diff --git a/compiler/rustc_infer/src/infer/outlives/obligations.rs b/compiler/rustc_infer/src/infer/outlives/obligations.rs index b989d419057b..a640dcb1b4e1 100644 --- a/compiler/rustc_infer/src/infer/outlives/obligations.rs +++ b/compiler/rustc_infer/src/infer/outlives/obligations.rs @@ -170,6 +170,10 @@ impl<'tcx> InferCtxt<'tcx> { std::mem::take(&mut self.inner.borrow_mut().region_obligations) } + pub fn clone_registered_region_obligations(&self) -> Vec> { + self.inner.borrow().region_obligations.clone() + } + pub fn register_region_assumption(&self, assumption: ty::ArgOutlivesPredicate<'tcx>) { let mut inner = self.inner.borrow_mut(); inner.undo_log.push(UndoLog::PushRegionAssumption); diff --git a/compiler/rustc_trait_selection/src/traits/query/type_op/implied_outlives_bounds.rs b/compiler/rustc_trait_selection/src/traits/query/type_op/implied_outlives_bounds.rs index 7540cbe3fd1a..e55ffb4d5fdb 100644 --- a/compiler/rustc_trait_selection/src/traits/query/type_op/implied_outlives_bounds.rs +++ b/compiler/rustc_trait_selection/src/traits/query/type_op/implied_outlives_bounds.rs @@ -55,6 +55,12 @@ pub fn compute_implied_outlives_bounds_inner<'tcx>( span: Span, disable_implied_bounds_hack: bool, ) -> Result>, NoSolution> { + // Inside mir borrowck, each computation starts with an empty list. + assert!( + ocx.infcx.inner.borrow().region_obligations().is_empty(), + "compute_implied_outlives_bounds assumes region obligations are empty before starting" + ); + let normalize_ty = |ty| -> Result<_, NoSolution> { // We must normalize the type so we can compute the right outlives components. // for example, if we have some constrained param type like `T: Trait`, @@ -143,7 +149,7 @@ pub fn compute_implied_outlives_bounds_inner<'tcx>( && ty.visit_with(&mut ContainsBevyParamSet { tcx: ocx.infcx.tcx }).is_break() { for TypeOutlivesConstraint { sup_type, sub_region, .. } in - ocx.infcx.take_registered_region_obligations() + ocx.infcx.clone_registered_region_obligations() { let mut components = smallvec![]; push_outlives_components(ocx.infcx.tcx, sup_type, &mut components);