On Tue, 18 Apr 2023 at 16:59, Jonathan Wakely via Libstdc++
<libstd...@gcc.gnu.org> wrote:
> diff --git a/libstdc++-v3/config/abi/pre/gnu.ver
> b/libstdc++-v3/config/abi/pre/gnu.ver
> index 4ae63094eb7..7c015524b62 100644
> --- a/libstdc++-v3/config/abi/pre/gnu.ver
> +++ b/libstdc++-v3/config/abi/pre/gnu.ver
> @@ -2512,6 +2512,20 @@ GLIBCXX_3.4.31 {
>
> _ZNKSt12__shared_ptrINSt10filesystem28recursive_directory_iterator10_Dir_stackELN9__gnu_cxx12_Lock_policyE[012]EEcvbEv;
>
> _ZNKSt12__shared_ptrINSt10filesystem7__cxx1128recursive_directory_iterator10_Dir_stackELN9__gnu_cxx12_Lock_policyE[012]EEcvbEv;
>
> +#if defined(_GLIBCXX_SYMVER_GNU) && defined(_GLIBCXX_SHARED) \
> + && defined(_GLIBCXX_HAVE_AS_SYMVER_DIRECTIVE) \
> + && defined(_GLIBCXX_HAVE_SYMVER_SYMBOL_RENAMING_RUNTIME_SUPPORT)
I've just noticed that these will never be defined, because this
linker script is preprocessed with config.h not c++config.h, and so it
should be:
#if defined(_GLIBCXX_SYMVER_GNU) && defined(_GLIBCXX_SHARED) \
&& defined(HAVE_AS_SYMVER_DIRECTIVE) \
&& defined(HAVE_SYMVER_SYMBOL_RENAMING_RUNTIME_SUPPORT)
The condition will never be true as currently written (which doesn't
actually seem to matter, but Jakub says that re-exporting the symbols
as the new version is needed in the linker script for older linkers).
> + # See src/c++98/globals_io.cc
> + _ZSt3cin;
> + _ZSt4cout;
> + _ZSt4cerr;
> + _ZSt4clog;
> + _ZSt4wcin;
> + _ZSt5wcout;
> + _ZSt5wcerr;
> + _ZSt5wclog;
> +#endif
> +
> } GLIBCXX_3.4.30;
>
> # Symbols in the support library (libsupc++) have their own tag.
