Re: [PATCH] configure.ac: rework/fix the NEEDS_RESOLV and NEEDS_LIBGEN tests

From: Junio C Hamano <gitster@pobox.com>
Date: Jul 21, 2009, 20:33 UTC
Message-ID: <7v3a8pdbdr.fsf@alter.siamese.dyndns.org>
In-Reply-To: <N0R1rELOlDFDG8pOY2LYJHmWygM5WFD8q_fNZgfE1A2QOX1yg6OPCZW4RbX5i03hokq4Bx2zOjM@cipher.nrlssc.navy.mil>

Brandon Casey <casey@nrlssc.navy.mil> writes:

> Maybe this is the appropriate thing to do?

Thanks.

Instead of saying that "hstrerror not in -lc means we do have -lresolv and the function will be found there" blindly, we may want to have a nested check.

	AC_CHECK_LIB([c], [hstrerror], [NEEDS_RESOLV=],
       	    AC_CHECK_LIB([resolv], [hstrerror], [NEEDS_RESOLV=YesPlease]))

But we do not have any provision for the case where -lc does not have it and -lresolv does not have it either (or -lresolv does not exist) anyway, so we might as well go with your patch.

I take it that swapping [if-found][if-not-found] parameters is what the autoconf documentation warns against? That is, both -lc and -lresolv may have it but -lresolv one may be a specialized one you would not normally want.

Show 25 quoted lines

>  configure.ac |    4 ++--
>  1 files changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/configure.ac b/configure.ac
> index 74d0af5..ba44cf2 100644
> --- a/configure.ac
> +++ b/configure.ac
> @@ -479,13 +479,13 @@ test -n "$NEEDS_SOCKET" && LIBS="$LIBS -lsocket"
>  # Define NEEDS_RESOLV if linking with -lnsl and/or -lsocket is not enough.
>  # Notably on Solaris hstrerror resides in libresolv and on Solaris 7
>  # inet_ntop and inet_pton additionally reside there.
> -AC_CHECK_LIB([resolv], [hstrerror],
> +AC_CHECK_LIB([c], [hstrerror],
>  [NEEDS_RESOLV=],
>  [NEEDS_RESOLV=YesPlease])
>  AC_SUBST(NEEDS_RESOLV)
>  test -n "$NEEDS_RESOLV" && LIBS="$LIBS -lresolv"
>  
> -AC_CHECK_LIB([gen], [basename],
> +AC_CHECK_LIB([c], [basename],
>  [NEEDS_LIBGEN=],
>  [NEEDS_LIBGEN=YesPlease])
>  AC_SUBST(NEEDS_LIBGEN)
> -- 
> 1.6.3.1.24.g152f4