[PATCH v2] libstdc++: Workaround for LLVM-61763 in ranges

[Jonathan Wakely]

On Mon, 16 Oct 2023 at 04:56, Benjamin Acker Brock <brock@berkeley.edu> wrote:
>
> > I don't think this patch counts as legally significant, but if you contribute again in future you should be aware of https://gcc.gnu.org/contribute.html#legal and either complete the copyright assignment paperwork, or add a DCO sign-off to the commit message.
>
> Thanks for the reminder. I just added a sign-off.

Thanks.

> > This should be a complete sentence, so capital letter and full stop.
>
> Fixed!

I actually adjusted the ChangeLog further, to name the modified components:

           * include/std/ranges (zip_view, adjacent_view): Implement
           workaround for LLVM-61763.

This is the usual convention.

Pushed to trunk now, thanks again for the fix!


> ---
>
> Signed-off-by: Benjamin Brock <brock@cs.berkeley.edu>
>
>     libstdc++-v3/ChangeLog:
>
>             * include/std/ranges: Implement workaround for LLVM-61763 in
>               zip_view and adjacency_view.
>
> ---
>
> diff --git a/libstdc++-v3/include/std/ranges b/libstdc++-v3/include/std/ranges
> index 1d529a886be..7893e3a84c9 100644
> --- a/libstdc++-v3/include/std/ranges
> +++ b/libstdc++-v3/include/std/ranges
> @@ -4632,6 +4632,9 @@ namespace views::__adaptor
>    class zip_view<_Vs...>::_Iterator
>      : public __detail::__zip_view_iter_cat<_Const, _Vs...>
>    {
> +#ifdef __clang__ // LLVM-61763 workaround
> +  public:
> +#endif
>      __detail::__tuple_or_pair_t<iterator_t<__detail::__maybe_const_t<_Const,
> _Vs>>...> _M_current;
>
>      constexpr explicit
> @@ -4652,11 +4655,13 @@ namespace views::__adaptor
>         return input_iterator_tag{};
>      }
>
> +#ifndef __clang__ // LLVM-61763 workaround
>      template<move_constructible _Fp, input_range... _Ws>
>        requires (view<_Ws> && ...) && (sizeof...(_Ws) > 0) && is_object_v<_Fp>
>         && regular_invocable<_Fp&, range_reference_t<_Ws>...>
>         && std::__detail::__can_reference<invoke_result_t<_Fp&,
> range_reference_t<_Ws>...>>
>        friend class zip_transform_view;
> +#endif
>
>    public:
>      // iterator_category defined in __zip_view_iter_cat
> @@ -5327,6 +5332,9 @@ namespace views::__adaptor
>    template<bool _Const>
>    class adjacent_view<_Vp, _Nm>::_Iterator
>    {
> +#ifdef __clang__ // LLVM-61763 workaround
> +  public:
> +#endif
>      using _Base = __detail::__maybe_const_t<_Const, _Vp>;
>      array<iterator_t<_Base>, _Nm> _M_current = array<iterator_t<_Base>, _Nm>();
>
> @@ -5367,12 +5375,14 @@ namespace views::__adaptor
>
>      friend class adjacent_view;
>
> +#ifndef __clang__ // LLVM-61763 workaround
>      template<forward_range _Wp, move_constructible _Fp, size_t _Mm>
>        requires view<_Wp> && (_Mm > 0) && is_object_v<_Fp>
>          && regular_invocable<__detail::__unarize<_Fp&, _Mm>,
> range_reference_t<_Wp>>
>          && std::__detail::__can_reference<invoke_result_t<__detail::__unarize<_Fp&,
> _Mm>,
>
> range_reference_t<_Wp>>>
>        friend class adjacent_transform_view;
> +#endif
>
>    public:
>      using iterator_category = input_iterator_tag;
>