Re: [committed][_GLIBCXX_INLINE_VERSION] Fix constract violation

[Jonathan Wakely <jwakely@redhat.com>]

On Sun, 29 Oct 2023 at 21:11, François Dumont <frs.dumont@gmail.com> wrote:
>
> This fixes handle_contract_violation under versioned namespace mode.
>
> Tested under Linux x64 and confirmed to also fix Darwin build.
>
> libstdc++: [_GLIBCXX_INLINE_VERSION] Provide handle_contract_violation
> symbol
>
> libstdc++-v3/ChangeLog:
>
>          * src/experimental/contract.cc
>          [_GLIBCXX_INLINE_VERSION](handle_contract_violation): Provide
> symbol
>          without version namespace decoration for gcc.

>+#if _GLIBCXX_INLINE_VERSION
>+// Provide symbol without version namespace decoration for gcc.

For the comment in the code, I think this would be better:

// The compiler expects the contract_violation class to be in an unversioned
// namespace, so provide a forwarding function with the expected symbol name.

Do we want the forwarding function to be a weak symbol? The main
handler function is weak because we want users to be able to override
it with their own handler. But for this new forwarding function, they
can't even declare it (because it has a reserved name that doesn't
demangle to a valid type for the versioned namespace build).