Re: [gentoo-alt] Update clang failed (El Captain)

[Fabian Groffen]

Hi Michael,

I think I understand your points:
- I don't understand why systems get messed up xcode-wise either, but
  I'm sure not everyone has root access to fix it
- My current workaround works currently, indeed, dunno about the future
- Doing more patchwork is discouraged by llvm maintainer(s?),
  didn't like my above patch, and in fact told me to leave the llvm
  ebuilds alone because the patches are not acceptable/accepted by
  upstream, if you got ideas for this...
- Currently we don't do much cross work indeed, it's never been an aim
  either, but until the day someone needs it, I guess
- The libcxx{abi,-headers} situation needs love too, since we have
  different ebuilds for Prefix

Fabian

On 11-09-2016 02:05:49 +0200, Michael Weiser wrote:
> Hi Fabian,
>
> On Sun, Sep 04, 2016 at 05:06:56PM +0200, Fabian Groffen wrote:
>
> > I've patched the function to return / in case xcodebuild returns nothing
> > useful, such that we fall back to /usr/include, which makes the whole
> > thing compile for me.
>
> Well, I'd like to stress again that having Command Line Tools selected
> as the currently selected Xcode does not seem to be supported by the
> llvm cmake build system in Apple mode. As far as it's concerned someone
> building llvm needs to have a proper Xcode selected using xcode-select
> -s so it can find the SDKs within it.
>
> Is it actually possible to have only Command Line Tools installed
> (without Xcode) and get stuff to compile? I'm quite sure it was not in
> the olden days (<= 10.6).
>
> Also, I don't understand why there's a separate instance of the Command
> Line Tools somewhere in /Library and how it happens to be the default
> "Xcode" for some/most people. And also2, I don't understand why
> xcode-select even accepts it as a parameter for -s. This is all very
> weird.
>
> Anyway, I thought of your solution as well while paddling along the
> Peene. :) But on second thought I was wondering if we shouldn't patch
> any SDK selection and osx-min-version/OSX_DEPLOYMENT_TARGET for the host
> system (!) out of llvm/clang for prefix altogether. Prefix is always
> meant for the host system, right? Without any of this selection stuff,
> the compiler will fall back to the default include paths like
> /usr/include anyways and we eliminate a whole lot of possible grief in
> the future. IIRC I did this for 3.4.2 for exactly that reason but that
> got lost on the move to cmake some time around 3.7, I think.
>
> The only place I can think of where we'd need SDKs in the context of
> prefix is if we wanted to provide a fully cross-capable Apple-like
> toolchain for iOS and WatchOS and stuff like that. While binutils-apple
> should be able to provide that I guess no-one's ever even tested or
> played with it in that direction. And again, we'd need a proper Xcode
> installed and selected to find and use the proper SDKs for that. Full
> circle...
> --
> Thanks, Micha
> Ich mag Kaba!
>

-- 
Fabian Groffen
Gentoo on a different level