Auto merge of #103902 - vincenzopalazzo:macros/obligation_rulesv2, r=oli-obk

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

This commit introduces a refactoring suggested by `@lcnr` to simplify the obligation clause resolution.

This is just the first PR that introduces a type of refactoring, but others PRs will follow this to introduce name changing to change from the variable name from `body_id` to something else.

Fixes #104827

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

`@rustbot` r? `@lcnr`

Author: bors

compiler/rustc_borrowck/src/diagnostics/conflict_errors.rs

@@ -766,7 +766,7 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> {
         let copy_did = infcx.tcx.require_lang_item(LangItem::Copy, Some(span));
         let cause = ObligationCause::new(
             span,
-            self.mir_hir_id(),
+            self.mir_def_id(),
             rustc_infer::traits::ObligationCauseCode::MiscObligation,
         );
         let errors = rustc_trait_selection::traits::fully_solve_bound(

compiler/rustc_borrowck/src/region_infer/mod.rs

@@ -7,7 +7,6 @@ use rustc_data_structures::fx::{FxHashMap, FxHashSet};
 use rustc_data_structures::graph::scc::Sccs;
 use rustc_errors::Diagnostic;
 use rustc_hir::def_id::CRATE_DEF_ID;
-use rustc_hir::CRATE_HIR_ID;
 use rustc_index::vec::IndexVec;
 use rustc_infer::infer::outlives::test_type_match;
 use rustc_infer::infer::region_constraints::{GenericKind, VarInfos, VerifyBound, VerifyIfEq};
@@ -2022,7 +2021,7 @@ impl<'tcx> RegionInferenceContext<'tcx> {
             .map(|constraint| BlameConstraint {
                 category: constraint.category,
                 from_closure: constraint.from_closure,
-                cause: ObligationCause::new(constraint.span, CRATE_HIR_ID, cause_code.clone()),
+                cause: ObligationCause::new(constraint.span, CRATE_DEF_ID, cause_code.clone()),
                 variance_info: constraint.variance_info,
                 outlives_constraint: *constraint,
             })

compiler/rustc_borrowck/src/region_infer/opaque_types.rs

@@ -273,7 +273,6 @@ impl<'tcx> InferCtxtExt<'tcx> for InferCtxt<'tcx> {
         // This logic duplicates most of `check_opaque_meets_bounds`.
         // FIXME(oli-obk): Also do region checks here and then consider removing `check_opaque_meets_bounds` entirely.
         let param_env = self.tcx.param_env(def_id);
-        let body_id = self.tcx.local_def_id_to_hir_id(def_id);
         // HACK This bubble is required for this tests to pass:
         // type-alias-impl-trait/issue-67844-nested-opaque.rs
         let infcx =
@@ -290,15 +289,15 @@ impl<'tcx> InferCtxtExt<'tcx> for InferCtxt<'tcx> {
         // the bounds that the function supplies.
         let opaque_ty = self.tcx.mk_opaque(def_id.to_def_id(), id_substs);
         if let Err(err) = ocx.eq(
-            &ObligationCause::misc(instantiated_ty.span, body_id),
+            &ObligationCause::misc(instantiated_ty.span, def_id),
             param_env,
             opaque_ty,
             definition_ty,
         ) {
             infcx
                 .err_ctxt()
                 .report_mismatched_types(
-                    &ObligationCause::misc(instantiated_ty.span, body_id),
+                    &ObligationCause::misc(instantiated_ty.span, def_id),
                     opaque_ty,
                     definition_ty,
                     err,
@@ -309,7 +308,7 @@ impl<'tcx> InferCtxtExt<'tcx> for InferCtxt<'tcx> {
         ocx.register_obligation(Obligation::misc(
             infcx.tcx,
             instantiated_ty.span,
-            body_id,
+            def_id,
             param_env,
             predicate,
         ));

compiler/rustc_const_eval/src/transform/check_consts/check.rs

@@ -754,12 +754,9 @@ impl<'tcx> Visitor<'tcx> for Checker<'_, 'tcx> {
                         let ocx = ObligationCtxt::new(&infcx);
 
                         let predicates = tcx.predicates_of(callee).instantiate(tcx, substs);
-                        let hir_id = tcx
-                            .hir()
-                            .local_def_id_to_hir_id(self.body.source.def_id().expect_local());
                         let cause = ObligationCause::new(
                             terminator.source_info.span,
-                            hir_id,
+                            self.body.source.def_id().expect_local(),
                             ObligationCauseCode::ItemObligation(callee),
                         );
                         let normalized_predicates = ocx.normalize(&cause, param_env, predicates);

compiler/rustc_hir_analysis/src/autoderef.rs

@@ -2,11 +2,11 @@ use crate::errors::AutoDerefReachedRecursionLimit;
 use crate::traits::query::evaluate_obligation::InferCtxtExt;
 use crate::traits::NormalizeExt;
 use crate::traits::{self, TraitEngine, TraitEngineExt};
-use rustc_hir as hir;
 use rustc_infer::infer::InferCtxt;
 use rustc_middle::ty::TypeVisitable;
 use rustc_middle::ty::{self, Ty, TyCtxt};
 use rustc_session::Limit;
+use rustc_span::def_id::LocalDefId;
 use rustc_span::def_id::LOCAL_CRATE;
 use rustc_span::Span;
 
@@ -28,7 +28,7 @@ pub struct Autoderef<'a, 'tcx> {
     // Meta infos:
     infcx: &'a InferCtxt<'tcx>,
     span: Span,
-    body_id: hir::HirId,
+    body_id: LocalDefId,
     param_env: ty::ParamEnv<'tcx>,
 
     // Current state:
@@ -96,14 +96,14 @@ impl<'a, 'tcx> Autoderef<'a, 'tcx> {
     pub fn new(
         infcx: &'a InferCtxt<'tcx>,
         param_env: ty::ParamEnv<'tcx>,
-        body_id: hir::HirId,
+        body_def_id: LocalDefId,
         span: Span,
         base_ty: Ty<'tcx>,
     ) -> Autoderef<'a, 'tcx> {
         Autoderef {
             infcx,
             span,
-            body_id,
+            body_id: body_def_id,
             param_env,
             state: AutoderefSnapshot {
                 steps: vec![],

compiler/rustc_hir_analysis/src/check/check.rs

@@ -412,7 +412,6 @@ fn check_opaque_meets_bounds<'tcx>(
     span: Span,
     origin: &hir::OpaqueTyOrigin,
 ) {
-    let hir_id = tcx.hir().local_def_id_to_hir_id(def_id);
     let defining_use_anchor = match *origin {
         hir::OpaqueTyOrigin::FnReturn(did) | hir::OpaqueTyOrigin::AsyncFn(did) => did,
         hir::OpaqueTyOrigin::TyAlias => def_id,
@@ -438,7 +437,7 @@ fn check_opaque_meets_bounds<'tcx>(
         _ => re,
     });
 
-    let misc_cause = traits::ObligationCause::misc(span, hir_id);
+    let misc_cause = traits::ObligationCause::misc(span, def_id);
 
     match ocx.eq(&misc_cause, param_env, opaque_ty, hidden_ty) {
         Ok(()) => {}

compiler/rustc_hir_analysis/src/check/compare_impl_item.rs

@@ -147,12 +147,12 @@ fn compare_method_predicate_entailment<'tcx>(
     //
     // FIXME(@lcnr): remove that after removing `cause.body_id` from
     // obligations.
-    let impl_m_hir_id = tcx.hir().local_def_id_to_hir_id(impl_m.def_id.expect_local());
+    let impl_m_def_id = impl_m.def_id.expect_local();
     let cause = ObligationCause::new(
         impl_m_span,
-        impl_m_hir_id,
+        impl_m_def_id,
         ObligationCauseCode::CompareImplItemObligation {
-            impl_item_def_id: impl_m.def_id.expect_local(),
+            impl_item_def_id: impl_m_def_id,
             trait_item_def_id: trait_m.def_id,
             kind: impl_m.kind,
         },
@@ -198,7 +198,7 @@ fn compare_method_predicate_entailment<'tcx>(
     // Construct trait parameter environment and then shift it into the placeholder viewpoint.
     // The key step here is to update the caller_bounds's predicates to be
     // the new hybrid bounds we computed.
-    let normalize_cause = traits::ObligationCause::misc(impl_m_span, impl_m_hir_id);
+    let normalize_cause = traits::ObligationCause::misc(impl_m_span, impl_m_def_id);
     let param_env = ty::ParamEnv::new(
         tcx.intern_predicates(&hybrid_preds.predicates),
         Reveal::UserFacing,
@@ -213,14 +213,14 @@ fn compare_method_predicate_entailment<'tcx>(
 
     let impl_m_own_bounds = impl_m_predicates.instantiate_own(tcx, impl_to_placeholder_substs);
     for (predicate, span) in impl_m_own_bounds {
-        let normalize_cause = traits::ObligationCause::misc(span, impl_m_hir_id);
+        let normalize_cause = traits::ObligationCause::misc(span, impl_m_def_id);
         let predicate = ocx.normalize(&normalize_cause, param_env, predicate);
 
         let cause = ObligationCause::new(
             span,
-            impl_m_hir_id,
+            impl_m_def_id,
             ObligationCauseCode::CompareImplItemObligation {
-                impl_item_def_id: impl_m.def_id.expect_local(),
+                impl_item_def_id: impl_m_def_id,
                 trait_item_def_id: trait_m.def_id,
                 kind: impl_m.kind,
             },
@@ -253,7 +253,7 @@ fn compare_method_predicate_entailment<'tcx>(
     );
     let unnormalized_impl_fty = tcx.mk_fn_ptr(ty::Binder::dummy(unnormalized_impl_sig));
 
-    let norm_cause = ObligationCause::misc(impl_m_span, impl_m_hir_id);
+    let norm_cause = ObligationCause::misc(impl_m_span, impl_m_def_id);
     let impl_sig = ocx.normalize(&norm_cause, param_env, unnormalized_impl_sig);
     debug!("compare_impl_method: impl_fty={:?}", impl_sig);
 
@@ -311,6 +311,7 @@ fn compare_method_predicate_entailment<'tcx>(
     if !errors.is_empty() {
         match check_implied_wf {
             CheckImpliedWfMode::Check => {
+                let impl_m_hir_id = tcx.hir().local_def_id_to_hir_id(impl_m_def_id);
                 return compare_method_predicate_entailment(
                     tcx,
                     impl_m,
@@ -336,7 +337,7 @@ fn compare_method_predicate_entailment<'tcx>(
     let outlives_env = OutlivesEnvironment::with_bounds(
         param_env,
         Some(infcx),
-        infcx.implied_bounds_tys(param_env, impl_m_hir_id, wf_tys.clone()),
+        infcx.implied_bounds_tys(param_env, impl_m_def_id, wf_tys.clone()),
     );
     infcx.process_registered_region_obligations(
         outlives_env.region_bound_pairs(),
@@ -346,6 +347,7 @@ fn compare_method_predicate_entailment<'tcx>(
     if !errors.is_empty() {
         // FIXME(compiler-errors): This can be simplified when IMPLIED_BOUNDS_ENTAILMENT
         // becomes a hard error (i.e. ideally we'd just call `resolve_regions_and_report_errors`
+        let impl_m_hir_id = tcx.hir().local_def_id_to_hir_id(impl_m_def_id);
         match check_implied_wf {
             CheckImpliedWfMode::Check => {
                 return compare_method_predicate_entailment(
@@ -371,7 +373,7 @@ fn compare_method_predicate_entailment<'tcx>(
             }
             CheckImpliedWfMode::Skip => {
                 if infcx.tainted_by_errors().is_none() {
-                    infcx.err_ctxt().report_region_errors(impl_m.def_id.expect_local(), &errors);
+                    infcx.err_ctxt().report_region_errors(impl_m_def_id, &errors);
                 }
                 return Err(tcx
                     .sess
@@ -610,13 +612,14 @@ pub(super) fn collect_return_position_impl_trait_in_trait_tys<'tcx>(
 
     let trait_to_impl_substs = impl_trait_ref.substs;
 
-    let impl_m_hir_id = tcx.hir().local_def_id_to_hir_id(impl_m.def_id.expect_local());
+    let impl_m_def_id = impl_m.def_id.expect_local();
+    let impl_m_hir_id = tcx.hir().local_def_id_to_hir_id(impl_m_def_id);
     let return_span = tcx.hir().fn_decl_by_hir_id(impl_m_hir_id).unwrap().output.span();
     let cause = ObligationCause::new(
         return_span,
-        impl_m_hir_id,
+        impl_m_def_id,
         ObligationCauseCode::CompareImplItemObligation {
-            impl_item_def_id: impl_m.def_id.expect_local(),
+            impl_item_def_id: impl_m_def_id,
             trait_item_def_id: trait_m.def_id,
             kind: impl_m.kind,
         },
@@ -633,7 +636,7 @@ pub(super) fn collect_return_position_impl_trait_in_trait_tys<'tcx>(
     let ocx = ObligationCtxt::new(infcx);
 
     // Normalize the impl signature with fresh variables for lifetime inference.
-    let norm_cause = ObligationCause::misc(return_span, impl_m_hir_id);
+    let norm_cause = ObligationCause::misc(return_span, impl_m_def_id);
     let impl_sig = ocx.normalize(
         &norm_cause,
         param_env,
@@ -650,7 +653,7 @@ pub(super) fn collect_return_position_impl_trait_in_trait_tys<'tcx>(
     // the ImplTraitInTraitCollector, which gathers all of the RPITITs and replaces
     // them with inference variables.
     // We will use these inference variables to collect the hidden types of RPITITs.
-    let mut collector = ImplTraitInTraitCollector::new(&ocx, return_span, param_env, impl_m_hir_id);
+    let mut collector = ImplTraitInTraitCollector::new(&ocx, return_span, param_env, impl_m_def_id);
     let unnormalized_trait_sig = tcx
         .liberate_late_bound_regions(
             impl_m.def_id,
@@ -732,12 +735,11 @@ pub(super) fn collect_return_position_impl_trait_in_trait_tys<'tcx>(
     let outlives_environment = OutlivesEnvironment::with_bounds(
         param_env,
         Some(infcx),
-        infcx.implied_bounds_tys(param_env, impl_m_hir_id, wf_tys),
+        infcx.implied_bounds_tys(param_env, impl_m_def_id, wf_tys),
     );
-    infcx.err_ctxt().check_region_obligations_and_report_errors(
-        impl_m.def_id.expect_local(),
-        &outlives_environment,
-    )?;
+    infcx
+        .err_ctxt()
+        .check_region_obligations_and_report_errors(impl_m_def_id, &outlives_environment)?;
 
     let mut collected_tys = FxHashMap::default();
     for (def_id, (ty, substs)) in collector.types {
@@ -819,15 +821,15 @@ struct ImplTraitInTraitCollector<'a, 'tcx> {
     types: FxHashMap<DefId, (Ty<'tcx>, ty::SubstsRef<'tcx>)>,
     span: Span,
     param_env: ty::ParamEnv<'tcx>,
-    body_id: hir::HirId,
+    body_id: LocalDefId,
 }
 
 impl<'a, 'tcx> ImplTraitInTraitCollector<'a, 'tcx> {
     fn new(
         ocx: &'a ObligationCtxt<'a, 'tcx>,
         span: Span,
         param_env: ty::ParamEnv<'tcx>,
-        body_id: hir::HirId,
+        body_id: LocalDefId,
     ) -> Self {
         ImplTraitInTraitCollector { ocx, types: FxHashMap::default(), span, param_env, body_id }
     }
@@ -1671,14 +1673,12 @@ pub(super) fn compare_impl_const_raw(
 
     // Create a parameter environment that represents the implementation's
     // method.
-    let impl_c_hir_id = tcx.hir().local_def_id_to_hir_id(impl_const_item_def);
-
     // Compute placeholder form of impl and trait const tys.
     let impl_ty = tcx.type_of(impl_const_item_def.to_def_id());
     let trait_ty = tcx.bound_type_of(trait_const_item_def).subst(tcx, trait_to_impl_substs);
     let mut cause = ObligationCause::new(
         impl_c_span,
-        impl_c_hir_id,
+        impl_const_item_def,
         ObligationCauseCode::CompareImplItemObligation {
             impl_item_def_id: impl_const_item_def,
             trait_item_def_id: trait_const_item_def,
@@ -1799,7 +1799,7 @@ fn compare_type_predicate_entailment<'tcx>(
     // This `HirId` should be used for the `body_id` field on each
     // `ObligationCause` (and the `FnCtxt`). This is what
     // `regionck_item` expects.
-    let impl_ty_hir_id = tcx.hir().local_def_id_to_hir_id(impl_ty.def_id.expect_local());
+    let impl_ty_def_id = impl_ty.def_id.expect_local();
     debug!("compare_type_predicate_entailment: trait_to_impl_substs={:?}", trait_to_impl_substs);
 
     // The predicates declared by the impl definition, the trait and the
@@ -1814,7 +1814,7 @@ fn compare_type_predicate_entailment<'tcx>(
 
     debug!("compare_type_predicate_entailment: bounds={:?}", hybrid_preds);
 
-    let normalize_cause = traits::ObligationCause::misc(impl_ty_span, impl_ty_hir_id);
+    let normalize_cause = traits::ObligationCause::misc(impl_ty_span, impl_ty_def_id);
     let param_env = ty::ParamEnv::new(
         tcx.intern_predicates(&hybrid_preds.predicates),
         Reveal::UserFacing,
@@ -1827,12 +1827,12 @@ fn compare_type_predicate_entailment<'tcx>(
     debug!("compare_type_predicate_entailment: caller_bounds={:?}", param_env.caller_bounds());
 
     for (predicate, span) in impl_ty_own_bounds {
-        let cause = ObligationCause::misc(span, impl_ty_hir_id);
+        let cause = ObligationCause::misc(span, impl_ty_def_id);
         let predicate = ocx.normalize(&cause, param_env, predicate);
 
         let cause = ObligationCause::new(
             span,
-            impl_ty_hir_id,
+            impl_ty_def_id,
             ObligationCauseCode::CompareImplItemObligation {
                 impl_item_def_id: impl_ty.def_id.expect_local(),
                 trait_item_def_id: trait_ty.def_id,
@@ -2008,7 +2008,7 @@ pub(super) fn check_type_bounds<'tcx>(
     };
     debug!(?normalize_param_env);
 
-    let impl_ty_hir_id = tcx.hir().local_def_id_to_hir_id(impl_ty.def_id.expect_local());
+    let impl_ty_def_id = impl_ty.def_id.expect_local();
     let impl_ty_substs = InternalSubsts::identity_for_item(tcx, impl_ty.def_id);
     let rebased_substs = impl_ty_substs.rebase_onto(tcx, container_id, impl_trait_ref.substs);
 
@@ -2020,7 +2020,7 @@ pub(super) fn check_type_bounds<'tcx>(
 
     let normalize_cause = ObligationCause::new(
         impl_ty_span,
-        impl_ty_hir_id,
+        impl_ty_def_id,
         ObligationCauseCode::CheckAssociatedTypeBounds {
             impl_item_def_id: impl_ty.def_id.expect_local(),
             trait_item_def_id: trait_ty.def_id,
@@ -2032,7 +2032,7 @@ pub(super) fn check_type_bounds<'tcx>(
         } else {
             traits::BindingObligation(trait_ty.def_id, span)
         };
-        ObligationCause::new(impl_ty_span, impl_ty_hir_id, code)
+        ObligationCause::new(impl_ty_span, impl_ty_def_id, code)
     };
 
     let obligations = tcx
@@ -2063,7 +2063,7 @@ pub(super) fn check_type_bounds<'tcx>(
 
     // Finally, resolve all regions. This catches wily misuses of
     // lifetime parameters.
-    let implied_bounds = infcx.implied_bounds_tys(param_env, impl_ty_hir_id, assumed_wf_types);
+    let implied_bounds = infcx.implied_bounds_tys(param_env, impl_ty_def_id, assumed_wf_types);
     let outlives_environment =
         OutlivesEnvironment::with_bounds(param_env, Some(&infcx), implied_bounds);
 

compiler/rustc_hir_analysis/src/check/intrinsic.rs

@@ -56,7 +56,8 @@ fn equate_intrinsic_type<'tcx>(
         && gen_count_ok(own_counts.consts, 0, "const")
     {
         let fty = tcx.mk_fn_ptr(sig);
-        let cause = ObligationCause::new(it.span, it.hir_id(), ObligationCauseCode::IntrinsicType);
+        let it_def_id = it.owner_id.def_id;
+        let cause = ObligationCause::new(it.span, it_def_id, ObligationCauseCode::IntrinsicType);
         require_same_types(tcx, &cause, tcx.mk_fn_ptr(tcx.fn_sig(it.owner_id)), fty);
     }
 }