Building Clang 8/9 in El Capitan

[Ryan Schmidt]

On Feb 13, 2021, at 03:42, Ken Cunningham wrote:

> Thread local includes __thread, Thread_local, and thread_local.
> 
> The compilers that support them are all different.
> 
> To make it easy for people to not think about it much, especially when you’re not talking about bootstrapping compiler, etc, MacPorts base just treats them all the same.
> 
> The system clang on 10.7 supports thread_local storage.
> 
> But base excludes it because it doesn’t support the “thread_local” keyword.
> 
> And 100 more complicated examples I could explain further to you if you are interested in learning more about it.

Ok, so it sounds like "compiler.thread_local_storage yes" might in some circumstances exclude a compiler that would have been able to build the code. I guess when this option was added to base it was thought to be simpler to have one option that encompasses several related features.

Per this thread, the clang in Xcode 7.3 doesn't have sufficient thread localness to build clang 8 on 10.11 but the clang in Xcode 8.2.1 does. That would seem to suggest that adding "compiler.thread_local_storage yes" would fix it. But a counterargument is that Xcode 7.2.1 is able to build clang 8 on 10.10. So it comes back to needing to see the build log of the failure.