[libcxx-commits] [PATCH] D68269: [libc++abi] Do not define new/delete by default

[Louis Dionne via Phabricator via libcxx-commits]

ldionne added a comment.

So, it turns out that even with GCC 9, this will cause errors like this (on my Linux Docker vm):

  <...>lib/libc++abi.so: undefined reference to `operator delete(void*)'
  <...>lib/libc++abi.so: undefined reference to `operator new[](unsigned long)'
  <...>lib/libc++abi.so: undefined reference to `operator delete[](void*)'
  <...>lib/libc++abi.so: undefined reference to `operator delete(void*, unsigned long)'

I see three solutions:

1. By default, provide new/delete in libc++abi but not in libc++. I'm not sure I like that.
2. Require that libc++abi be built with `-DLIBCXXABI_ENABLE_NEW_DELETE_DEFINITIONS=ON` on GCC. This means we need to change the CI builders to add that option.
3. "Fix" GCC and wait multiple years for GCC 9 not to be supported anymore before we switch the default.

I don't care whether we do (1) or (2) -- at Apple we specify `-DLIBCXXABI_ENABLE_NEW_DELETE_DEFINITIONS=ON` explicitly when we build libc++abi anyway. However, we need to align libc++abi and libc++ regarding who provides new/delete in the default LLVM configuration.


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D68269/new/

https://reviews.llvm.org/D68269