Eric Blake <eblake@xxxxxxxxxx> writes: > Indeed. The problem is that autoconf cannot tell if a non-empty literal > will expand to empty text (m4_ifdef results in no output). You'll have > to workaround it yourself: > AS_IF([test x"$var" != xfalse], > [$test=1], > [: m4_ifdef(...)]) But if the contents of m4_ifdef expand into shell code, doesn't this prepend : to the first line of that shell code, effectively commenting it out? It seems cleaner to use [:] in the else branch of m4_ifdef for that reason. -- Russ Allbery (rra@xxxxxxxxxxxx) <http://www.eyrie.org/~eagle/> _______________________________________________ Autoconf mailing list Autoconf@xxxxxxx https://lists.gnu.org/mailman/listinfo/autoconf
