Stop bubbling out hidden types from the eval obligation queries

Author: oli-obk

compiler/rustc_traits/src/evaluate_obligation.rs

@@ -1,6 +1,5 @@
 use rustc_infer::infer::TyCtxtInferExt;
 use rustc_middle::query::Providers;
-use rustc_middle::traits::DefiningAnchor;
 use rustc_middle::ty::{ParamEnvAnd, TyCtxt};
 use rustc_span::source_map::DUMMY_SP;
 use rustc_trait_selection::traits::query::CanonicalPredicateGoal;
@@ -18,12 +17,8 @@ fn evaluate_obligation<'tcx>(
 ) -> Result<EvaluationResult, OverflowError> {
     assert!(!tcx.next_trait_solver_globally());
     debug!("evaluate_obligation(canonical_goal={:#?})", canonical_goal);
-    // HACK This bubble is required for this tests to pass:
-    // impl-trait/issue99642.rs
-    let (ref infcx, goal, _canonical_inference_vars) = tcx
-        .infer_ctxt()
-        .with_opaque_type_inference(DefiningAnchor::Bubble)
-        .build_with_canonical(DUMMY_SP, &canonical_goal);
+    let (ref infcx, goal, _canonical_inference_vars) =
+        tcx.infer_ctxt().build_with_canonical(DUMMY_SP, &canonical_goal);
     debug!("evaluate_obligation: goal={:#?}", goal);
     let ParamEnvAnd { param_env, value: predicate } = goal;
 

compiler/rustc_traits/src/type_op.rs

@@ -2,7 +2,6 @@ use rustc_infer::infer::canonical::{Canonical, QueryResponse};
 use rustc_infer::infer::TyCtxtInferExt;
 use rustc_middle::query::Providers;
 use rustc_middle::traits::query::NoSolution;
-use rustc_middle::traits::DefiningAnchor;
 use rustc_middle::ty::{FnSig, Lift, PolyFnSig, Ty, TyCtxt, TypeFoldable};
 use rustc_middle::ty::{ParamEnvAnd, Predicate};
 use rustc_trait_selection::infer::InferCtxtBuilderExt;
@@ -106,15 +105,10 @@ fn type_op_prove_predicate<'tcx>(
     tcx: TyCtxt<'tcx>,
     canonicalized: Canonical<'tcx, ParamEnvAnd<'tcx, ProvePredicate<'tcx>>>,
 ) -> Result<&'tcx Canonical<'tcx, QueryResponse<'tcx, ()>>, NoSolution> {
-    // HACK This bubble is required for this test to pass:
-    // impl-trait/issue-99642.rs
-    tcx.infer_ctxt().with_opaque_type_inference(DefiningAnchor::Bubble).enter_canonical_trait_query(
-        &canonicalized,
-        |ocx, key| {
-            type_op_prove_predicate_with_cause(ocx, key, ObligationCause::dummy());
-            Ok(())
-        },
-    )
+    tcx.infer_ctxt().enter_canonical_trait_query(&canonicalized, |ocx, key| {
+        type_op_prove_predicate_with_cause(ocx, key, ObligationCause::dummy());
+        Ok(())
+    })
 }
 
 /// The core of the `type_op_prove_predicate` query: for diagnostics purposes in NLL HRTB errors,