Re: [PATCH 2/4] libstdc++: Avoid '-Wunused-parameter' for 'nofollow' in static member function 'static std::filesystem::__gnu_posix::DIR* std::filesystem::_Dir_base::openat(const _At_path&, bool)'

[Jonathan Wakely]

On Thu, 20 Feb 2025 at 16:58, Thomas Schwinge <tschwi...@baylibre.com> wrote:
>
> In a newlib configuration:
>
>     In file included from 
> ../../../../../source-gcc/libstdc++-v3/src/c++17/fs_dir.cc:37,
>                      from 
> ../../../../../source-gcc/libstdc++-v3/src/c++17/cow-fs_dir.cc:26:
>     
> ../../../../../source-gcc/libstdc++-v3/src/c++17/../filesystem/dir-common.h: 
> In static member function ‘static std::filesystem::__gnu_posix::DIR* 
> std::filesystem::_Dir_base::openat(const _At_path&, bool)’:
>     
> ../../../../../source-gcc/libstdc++-v3/src/c++17/../filesystem/dir-common.h:210:36:
>  error: unused parameter ‘nofollow’ [-Werror=unused-parameter]
>       210 |   openat(const _At_path& atp, bool nofollow)
>           |                               ~~~~~^~~~~~~~
>
>         libstdc++-v3/
>         * src/filesystem/dir-common.h (openat): Tag 'nofollow' as
>         '[[maybe_unused]]'.

OK (there are quite a few unused params in the filesystem code that I
haven't bothered to mark with the attribute, because I don't see the
warnings on the targets I usually test).


> ---
>  libstdc++-v3/src/filesystem/dir-common.h | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/libstdc++-v3/src/filesystem/dir-common.h 
> b/libstdc++-v3/src/filesystem/dir-common.h
> index 5ff621c3380..c7d4bc4e6ed 100644
> --- a/libstdc++-v3/src/filesystem/dir-common.h
> +++ b/libstdc++-v3/src/filesystem/dir-common.h
> @@ -207,7 +207,7 @@ struct _Dir_base
>    }
>
>    static posix::DIR*
> -  openat(const _At_path& atp, bool nofollow)
> +  openat(const _At_path& atp, [[maybe_unused]] bool nofollow)
>    {
>  #if _GLIBCXX_HAVE_FDOPENDIR && defined O_RDONLY && defined O_DIRECTORY \
>      && ! _GLIBCXX_FILESYSTEM_IS_WINDOWS
> --
> 2.34.1
>