On 2/4/19 9:31 AM, Patrick Steinhardt wrote: > Since glibc 2.2, the function res_querydomain(3) is implemented as a > define to `__res_querydomain`. Due to this implementation detail, using > `AC_CHECK_LIB` with a symbol name of "res_querydomain" will cause a > linking failure and thus fail to detect its availability. This is why > right now, we try to detect availability of `__res_querydomain` instead. > > Unfortunately, this may break on other platforms where there is no > `__res_querydomain` but only the function without leading underscores. > To fix this, we can perform another `AC_CHECK_LIB([resolv], > [res_querydomain], ...)` call in case where the other one was not found > and only raise an error if both symbols weren't found. > > Signed-off-by: Patrick Steinhardt <ps@xxxxxx> Committed... steved. > --- > configure.ac | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/configure.ac b/configure.ac > index 4bf5aea..cb9d921 100644 > --- a/configure.ac > +++ b/configure.ac > @@ -411,7 +411,8 @@ if test "$enable_gss" = yes; then > fi > > dnl libdnsidmap specific checks > -AC_CHECK_LIB([resolv], [__res_querydomain], , AC_MSG_ERROR(res_querydomain needed)) > +AC_CHECK_LIB([resolv], [__res_querydomain], , > + AC_CHECK_LIB([resolv], [res_querydomain], , AC_MSG_ERROR(res_querydomain needed))) > > AC_ARG_ENABLE([ldap], > [AS_HELP_STRING([--disable-ldap],[Disable support for LDAP @<:default=detect@:>@])]) >
