APRVARS versus make variables

["Roy T. Fielding" <fi...@ebuilt.com>]

Another thing I am having a hard time deciding is whether it is better
to generate a file of environment variables, like APRVARS, or a file
of make variables, like httpd's config_vars.mk.

The value of config_vars.mk is that variable substitution can have
late binding.  It is possible to turn them into environment
variables by running a make rule that echo's a variable setting
syntax.  And it is easier to simply include them in other makefiles.

The value of APRVARS is that it can simply be sourced by a shell
script.  However, by doing so it creates a recursive definition that
results is multiple inclusion of the same flags (whatever is already
present in the environment).

So, it seems to me like an easy decision, but that may be because I
don't know about some other use of APRVARS external to apache.

If nobody has any objections, I'll start work on an includes/apr_make_vars.mk
that can be installed with apr and used by clients to pick up all of the
portability definitions needed to replicate the way APR was made.
Because that is what httpd needs to use apr as the center of its make
universe.

....Roy