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

[Louis Dionne via libcxx-commits]

ldionne wrote:

Summarizing the changes needed before we land this:

1. Drop formatting-only changes (e.g. in `global_new_delete.h`)
2. Split `[[nodiscard]]` into a separate PR
3. Add a test for new handler being called on allocation failure
4. Add a release note for LLVM 23
5. Let's document the Windows/MSVC support goals in libcxx/docs/DesignDocs/WindowsSupport.rst (which does not exist today). This should cover the dependency model (using vcruntime as the ABI layer, and our goal to decouple from the MSVC STL). Let's also mention that allowing interoperation between the two (e.g. linking a binary built with libc++ and one built with MSVC STL and expecting they share the same new handler) is not a goal, unless I've misunderstood the discussion on this point (@mstorsjo).

Once those are addressed, I think this is good to go and I'm glad that folks who care about Windows support are aligned that this is the right path forward.

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