libjava configure question

[Steve Ellcey <sje at shale dot cup dot hp dot com>]

I am looking at a problem where libjava is generating calls to finite().
They are coming from libjava/java/lang/*.c files.  This routine is not
defined on HP-UX where I am trying to build libjava so I am looking at
how to fix this.  This was fixed in libgfortran with the patch:

http://gcc.gnu.org/ml/fortran/2004-11/msg00175.html

I was hoping to do something similar for libjava but I am confused as to
how the libjava configure works.  The top level configure.ac for libjava
does not have many function checks in it.  In the libjava/include
directory I see a config.h.in file but I dont't see a configure.ac file
that it was created from.  Can somone enlighten me how the libjava
configure works?  Where should I put a check for finite() and what do
I need to regenerate?

Steve Ellcey
sje@cup.hp.com