[libcxx-commits] [libcxx] [libc++] Fix missing 'get_new_handler()' for Windows builds (PR #150182)

[A. Jiang via libcxx-commits]

frederick-vs-ja wrote:

> But do I understand things correctly, that we so far have been using the function from vcruntime, and MS STL also reimplements this on top of vcruntime?

Yeah. I believe this is true.

The crux is that
- VCRuntime doesn't provide `get_new_handler`/`set_new_handler`, and
- MSVC STL has them built together with other MSVC STL's separately compiled functions, but
- UCRT declares `set_new_handler` but not `get_new_handler`, despite that UCRT doesn't provide `set_new_handler` itself.

> And we can't use those functions from MS STL, but also need to reimplement it on top of vcruntime separately?

I'm not very sure. But at least we need to redeclare MSVC STL's `get_new_handler` if we want to reuse it.

https://github.com/llvm/llvm-project/pull/150182