On 29/02/2024 4:21 pm, Nicola Vetrini wrote: > On 2024-02-29 17:10, Andrew Cooper wrote: >> On 29/02/2024 3:27 pm, Nicola Vetrini wrote: >>> diff --git a/xen/include/xen/kconfig.h b/xen/include/xen/kconfig.h >>> index c25dc0f6c2a9..b7e70289737b 100644 >>> --- a/xen/include/xen/kconfig.h >>> +++ b/xen/include/xen/kconfig.h >>> @@ -25,7 +25,7 @@ >>> #define __ARG_PLACEHOLDER_1 0, >>> #define config_enabled(cfg) _config_enabled(cfg) >>> #define _config_enabled(value) >>> __config_enabled(__ARG_PLACEHOLDER_##value) >>> -#define __config_enabled(arg1_or_junk) >>> ___config_enabled(arg1_or_junk 1, 0) >>> +#define __config_enabled(arg1_or_junk) >>> ___config_enabled(arg1_or_junk (1), (0)) >>> #define ___config_enabled(__ignored, val, ...) val >> >> This one hunk I suggest we deviate rather than adjust. You've subtly >> broken it, and it's extreme preprocessor magic in the first place to >> turn an absent symbol into a 0. >> > > How so? I did test this because I was very wary of it, but it seemed > to expand fine (either if ((0)) or if ((1)) ). I may of course be > wrong, and it could be deviated regardless. >
arg1_or_junk(1) can now be a function or macro expansion depending on context, where previously it couldn't be. ~Andrew
