How to modify configure.ac for add new lib into Makefile variable LIBS?

[Dan Nicholson]

On 8/30/07, Xue Wei <Wei.Xue at sun.com> wrote:
>
>  I am trying to add some file into libX117.2, but when I compiled, I need
> add some used library into Makefile, for example,  add -llayout to variable
> LIBS which in Makefile. As you known, libX117.2 use auto configure tool to
> generic Makefile, so I have to modify file configure.ac .
>  But unfortunately I am not a export about auto configure. Could anyone
> please tell me how to modify configure.ac to make variable LIBS in Makefile
> be add new libs such lick -llayout?

There are a lot of different ways to do this. If the liblayout library
has an associated pkg-config file (/usr/lib/pkgconfig/layout.pc or
something), then you'd do something like this

configure.ac:
PKG_CHECK_MODULES(LAYOUT, layout)

Makefile.am:
AM_CFLAGS = $(LAYOUT_CFLAGS)
theprogram_LIBADD = $(LAYOUT_LIBS)

If you don't have a pkg-config file, then it's a little different.

configure.ac:
AC_CHECK_LIB(layout, some_function_in_liblayout)

This will add -llayout to the LIBS variable if it's found, and then it
will be linked into all programs and libraries. The drawback is that
this doesn't handle the case where liblayout and its headers aren't in
a standard location. It also doesn't say what to do if liblayout is or
is not found.

You should be able to find many examples in the Xorg sources.

--
Dan