diff options
| -rw-r--r-- | src/librustc_typeck/check/mod.rs | 33 | ||||
| -rw-r--r-- | src/librustc_typeck/lib.rs | 11 |
2 files changed, 28 insertions, 16 deletions
diff --git a/src/librustc_typeck/check/mod.rs b/src/librustc_typeck/check/mod.rs index 159340d19a7..e99633519f4 100644 --- a/src/librustc_typeck/check/mod.rs +++ b/src/librustc_typeck/check/mod.rs @@ -1066,20 +1066,25 @@ fn check_fn<'a, 'gcx, 'tcx>(inherited: &'a Inherited<'a, 'gcx, 'tcx>, } fcx.demand_suptype(span, ret_ty, actual_return_ty); - if let Some((id, _)) = *fcx.tcx.sess.entry_fn.borrow() { - if id == fn_id { - match fcx.sess().entry_type.get() { - Some(config::EntryMain) => { - let term_id = fcx.tcx.require_lang_item(TerminationTraitLangItem); - - let substs = fcx.tcx.mk_substs(iter::once(Kind::from(ret_ty))); - let trait_ref = ty::TraitRef::new(term_id, substs); - let cause = traits::ObligationCause::new(span, fn_id, - ObligationCauseCode::MainFunctionType); - inherited.register_predicate( - traits::Obligation::new(cause, param_env, trait_ref.to_predicate())); - }, - _ => {}, + // If the termination trait language item is activated, check that the main return type + // implements the termination trait. + if fcx.tcx.lang_items().termination().is_some() { + if let Some((id, _)) = *fcx.tcx.sess.entry_fn.borrow() { + if id == fn_id { + match fcx.sess().entry_type.get() { + Some(config::EntryMain) => { + let term_id = fcx.tcx.require_lang_item(TerminationTraitLangItem); + + let substs = fcx.tcx.mk_substs(iter::once(Kind::from(ret_ty))); + let trait_ref = ty::TraitRef::new(term_id, substs); + let cause = traits::ObligationCause::new( + span, fn_id, ObligationCauseCode::MainFunctionType); + + inherited.register_predicate( + traits::Obligation::new(cause, param_env, trait_ref.to_predicate())); + }, + _ => {}, + } } } } diff --git a/src/librustc_typeck/lib.rs b/src/librustc_typeck/lib.rs index f11328b2424..f02998f7edf 100644 --- a/src/librustc_typeck/lib.rs +++ b/src/librustc_typeck/lib.rs @@ -203,12 +203,19 @@ fn check_main_fn_ty<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>, } let actual = tcx.fn_sig(main_def_id); + let expected_return_type = if tcx.lang_items().termination().is_some() { + // we take the return type of the given main function, the real check is done + // in `check_fn` + actual.output().skip_binder() + } else { + // standard () main return type + tcx.mk_nil() + }; let se_ty = tcx.mk_fn_ptr(ty::Binder( tcx.mk_fn_sig( iter::empty(), - // the return type is checked in `check_fn` - actual.output().skip_binder(), + expected_return_type, false, hir::Unsafety::Normal, Abi::Rust |