Tested on Linux-PPC64. This ain't no regression. But it seems to hamper attempts to fix library regressions (see https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94033).
2020-03-16 Ville Voutilainen <ville.voutilai...@gmail.com> gcc/ PR c++/94197 * cp/method.c (assignable_expr, constructible_expr): Push a deferred access check for the stub object. testsuite/ PR c++/94197 * g++.dg/ext/pr94197.C: New.
diff --git a/gcc/cp/method.c b/gcc/cp/method.c index 790d5704092..b429ea48049 100644 --- a/gcc/cp/method.c +++ b/gcc/cp/method.c @@ -1739,11 +1739,11 @@ check_nontriv (tree *tp, int *, void *) static tree assignable_expr (tree to, tree from) { - ++cp_unevaluated_operand; + cp_unevaluated cp_uneval_guard; + deferring_access_check_sentinel acs (dk_no_deferred); to = build_stub_object (to); from = build_stub_object (from); tree r = cp_build_modify_expr (input_location, to, NOP_EXPR, from, tf_none); - --cp_unevaluated_operand; return r; } @@ -1759,6 +1759,7 @@ constructible_expr (tree to, tree from) { tree expr; cp_unevaluated cp_uneval_guard; + deferring_access_check_sentinel acs (dk_no_deferred); if (CLASS_TYPE_P (to)) { tree ctype = to; diff --git a/gcc/testsuite/g++.dg/ext/pr94197.C b/gcc/testsuite/g++.dg/ext/pr94197.C new file mode 100644 index 00000000000..768bfbac0a6 --- /dev/null +++ b/gcc/testsuite/g++.dg/ext/pr94197.C @@ -0,0 +1,75 @@ +// { dg-do compile } +// { dg-options "-std=c++11" } + +template<typename T> + T&& declval() noexcept; + +template<bool B> +struct bool_constant +{ + static constexpr bool value = B; + using type = bool_constant; +}; + +using true_type = bool_constant<true>; +using false_type = bool_constant<false>; + +template<bool, typename T, typename Arg> + struct __is_nt_constructible_impl + : public false_type + { }; + +template<typename T, typename Arg> + struct __is_nt_constructible_impl<true, T, Arg> + : public bool_constant<noexcept(static_cast<T>(declval<Arg>()))> + { }; + +template<typename T, typename Arg> + using __is_nothrow_constructible_impl + = __is_nt_constructible_impl<__is_constructible(T, Arg), T, Arg>; + +template<typename T> + struct __is_nothrow_copy_constructible_impl + : public __is_nothrow_constructible_impl<T, const T&> + { }; + +template<typename T> + struct is_nothrow_copy_constructible + : public __is_nothrow_copy_constructible_impl<T>::type + { }; + +template<bool, typename T, typename Arg> + struct __is_nt_assignable_impl + : public false_type + { }; + +template<typename T, typename Arg> + struct __is_nt_assignable_impl<true, T, Arg> + : public bool_constant<noexcept(declval<T&>() = declval<Arg>())> + { }; + +template<typename T, typename Arg> + using __is_nothrow_assignable_impl + = __is_nt_assignable_impl<__is_assignable(T, Arg), T, Arg>; + +template<typename T> + struct __is_nothrow_copy_assignable_impl + : public __is_nothrow_assignable_impl<T, const T&> + { }; + +template<typename T> + struct is_nothrow_copy_assignable + : public __is_nothrow_copy_assignable_impl<T>::type + { }; + +struct NType +{ + NType(); +private: + NType(const NType&); + NType& operator=(const NType&); +}; + + +static_assert( !is_nothrow_copy_constructible<NType>::value, "" ); +static_assert( !is_nothrow_copy_assignable<NType>::value, "" );