Re: [patch V2a 2/6] kbuild: Disable CC_HAS_ASM_GOTO_OUTPUT on clang < version 17

[David Laight <david.laight.linux@gmail.com>]

On Mon, 29 Sep 2025 08:53:37 -0700
Linus Torvalds <torvalds@linux-foundation.org> wrote:

> On Mon, 29 Sept 2025 at 04:10, Geert Uytterhoeven <geert@linux-m68k.org> wrote:
> >  
> > >
> > > Ah, d'0h indeed.
> > >
> > > void b(void **);void* c();int f(void){{asm goto(""::::l0);return 0;l0:return 1;}void *x __attribute__((cleanup(b))) = c();{asm goto(""::::l1);return 2;l1:return 1;}}

Should that be 'void *c(void);' (with an extra void) to avoid failing because
of the K&R function declaration?

	David

> > >
> > > Seems to still finger the issue on x86_64. That should build on !x86
> > > too, right?  
> >
> > Thanks, builds fine on arm32, arm64, riscv, m68k, powerpc, mips, s390.  
> 
> Ok, I just applied that fix directly. It's clearly not a fatal bug
> since it just falls back on the non-optimal code, but it's one of
> those "silly and subtle code generation issues" so I'd rather have it
> fixed asap in the upstream kernel.
> 
> Geert, thanks for noticing.
> 
>              Linus
>