OK for trunk and 8.
On Tue, May 8, 2018 at 2:33 PM, Marek Polacek <pola...@redhat.com> wrote:
> Here we were confused by a typedef so the "== boolean_type_node" check didn't
> work as intended. We can use TYPE_MAIN_VARIANT to see the real type.
>
> Bootstrapped/regtested on x86_64-linux, ok for trunk?
>
> 2018-05-08 Marek Polacek <pola...@redhat.com>
>
> PR c++/85695
> * semantics.c (finish_if_stmt_cond): See through typedefs.
>
> * g++.dg/cpp1z/constexpr-if22.C: New test.
>
> diff --git gcc/cp/semantics.c gcc/cp/semantics.c
> index 2b2b51b2a7e..195286ca751 100644
> --- gcc/cp/semantics.c
> +++ gcc/cp/semantics.c
> @@ -736,7 +736,7 @@ finish_if_stmt_cond (tree cond, tree if_stmt)
> && !instantiation_dependent_expression_p (cond)
> /* Wait until instantiation time, since only then COND has been
> converted to bool. */
> - && TREE_TYPE (cond) == boolean_type_node)
> + && TYPE_MAIN_VARIANT (TREE_TYPE (cond)) == boolean_type_node)
> {
> cond = instantiate_non_dependent_expr (cond);
> cond = cxx_constant_value (cond, NULL_TREE);
> diff --git gcc/testsuite/g++.dg/cpp1z/constexpr-if22.C
> gcc/testsuite/g++.dg/cpp1z/constexpr-if22.C
> index e69de29bb2d..76f0c73476b 100644
> --- gcc/testsuite/g++.dg/cpp1z/constexpr-if22.C
> +++ gcc/testsuite/g++.dg/cpp1z/constexpr-if22.C
> @@ -0,0 +1,21 @@
> +// PR c++/85695
> +// { dg-options -std=c++17 }
> +
> +template <typename T, T v>
> +struct integral_constant {
> + using value_type = T;
> + static constexpr const value_type value = v;
> + constexpr operator value_type (void) const { return value; }
> +};
> +template <typename T> struct is_trivial
> + : public integral_constant<bool, __is_trivial(T)> {};
> +
> +template <typename T>
> +T clone_object (const T& p)
> +{
> + if constexpr (is_trivial<T>::value)
> + return p;
> + else
> + return p.clone();
> +}
> +int main (void) { return clone_object(0); }
