[CAULDRON] Topics for the Toolchain and Linux kernel BoF

[Xi Ruoyao]

On Thu, 2024-09-12 at 18:13 +0200, Jose E. Marchesi wrote:
> - "noreturn" and jump tables run-time hints
> 
>   It has been expressed on the kernel side the desire of having the C compiler
>   emit run-time hints marking functions that are not supposed to return and
>   also to provide annotations on jump tables.  This is for the benefit of
>   objtool in arm64, see references below.
> 
>   Goal of the discussion:
> 
>   Collect and assess the requirements of these features, discuss their
>   pertinence and the way it could be best implemented.  The outcome of the
>   discussion will then be used to continue the discussion with the clang/llvm
>   and kernel hackers at LPC.
> 
>   References:
>   https://lore.kernel.org/linux-arm-kernel/YyLmhUxTUaNzaieC@hirez.programming.kicks-ass.net/

FWIW we are having very similar issues for using objtool in loongarch. 
And we also hit a similar issue with table-based computed goto.  I'm not
sure if the computed goto is an issue for arm64 either.

Some related materials:

- https://gcc.gnu.org/PR82365#c13
- https://gcc.gnu.org/PR116483
- https://gcc.gnu.org/pipermail/gcc-patches/2024-July/657641.html
(Nacked off-line)

-- 
Xi Ruoyao <xry111@xry111.site>
School of Aerospace Science and Technology, Xidian University