According to Diego Elio “Flameeyes” Pettenò on 2/24/2010 8:27 AM:
The shell expansion ${a#b} is not portable to Solaris /bin/sh. Is that a problem for libvirt, or are we Linux-centric enough to not care?
That's definitely a problem I didn't think about, I was expecting POSIX shell to support that, but I'll look for another way.
POSIX, yes. But Solaris /bin/sh is not POSIX.
Underquoted; if the AC_MSG_ERROR were ever changed to contain a comma, then this would be passing an unintentional extra argument to AC_SEARCH_LIBS.
I have to double check that one but I think that if I were to quote that it wouldn't expand properly.
Maybe the alternative is to use m4_default_quoted (oops, not portable to older autoconf), or m4_default([$2], [[AC_MSG_ERROR([])]]) in the definition of action_if_not_found. The problem I'm trying to avoid is that you should be sure that AC_SEARCH_LIBS sees [AC_MSG_ERROR([])], and not the underquoted AC_MSG_ERROR([]), so that the contents of the error message can safely be changed to have m4 metacharacters without any impact.
Is this something that would be worth wrapping in an AC_CACHE_CHECK, to avoid repeating the check if config.cache exists?
The inner check is already cached, so I don't think there is much need for adding one further cache…
Good point. All of the heavy lifting is already in AC_SEARCH_LIBS, so adding another cache layer doesn't buy anything.
But this actually made me think that we might as well just use AC_SEARCH_LIB and rely on the value stored in the cache to begin with so I'll send a different version in a moment.
Which may render all of the above comments obsolete, depending on what you come up with. -- Eric Blake eblake@redhat.com +1-801-349-2682 Libvirt virtualization library http://libvirt.org