standardized add-on package configuration

Torsten Hothorn writes:

On Wed, 15 Nov 2000, Kurt Hornik wrote:

Several add-on packages (e.g., most DBMS ones, XML, ...) come with a
configure script which tries to find headers and libraries required by
the package.  I was wondering whether we could/should standardize how
this is done.

IMO the main problem is that header files and libraries are not in
/usr/include or /usr/lib but, for example, for mysql in
/usr/local/mysql/{include,lib} by default. A package should build
without interaction if headers and libs are in their default place.

In what follows, suppose package FOO needs functionality BAR.

* One approach would be via command-line arguments to configure.  There
seems to be no standard for this.  GNOME uses

--with-FOO-prefix
--with-FOO-exec-prefix

in several of its components.  However, this, assumes that the GNU
standards are followed in the sense that headers go into

FOO-prefix/include

and libs go into

FOO-exec-prefix/lib

which might not necessarily be the case.

Alternatively, we could have

--with-FOO-libraries
--with-FOO-libs

and

--with-FOO-includes
--with-FOO-headers

(one of each only, of course).

Can one define default values here?

* The other possibility would be via environment variables, such as
CPPFLAGS and LIBS or maybe FOO_CPPFLAGS and FOO_LIBS.  (E.g., for
package XML we would use LIBXML_CPPFLAGS and LIBXML_LIBS.)

I think the simplest solution would be via CPPFLAGS and LIBS because it
is not package-specific.  So installation would happen via

CPPFLAGS=... LIBS=... R CMD INSTALL /path/to/pkg.tar.gz

Maybe it is possible to check if CPPFLAGS is empty (replace it with a
default value) or not (try to build the package and give an error
message if it failed, pointing to the appropriate environment
variable)?

(did not check if this works now).

Now I did not check all packages, so is there something I may be
overlooking?

(Once we agree on a standard, I would like to document it in R-exts.)

-k