Problem recursing configure into add-on's stand alone sub-project.

[Ryan Arnold]

I have an add-on 'foo' which I enable with

--enable-add-ons=foo,nptl

The addon 'foo' requires a sub-project to be statically linked into
it.  We'll call this 'bar'.

Sub-project 'bar' is maintained officially out-of-tree and has it's
own configure.ac and Makefile.in.

So the structure is:

glibc/foo/
glibc/foo/configure.in
glibc/foo/bar
glibc/foo/bar/configure.ac

The glibc/foo/configure.in looks like this:

     GLIBC_PROVIDES

     libc_add_on_canonical=dfp

     AC_CONFIG_SUBDIRS([bar])

The GLIBC configure stage does indeed recurse into here and generates
configure as:

     # This file is generated from configure.in by Autoconf.  DO NOT EDIT!

     libc_add_on_canonical=dfp

     subdirs="$subdirs bar"

Unfortunately configure DOESN'T recurse into foo/bar/configure.in.

Does anyone know how to get this to work?  The documentation isn't helpful.

I tried doing AC_CONFIG_SUBDIRS([foo/bar]) but that doesn't work.

I've also tried adding libc_add_on_subdirs=bar to foo/configure.in but
that doesn't work either.

Outside of the glibc build system AC_CONFIG_SUBDIRS(bar) is enough to
get this to work.  I suspect it's due to the 'addon' machinery.

Ryan S. Arnold