diff options
Diffstat (limited to 'drivers/gpu/drm/xe/xe_args.h')
| -rw-r--r-- | drivers/gpu/drm/xe/xe_args.h | 27 |
1 files changed, 27 insertions, 0 deletions
diff --git a/drivers/gpu/drm/xe/xe_args.h b/drivers/gpu/drm/xe/xe_args.h index 4dbc7e53c624..f550b5e3b993 100644 --- a/drivers/gpu/drm/xe/xe_args.h +++ b/drivers/gpu/drm/xe/xe_args.h @@ -122,6 +122,33 @@ #define PICK_ARG12(args...) PICK_ARG11(DROP_FIRST_ARG(args)) /** + * IF_ARGS() - Make selection based on optional argument list. + * @then: token to return if arguments are present + * @else: token to return if arguments are empty + * @...: arguments to check (optional) + * + * This macro allows to select a token based on the presence of the argument list. + * + * Example: + * + * #define foo X, Y + * #define bar IF_ARGS(Z, Q, foo) + * #define buz IF_ARGS(Z, Q, DROP_FIRST_ARG(FIRST_ARG(foo))) + * + * With above definitions bar expands to Z while buz expands to Q. + */ +#if defined(CONFIG_CC_IS_CLANG) || GCC_VERSION >= 100100 +#define IF_ARGS(then, else, ...) FIRST_ARG(__VA_OPT__(then,) else) +#else +#define IF_ARGS(then, else, ...) _IF_ARGS(then, else, CALL_ARGS(FIRST_ARG, __VA_ARGS__)) +#define _IF_ARGS(then, else, ...) __IF_ARGS(then, else, CALL_ARGS(COUNT_ARGS, __VA_ARGS__)) +#define __IF_ARGS(then, else, n) ___IF_ARGS(then, else, CALL_ARGS(CONCATENATE, ___IF_ARG, n)) +#define ___IF_ARGS(then, else, if) CALL_ARGS(if, then, else) +#define ___IF_ARG1(then, else) then +#define ___IF_ARG0(then, else) else +#endif + +/** * ARGS_SEP_COMMA - Definition of a comma character. * * This definition can be used in cases where any intermediate macro expects |