Re: [PATCH 0/2] RISC-V: Fix CONFIG_AS_HAS_OPTION_ARCH with tip of tree LLVM

[Eric Biggers <ebiggers@kernel.org>]

On Thu, Jan 25, 2024 at 10:32:10AM -0700, Nathan Chancellor wrote:
> Hi all,
> 
> Eric reported that builds of LLVM with [1] (close to tip of tree) have
> CONFIG_AS_HAS_OPTION_ARCH=n because the test for expected failure on
> invalid input has started succeeding.
> 
> This Kconfig test was added because '.option arch' only causes an
> assembler warning when it is unsupported, rather than a hard error,
> which is what users of as-instr expect when something is unsupported.
> 
> This can be resolved by turning assembler warnings into errors with
> '-Wa,--fatal-warnings' like we do with the compiler with '-Werror',
> which is what the first patch does. The second patch removes the invalid
> test, as the valid test is good enough with fatal warnings.
> 
> I have diffed several configurations for the different architectures
> that use as-instr and I have found no issues.
> 
> I think this could go in through either the kbuild or RISC-V tree with
> sufficient acks but I will let them fight over who takes it :)
> 
> [1]: https://github.com/llvm/llvm-project/commit/3ac9fe69f70a2b3541266daedbaaa7dc9c007a2a
> 
> ---
> Nathan Chancellor (2):
>       kbuild: Add -Wa,--fatal-warnings to as-instr invocation
>       RISC-V: Drop invalid test from CONFIG_AS_HAS_OPTION_ARCH
> 
>  arch/riscv/Kconfig        | 1 -
>  scripts/Kconfig.include   | 2 +-
>  scripts/Makefile.compiler | 2 +-
>  3 files changed, 2 insertions(+), 3 deletions(-)

Looks good,

Tested-by: Eric Biggers <ebiggers@google.com>

Unfortunately another LLVM commit just broke TOOLCHAIN_HAS_VECTOR_CRYPTO, so
I've sent out a patch to fix that too...

But with all the fixes applied it works again.

- Eric