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`

compiler/rustc_hir_analysis/src/collect/predicates_of.rs

@@ -37,7 +37,7 @@ pub(super) fn predicates_of(tcx: TyCtxt<'_>, def_id: DefId) -> ty::GenericPredic
         // from the trait itself that *shouldn't* be shown as the source of
         // an obligation and instead be skipped. Otherwise we'd use
         // `tcx.def_span(def_id);`
-        let span = rustc_span::DUMMY_SP;
+        let span = DUMMY_SP;
 
         result.predicates =
             tcx.arena.alloc_from_iter(result.predicates.iter().copied().chain(std::iter::once((

compiler/rustc_hir_analysis/src/collect/resolve_bound_vars.rs

@@ -13,7 +13,7 @@ use rustc_hir as hir;
 use rustc_hir::def::{DefKind, Res};
 use rustc_hir::def_id::LocalDefId;
 use rustc_hir::intravisit::{self, Visitor};
-use rustc_hir::{GenericArg, GenericParam, GenericParamKind, HirIdMap, LifetimeName, Node};
+use rustc_hir::{GenericArg, GenericParam, GenericParamKind, HirId, HirIdMap, LifetimeName, Node};
 use rustc_macros::extension;
 use rustc_middle::bug;
 use rustc_middle::hir::nested_filter;
@@ -107,7 +107,7 @@ enum Scope<'a> {
         /// queried later. However, if we enter an elision scope, we have to
         /// later append the elided bound vars to the list and need to know what
         /// to append to.
-        hir_id: hir::HirId,
+        hir_id: HirId,
 
         s: ScopeRef<'a>,
 
@@ -825,7 +825,7 @@ impl<'a, 'tcx> Visitor<'tcx> for BoundVarContext<'a, 'tcx> {
         }
     }
 
-    fn visit_path(&mut self, path: &hir::Path<'tcx>, hir_id: hir::HirId) {
+    fn visit_path(&mut self, path: &hir::Path<'tcx>, hir_id: HirId) {
         for (i, segment) in path.segments.iter().enumerate() {
             let depth = path.segments.len() - i - 1;
             if let Some(args) = segment.args {
@@ -1027,7 +1027,7 @@ impl<'a, 'tcx> BoundVarContext<'a, 'tcx> {
         }
     }
 
-    fn record_late_bound_vars(&mut self, hir_id: hir::HirId, binder: Vec<ty::BoundVariableKind>) {
+    fn record_late_bound_vars(&mut self, hir_id: HirId, binder: Vec<ty::BoundVariableKind>) {
         if let Some(old) = self.map.late_bound_vars.insert(hir_id, binder) {
             bug!(
                 "overwrote bound vars for {hir_id:?}:\nold={old:?}\nnew={:?}",
@@ -1054,12 +1054,8 @@ impl<'a, 'tcx> BoundVarContext<'a, 'tcx> {
     /// already in scope (for a fn item, that will be 0, but for a method it might not be). Late
     /// bound lifetimes are resolved by name and associated with a binder ID (`binder_id`), so the
     /// ordering is not important there.
-    fn visit_early_late<F>(
-        &mut self,
-        hir_id: hir::HirId,
-        generics: &'tcx hir::Generics<'tcx>,
-        walk: F,
-    ) where
+    fn visit_early_late<F>(&mut self, hir_id: HirId, generics: &'tcx hir::Generics<'tcx>, walk: F)
+    where
         F: for<'b, 'c> FnOnce(&'b mut BoundVarContext<'c, 'tcx>),
     {
         let mut named_late_bound_vars = 0;
@@ -1106,7 +1102,7 @@ impl<'a, 'tcx> BoundVarContext<'a, 'tcx> {
         self.with(scope, walk);
     }
 
-    fn visit_early<F>(&mut self, hir_id: hir::HirId, generics: &'tcx hir::Generics<'tcx>, walk: F)
+    fn visit_early<F>(&mut self, hir_id: HirId, generics: &'tcx hir::Generics<'tcx>, walk: F)
     where
         F: for<'b, 'c> FnOnce(&'b mut BoundVarContext<'c, 'tcx>),
     {
@@ -1332,7 +1328,7 @@ impl<'a, 'tcx> BoundVarContext<'a, 'tcx> {
         );
     }
 
-    fn resolve_type_ref(&mut self, param_def_id: LocalDefId, hir_id: hir::HirId) {
+    fn resolve_type_ref(&mut self, param_def_id: LocalDefId, hir_id: HirId) {
         // Walk up the scope chain, tracking the number of fn scopes
         // that we pass through, until we find a lifetime with the
         // given name or we run out of scopes.

compiler/rustc_hir_analysis/src/hir_ty_lowering/mod.rs

@@ -35,7 +35,7 @@ use rustc_hir as hir;
 use rustc_hir::def::{CtorOf, DefKind, Namespace, Res};
 use rustc_hir::def_id::{DefId, LocalDefId};
 use rustc_hir::intravisit::{walk_generics, Visitor as _};
-use rustc_hir::{GenericArg, GenericArgs};
+use rustc_hir::{GenericArg, GenericArgs, HirId};
 use rustc_infer::infer::{InferCtxt, TyCtxtInferExt};
 use rustc_infer::traits::ObligationCause;
 use rustc_middle::middle::stability::AllowUnstable;
@@ -158,7 +158,7 @@ pub trait HirTyLowerer<'tcx> {
     fn probe_adt(&self, span: Span, ty: Ty<'tcx>) -> Option<ty::AdtDef<'tcx>>;
 
     /// Record the lowered type of a HIR node in this context.
-    fn record_ty(&self, hir_id: hir::HirId, ty: Ty<'tcx>, span: Span);
+    fn record_ty(&self, hir_id: HirId, ty: Ty<'tcx>, span: Span);
 
     /// The inference context of the lowering context if applicable.
     fn infcx(&self) -> Option<&InferCtxt<'tcx>>;
@@ -999,7 +999,7 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ {
     #[instrument(level = "debug", skip_all, ret)]
     pub fn lower_assoc_path(
         &self,
-        hir_ref_id: hir::HirId,
+        hir_ref_id: HirId,
         span: Span,
         qself_ty: Ty<'tcx>,
         qself: &'tcx hir::Ty<'tcx>,
@@ -1200,7 +1200,7 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ {
         segment: &hir::PathSegment<'tcx>,
         adt_did: DefId,
         self_ty: Ty<'tcx>,
-        block: hir::HirId,
+        block: HirId,
         span: Span,
     ) -> Result<Option<(Ty<'tcx>, DefId)>, ErrorGuaranteed> {
         let tcx = self.tcx();
@@ -1349,13 +1349,7 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ {
         }
     }
 
-    fn probe_assoc_ty(
-        &self,
-        name: Ident,
-        block: hir::HirId,
-        span: Span,
-        scope: DefId,
-    ) -> Option<DefId> {
+    fn probe_assoc_ty(&self, name: Ident, block: HirId, span: Span, scope: DefId) -> Option<DefId> {
         let (item, def_scope) = self.probe_assoc_ty_unchecked(name, block, scope)?;
         self.check_assoc_ty(item, name, def_scope, block, span);
         Some(item)
@@ -1364,7 +1358,7 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ {
     fn probe_assoc_ty_unchecked(
         &self,
         name: Ident,
-        block: hir::HirId,
+        block: HirId,
         scope: DefId,
     ) -> Option<(DefId, DefId)> {
         let tcx = self.tcx();
@@ -1381,14 +1375,7 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ {
         Some((item.def_id, def_scope))
     }
 
-    fn check_assoc_ty(
-        &self,
-        item: DefId,
-        name: Ident,
-        def_scope: DefId,
-        block: hir::HirId,
-        span: Span,
-    ) {
+    fn check_assoc_ty(&self, item: DefId, name: Ident, def_scope: DefId, block: HirId, span: Span) {
         let tcx = self.tcx();
         let kind = DefKind::AssocTy;
 
@@ -1714,7 +1701,7 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ {
         &self,
         opt_self_ty: Option<Ty<'tcx>>,
         path: &hir::Path<'tcx>,
-        hir_id: hir::HirId,
+        hir_id: HirId,
         permit_variants: bool,
     ) -> Ty<'tcx> {
         debug!(?path.res, ?opt_self_ty, ?path.segments);
@@ -1887,7 +1874,7 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ {
     ///
     /// Early-bound type parameters get lowered to [`ty::Param`]
     /// and late-bound ones to [`ty::Bound`].
-    pub(crate) fn lower_ty_param(&self, hir_id: hir::HirId) -> Ty<'tcx> {
+    pub(crate) fn lower_ty_param(&self, hir_id: HirId) -> Ty<'tcx> {
         let tcx = self.tcx();
         match tcx.named_bound_var(hir_id) {
             Some(rbv::ResolvedArg::LateBound(debruijn, index, def_id)) => {
@@ -1914,7 +1901,7 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ {
     ///
     /// Early-bound const parameters get lowered to [`ty::ConstKind::Param`]
     /// and late-bound ones to [`ty::ConstKind::Bound`].
-    pub(crate) fn lower_const_param(&self, hir_id: hir::HirId, param_ty: Ty<'tcx>) -> Const<'tcx> {
+    pub(crate) fn lower_const_param(&self, hir_id: HirId, param_ty: Ty<'tcx>) -> Const<'tcx> {
         let tcx = self.tcx();
         match tcx.named_bound_var(hir_id) {
             Some(rbv::ResolvedArg::EarlyBound(def_id)) => {
@@ -2341,7 +2328,7 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ {
     #[instrument(level = "debug", skip(self, hir_id, unsafety, abi, decl, generics, hir_ty), ret)]
     pub fn lower_fn_ty(
         &self,
-        hir_id: hir::HirId,
+        hir_id: HirId,
         unsafety: hir::Unsafety,
         abi: abi::Abi,
         decl: &hir::FnDecl<'tcx>,
@@ -2469,7 +2456,7 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ {
     /// corresponds to the return type.
     fn suggest_trait_fn_ty_for_impl_fn_infer(
         &self,
-        fn_hir_id: hir::HirId,
+        fn_hir_id: HirId,
         arg_idx: Option<usize>,
     ) -> Option<Ty<'tcx>> {
         let tcx = self.tcx();