Re: [RFC 05/31] x86/compiler: Tweak __UNIQUE_ID naming

Peter Zijlstra
2024-09-03T07:56:39Z

On Mon, Sep 02, 2024 at 08:59:48PM -0700, Josh Poimboeuf wrote:
> Add an underscore between the "name" and the counter so tooling can
> distinguish between the non-unique and unique portions of the symbol
> name.
>
> This will come in handy for "objtool klp diff".
>
> Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
> ---
> include/linux/compiler.h | 8 ++++++--
> 1 file changed, 6 insertions(+), 2 deletions(-)
>
> diff --git a/include/linux/compiler.h b/include/linux/compiler.h
> index 8c252e073bd8..d3f100821d45 100644
> --- a/include/linux/compiler.h
> +++ b/include/linux/compiler.h
> @@ -186,7 +186,11 @@ void ftrace_likely_update(struct ftrace_likely_data *f, int val,
> __asm__ ("" : "=r" (var) : "0" (var))
> #endif
>
> -#define __UNIQUE_ID(prefix) __PASTE(__PASTE(__UNIQUE_ID_, prefix), __COUNTER__)
> +/* Format: __UNIQUE_ID_<name>_<__COUNTER__> */
> +#define __UNIQUE_ID(name) \
> + __PASTE(__UNIQUE_ID_, \
> + __PASTE(name, \
> + __PASTE(_, __COUNTER__)))

OK, that's just painful to read; how about so?

__PASTE(__UNIQUE_ID_, \
__PASTE(name, \
__PASTE(_, __COUNTER)))

>
> /**
> * data_race - mark an expression as containing intentional data races
> @@ -218,7 +222,7 @@ void ftrace_likely_update(struct ftrace_likely_data *f, int val,
> */
> #define ___ADDRESSABLE(sym, __attrs) \
> static void * __used __attrs \
> - __UNIQUE_ID(__PASTE(__addressable_,sym)) = (void *)(uintptr_t)&sym;
> + __UNIQUE_ID(__PASTE(addressable_, sym)) = (void *)(uintptr_t)&sym;

This change doesn't get mention ?

> #define __ADDRESSABLE(sym) \
> ___ADDRESSABLE(sym, __section(".discard.addressable"))
>
> --
> 2.45.2
>