Am 01.08.2016 um 17:33 schrieb Gedare Bloom: > On Mon, Aug 1, 2016 at 10:04 AM, Christian Mauderer > <christian.maude...@embedded-brains.de> wrote: >> Hello, >> >> we have a special use case where we want to use the new network stack >> but without the IPv6 support. I could need some advice how this could be >> integrated into the waf build system. If we find a good solution, this >> could also be an example for other BSD Kernel options. >> >> >> I found multiple places where IPv6 is enabled in libbsd: >> >> If I remove the INET6 option out of the FreeBSD kernel configuration on >> a FreeBSD system, this has the effect, that the "opt_inet6.h" is >> generated as an empty file instead of with a single define "#define >> INET6 1". In the rtems-libbsd the configuration header is located at >> rtemsbsd/include/rtems/bsd/local/opt_inet6.h. It has a fixed content >> with the define set. This would be the first place where the support >> would have to be disabled. >> >> Beneath that, some user space tools have a special option to enable IPv6 >> which is currently set in libbsd.py. One such example is tcpdump with a >> compiler flag '-DINET6' set. As far as I could tell, the kernel and >> every application that is included in libbsd currently uses the INET6 >> macro. But I think this is more of a convention than a general rule. >> >> >> So I think we would roughly need the following: >> >> If i configure libbsd using >> >> waf configure --disable-ipv6 >> >> the build system would either have to regenerate opt_inet6.h or use an >> alternative version of it. Further I would need the ability to set >> compiler flags in libbsd.py depending on this configure option. >> >> >> Are there any better ideas how to implement such an option? >> >> I'm quite inexperienced on how to use waf, so I would need some guidance >> how this could be implemented. Are there any hints how I could start >> implementing such an option? Some examples or similar code? >> > The "Waf Book" is handy for learning how to hack on waf. Sounds like > you should add your option in the top-level wscript options(), then > parse it in libbsd_waf to determine whether or not to use ipv6. waf > does not modify the source files, and these includes appear to remain > in the source, so it might be easier to generate an empty header file > and always provide the define through the command line instead, by > adding e.g. -DINET6 to cflags by default and removing it in case the > option is used. >
Hello Gedare, thanks for the hint directing to the Waf Book. I'll use it as a reference. For the define I would prefer the solution that Chris suggested (adding a custom RTEMS define and set the INET6 in the header dependent on this). That prevents that a macro with a generic name like INET6 is set over a large number of files that don't use it or might want to use the name for something else. Kind Regards Christian Mauderer -- -------------------------------------------- embedded brains GmbH Christian Mauderer Dornierstr. 4 D-82178 Puchheim Germany email: christian.maude...@embedded-brains.de Phone: +49-89-18 94 741 - 18 Fax: +49-89-18 94 741 - 08 PGP: Public key available on request. Diese Nachricht ist keine geschäftliche Mitteilung im Sinne des EHUG. _______________________________________________ devel mailing list devel@rtems.org http://lists.rtems.org/mailman/listinfo/devel
