Rollup merge of #122813 - nnethercote:nicer-quals, r=compiler-errors

Qualifier tweaking

Adding and removing qualifiers in some cases that make things nicer. Details in individual commits.

r? `@compiler-errors`

clippy_lints/src/derivable_impls.rs

@@ -9,7 +9,7 @@ use rustc_hir::{
 };
 use rustc_lint::{LateContext, LateLintPass};
 use rustc_middle::ty::adjustment::{Adjust, PointerCoercion};
-use rustc_middle::ty::{self, Adt, AdtDef, GenericArgsRef, Ty, TypeckResults};
+use rustc_middle::ty::{self, AdtDef, GenericArgsRef, Ty, TypeckResults};
 use rustc_session::impl_lint_pass;
 use rustc_span::sym;
 
@@ -79,7 +79,7 @@ fn is_path_self(e: &Expr<'_>) -> bool {
 fn contains_trait_object(ty: Ty<'_>) -> bool {
     match ty.kind() {
         ty::Ref(_, ty, _) => contains_trait_object(*ty),
-        Adt(def, args) => def.is_box() && args[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,
     }
@@ -198,7 +198,7 @@ impl<'tcx> LateLintPass<'tcx> for DerivableImpls {
             && let Node::ImplItem(impl_item) = cx.tcx.hir_node(impl_item_hir)
             && let ImplItemKind::Fn(_, b) = &impl_item.kind
             && let Body { value: func_expr, .. } = cx.tcx.hir().body(*b)
-            && let &Adt(adt_def, args) = cx.tcx.type_of(item.owner_id).instantiate_identity().kind()
+            && let &ty::Adt(adt_def, args) = cx.tcx.type_of(item.owner_id).instantiate_identity().kind()
             && let attrs = cx.tcx.hir().attrs(item.hir_id())
             && !attrs.iter().any(|attr| attr.doc_str().is_some())
             && cx.tcx.hir().attrs(impl_item_hir).is_empty()

clippy_lints/src/from_raw_with_void_ptr.rs

@@ -4,7 +4,7 @@ use clippy_utils::ty::is_c_void;
 use rustc_hir::def_id::DefId;
 use rustc_hir::{Expr, ExprKind, QPath};
 use rustc_lint::{LateContext, LateLintPass};
-use rustc_middle::ty::RawPtr;
+use rustc_middle::ty;
 use rustc_session::declare_lint_pass;
 use rustc_span::sym;
 
@@ -44,7 +44,7 @@ impl LateLintPass<'_> for FromRawWithVoidPtr {
             && seg.ident.name == sym!(from_raw)
             && let Some(type_str) = path_def_id(cx, ty).and_then(|id| def_id_matches_type(cx, id))
             && let arg_kind = cx.typeck_results().expr_ty(arg).kind()
-            && let RawPtr(ty, _) = arg_kind
+            && let ty::RawPtr(ty, _) = arg_kind
             && is_c_void(cx, *ty)
         {
             let msg = format!("creating a `{type_str}` from a void raw pointer");

clippy_lints/src/functions/not_unsafe_ptr_arg_deref.rs

@@ -1,4 +1,4 @@
-use rustc_hir::{self as hir, intravisit, HirIdSet};
+use rustc_hir::{self as hir, intravisit, HirId, HirIdSet};
 use rustc_lint::LateContext;
 use rustc_middle::ty;
 use rustc_span::def_id::LocalDefId;
@@ -74,7 +74,7 @@ fn check_raw_ptr<'tcx>(
     }
 }
 
-fn raw_ptr_arg(cx: &LateContext<'_>, arg: &hir::Param<'_>) -> Option<hir::HirId> {
+fn raw_ptr_arg(cx: &LateContext<'_>, arg: &hir::Param<'_>) -> Option<HirId> {
     if let (&hir::PatKind::Binding(_, id, _, _), Some(&ty::RawPtr(_, _))) = (
         &arg.pat.kind,
         cx.maybe_typeck_results()

clippy_lints/src/functions/result.rs

@@ -2,7 +2,7 @@ use rustc_errors::Diag;
 use rustc_hir as hir;
 use rustc_lint::{LateContext, LintContext};
 use rustc_middle::lint::in_external_macro;
-use rustc_middle::ty::{Adt, Ty};
+use rustc_middle::ty::{self, Ty};
 use rustc_span::{sym, Span};
 
 use clippy_utils::diagnostics::{span_lint_and_help, span_lint_and_then};
@@ -25,7 +25,7 @@ fn result_err_ty<'tcx>(
             .tcx
             .instantiate_bound_regions_with_erased(cx.tcx.fn_sig(id).instantiate_identity().output())
         && is_type_diagnostic_item(cx, ty, sym::Result)
-        && let Adt(_, args) = ty.kind()
+        && let ty::Adt(_, args) = ty.kind()
     {
         let err_ty = args.type_at(1);
         Some((hir_ty, err_ty))
@@ -86,7 +86,7 @@ fn check_result_unit_err(cx: &LateContext<'_>, err_ty: Ty<'_>, fn_header_span: S
 }
 
 fn check_result_large_err<'tcx>(cx: &LateContext<'tcx>, err_ty: Ty<'tcx>, hir_ty_span: Span, large_err_threshold: u64) {
-    if let Adt(adt, subst) = err_ty.kind()
+    if let ty::Adt(adt, subst) = err_ty.kind()
         && let Some(local_def_id) = err_ty
             .ty_adt_def()
             .expect("already checked this is adt")

clippy_lints/src/implicit_saturating_add.rs

@@ -7,7 +7,7 @@ use rustc_data_structures::packed::Pu128;
 use rustc_errors::Applicability;
 use rustc_hir::{BinOpKind, Block, Expr, ExprKind, Stmt, StmtKind};
 use rustc_lint::{LateContext, LateLintPass};
-use rustc_middle::ty::{Int, IntTy, Ty, Uint, UintTy};
+use rustc_middle::ty::{IntTy, Ty, UintTy};
 use rustc_session::declare_lint_pass;
 
 declare_clippy_lint! {
@@ -97,6 +97,7 @@ impl<'tcx> LateLintPass<'tcx> for ImplicitSaturatingAdd {
 }
 
 fn get_int_max(ty: Ty<'_>) -> Option<u128> {
+    use rustc_middle::ty::{Int, Uint};
     match ty.peel_refs().kind() {
         Int(IntTy::I8) => i8::MAX.try_into().ok(),
         Int(IntTy::I16) => i16::MAX.try_into().ok(),

clippy_lints/src/index_refutable_slice.rs

@@ -7,6 +7,7 @@ use clippy_utils::{is_expn_of, is_lint_allowed, path_to_local};
 use rustc_data_structures::fx::{FxHashSet, FxIndexMap};
 use rustc_errors::Applicability;
 use rustc_hir as hir;
+use rustc_hir::HirId;
 use rustc_hir::intravisit::{self, Visitor};
 use rustc_lint::{LateContext, LateLintPass};
 use rustc_middle::hir::nested_filter;
@@ -87,9 +88,9 @@ impl<'tcx> LateLintPass<'tcx> for IndexRefutableSlice {
     extract_msrv_attr!(LateContext);
 }
 
-fn find_slice_values(cx: &LateContext<'_>, pat: &hir::Pat<'_>) -> FxIndexMap<hir::HirId, SliceLintInformation> {
-    let mut removed_pat: FxHashSet<hir::HirId> = FxHashSet::default();
-    let mut slices: FxIndexMap<hir::HirId, SliceLintInformation> = FxIndexMap::default();
+fn find_slice_values(cx: &LateContext<'_>, pat: &hir::Pat<'_>) -> FxIndexMap<HirId, SliceLintInformation> {
+    let mut removed_pat: FxHashSet<HirId> = FxHashSet::default();
+    let mut slices: FxIndexMap<HirId, SliceLintInformation> = FxIndexMap::default();
     pat.walk_always(|pat| {
         // We'll just ignore mut and ref mut for simplicity sake right now
         if let hir::PatKind::Binding(
@@ -206,10 +207,10 @@ impl SliceLintInformation {
 
 fn filter_lintable_slices<'tcx>(
     cx: &LateContext<'tcx>,
-    slice_lint_info: FxIndexMap<hir::HirId, SliceLintInformation>,
+    slice_lint_info: FxIndexMap<HirId, SliceLintInformation>,
     max_suggested_slice: u64,
     scope: &'tcx hir::Expr<'tcx>,
-) -> FxIndexMap<hir::HirId, SliceLintInformation> {
+) -> FxIndexMap<HirId, SliceLintInformation> {
     let mut visitor = SliceIndexLintingVisitor {
         cx,
         slice_lint_info,
@@ -223,7 +224,7 @@ fn filter_lintable_slices<'tcx>(
 
 struct SliceIndexLintingVisitor<'a, 'tcx> {
     cx: &'a LateContext<'tcx>,
-    slice_lint_info: FxIndexMap<hir::HirId, SliceLintInformation>,
+    slice_lint_info: FxIndexMap<HirId, SliceLintInformation>,
     max_suggested_slice: u64,
 }
 

clippy_lints/src/large_enum_variant.rs

@@ -7,7 +7,7 @@ use rustc_errors::Applicability;
 use rustc_hir::{Item, ItemKind};
 use rustc_lint::{LateContext, LateLintPass};
 use rustc_middle::lint::in_external_macro;
-use rustc_middle::ty::{Adt, Ty};
+use rustc_middle::ty::{self, Ty};
 use rustc_session::impl_lint_pass;
 use rustc_span::Span;
 
@@ -82,7 +82,7 @@ impl<'tcx> LateLintPass<'tcx> for LargeEnumVariant {
         }
         if let ItemKind::Enum(ref def, _) = item.kind {
             let ty = cx.tcx.type_of(item.owner_id).instantiate_identity();
-            let Adt(adt, subst) = ty.kind() else {
+            let ty::Adt(adt, subst) = ty.kind() else {
                 panic!("already checked whether this is an enum")
             };
             if adt.variants().len() <= 1 {
@@ -167,7 +167,7 @@ impl<'tcx> LateLintPass<'tcx> for LargeEnumVariant {
 }
 
 fn maybe_copy<'tcx>(cx: &LateContext<'tcx>, ty: Ty<'tcx>) -> bool {
-    if let Adt(_def, args) = ty.kind()
+    if let ty::Adt(_def, args) = ty.kind()
         && args.types().next().is_some()
         && let Some(copy_trait) = cx.tcx.lang_items().copy_trait()
     {

clippy_lints/src/methods/unnecessary_join.rs

@@ -4,7 +4,7 @@ use rustc_ast::ast::LitKind;
 use rustc_errors::Applicability;
 use rustc_hir::{Expr, ExprKind, LangItem};
 use rustc_lint::LateContext;
-use rustc_middle::ty::{Ref, Slice};
+use rustc_middle::ty;
 use rustc_span::Span;
 
 use super::UNNECESSARY_JOIN;
@@ -18,9 +18,9 @@ pub(super) fn check<'tcx>(
 ) {
     let applicability = Applicability::MachineApplicable;
     let collect_output_adjusted_type = cx.typeck_results().expr_ty_adjusted(join_self_arg);
-    if let Ref(_, ref_type, _) = collect_output_adjusted_type.kind()
+    if let ty::Ref(_, ref_type, _) = collect_output_adjusted_type.kind()
         // the turbofish for collect is ::<Vec<String>>
-        && let Slice(slice) = ref_type.kind()
+        && let ty::Slice(slice) = ref_type.kind()
         && is_type_lang_item(cx, *slice, LangItem::String)
         // the argument for join is ""
         && let ExprKind::Lit(spanned) = &join_arg.kind

clippy_lints/src/mut_key.rs

@@ -4,7 +4,7 @@ use clippy_utils::{def_path_def_ids, trait_ref_of_method};
 use rustc_data_structures::fx::FxHashSet;
 use rustc_hir as hir;
 use rustc_lint::{LateContext, LateLintPass};
-use rustc_middle::ty::{Adt, Ty};
+use rustc_middle::ty::{self, Ty};
 use rustc_session::impl_lint_pass;
 use rustc_span::def_id::LocalDefId;
 use rustc_span::symbol::sym;
@@ -153,7 +153,7 @@ 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, args) = ty.kind() {
+        if let ty::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()));

clippy_lints/src/non_copy_const.rs

@@ -18,7 +18,7 @@ use rustc_middle::mir::interpret::{ErrorHandled, EvalToValTreeResult, GlobalId};
 use rustc_middle::ty::adjustment::Adjust;
 use rustc_middle::ty::{self, Ty, TyCtxt};
 use rustc_session::impl_lint_pass;
-use rustc_span::{sym, InnerSpan, Span};
+use rustc_span::{sym, DUMMY_SP, InnerSpan, Span};
 use rustc_target::abi::VariantIdx;
 
 // FIXME: this is a correctness problem but there's no suitable
@@ -290,9 +290,7 @@ impl NonCopyConst {
             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, rustc_span::DUMMY_SP);
+        let result = cx.tcx.const_eval_global_id_for_typeck(param_env, cid, DUMMY_SP);
         self.is_value_unfrozen_raw(cx, result, ty)
     }
 
@@ -303,7 +301,7 @@ impl NonCopyConst {
             cx.tcx,
             cx.param_env,
             ty::UnevaluatedConst::new(def_id, args),
-            rustc_span::DUMMY_SP,
+            DUMMY_SP,
         );
         self.is_value_unfrozen_raw(cx, result, ty)
     }

clippy_lints/src/operators/assign_op_pattern.rs

@@ -6,6 +6,7 @@ use clippy_utils::{binop_traits, eq_expr_value, trait_ref_of_method};
 use core::ops::ControlFlow;
 use rustc_errors::Applicability;
 use rustc_hir as hir;
+use rustc_hir::{HirId, HirIdSet};
 use rustc_hir_typeck::expr_use_visitor::{Delegate, ExprUseVisitor, PlaceBase, PlaceWithHirId};
 use rustc_lint::LateContext;
 use rustc_middle::mir::FakeReadCause;
@@ -98,10 +99,10 @@ pub(super) fn check<'tcx>(
     }
 }
 
-fn imm_borrows_in_expr(cx: &LateContext<'_>, e: &hir::Expr<'_>) -> hir::HirIdSet {
-    struct S(hir::HirIdSet);
+fn imm_borrows_in_expr(cx: &LateContext<'_>, e: &hir::Expr<'_>) -> HirIdSet {
+    struct S(HirIdSet);
     impl Delegate<'_> for S {
-        fn borrow(&mut self, place: &PlaceWithHirId<'_>, _: hir::HirId, kind: BorrowKind) {
+        fn borrow(&mut self, place: &PlaceWithHirId<'_>, _: HirId, kind: BorrowKind) {
             if matches!(kind, BorrowKind::ImmBorrow | BorrowKind::UniqueImmBorrow) {
                 self.0.insert(match place.place.base {
                     PlaceBase::Local(id) => id,
@@ -111,13 +112,13 @@ fn imm_borrows_in_expr(cx: &LateContext<'_>, e: &hir::Expr<'_>) -> hir::HirIdSet
             }
         }
 
-        fn consume(&mut self, _: &PlaceWithHirId<'_>, _: hir::HirId) {}
-        fn mutate(&mut self, _: &PlaceWithHirId<'_>, _: hir::HirId) {}
-        fn fake_read(&mut self, _: &PlaceWithHirId<'_>, _: FakeReadCause, _: hir::HirId) {}
-        fn copy(&mut self, _: &PlaceWithHirId<'_>, _: hir::HirId) {}
+        fn consume(&mut self, _: &PlaceWithHirId<'_>, _: HirId) {}
+        fn mutate(&mut self, _: &PlaceWithHirId<'_>, _: HirId) {}
+        fn fake_read(&mut self, _: &PlaceWithHirId<'_>, _: FakeReadCause, _: HirId) {}
+        fn copy(&mut self, _: &PlaceWithHirId<'_>, _: HirId) {}
     }
 
-    let mut s = S(hir::HirIdSet::default());
+    let mut s = S(HirIdSet::default());
     let infcx = cx.tcx.infer_ctxt().build();
     let mut v = ExprUseVisitor::new(
         &mut s,
@@ -130,10 +131,10 @@ fn imm_borrows_in_expr(cx: &LateContext<'_>, e: &hir::Expr<'_>) -> hir::HirIdSet
     s.0
 }
 
-fn mut_borrows_in_expr(cx: &LateContext<'_>, e: &hir::Expr<'_>) -> hir::HirIdSet {
-    struct S(hir::HirIdSet);
+fn mut_borrows_in_expr(cx: &LateContext<'_>, e: &hir::Expr<'_>) -> HirIdSet {
+    struct S(HirIdSet);
     impl Delegate<'_> for S {
-        fn borrow(&mut self, place: &PlaceWithHirId<'_>, _: hir::HirId, kind: BorrowKind) {
+        fn borrow(&mut self, place: &PlaceWithHirId<'_>, _: HirId, kind: BorrowKind) {
             if matches!(kind, BorrowKind::MutBorrow) {
                 self.0.insert(match place.place.base {
                     PlaceBase::Local(id) => id,
@@ -143,13 +144,13 @@ fn mut_borrows_in_expr(cx: &LateContext<'_>, e: &hir::Expr<'_>) -> hir::HirIdSet
             }
         }
 
-        fn consume(&mut self, _: &PlaceWithHirId<'_>, _: hir::HirId) {}
-        fn mutate(&mut self, _: &PlaceWithHirId<'_>, _: hir::HirId) {}
-        fn fake_read(&mut self, _: &PlaceWithHirId<'_>, _: FakeReadCause, _: hir::HirId) {}
-        fn copy(&mut self, _: &PlaceWithHirId<'_>, _: hir::HirId) {}
+        fn consume(&mut self, _: &PlaceWithHirId<'_>, _: HirId) {}
+        fn mutate(&mut self, _: &PlaceWithHirId<'_>, _: HirId) {}
+        fn fake_read(&mut self, _: &PlaceWithHirId<'_>, _: FakeReadCause, _: HirId) {}
+        fn copy(&mut self, _: &PlaceWithHirId<'_>, _: HirId) {}
     }
 
-    let mut s = S(hir::HirIdSet::default());
+    let mut s = S(HirIdSet::default());
     let infcx = cx.tcx.infer_ctxt().build();
     let mut v = ExprUseVisitor::new(
         &mut s,

clippy_lints/src/ptr.rs

@@ -8,7 +8,7 @@ use clippy_utils::{get_expr_use_or_unification_node, is_lint_allowed, path_def_i
 use hir::LifetimeName;
 use rustc_errors::{Applicability, MultiSpan};
 use rustc_hir::def_id::DefId;
-use rustc_hir::hir_id::HirIdMap;
+use rustc_hir::hir_id::{HirId, HirIdMap};
 use rustc_hir::intravisit::{walk_expr, Visitor};
 use rustc_hir::{
     self as hir, AnonConst, BinOpKind, BindingAnnotation, Body, Expr, ExprKind, FnRetTy, FnSig, GenericArg,
@@ -324,7 +324,7 @@ struct PtrArgReplacement {
 
 struct PtrArg<'tcx> {
     idx: usize,
-    emission_id: hir::HirId,
+    emission_id: HirId,
     span: Span,
     ty_did: DefId,
     ty_name: Symbol,