[swift-evolution] [Draft] Unify "import Darwin/Glibc" to simply "Libc"

[Brent Royal-Gordon]

> On Sep 13, 2016, at 12:29 PM, Brian Gesiak via swift-evolution <swift-evolution at swift.org> wrote:
> 
> I hadn't thought about a unified overlay for POSIX. I think the simplified import alone has benefit to warrant its own evolution proposal. Would it be possible to have a separate discussion for the POSIX overlay idea? Or is there a reason that I'm missing that prevents the import from being viable on its own? (Apologies in advance if there's an obvious answer to this question!)

I've heard the argument before that we should do a full overlay, but I think this is becoming a case of the perfect being the enemy of the good. Having some sort of "just import whatever the system libc is called" module would be a significant improvement in practice over the state of the art, even if we don't do any other adaptation.

Here's what I would suggest. We have a convention for exposing "raw" imports of C libraries: you call them `C\(libraryName)`. So I would suggest we introduce a `CLibc` module which provides a raw import of the system's libc. If we later decide to do a full-featured overlay, that's great—we can call it `Libc`. But `CLibc` by itself would be an improvement over the status quo and a step in the right direction.

-- 
Brent Royal-Gordon
Architechies