[PATCH] D34588: Check for _MSC_VER before define _LIBCPP_MSVCRT

[Saleem Abdulrasool via Phabricator via cfe-commits]

compnerd added a comment.

Thinking more about this, on Windows, is there a strong reason to default to a different libc by default on Windows?  @bruno would reusing `-ffreestanding` work for you here?  Or is there something else that we can identify about the target environment that can indicate that the MS CRT is unavailable?  I think that what is weird to me about this is that this is not about compatibility with Visual Studio but about the underlying libc.  It feels like it would be similar in spirit to say that libc++ defaults to libSystem as the underlying libc on Linux.

@bcraig thoughts on `_LIBCPP_MS_CRT` as the alternate name?


https://reviews.llvm.org/D34588