[LLVMdev] RFC: Drop support running LLVM on Windows XP

[Aaron Ballman]

On Thu, Oct 30, 2014 at 4:29 PM, Reid Kleckner <rnk at google.com> wrote:
> I'd like to raise our baseline Windows system requirements to Vista,
> dropping support for running LLVM on Windows XP. Microsoft dropped support
> for XP half a year ago in April 2014.
>
> Our current status is that we require VS 2012 to build LLVM, and VS 2012
> only runs on Vista+, but it has the ability produce binaries that run on XP.
> During the C++11-pocalypse, users expressed interest in keeping this
> working. I'm proposing that we drop support for this.
>
> Vista introduced a lot of handy system APIs that could significantly
> simplify LLVM's Support library. For example, I'd really like to use the
> blessed one-time initialization routines in this CL:
> http://reviews.llvm.org/D5922
>
> Vista also introduced a bunch of condition variable APIs that I know less
> about, but that's another reason we might want to raise our base requirement
> as people look into parallel LTO and codegen. It also seems likely that we
> will want to use some of the new C++11 library features that are only
> present in newer CRTs, which don't run on XP.
>
> Please respond if you have any objections. If there are no strong
> objections, I think we can start using Vista+ APIs in a week or so. We can
> still change our minds and revert stuff before the release if users feel
> this is too short notice.

I am in favor of this switch, assuming there are no strong objections.

~Aaron