[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-devel] [PATCH v5 1/8] Kconfig: import kconfig.h from Linux 4.3
From: Shannon Zhao <shannon.zhao@xxxxxxxxxx> To support using CONFIG_ options in C/CPP expressions, import kconfig.h from the Linux v4.3 tag (commit id 6a13feb9c82803e2b815eca72fa7a9f5561d7861). CC: Doug Goldstein <cardoe@xxxxxxxxxx> Signed-off-by: Shannon Zhao <shannon.zhao@xxxxxxxxxx> --- xen/include/xen/config.h | 2 +- xen/include/xen/kconfig.h | 54 +++++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 55 insertions(+), 1 deletion(-) create mode 100644 xen/include/xen/kconfig.h diff --git a/xen/include/xen/config.h b/xen/include/xen/config.h index 7595599..eeb49db 100644 --- a/xen/include/xen/config.h +++ b/xen/include/xen/config.h @@ -7,7 +7,7 @@ #ifndef __XEN_CONFIG_H__ #define __XEN_CONFIG_H__ -#include <generated/autoconf.h> +#include <xen/kconfig.h> #ifndef __ASSEMBLY__ #include <xen/compiler.h> diff --git a/xen/include/xen/kconfig.h b/xen/include/xen/kconfig.h new file mode 100644 index 0000000..d68a7ed --- /dev/null +++ b/xen/include/xen/kconfig.h @@ -0,0 +1,54 @@ +#ifndef __XEN_KCONFIG_H +#define __XEN_KCONFIG_H + +#include <generated/autoconf.h> + +/* + * Helper macros to use CONFIG_ options in C/CPP expressions. Note that + * these only work with boolean and tristate options. + */ + +/* + * Getting something that works in C and CPP for an arg that may or may + * not be defined is tricky. Here, if we have "#define CONFIG_BOOGER 1" + * we match on the placeholder define, insert the "0," for arg1 and generate + * the triplet (0, 1, 0). Then the last step cherry picks the 2nd arg (a one). + * When CONFIG_BOOGER is not defined, we generate a (... 1, 0) pair, and when + * the last step cherry picks the 2nd arg, we get a zero. + */ +#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(__ignored, val, ...) val + +/* + * IS_BUILTIN(CONFIG_FOO) evaluates to 1 if CONFIG_FOO is set to 'y', 0 + * otherwise. For boolean options, this is equivalent to + * IS_ENABLED(CONFIG_FOO). + */ +#define IS_BUILTIN(option) config_enabled(option) + +/* + * IS_MODULE(CONFIG_FOO) evaluates to 1 if CONFIG_FOO is set to 'm', 0 + * otherwise. + */ +#define IS_MODULE(option) config_enabled(option##_MODULE) + +/* + * IS_REACHABLE(CONFIG_FOO) evaluates to 1 if the currently compiled + * code can call a function defined in code compiled based on CONFIG_FOO. + * This is similar to IS_ENABLED(), but returns false when invoked from + * built-in code when CONFIG_FOO is set to 'm'. + */ +#define IS_REACHABLE(option) (config_enabled(option) || \ + (config_enabled(option##_MODULE) && config_enabled(MODULE))) + +/* + * IS_ENABLED(CONFIG_FOO) evaluates to 1 if CONFIG_FOO is set to 'y' or 'm', + * 0 otherwise. + */ +#define IS_ENABLED(option) \ + (IS_BUILTIN(option) || IS_MODULE(option)) + +#endif /* __XEN_KCONFIG_H */ -- 2.0.4 _______________________________________________ Xen-devel mailing list Xen-devel@xxxxxxxxxxxxx http://lists.xen.org/xen-devel
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