Move supertrait_def_ids into the elaborate module like all other fns

compiler/rustc_borrowck/src/diagnostics/conflict_errors.rs

@@ -39,7 +39,9 @@ use rustc_trait_selection::error_reporting::traits::FindExprBySpan;
 use rustc_trait_selection::error_reporting::traits::call_kind::CallKind;
 use rustc_trait_selection::infer::InferCtxtExt;
 use rustc_trait_selection::traits::query::evaluate_obligation::InferCtxtExt as _;
-use rustc_trait_selection::traits::{Obligation, ObligationCause, ObligationCtxt};
+use rustc_trait_selection::traits::{
+    Obligation, ObligationCause, ObligationCtxt, supertrait_def_ids,
+};
 use tracing::{debug, instrument};
 
 use super::explain_borrow::{BorrowExplanation, LaterUseKind};
@@ -658,8 +660,7 @@ impl<'infcx, 'tcx> MirBorrowckCtxt<'_, 'infcx, 'tcx> {
             clause.as_trait_clause().is_some_and(|tc| {
                 tc.self_ty().skip_binder().is_param(param.index)
                     && tc.polarity() == ty::PredicatePolarity::Positive
-                    && tcx
-                        .supertrait_def_ids(tc.def_id())
+                    && supertrait_def_ids(tcx, tc.def_id())
                         .flat_map(|trait_did| tcx.associated_items(trait_did).in_definition_order())
                         .any(|item| item.fn_has_self_parameter)
             })

compiler/rustc_hir_analysis/src/coherence/mod.rs

@@ -13,6 +13,7 @@ use rustc_middle::query::Providers;
 use rustc_middle::ty::{self, TyCtxt, TypeVisitableExt};
 use rustc_session::parse::feature_err;
 use rustc_span::{ErrorGuaranteed, sym};
+use rustc_type_ir::elaborate;
 use tracing::debug;
 
 use crate::errors;
@@ -205,7 +206,7 @@ fn check_object_overlap<'tcx>(
                 // With the feature enabled, the trait is not implemented automatically,
                 // so this is valid.
             } else {
-                let mut supertrait_def_ids = tcx.supertrait_def_ids(component_def_id);
+                let mut supertrait_def_ids = elaborate::supertrait_def_ids(tcx, component_def_id);
                 if supertrait_def_ids
                     .any(|d| d == trait_def_id && tcx.trait_def(d).implement_via_object)
                 {

compiler/rustc_hir_typeck/src/cast.rs

@@ -45,6 +45,7 @@ use rustc_session::lint;
 use rustc_span::def_id::LOCAL_CRATE;
 use rustc_span::{DUMMY_SP, Span, sym};
 use rustc_trait_selection::infer::InferCtxtExt;
+use rustc_type_ir::elaborate;
 use tracing::{debug, instrument};
 
 use super::FnCtxt;
@@ -923,7 +924,7 @@ impl<'a, 'tcx> CastCheck<'tcx> {
                         let src_auto: FxHashSet<_> = src_tty
                             .auto_traits()
                             .chain(
-                                tcx.supertrait_def_ids(src_principal.def_id())
+                                elaborate::supertrait_def_ids(tcx, src_principal.def_id())
                                     .filter(|def_id| tcx.trait_is_auto(*def_id)),
                             )
                             .collect();

compiler/rustc_middle/src/ty/context.rs

@@ -52,7 +52,9 @@ use rustc_type_ir::TyKind::*;
 use rustc_type_ir::fold::TypeFoldable;
 use rustc_type_ir::lang_items::TraitSolverLangItem;
 pub use rustc_type_ir::lift::Lift;
-use rustc_type_ir::{CollectAndApply, Interner, TypeFlags, WithCachedTypeInfo, search_graph};
+use rustc_type_ir::{
+    CollectAndApply, Interner, TypeFlags, WithCachedTypeInfo, elaborate, search_graph,
+};
 use tracing::{debug, instrument};
 
 use crate::arena::Arena;
@@ -2558,7 +2560,7 @@ impl<'tcx> TyCtxt<'tcx> {
     /// Given the def_id of a Trait `trait_def_id` and the name of an associated item `assoc_name`
     /// returns true if the `trait_def_id` defines an associated item of name `assoc_name`.
     pub fn trait_may_define_assoc_item(self, trait_def_id: DefId, assoc_name: Ident) -> bool {
-        self.supertrait_def_ids(trait_def_id).any(|trait_did| {
+        elaborate::supertrait_def_ids(self, trait_def_id).any(|trait_did| {
             self.associated_items(trait_did)
                 .filter_by_name_unhygienic(assoc_name.name)
                 .any(|item| self.hygienic_eq(assoc_name, item.ident(self), trait_did))
@@ -2579,14 +2581,6 @@ impl<'tcx> TyCtxt<'tcx> {
         })
     }
 
-    /// Computes the def-ids of the transitive supertraits of `trait_def_id`. This (intentionally)
-    /// does not compute the full elaborated super-predicates but just the set of def-ids. It is used
-    /// to identify which traits may define a given associated type to help avoid cycle errors,
-    /// and to make size estimates for vtable layout computation.
-    pub fn supertrait_def_ids(self, trait_def_id: DefId) -> impl Iterator<Item = DefId> + 'tcx {
-        rustc_type_ir::elaborate::supertrait_def_ids(self, trait_def_id)
-    }
-
     /// Given a closure signature, returns an equivalent fn signature. Detuples
     /// and so forth -- so e.g., if we have a sig with `Fn<(u32, i32)>` then
     /// you would get a `fn(u32, i32)`.

compiler/rustc_middle/src/ty/vtable.rs

@@ -2,6 +2,7 @@ use std::fmt;
 
 use rustc_ast::Mutability;
 use rustc_macros::HashStable;
+use rustc_type_ir::elaborate;
 
 use crate::mir::interpret::{AllocId, Allocation, CTFE_ALLOC_SALT, Pointer, Scalar, alloc_range};
 use crate::ty::{self, Instance, PolyTraitRef, Ty, TyCtxt};
@@ -64,7 +65,7 @@ pub(crate) fn vtable_min_entries<'tcx>(
     };
 
     // This includes self in supertraits.
-    for def_id in tcx.supertrait_def_ids(trait_ref.def_id()) {
+    for def_id in elaborate::supertrait_def_ids(tcx, trait_ref.def_id()) {
         count += tcx.own_existential_vtable_entries(def_id).len();
     }
 

compiler/rustc_trait_selection/src/traits/dyn_compatibility.rs

@@ -19,6 +19,7 @@ use rustc_middle::ty::{
     TypeVisitableExt, TypeVisitor, TypingMode, Upcast,
 };
 use rustc_span::Span;
+use rustc_type_ir::elaborate;
 use smallvec::SmallVec;
 use tracing::{debug, instrument};
 
@@ -39,7 +40,7 @@ pub fn hir_ty_lowering_dyn_compatibility_violations(
     trait_def_id: DefId,
 ) -> Vec<DynCompatibilityViolation> {
     debug_assert!(tcx.generics_of(trait_def_id).has_self);
-    tcx.supertrait_def_ids(trait_def_id)
+    elaborate::supertrait_def_ids(tcx, trait_def_id)
         .map(|def_id| predicates_reference_self(tcx, def_id, true))
         .filter(|spans| !spans.is_empty())
         .map(DynCompatibilityViolation::SupertraitSelf)
@@ -54,7 +55,7 @@ fn dyn_compatibility_violations(
     debug!("dyn_compatibility_violations: {:?}", trait_def_id);
 
     tcx.arena.alloc_from_iter(
-        tcx.supertrait_def_ids(trait_def_id)
+        elaborate::supertrait_def_ids(tcx, trait_def_id)
             .flat_map(|def_id| dyn_compatibility_violations_for_trait(tcx, def_id)),
     )
 }

compiler/rustc_trait_selection/src/traits/mod.rs

@@ -67,7 +67,7 @@ pub use self::specialize::{
 pub use self::structural_normalize::StructurallyNormalizeExt;
 pub use self::util::{
     BoundVarReplacer, PlaceholderReplacer, TraitAliasExpander, TraitAliasExpansionInfo, elaborate,
-    expand_trait_aliases, impl_item_is_final, supertraits,
+    expand_trait_aliases, impl_item_is_final, supertrait_def_ids, supertraits,
     transitive_bounds_that_define_assoc_item, upcast_choices, with_replaced_escaping_bound_vars,
 };
 use crate::error_reporting::InferCtxtErrorExt;

compiler/rustc_trait_selection/src/traits/project.rs

@@ -18,6 +18,7 @@ use rustc_middle::ty::visit::TypeVisitableExt;
 use rustc_middle::ty::{self, Term, Ty, TyCtxt, TypingMode, Upcast};
 use rustc_middle::{bug, span_bug};
 use rustc_span::sym;
+use rustc_type_ir::elaborate;
 use thin_vec::thin_vec;
 use tracing::{debug, instrument};
 
@@ -836,8 +837,7 @@ fn assemble_candidates_from_object_ty<'cx, 'tcx>(
     if tcx.is_impl_trait_in_trait(obligation.predicate.def_id)
         && let Some(out_trait_def_id) = data.principal_def_id()
         && let rpitit_trait_def_id = tcx.parent(obligation.predicate.def_id)
-        && tcx
-            .supertrait_def_ids(out_trait_def_id)
+        && elaborate::supertrait_def_ids(tcx, out_trait_def_id)
             .any(|trait_def_id| trait_def_id == rpitit_trait_def_id)
     {
         candidate_set.push_candidate(ProjectionCandidate::ObjectRpitit);

compiler/rustc_trait_selection/src/traits/select/candidate_assembly.rs

@@ -18,7 +18,7 @@ use rustc_infer::traits::{
 use rustc_middle::ty::fast_reject::DeepRejectCtxt;
 use rustc_middle::ty::{self, ToPolyTraitRef, Ty, TypeVisitableExt, TypingMode};
 use rustc_middle::{bug, span_bug};
-use rustc_type_ir::Interner;
+use rustc_type_ir::{Interner, elaborate};
 use tracing::{debug, instrument, trace};
 
 use super::SelectionCandidate::*;
@@ -1002,8 +1002,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
                     let a_auto_traits: FxIndexSet<DefId> = a_data
                         .auto_traits()
                         .chain(principal_def_id_a.into_iter().flat_map(|principal_def_id| {
-                            self.tcx()
-                                .supertrait_def_ids(principal_def_id)
+                            elaborate::supertrait_def_ids(self.tcx(), principal_def_id)
                                 .filter(|def_id| self.tcx().trait_is_auto(*def_id))
                         }))
                         .collect();

compiler/rustc_trait_selection/src/traits/select/mod.rs

@@ -32,6 +32,7 @@ use rustc_middle::ty::{
     TypingMode, Upcast,
 };
 use rustc_span::{Symbol, sym};
+use rustc_type_ir::elaborate;
 use tracing::{debug, instrument, trace};
 
 use self::EvaluationResult::*;
@@ -2531,7 +2532,8 @@ impl<'tcx> SelectionContext<'_, 'tcx> {
         let a_auto_traits: FxIndexSet<DefId> = a_data
             .auto_traits()
             .chain(a_data.principal_def_id().into_iter().flat_map(|principal_def_id| {
-                tcx.supertrait_def_ids(principal_def_id).filter(|def_id| tcx.trait_is_auto(*def_id))
+                elaborate::supertrait_def_ids(tcx, principal_def_id)
+                    .filter(|def_id| tcx.trait_is_auto(*def_id))
             }))
             .collect();
 

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

@@ -18,6 +18,7 @@ use rustc_session::declare_lint_pass;
 use rustc_span::source_map::Spanned;
 use rustc_span::symbol::sym;
 use rustc_span::{Span, Symbol};
+use rustc_trait_selection::traits::supertrait_def_ids;
 
 declare_clippy_lint! {
     /// ### What it does
@@ -270,7 +271,7 @@ fn check_trait_items(cx: &LateContext<'_>, visited_trait: &Item<'_>, trait_items
     // fill the set with current and super traits
     fn fill_trait_set(traitt: DefId, set: &mut DefIdSet, cx: &LateContext<'_>) {
         if set.insert(traitt) {
-            for supertrait in cx.tcx.supertrait_def_ids(traitt) {
+            for supertrait in supertrait_def_ids(cx.tcx, traitt) {
                 fill_trait_set(supertrait, set, cx);
             }
         }