[PATCH] D110289: [libc++] Remove unused macro in __config

Thu Sep 23 05:46:52 PDT 2021

ldionne added a comment.

In D110289#3016525 <https://reviews.llvm.org/D110289#3016525>, @jloser wrote:

> I think it's used in a few places from a quick `git grep`: [...]

`__MAC_OS_X_VERSION_MIN_REQUIRED` is defined by Apple's `<Availability.h>`. It is equivalent to `__ENVIRONMENT_MAC_OS_X_VERSION_MIN_REQUIRED__`, which is set by the compiler. I suspect libc++ was defining it at some point for internal use (e.g. in the code I removed in https://reviews.llvm.org/rGebaf1d5e2b87), but now it's not needed anymore.

> This is safe for `libc++` use, so LGTM since CI is passing. As an aside, it looks like there are a few other spots in `llvm` that could benefit from the removal too:
>
>   git grep '__MAC_OS_X_VERSION_MIN_REQUIRED'
>   clang-tools-extra/clangd/unittests/JSONTransportTests.cpp:#if !(defined(_WIN32) || (defined(__MAC_OS_X_VERSION_MIN_REQUIRED) &&          \
>   clang-tools-extra/clangd/unittests/JSONTransportTests.cpp:                          __MAC_OS_X_VERSION_MIN_REQUIRED < 101300))
>   llvm/lib/Support/LockFileManager.cpp:#if defined(__APPLE__) && defined(__MAC_OS_X_VERSION_MIN_REQUIRED) && (__MAC_OS_X_VERSION_MIN_REQUIRED > 1050)

Good point -- those could either have been using the value defined in `<Availability.h>` or unknowingly using the one set by libc++. I'll move those over to `__ENVIRONMENT_MAC_OS_X_VERSION_MIN_REQUIRED__`, which is always defined by the compiler.

Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D110289/new/

https://reviews.llvm.org/D110289