From d2482fd36ac144b5dac106026b90d112d4707d79 Mon Sep 17 00:00:00 2001 From: "Felix S. Klock II" Date: Wed, 6 Mar 2019 13:49:48 +0100 Subject: [PATCH] Avoid ICE during `repr(packed)` well-formedness check via delay_span_bug. (It is possible that there is a more fundamental invariant being violated, in terms of the `check_type_defn` code assuming that lifting to tcx will always succeed. But I am unaware of any test input that hits this that isn't already type-incorrect in some fashion.) --- src/librustc_typeck/check/wfcheck.rs | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-) diff --git a/src/librustc_typeck/check/wfcheck.rs b/src/librustc_typeck/check/wfcheck.rs index 860fa526a1b9..e9ff8aa02967 100644 --- a/src/librustc_typeck/check/wfcheck.rs +++ b/src/librustc_typeck/check/wfcheck.rs @@ -250,11 +250,14 @@ fn check_type_defn<'a, 'tcx, F>(tcx: TyCtxt<'a, 'tcx, 'tcx>, let needs_drop_copy = || { packed && { let ty = variant.fields.last().unwrap().ty; - let ty = fcx.tcx.erase_regions(&ty).lift_to_tcx(fcx_tcx) + fcx.tcx.erase_regions(&ty).lift_to_tcx(fcx_tcx) + .map(|ty| ty.needs_drop(fcx_tcx, fcx_tcx.param_env(def_id))) .unwrap_or_else(|| { - span_bug!(item.span, "inference variables in {:?}", ty) - }); - ty.needs_drop(fcx_tcx, fcx_tcx.param_env(def_id)) + fcx_tcx.sess.delay_span_bug( + item.span, &format!("inference variables in {:?}", ty)); + // Just treat unresolved type expression as if it needs drop. + true + }) } }; let all_sized =