> On 24 Dec 2022, at 12:12, Jonathan Wakely <jwakely....@gmail.com> wrote:
>
>
>
> On Sat, 24 Dec 2022, 11:35 Iain Sandoe via Libstdc++, <libstd...@gcc.gnu.org>
> wrote:
> If this is not the right place to export the symbol (or you do not want
> to export it in the general case), I can always add a platform-specific
> file for it. So far, tested on x86_64-darwin21, wider testing will
> follow over the holidays.
>
> OK for trunk?
>
> I'd like to check if this causes the undefined weak symbol to be exported on
> ELF,
I’d expect so, since it’s in the common file.
> but I suppose that doesn't really cause any harm if it is. The symbol name is
> in our own namespace so can't clash with user symbols. We can't declare that
> function in a header, because "zoneinfo_dir_override" is not a reserved name
> so could clash with user macros (we could prefix it with underscores, but
> since it's possible to override it without the library providing a
> declaration, I think it would be "nicer" to not use an ugly reserved name for
> something users are supposed to define themselves).
I can also investigate the alternate solution for Darwin - where we pass
-U,symbolname to the linker.
In that case, we do not need to provide a weak def. in the library (it looks
more ELF-like) but the symbol
does still need to be exported - however that could Darwin-local too as noted
above.
(none of this is urgent, bootstrap is fixed - I was just poking at the problems
while they were fresh in
my mind; although the fails are removed when I configure to an installation
with tzdata.zi, there are
still fails to deal with when using the system installation .. so I’m not
’there’ yet .. )
cheers
Iain
>
>
>
>
> Iain
>
> --- 8< ---
>
> This symbol needs to be visible in the library interface for Darwin
> to override it with a user-provided one.
>
> Signed-off-by: Iain Sandoe <i...@sandoe.co.uk>
>
> libstdc++-v3/ChangeLog:
>
> * config/abi/pre/gnu.ver (GLIBCXX_3.4):
> Add __gnu_cxx::zoneinfo_dir_override().
> ---
> libstdc++-v3/config/abi/pre/gnu.ver | 3 +++
> 1 file changed, 3 insertions(+)
>
> diff --git a/libstdc++-v3/config/abi/pre/gnu.ver
> b/libstdc++-v3/config/abi/pre/gnu.ver
> index 570ffca8710..bd4ab450652 100644
> --- a/libstdc++-v3/config/abi/pre/gnu.ver
> +++ b/libstdc++-v3/config/abi/pre/gnu.ver
> @@ -1104,6 +1104,9 @@ GLIBCXX_3.4 {
> # std::uncaught_exception()
> _ZSt18uncaught_exceptionv;
>
> + # __gnu_cxx::zoneinfo_dir_override()
> + _ZN9__gnu_cxx21zoneinfo_dir_overrideEv
> +
> # DO NOT DELETE THIS LINE. Port-specific symbols, if any, will be here.
>
> local:
> --
> 2.37.1 (Apple Git-137.1)
>
