[llvm] r320413 - [cmake] Pass TARGETS_TO_BUILD through to host tools build

[Alex Bradbury via llvm-commits]

On 12 December 2017 at 22:04, Justin Bogner via llvm-commits
<llvm-commits at lists.llvm.org> wrote:
> Alex Bradbury <asb at lowrisc.org> writes:
>> Justin: which resolution would you prefer? Passing through an escaped
>> LLVM_EXPERIMENTAL_TARGETS_TO_BUILD does fix the build for me. So does
>> reverting of course :)
>
> The way EXPERIMENTAL_TARGETS_TO_BUILD works is kind of insane. It really
> doesn't make sense that saying TARGETS_TO_BUILD=RISCV doesn't just
> work. I think the correct medium/long term solution is to rework
> experimental targets so you can add them to the regular targets list,
> but they just aren't included as part of the default "All". Maybe also
> allow things like "All;RISCV", "Experimental", and "All;Experimental".
>
> Of course, I'm not sure if you or I have the bandwidth to take on fixing
> that right now, so the below seems fine as a short term solution. It
> certainly can't hurt anything. Feel free to commit that.

Committed in r320556.

Honestly I'm not sure the current interface is so bad - there's an
advantage in making it really obvious in your cmake invocation that
you're building an experimental target. It might not work, it might be
removed next week and having these targets segregated clearly in
-DLLVM_EXPERIMENTAL_TARGETS_TO_BUILD means it's impossible to miss.

Best,

Alex