diff options
| -rw-r--r-- | sys/sys/param.h | 16 |
1 files changed, 16 insertions, 0 deletions
diff --git a/sys/sys/param.h b/sys/sys/param.h index d2ead83edecd..87eba11e0e8f 100644 --- a/sys/sys/param.h +++ b/sys/sys/param.h @@ -60,6 +60,22 @@ #undef __FreeBSD_version #define __FreeBSD_version 1000001 /* Master, propagated to newvers */ +/* + * __FreeBSD_kernel__ indicates that this system uses the kernel of FreeBSD, + * which by definition is always true on FreeBSD. This macro is also defined + * on other systems that use the kernel of FreeBSD, such as GNU/kFreeBSD. + * + * It is tempting to use this macro in userland code when we want to enable + * kernel-specific routines, and in fact it's fine to do this in code that + * is part of FreeBSD itself. However, be aware that as presence of this + * macro is still not widespread (e.g. older FreeBSD versions, 3rd party + * compilers, etc), it is STRONGLY DISCOURAGED to check for this macro in + * external applications without also checking for __FreeBSD__ as an + * alternative. + */ +#undef __FreeBSD_kernel__ +#define __FreeBSD_kernel__ + #ifdef _KERNEL #define P_OSREL_SIGWAIT 700000 #define P_OSREL_SIGSEGV 700004 |