Re: [PATCH] scripts: headers_install.sh: Normalize __ASSEMBLY__ to __ASSEMBLER__

[Thomas Huth]

On 09/03/2026 16.58, Thomas Weißschuh wrote:
> There is an ongoing effort to replace the usage of __ASSEMBLER__ with
> __ASSEMBLY__ throughout the kernel tree, see for example
> commit 287d163322b7 ("arm64: Replace __ASSEMBLY__ with __ASSEMBLER__ in
> non-uapi headers"). The latter is automatically provided by all compilers
> and preprocessors supported by the kernel, so the explicit definitions
> of __ASSEMBLER__ can be removed.
>
> However the UAPI headers might be used with older (< GCC 3.0) or
> non-GCC-compatible compilers, which do not define __ASSEMBLY__
> automatically.

 Hi!

I just had a try with gcc 2.95.4 from a Debian Woody installation, and it 
defines __ASSEMBLER__ automatically when compiling *.S files, i.e. gcc 2.95 
does not seem to be a problem. So can you point me to a real case where 
someone tried to use a user space compiler where __ASSEMBLER__ was not 
defined automatically? Otherwise, I think this patch could be reverted again.

 Thanks,
  Thomas

> So this migration may brake users.
> Also during the migration phase, the UAPI headers will use a mix of
> *both* __ASSEMBLY__ and __ASSEMBLER__ at the same time, which is ugly.
>
> For now make sure that the exported UAPI headers consistently use
> __ASSEMBLER__ as before.
>
> Link: https://lore.kernel.org/lkml/164baf81-2824-4943-bbc1-4ae8a160c0cc@xxxxxxxx/
> Signed-off-by: Thomas Weißschuh <linux@xxxxxxxxxxxxxx>
> ---
> This should go either through kbuild or asm-generic, I think.
> ---
>   scripts/headers_install.sh | 1 +
>   1 file changed, 1 insertion(+)
>
> diff --git a/scripts/headers_install.sh b/scripts/headers_install.sh
> index 9c15e748761c..2f1d1767ca26 100755
> --- a/scripts/headers_install.sh
> +++ b/scripts/headers_install.sh
> @@ -36,6 +36,7 @@ sed -E -e '
>   	s/(^|[^a-zA-Z0-9])__packed([^a-zA-Z0-9_]|$)/\1__attribute__((packed))\2/g
>   	s/(^|[[:space:](])(inline|asm|volatile)([[:space:](]|$)/\1__\2__\3/g
>   	s@#(ifndef|define|endif[[:space:]]*/[*])[[:space:]]*_UAPI@#\1 @
> +	s/__ASSEMBLY__/__ASSEMBLER__/g
>   ' $INFILE > $TMPFILE || exit 1
>   
>   scripts/unifdef -U__KERNEL__ -D__EXPORTED_HEADERS__ $TMPFILE > $OUTFILE