id, ty.substs))
+            .query_normalize(Ty::new_projection(tcx,ty.def_id, ty.args))
         {
             Ok(ty) => Some(ty.value),
             Err(e) => {
@@ -1216,7 +1216,7 @@ pub fn make_normalized_projection_with_regions<'tcx>(
             },
         }
     }
-    helper(tcx, param_env, make_projection(tcx, container_id, assoc_ty, substs)?)
+    helper(tcx, param_env, make_projection(tcx, container_id, assoc_ty, args)?)
 }
 
 pub fn normalize_with_regions<'tcx>(tcx: TyCtxt<'tcx>, param_env: ParamEnv<'tcx>, ty: Ty<'tcx>) -> Ty<'tcx> {

tests/ui/crashes/ice-6256.rs

@@ -1,5 +1,5 @@
 // originally from rustc ./tests/ui/regions/issue-78262.rs
-// ICE: to get the signature of a closure, use substs.as_closure().sig() not fn_sig()
+// ICE: to get the signature of a closure, use args.as_closure().sig() not fn_sig()
 #![allow(clippy::upper_case_acronyms)]
 
 trait TT {}

tests/ui/eta.fixed

@@ -331,7 +331,7 @@ impl dyn TestTrait + '_ {
 }
 
 // https://github.com/rust-lang/rust-clippy/issues/7746
-fn angle_brackets_and_substs() {
+fn angle_brackets_and_args() {
     let array_opt: Option<&[u8; 3]> = Some(&[4, 8, 7]);
     array_opt.map(<[u8; 3]>::as_slice);
 

tests/ui/eta.rs

@@ -331,7 +331,7 @@ impl dyn TestTrait + '_ {
 }
 
 // https://github.com/rust-lang/rust-clippy/issues/7746
-fn angle_brackets_and_substs() {
+fn angle_brackets_and_args() {
     let array_opt: Option<&[u8; 3]> = Some(&[4, 8, 7]);
     array_opt.map(|a| a.as_slice());