Ok.
On Fri, Dec 11, 2020, 12:45 AM Patrick Palka <ppa...@redhat.com> wrote:
> This fixes a missed SFINAE when subtracting pointers to an incomplete
> type.
>
> Bootstrapped and regtested on x86_64-pc-linux-gnu, does this look OK for
> trunk?
>
> gcc/cp/ChangeLog:
>
> PR c++/78173
> * typeck.c (pointer_diff): Use complete_type_or_maybe_complain
> instead of complete_type_or_else.
>
> gcc/testsuite/ChangeLog:
>
> PR c++/78173
> * g++.dg/cpp2a/concepts-pr78173.C: New test.
> ---
> gcc/cp/typeck.c | 2 +-
> gcc/testsuite/g++.dg/cpp2a/concepts-pr78173.C | 9 +++++++++
> 2 files changed, 10 insertions(+), 1 deletion(-)
> create mode 100644 gcc/testsuite/g++.dg/cpp2a/concepts-pr78173.C
>
> diff --git a/gcc/cp/typeck.c b/gcc/cp/typeck.c
> index dd84674a5e6..c41457bcce8 100644
> --- a/gcc/cp/typeck.c
> +++ b/gcc/cp/typeck.c
> @@ -5985,7 +5985,7 @@ pointer_diff (location_t loc, tree op0, tree op1,
> tree ptrtype,
> tree restype = ptrdiff_type_node;
> tree target_type = TREE_TYPE (ptrtype);
>
> - if (!complete_type_or_else (target_type, NULL_TREE))
> + if (!complete_type_or_maybe_complain (target_type, NULL_TREE, complain))
> return error_mark_node;
>
> if (VOID_TYPE_P (target_type))
> diff --git a/gcc/testsuite/g++.dg/cpp2a/concepts-pr78173.C
> b/gcc/testsuite/g++.dg/cpp2a/concepts-pr78173.C
> new file mode 100644
> index 00000000000..50f561abcce
> --- /dev/null
> +++ b/gcc/testsuite/g++.dg/cpp2a/concepts-pr78173.C
> @@ -0,0 +1,9 @@
> +// PR c++/78173
> +// { dg-do compile { target c++20 } }
> +
> +template <class T>
> +concept CanDifference = requires(T x, T y) {
> + x - y;
> +};
> +
> +static_assert(!CanDifference<void*>);
> --
> 2.29.2.540.g3cf59784d4
>
>
