diff options
Diffstat (limited to 'compiler')
| -rw-r--r-- | compiler/rustc_hir_typeck/src/expr.rs | 22 |
1 files changed, 18 insertions, 4 deletions
diff --git a/compiler/rustc_hir_typeck/src/expr.rs b/compiler/rustc_hir_typeck/src/expr.rs index 4b7de36e7c7..84e0b56dab1 100644 --- a/compiler/rustc_hir_typeck/src/expr.rs +++ b/compiler/rustc_hir_typeck/src/expr.rs @@ -3067,7 +3067,9 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> { return None; }; - self.commit_if_ok(|_| { + self.commit_if_ok(|snapshot| { + let outer_universe = self.universe(); + let ocx = ObligationCtxt::new(self); let impl_args = self.fresh_args_for_item(base_expr.span, impl_def_id); let impl_trait_ref = @@ -3077,7 +3079,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> { // Match the impl self type against the base ty. If this fails, // we just skip this impl, since it's not particularly useful. let impl_trait_ref = ocx.normalize(&cause, self.param_env, impl_trait_ref); - ocx.eq(&cause, self.param_env, impl_trait_ref.self_ty(), base_ty)?; + ocx.eq(&cause, self.param_env, base_ty, impl_trait_ref.self_ty())?; // Register the impl's predicates. One of these predicates // must be unsatisfied, or else we wouldn't have gotten here @@ -3113,11 +3115,23 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> { Ty::new_projection(self.tcx, index_trait_output_def_id, impl_trait_ref.args), ); - let errors = ocx.select_where_possible(); + let true_errors = ocx.select_where_possible(); + + // Do a leak check -- we can't really report report a useful error here, + // but it at least avoids an ICE when the error has to do with higher-ranked + // lifetimes. + self.leak_check(outer_universe, Some(snapshot))?; + + // Bail if we have ambiguity errors, which we can't report in a useful way. + let ambiguity_errors = ocx.select_all_or_error(); + if true_errors.is_empty() && !ambiguity_errors.is_empty() { + return Err(NoSolution); + } + // There should be at least one error reported. If not, we // will still delay a span bug in `report_fulfillment_errors`. Ok::<_, NoSolution>(( - self.err_ctxt().report_fulfillment_errors(errors), + self.err_ctxt().report_fulfillment_errors(true_errors), impl_trait_ref.args.type_at(1), element_ty, )) |