[libcxx-commits] [PATCH] D64191: [libcxxabi] Don't process exceptions in cxa_handlers when they're disabled

[Petr Hosek via Phabricator via libcxx-commits]

phosek added a comment.

In D64191#1576221 <https://reviews.llvm.org/D64191#1576221>, @ldionne wrote:

> The only thing iffy about this is that it's not 100% clear to me what `_LIBCXXABI_NO_EXCEPTIONS` mean. It could either mean (a) that libc++abi itself doesn't use exceptions in its implementation, or (b) that it doesn't provide support for exceptions in the runtime, or both (a) and (b).
>
> It clearly means at least (a) from a quick `grep`, however it's not clear to me that it also means (b).


We assumed both (a) and (b). This is really valuable for us since we use libc++abi built with `_LIBCXXABI_NO_EXCEPTIONS` when `-fno-exceptions` is specified which can save a lot of space in embedded use cases because we can avoid pulling in all the demangling code.

If `_LIBCXXABI_NO_EXCEPTIONS` is meant to imply just (a), could we introduce a second definition/option for (b), e.g. `_LIBCXXABI_NO_EXCEPTIONS` and `_LIBCXXABI_HAS_NO_EXCEPTIONS`?


Repository:
  rCXXA libc++abi

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D64191/new/

https://reviews.llvm.org/D64191