On 07/17/2013 01:05 PM, Guido Günther wrote:
Some versions of kFreeBSD (like 9.0) declare link_addr in a header but lack an implementation. This makes ./configure pass but breaks compilation later with a
undefined reference to `link_addr'
Althought that's a bug in the OS header we can detect it easily by also trying to link.
http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=715320 --- configure.ac | 14 ++++++++------ 1 file changed, 8 insertions(+), 6 deletions(-)
+ # Check for BSD approach for setting MAC addr -AC_CHECK_DECLS([link_addr], - [], [], - [#include <sys/types.h> - #include <sys/socket.h> - #include <net/if_dl.h> - ]) +AC_TRY_LINK([#include <sys/types.h>
I'd prefer we use AC_LINK_IFELSE here (upstream autoconf has deprecated AC_TRY_LINK on the grounds that AC_LINK_IFELSE has saner quoting rules in relation to the rest of the configure.ac file).
+ #include <sys/socket.h> + #include <net/if_dl.h>], + [link_addr(NULL, NULL)], + [AC_DEFINE([HAVE_DECL_LINK_ADDR], + [1], + [whether link_addr is available])])
The concept makes sense, but it's probably worth seeing a v2 just to make sure the modernized autoconf magic is correct. -- Eric Blake eblake redhat com +1-919-301-3266 Libvirt virtualization library http://libvirt.org