fix: use LocalDefId instead of HirId in trait res

use LocalDefId instead of HirId in trait resolution to simplify
the obligation clause resolution

Signed-off-by: Vincenzo Palazzo <vincenzopalazzodev@gmail.com>

9 files changed, 60 insertions, 73 deletions

diff --git a/compiler/rustc_trait_selection/src/traits/coherence.rs b/compiler/rustc_trait_selection/src/traits/coherence.rs
index 225c1050c7c..ecee0bf7a6d 100644
--- a/compiler/rustc_trait_selection/src/traits/coherence.rs
+++ b/compiler/rustc_trait_selection/src/traits/coherence.rs
@@ -17,7 +17,6 @@ use crate::traits::{
 use rustc_data_structures::fx::FxIndexSet;
 use rustc_errors::Diagnostic;
 use rustc_hir::def_id::{DefId, CRATE_DEF_ID, LOCAL_CRATE};
-use rustc_hir::CRATE_HIR_ID;
 use rustc_infer::infer::{DefiningAnchor, InferCtxt, TyCtxtInferExt};
 use rustc_infer::traits::util;
 use rustc_middle::traits::specialization_graph::OverlapMode;
@@ -382,18 +381,14 @@ fn resolve_negative_obligation<'tcx>(
         return false;
     }
 
-    let (body_id, body_def_id) = if let Some(body_def_id) = body_def_id.as_local() {
-        (tcx.hir().local_def_id_to_hir_id(body_def_id), body_def_id)
-    } else {
-        (CRATE_HIR_ID, CRATE_DEF_ID)
-    };
+    let body_def_id = body_def_id.as_local().unwrap_or(CRATE_DEF_ID);
 
     let ocx = ObligationCtxt::new(&infcx);
     let wf_tys = ocx.assumed_wf_types(param_env, DUMMY_SP, body_def_id);
     let outlives_env = OutlivesEnvironment::with_bounds(
         param_env,
         Some(&infcx),
-        infcx.implied_bounds_tys(param_env, body_id, wf_tys),
+        infcx.implied_bounds_tys(param_env, body_def_id, wf_tys),
     );
 
     infcx.process_registered_region_obligations(outlives_env.region_bound_pairs(), param_env);
diff --git a/compiler/rustc_trait_selection/src/traits/engine.rs b/compiler/rustc_trait_selection/src/traits/engine.rs
index 369f80139a8..a2ddd91546c 100644
--- a/compiler/rustc_trait_selection/src/traits/engine.rs
+++ b/compiler/rustc_trait_selection/src/traits/engine.rs
@@ -190,8 +190,7 @@ impl<'a, 'tcx> ObligationCtxt<'a, 'tcx> {
         let tcx = self.infcx.tcx;
         let assumed_wf_types = tcx.assumed_wf_types(def_id);
         let mut implied_bounds = FxIndexSet::default();
-        let hir_id = tcx.hir().local_def_id_to_hir_id(def_id);
-        let cause = ObligationCause::misc(span, hir_id);
+        let cause = ObligationCause::misc(span, def_id);
         for ty in assumed_wf_types {
             // FIXME(@lcnr): rustc currently does not check wf for types
             // pre-normalization, meaning that implied bounds are sometimes
diff --git a/compiler/rustc_trait_selection/src/traits/error_reporting/ambiguity.rs b/compiler/rustc_trait_selection/src/traits/error_reporting/ambiguity.rs
index 0419bb3f724..6bf453c3ff0 100644
--- a/compiler/rustc_trait_selection/src/traits/error_reporting/ambiguity.rs
+++ b/compiler/rustc_trait_selection/src/traits/error_reporting/ambiguity.rs
@@ -81,7 +81,7 @@ pub fn recompute_applicable_impls<'tcx>(
     );
 
     let predicates =
-        tcx.predicates_of(obligation.cause.body_id.owner.to_def_id()).instantiate_identity(tcx);
+        tcx.predicates_of(obligation.cause.body_id.to_def_id()).instantiate_identity(tcx);
     for obligation in elaborate_predicates_with_span(tcx, predicates.into_iter()) {
         let kind = obligation.predicate.kind();
         if let ty::PredicateKind::Clause(ty::Clause::Trait(trait_pred)) = kind.skip_binder()
diff --git a/compiler/rustc_trait_selection/src/traits/error_reporting/mod.rs b/compiler/rustc_trait_selection/src/traits/error_reporting/mod.rs
index 52971486c55..aaeb3def06a 100644
--- a/compiler/rustc_trait_selection/src/traits/error_reporting/mod.rs
+++ b/compiler/rustc_trait_selection/src/traits/error_reporting/mod.rs
@@ -839,14 +839,7 @@ impl<'tcx> TypeErrCtxtExt<'tcx> for TypeErrCtxt<'_, 'tcx> {
                             err.note(s.as_str());
                         }
                         if let Some(ref s) = parent_label {
-                            let body = tcx
-                                .hir()
-                                .opt_local_def_id(obligation.cause.body_id)
-                                .unwrap_or_else(|| {
-                                    tcx.hir().body_owner_def_id(hir::BodyId {
-                                        hir_id: obligation.cause.body_id,
-                                    })
-                                });
+                            let body = obligation.cause.body_id;
                             err.span_label(tcx.def_span(body), s);
                         }
 
@@ -934,6 +927,8 @@ impl<'tcx> TypeErrCtxtExt<'tcx> for TypeErrCtxt<'_, 'tcx> {
                             );
                         }
 
+                        let body_hir_id =
+                            self.tcx.hir().local_def_id_to_hir_id(obligation.cause.body_id);
                         // Try to report a help message
                         if is_fn_trait
                             && let Ok((implemented_kind, params)) = self.type_implements_fn_trait(
@@ -1014,7 +1009,7 @@ impl<'tcx> TypeErrCtxtExt<'tcx> for TypeErrCtxt<'_, 'tcx> {
                             if !self.report_similar_impl_candidates(
                                 impl_candidates,
                                 trait_ref,
-                                obligation.cause.body_id,
+                                body_hir_id,
                                 &mut err,
                                 true,
                             ) {
@@ -1050,7 +1045,7 @@ impl<'tcx> TypeErrCtxtExt<'tcx> for TypeErrCtxt<'_, 'tcx> {
                                     self.report_similar_impl_candidates(
                                         impl_candidates,
                                         trait_ref,
-                                        obligation.cause.body_id,
+                                        body_hir_id,
                                         &mut err,
                                         true,
                                     );
@@ -2305,10 +2300,12 @@ impl<'tcx> InferCtxtPrivExt<'tcx> for TypeErrCtxt<'_, 'tcx> {
                                 predicate.to_opt_poly_trait_pred().unwrap(),
                             );
                             if impl_candidates.len() < 10 {
+                                let hir =
+                                    self.tcx.hir().local_def_id_to_hir_id(obligation.cause.body_id);
                                 self.report_similar_impl_candidates(
                                     impl_candidates,
                                     trait_ref,
-                                    body_id.map(|id| id.hir_id).unwrap_or(obligation.cause.body_id),
+                                    body_id.map(|id| id.hir_id).unwrap_or(hir),
                                     &mut err,
                                     false,
                                 );
diff --git a/compiler/rustc_trait_selection/src/traits/error_reporting/on_unimplemented.rs b/compiler/rustc_trait_selection/src/traits/error_reporting/on_unimplemented.rs
index 18d308f7123..a3209d35e58 100644
--- a/compiler/rustc_trait_selection/src/traits/error_reporting/on_unimplemented.rs
+++ b/compiler/rustc_trait_selection/src/traits/error_reporting/on_unimplemented.rs
@@ -149,10 +149,9 @@ impl<'tcx> TypeErrCtxtExt<'tcx> for TypeErrCtxt<'_, 'tcx> {
             .unwrap_or_else(|| (trait_ref.def_id(), trait_ref.skip_binder().substs));
         let trait_ref = trait_ref.skip_binder();
 
-        let mut flags = vec![(
-            sym::ItemContext,
-            self.describe_enclosure(obligation.cause.body_id).map(|s| s.to_owned()),
-        )];
+        let body_hir = self.tcx.hir().local_def_id_to_hir_id(obligation.cause.body_id);
+        let mut flags =
+            vec![(sym::ItemContext, self.describe_enclosure(body_hir).map(|s| s.to_owned()))];
 
         match obligation.cause.code() {
             ObligationCauseCode::BuiltinDerivedObligation(..)
diff --git a/compiler/rustc_trait_selection/src/traits/error_reporting/suggestions.rs b/compiler/rustc_trait_selection/src/traits/error_reporting/suggestions.rs
index 39e50b2accf..bf5e77e6ce1 100644
--- a/compiler/rustc_trait_selection/src/traits/error_reporting/suggestions.rs
+++ b/compiler/rustc_trait_selection/src/traits/error_reporting/suggestions.rs
@@ -9,7 +9,6 @@ use crate::infer::InferCtxt;
 use crate::traits::{NormalizeExt, ObligationCtxt};
 
 use hir::def::CtorOf;
-use hir::{Expr, HirId};
 use rustc_data_structures::fx::FxHashSet;
 use rustc_data_structures::stack::ensure_sufficient_stack;
 use rustc_errors::{
@@ -22,6 +21,7 @@ use rustc_hir::def_id::DefId;
 use rustc_hir::intravisit::Visitor;
 use rustc_hir::lang_items::LangItem;
 use rustc_hir::{AsyncGeneratorKind, GeneratorKind, Node};
+use rustc_hir::{Expr, HirId};
 use rustc_infer::infer::error_reporting::TypeErrCtxt;
 use rustc_infer::infer::type_variable::{TypeVariableOrigin, TypeVariableOriginKind};
 use rustc_infer::infer::{InferOk, LateBoundRegionConversionTime};
@@ -34,6 +34,7 @@ use rustc_middle::ty::{
     IsSuggestable, ToPredicate, Ty, TyCtxt, TypeAndMut, TypeFoldable, TypeFolder,
     TypeSuperFoldable, TypeVisitable, TypeckResults,
 };
+use rustc_span::def_id::LocalDefId;
 use rustc_span::symbol::{sym, Ident, Symbol};
 use rustc_span::{BytePos, DesugaringKind, ExpnKind, MacroKind, Span, DUMMY_SP};
 use rustc_target::spec::abi;
@@ -179,7 +180,7 @@ pub trait TypeErrCtxtExt<'tcx> {
         err: &mut Diagnostic,
         trait_pred: ty::PolyTraitPredicate<'tcx>,
         associated_item: Option<(&'static str, Ty<'tcx>)>,
-        body_id: hir::HirId,
+        body_id: LocalDefId,
     );
 
     fn suggest_dereferences(
@@ -522,7 +523,7 @@ impl<'tcx> TypeErrCtxtExt<'tcx> for TypeErrCtxt<'_, 'tcx> {
         mut err: &mut Diagnostic,
         trait_pred: ty::PolyTraitPredicate<'tcx>,
         associated_ty: Option<(&'static str, Ty<'tcx>)>,
-        body_id: hir::HirId,
+        body_id: LocalDefId,
     ) {
         let trait_pred = self.resolve_numeric_literals_with_default(trait_pred);
 
@@ -535,8 +536,9 @@ impl<'tcx> TypeErrCtxtExt<'tcx> for TypeErrCtxt<'_, 'tcx> {
 
         // FIXME: Add check for trait bound that is already present, particularly `?Sized` so we
         //        don't suggest `T: Sized + ?Sized`.
-        let mut hir_id = body_id;
-        while let Some(node) = self.tcx.hir().find(hir_id) {
+        let mut body_id = body_id;
+        while let Some(node) = self.tcx.hir().find_by_def_id(body_id) {
+            let hir_id = self.tcx.hir().local_def_id_to_hir_id(body_id);
             match node {
                 hir::Node::Item(hir::Item {
                     ident,
@@ -713,8 +715,7 @@ impl<'tcx> TypeErrCtxtExt<'tcx> for TypeErrCtxt<'_, 'tcx> {
 
                 _ => {}
             }
-
-            hir_id = self.tcx.hir().get_parent_item(hir_id).into();
+            body_id = self.tcx.local_parent(body_id);
         }
     }
 
@@ -905,8 +906,9 @@ impl<'tcx> TypeErrCtxtExt<'tcx> for TypeErrCtxt<'_, 'tcx> {
             trait_pred.self_ty(),
         );
 
+        let body_hir_id = self.tcx.hir().local_def_id_to_hir_id(obligation.cause.body_id);
         let Some((def_id_or_name, output, inputs)) = self.extract_callable_info(
-            obligation.cause.body_id,
+            body_hir_id,
             obligation.param_env,
             self_ty,
         ) else { return false; };
@@ -1004,8 +1006,9 @@ impl<'tcx> TypeErrCtxtExt<'tcx> for TypeErrCtxt<'_, 'tcx> {
             span.remove_mark();
         }
         let mut expr_finder = FindExprBySpan::new(span);
-        let Some(hir::Node::Expr(body)) = self.tcx.hir().find(obligation.cause.body_id) else { return; };
-        expr_finder.visit_expr(&body);
+        let Some(body_id) = self.tcx.hir().maybe_body_owned_by(obligation.cause.body_id) else { return; };
+        let body = self.tcx.hir().body(body_id);
+        expr_finder.visit_expr(body.value);
         let Some(expr) = expr_finder.result else { return; };
         let Some(typeck) = &self.typeck_results else { return; };
         let Some(ty) = typeck.expr_ty_adjusted_opt(expr) else { return; };
@@ -1060,8 +1063,7 @@ impl<'tcx> TypeErrCtxtExt<'tcx> for TypeErrCtxt<'_, 'tcx> {
     ) -> bool {
         let self_ty = self.resolve_vars_if_possible(trait_pred.self_ty());
         let ty = self.tcx.erase_late_bound_regions(self_ty);
-        let owner = self.tcx.hir().get_parent_item(obligation.cause.body_id);
-        let Some(generics) = self.tcx.hir().get_generics(owner.def_id) else { return false };
+        let Some(generics) = self.tcx.hir().get_generics(obligation.cause.body_id) else { return false };
         let ty::Ref(_, inner_ty, hir::Mutability::Not) = ty.kind() else { return false };
         let ty::Param(param) = inner_ty.kind() else { return false };
         let ObligationCauseCode::FunctionArgumentObligation { arg_hir_id, .. } = obligation.cause.code() else { return false };
@@ -1104,6 +1106,7 @@ impl<'tcx> TypeErrCtxtExt<'tcx> for TypeErrCtxt<'_, 'tcx> {
     /// Extracts information about a callable type for diagnostics. This is a
     /// heuristic -- it doesn't necessarily mean that a type is always callable,
     /// because the callable type must also be well-formed to be called.
+    // FIXME(vincenzopalazzo): move the HirId to a LocalDefId
     fn extract_callable_info(
         &self,
         hir_id: HirId,
@@ -1429,10 +1432,11 @@ impl<'tcx> TypeErrCtxtExt<'tcx> for TypeErrCtxt<'_, 'tcx> {
             span.remove_mark();
         }
         let mut expr_finder = super::FindExprBySpan::new(span);
-        let Some(hir::Node::Expr(body)) = self.tcx.hir().find(obligation.cause.body_id) else {
+        let Some(body_id) = self.tcx.hir().maybe_body_owned_by(obligation.cause.body_id) else {
             return false;
         };
-        expr_finder.visit_expr(&body);
+        let body = self.tcx.hir().body(body_id);
+        expr_finder.visit_expr(body.value);
         let mut maybe_suggest = |suggested_ty, count, suggestions| {
             // Remapping bound vars here
             let trait_pred_and_suggested_ty =
@@ -1670,8 +1674,7 @@ impl<'tcx> TypeErrCtxtExt<'tcx> for TypeErrCtxt<'_, 'tcx> {
         trait_pred: ty::PolyTraitPredicate<'tcx>,
     ) -> bool {
         let hir = self.tcx.hir();
-        let parent_node = hir.parent_id(obligation.cause.body_id);
-        let node = hir.find(parent_node);
+        let node = hir.find_by_def_id(obligation.cause.body_id);
         if let Some(hir::Node::Item(hir::Item { kind: hir::ItemKind::Fn(sig, _, body_id), .. })) = node
             && let hir::ExprKind::Block(blk, _) = &hir.body(*body_id).value.kind
             && sig.decl.output.span().overlaps(span)
@@ -1707,8 +1710,7 @@ impl<'tcx> TypeErrCtxtExt<'tcx> for TypeErrCtxt<'_, 'tcx> {
 
     fn return_type_span(&self, obligation: &PredicateObligation<'tcx>) -> Option<Span> {
         let hir = self.tcx.hir();
-        let parent_node = hir.parent_id(obligation.cause.body_id);
-        let Some(hir::Node::Item(hir::Item { kind: hir::ItemKind::Fn(sig, ..), .. })) = hir.find(parent_node) else {
+        let Some(hir::Node::Item(hir::Item { kind: hir::ItemKind::Fn(sig, ..), .. })) = hir.find_by_def_id(obligation.cause.body_id) else {
             return None;
         };
 
@@ -1732,8 +1734,8 @@ impl<'tcx> TypeErrCtxtExt<'tcx> for TypeErrCtxt<'_, 'tcx> {
         }
 
         let hir = self.tcx.hir();
-        let fn_hir_id = hir.parent_id(obligation.cause.body_id);
-        let node = hir.find(fn_hir_id);
+        let fn_hir_id = hir.local_def_id_to_hir_id(obligation.cause.body_id);
+        let node = hir.find_by_def_id(obligation.cause.body_id);
         let Some(hir::Node::Item(hir::Item {
             kind: hir::ItemKind::Fn(sig, _, body_id),
             ..
@@ -1806,7 +1808,7 @@ impl<'tcx> TypeErrCtxtExt<'tcx> for TypeErrCtxt<'_, 'tcx> {
 
         match liberated_sig.output().kind() {
             ty::Dynamic(predicates, _, ty::Dyn) => {
-                let cause = ObligationCause::misc(ret_ty.span, fn_hir_id);
+                let cause = ObligationCause::misc(ret_ty.span, obligation.cause.body_id);
                 let param_env = ty::ParamEnv::empty();
 
                 if !only_never_return {
@@ -1944,8 +1946,7 @@ impl<'tcx> TypeErrCtxtExt<'tcx> for TypeErrCtxt<'_, 'tcx> {
         }
 
         let hir = self.tcx.hir();
-        let parent_node = hir.parent_id(obligation.cause.body_id);
-        let node = hir.find(parent_node);
+        let node = hir.find_by_def_id(obligation.cause.body_id);
         if let Some(hir::Node::Item(hir::Item { kind: hir::ItemKind::Fn(_, _, body_id), .. })) =
             node
         {
@@ -3283,12 +3284,7 @@ impl<'tcx> TypeErrCtxtExt<'tcx> for TypeErrCtxt<'_, 'tcx> {
         trait_pred: ty::PolyTraitPredicate<'tcx>,
         span: Span,
     ) {
-        let body_hir_id = obligation.cause.body_id;
-        let item_id = self.tcx.hir().parent_id(body_hir_id);
-
-        if let Some(body_id) =
-            self.tcx.hir().maybe_body_owned_by(self.tcx.hir().local_def_id(item_id))
-        {
+        if let Some(body_id) = self.tcx.hir().maybe_body_owned_by(obligation.cause.body_id) {
             let body = self.tcx.hir().body(body_id);
             if let Some(hir::GeneratorKind::Async(_)) = body.generator_kind {
                 let future_trait = self.tcx.require_lang_item(LangItem::Future, None);
@@ -3727,9 +3723,14 @@ impl<'tcx> TypeErrCtxtExt<'tcx> for TypeErrCtxt<'_, 'tcx> {
                     term: ty_var.into(),
                 },
             )));
+            let body_def_id = self.tcx.hir().enclosing_body_owner(body_id);
             // Add `<ExprTy as Iterator>::Item = _` obligation.
             ocx.register_obligation(Obligation::misc(
-                self.tcx, span, body_id, param_env, projection,
+                self.tcx,
+                span,
+                body_def_id,
+                param_env,
+                projection,
             ));
             if ocx.select_where_possible().is_empty() {
                 // `ty_var` now holds the type that `Item` is for `ExprTy`.
diff --git a/compiler/rustc_trait_selection/src/traits/mod.rs b/compiler/rustc_trait_selection/src/traits/mod.rs
index 3c640cdc503..83458017e00 100644
--- a/compiler/rustc_trait_selection/src/traits/mod.rs
+++ b/compiler/rustc_trait_selection/src/traits/mod.rs
@@ -26,12 +26,11 @@ use crate::infer::{InferCtxt, TyCtxtInferExt};
 use crate::traits::error_reporting::TypeErrCtxtExt as _;
 use crate::traits::query::evaluate_obligation::InferCtxtExt as _;
 use rustc_errors::ErrorGuaranteed;
-use rustc_hir as hir;
-use rustc_hir::def_id::DefId;
 use rustc_middle::ty::fold::TypeFoldable;
 use rustc_middle::ty::visit::TypeVisitable;
 use rustc_middle::ty::{self, DefIdTree, ToPredicate, Ty, TyCtxt, TypeSuperVisitable};
 use rustc_middle::ty::{InternalSubsts, SubstsRef};
+use rustc_span::def_id::{DefId, CRATE_DEF_ID};
 use rustc_span::Span;
 
 use std::fmt::Debug;
@@ -151,7 +150,7 @@ fn pred_known_to_hold_modulo_regions<'tcx>(
         // We can use a dummy node-id here because we won't pay any mind
         // to region obligations that arise (there shouldn't really be any
         // anyhow).
-        cause: ObligationCause::misc(span, hir::CRATE_HIR_ID),
+        cause: ObligationCause::misc(span, CRATE_DEF_ID),
         recursion_depth: 0,
         predicate: pred.to_predicate(infcx.tcx),
     };
@@ -166,14 +165,12 @@ fn pred_known_to_hold_modulo_regions<'tcx>(
         // that guess. While imperfect, I believe this is sound.
 
         // FIXME(@lcnr): this function doesn't seem right.
+        //
         // The handling of regions in this area of the code is terrible,
         // see issue #29149. We should be able to improve on this with
         // NLL.
         let errors = fully_solve_obligation(infcx, obligation);
 
-        // Note: we only assume something is `Copy` if we can
-        // *definitively* show that it implements `Copy`. Otherwise,
-        // assume it is move; linear is always ok.
         match &errors[..] {
             [] => true,
             errors => {
diff --git a/compiler/rustc_trait_selection/src/traits/outlives_bounds.rs b/compiler/rustc_trait_selection/src/traits/outlives_bounds.rs
index f2c5f730b31..6cb64ad574f 100644
--- a/compiler/rustc_trait_selection/src/traits/outlives_bounds.rs
+++ b/compiler/rustc_trait_selection/src/traits/outlives_bounds.rs
@@ -3,9 +3,8 @@ use crate::traits::query::type_op::{self, TypeOp, TypeOpOutput};
 use crate::traits::query::NoSolution;
 use crate::traits::ObligationCause;
 use rustc_data_structures::fx::FxIndexSet;
-use rustc_hir as hir;
-use rustc_hir::HirId;
 use rustc_middle::ty::{self, ParamEnv, Ty};
+use rustc_span::def_id::LocalDefId;
 
 pub use rustc_middle::traits::query::OutlivesBound;
 
@@ -14,14 +13,14 @@ pub trait InferCtxtExt<'a, 'tcx> {
     fn implied_outlives_bounds(
         &self,
         param_env: ty::ParamEnv<'tcx>,
-        body_id: hir::HirId,
+        body_id: LocalDefId,
         ty: Ty<'tcx>,
     ) -> Vec<OutlivesBound<'tcx>>;
 
     fn implied_bounds_tys(
         &'a self,
         param_env: ty::ParamEnv<'tcx>,
-        body_id: hir::HirId,
+        body_id: LocalDefId,
         tys: FxIndexSet<Ty<'tcx>>,
     ) -> Bounds<'a, 'tcx>;
 }
@@ -50,10 +49,10 @@ impl<'a, 'tcx: 'a> InferCtxtExt<'a, 'tcx> for InferCtxt<'tcx> {
     fn implied_outlives_bounds(
         &self,
         param_env: ty::ParamEnv<'tcx>,
-        body_id: hir::HirId,
+        body_id: LocalDefId,
         ty: Ty<'tcx>,
     ) -> Vec<OutlivesBound<'tcx>> {
-        let span = self.tcx.hir().span(body_id);
+        let span = self.tcx.def_span(body_id);
         let result = param_env
             .and(type_op::implied_outlives_bounds::ImpliedOutlivesBounds { ty })
             .fully_perform(self);
@@ -102,7 +101,7 @@ impl<'a, 'tcx: 'a> InferCtxtExt<'a, 'tcx> for InferCtxt<'tcx> {
     fn implied_bounds_tys(
         &'a self,
         param_env: ParamEnv<'tcx>,
-        body_id: HirId,
+        body_id: LocalDefId,
         tys: FxIndexSet<Ty<'tcx>>,
     ) -> Bounds<'a, 'tcx> {
         tys.into_iter()
diff --git a/compiler/rustc_trait_selection/src/traits/wf.rs b/compiler/rustc_trait_selection/src/traits/wf.rs
index 12d4cb4fc69..d9556848099 100644
--- a/compiler/rustc_trait_selection/src/traits/wf.rs
+++ b/compiler/rustc_trait_selection/src/traits/wf.rs
@@ -1,10 +1,10 @@
 use crate::infer::InferCtxt;
 use crate::traits;
 use rustc_hir as hir;
-use rustc_hir::def_id::DefId;
 use rustc_hir::lang_items::LangItem;
 use rustc_middle::ty::subst::{GenericArg, GenericArgKind, SubstsRef};
 use rustc_middle::ty::{self, Ty, TyCtxt, TypeVisitable};
+use rustc_span::def_id::{DefId, LocalDefId};
 use rustc_span::Span;
 
 use std::iter;
@@ -17,7 +17,7 @@ use std::iter;
 pub fn obligations<'tcx>(
     infcx: &InferCtxt<'tcx>,
     param_env: ty::ParamEnv<'tcx>,
-    body_id: hir::HirId,
+    body_id: LocalDefId,
     recursion_depth: usize,
     arg: GenericArg<'tcx>,
     span: Span,
@@ -82,7 +82,7 @@ pub fn obligations<'tcx>(
 pub fn trait_obligations<'tcx>(
     infcx: &InferCtxt<'tcx>,
     param_env: ty::ParamEnv<'tcx>,
-    body_id: hir::HirId,
+    body_id: LocalDefId,
     trait_pred: &ty::TraitPredicate<'tcx>,
     span: Span,
     item: &'tcx hir::Item<'tcx>,
@@ -105,7 +105,7 @@ pub fn trait_obligations<'tcx>(
 pub fn predicate_obligations<'tcx>(
     infcx: &InferCtxt<'tcx>,
     param_env: ty::ParamEnv<'tcx>,
-    body_id: hir::HirId,
+    body_id: LocalDefId,
     predicate: ty::Predicate<'tcx>,
     span: Span,
 ) -> Vec<traits::PredicateObligation<'tcx>> {
@@ -167,7 +167,7 @@ pub fn predicate_obligations<'tcx>(
 struct WfPredicates<'tcx> {
     tcx: TyCtxt<'tcx>,
     param_env: ty::ParamEnv<'tcx>,
-    body_id: hir::HirId,
+    body_id: LocalDefId,
     span: Span,
     out: Vec<traits::PredicateObligation<'tcx>>,
     recursion_depth: usize,