From: Eric Blake <ebb9@byu.net>
Date: Sun, 19 Jul 2009 22:53:16 GMT
Subject: Re: [PATCH] Re: configure: use AC_SEARCH_LIBS instead of AC_CHECK_LIB
Message-ID: <loom.20090719T225210-990@post.gmane.org>
In-Reply-To: <7v3a8szm4q.fsf@alter.siamese.dyndns.org>

Junio C Hamano <gitster <at> pobox.com> writes:

> The autoconf documentation does not give much confidence either way:
> 
> 	AC_CHECK_LIB requires some care in usage, and should be avoided in
> 	some common cases.
> 
> It is unclear what these "some" are, and is sufficiently unclear for us to
> decide if our situation falls into these "some common cases."  The only
> problem it cites is that alternative libraries may contain a variant
> implementation of the same function found in a more common library, in
> which case you may not want to use such an alternative implementation, and
> I do not think "basename() in -lgen" falls into that category.

Please report that as a bug to the autoconf lists, then.

> If autoconf people say AC_SEARCH_LIBS() should be preferred over
> AC_CHECK_LIB(), it probably is the right thing to do.  But I want to have
> a warmer-and-fuzzier feeling that we understand why it went wrong, rather
> than blindly doing what the documentation says because the documentation
> tells us to.

As autoconf maintainer (and hoping to release autoconf 2.64 soon), yes, I can
definitively say that AC_SEARCH_LIBS is nicer than AC_CHECK_LIB.

-- 
Eric Blake