Re: [PATCH v3] docs: rust: Add rusttest info

[John Hubbard <jhubbard@nvidia.com>]

On 12/12/23 04:43, Miguel Ojeda wrote:
> On Tue, Dec 12, 2023 at 4:14 AM John Hubbard <jhubbard@nvidia.com> wrote:
>>
>> "make LLVM=1 <anything>" doesn't work for me, and therefore I suspect it
>> doesn't work for at least a few other people, as well.
>>
>> Instead, I have to run "make CC=clang <anything>", which works just
>> fine.
>>
>> The docs should consistently reflect this, yes?
> 
> No, they should not. `LLVM=1` is the "right" one for all architectures
> (except s390) -- see Documentation/kbuild/llvm.rst.

ah OK. I appear to have been slightly misled by
Documentation/rust/quick-start.rst, which made it seem like CC=clang
was...a thing. This excerpt made me do it:

Building a kernel with a complete LLVM toolchain is the best supported setup
at the moment. That is::

	make LLVM=1

For architectures that do not support a full LLVM toolchain, use::

	make CC=clang


> 
> If `LLVM=1` does not work for you, then that should be fixed. Could
> you please give some details? For instance, is it related to Rust
> (does it work with a `defconfig` build without enabling Rust)? Do you
> have all the LLVM software installed with the right names (see what
> `LLVM=1` expands to)? etc.
> 
> (Cc'ing Nathan)
> 

Probably just a basic failure to fully set up LLVM on my part. I'll
use the bug reporting that Nathan pointed to, if it turns out that
there is anything actually wrong upstream. I just short-circuited
the whole investigation (it's a "quick" start, after all) when I
saw the CC=clang point.

Anyway, I wanted to provide this "how does the documentation look
to a newcomer" feedback, in case it helps.


thanks,
-- 
John Hubbard
NVIDIA