On 11/11/2016 07:08 AM, Felix Janda wrote: > Currently, libc-compat.h detects inclusion of specific glibc headers, > and defines corresponding _UAPI_DEF_* macros, which in turn are used in > uapi headers to prevent definition of conflicting structures/constants. > There is no such detection for other c libraries, for them the > _UAPI_DEF_* macros are always defined as 1, and so none of the possibly > conflicting definitions are suppressed. > > This patch enables non-glibc c libraries to request the suppression of > any specific interface by defining the corresponding _UAPI_DEF_* macro > as 0. > > This patch together with the recent musl libc commit > > http://git.musl-libc.org/cgit/musl/commit/?id=04983f2272382af92eb8f8838964ff944fbb8258 Would it be possible to amend the musl patch to define the macros to 1. A defined or undefined macro is typo prone. Please see this wiki for examples of the problems it causes: https://sourceware.org/glibc/wiki/Wundef Having the UAPI macros always defined and be 0 or 1 allows you to create tooling to check for problems, while an undefined macro is just that, either a mistake or the intended value. > fixes the following compiler errors when <linux/in6.h> is included > after musl <netinet/in.h>: > > ./linux/in6.h:32:8: error: redefinition of 'struct in6_addr' > ./linux/in6.h:49:8: error: redefinition of 'struct sockaddr_in6' > ./linux/in6.h:59:8: error: redefinition of 'struct ipv6_mreq' Do you have plans for fixing the error when the inclusion order is the other way? It will require kernel header changes to have each individual kernel header define the requisite __UAPI_* values to 1 e.g. moving libc-compat.h into the header. Do you plan to do that in a next step? > Signed-off-by: Felix Janda <felix.janda@xxxxxxxxx> > --- > The previous mail misspelled the kernel mailing list. I am sorry for > this resulting spam. > > There has already been one reply, which is available at > > http://www.openwall.com/lists/musl/2016/11/11/2 > --- > include/uapi/linux/libc-compat.h | 52 ++++++++++++++++++++++++++++++++++++++++ > 1 file changed, 52 insertions(+) > > diff --git a/include/uapi/linux/libc-compat.h b/include/uapi/linux/libc-compat.h > index 44b8a6b..c316725 100644 > --- a/include/uapi/linux/libc-compat.h > +++ b/include/uapi/linux/libc-compat.h > @@ -171,42 +171,94 @@ > #else /* !defined(__GLIBC__) */ Would you please update the lead comment in libc-compat.h explaining this usage model so glibc and other libc's can follow best practice. Any new usage model should express how to fix header inclusion ordering in both directions. > /* Definitions for if.h */ > +#if !defined(__UAPI_DEF_IF_IFCONF) Typo prone. Please use #if __UAPI_DEF_IF_IFCONF for all of this. > #define __UAPI_DEF_IF_IFCONF 1 > +#endif > +#if !defined(__UAPI_DEF_IF_IFMAP) > #define __UAPI_DEF_IF_IFMAP 1 > +#endif > +#if !defined(__UAPI_DEF_IFNAMSIZ) > #define __UAPI_DEF_IF_IFNAMSIZ 1 > +#endif > +#if !defined(__UAPI_DEF_IFREQ) > #define __UAPI_DEF_IF_IFREQ 1 > +#endif > /* Everything up to IFF_DYNAMIC, matches net/if.h until glibc 2.23 */ > +#if !defined(__UAPI_DEF_IF_NET_DEVICE_FLAGS) > #define __UAPI_DEF_IF_NET_DEVICE_FLAGS 1 > +#endif > /* For the future if glibc adds IFF_LOWER_UP, IFF_DORMANT and IFF_ECHO */ > +#if !defined(__UAPI_DEF_IF_NET_DEVICE_FLAGS_LOWER_UP_DORMANT_ECHO) > #define __UAPI_DEF_IF_NET_DEVICE_FLAGS_LOWER_UP_DORMANT_ECHO 1 > +#endif > > /* Definitions for in.h */ > +#if !defined(__UAPI_DEF_IN_ADDR) > #define __UAPI_DEF_IN_ADDR 1 > +#endif > +#if !defined(__UAPI_DEF_IN_IPPROTO) > #define __UAPI_DEF_IN_IPPROTO 1 > +#endif > +#if !defined(__UAPI_DEF_IN_PKTINFO) > #define __UAPI_DEF_IN_PKTINFO 1 > +#endif > +#if !defined(__UAPI_DEF_IP_MREQ) > #define __UAPI_DEF_IP_MREQ 1 > +#endif > +#if !defined(__UAPI_DEF_SOCKADDR_IN) > #define __UAPI_DEF_SOCKADDR_IN 1 > +#endif > +#if !defined(__UAPI_DEF_IN_CLASS) > #define __UAPI_DEF_IN_CLASS 1 > +#endif > > /* Definitions for in6.h */ > +#if !defined(__UAPI_DEF_IN6_ADDR) > #define __UAPI_DEF_IN6_ADDR 1 > +#endif > +#if !defined(__UAPI_DEF_IN6_ADDR_ALT) > #define __UAPI_DEF_IN6_ADDR_ALT 1 > +#endif > +#if !defined(__UAPI_DEF_SOCKADDR_IN6) > #define __UAPI_DEF_SOCKADDR_IN6 1 > +#endif > +#if !defined(__UAPI_DEF_IPV6_MREQ) > #define __UAPI_DEF_IPV6_MREQ 1 > +#endif > +#if !defined(__UAPI_DEF_IPPROTO_V6) > #define __UAPI_DEF_IPPROTO_V6 1 > +#endif > +#if !defined(__UAPI_DEF_IPV6_OPTIONS) > #define __UAPI_DEF_IPV6_OPTIONS 1 > +#endif > +#if !defined(__UAPI_DEF_IN6_PKTINFO) > #define __UAPI_DEF_IN6_PKTINFO 1 > +#endif > +#if !defined(__UAPI_DEF_IP6_MTUINFO) > #define __UAPI_DEF_IP6_MTUINFO 1 > +#endif > > /* Definitions for ipx.h */ > +#if !defined(__UAPI_DEF_SOCKADDR_IPX) > #define __UAPI_DEF_SOCKADDR_IPX 1 > +#endif > +#if !defined(__UAPI_DEF_IPX_ROUTE_DEFINITION) > #define __UAPI_DEF_IPX_ROUTE_DEFINITION 1 > +#endif > +#if !defined(__UAPI_DEF_IPX_INTERFACE_DEFINITION) > #define __UAPI_DEF_IPX_INTERFACE_DEFINITION 1 > +#endif > +#if !defined(__UAPI_DEF_IPX_CONFIG_DATA) > #define __UAPI_DEF_IPX_CONFIG_DATA 1 > +#endif > +#if !defined(__UAPI_DEF_IPX_ROUTE_DEF) > #define __UAPI_DEF_IPX_ROUTE_DEF 1 > +#endif > > /* Definitions for xattr.h */ > +#if !defined(__UAPI_DEF_XATTR) > #define __UAPI_DEF_XATTR 1 > +#endif > > #endif /* __GLIBC__ */ > > -- Cheers, Carlos. -- To unsubscribe from this list: send the line "unsubscribe linux-api" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
