[libvirt] [PATCH v3 1/5] config-post.h: define __GNUC_PREREQ if not defined

Several gnulib headers rely on features.h being included by ctype.h to provide __GNUC_PREREQ, but on systems without glibc, this is not provided. In these cases __GNUC_PREREQ gets redefined to 0, which causes build errors from checks in src/internal.h. Therefore, define __GNUC_PREREQ as early as possible. config.h is probably the first header that is included, before any other headers. --- config-post.h | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+) diff --git a/config-post.h b/config-post.h index 2398d3d..9243d7d 100644 --- a/config-post.h +++ b/config-post.h @@ -67,3 +67,21 @@ # undef WITH_SECDRIVER_APPARMOR # undef WITH_CAPNG #endif /* LIBVIRT_NSS */ + +/* + * Define __GNUC__ to a sane default if it isn't yet defined. + * This is done here so that it's included as early as possible; gnulib relies + * on this to be defined in features.h, which should be included from ctype.h. + * This doesn't happen on many non-glibc systems. + * When __GNUC__ is not defined, gnulib defines it to 0, which breaks things. + */ +#ifdef __GNUC__ +# ifndef __GNUC_PREREQ +# if defined __GNUC__ && defined __GNUC_MINOR__ +# define __GNUC_PREREQ(maj, min) \ + ((__GNUC__ << 16) + __GNUC_MINOR__ >= ((maj) << 16) + (min)) +# else +# define __GNUC_PREREQ(maj, min) 0 +# endif +# endif +#endif -- 2.7.0