AC_CONFIG_FILES not configing file?

[dave]

Inside configure.ac I have the command
AC_CONFIG_FILES(doxygen.cfg)

inside source dir I have doxygen.cfg.in

but inside the build directory (outside of source) when I run configure
is says it configuring doxygen.cfg

[***@localhost build]$ ../cexp/configure $CEXP_FLAGS --enable-html
--enable-doc | grep doxygen
checking for i386-rtems4.11-doxygen... no
checking for doxygen... /usr/bin/doxygen
configure: WARNING: using cross tools not prefixed with host triplet
config.status: creating doxygen.cfg
doxygen: /usr/bin/doxygen
doxygen_directory doxygen-doc


but inside the log it doesn't

## ---------------------- ##
## Running config.status. ##
## ---------------------- ##

This file was extended by cexp config.status CEXP_Release_2_2, which was
generated by GNU Autoconf 2.69. Invocation command line was

CONFIG_FILES =
CONFIG_HEADERS =
CONFIG_LINKS =
CONFIG_COMMANDS =
$ ./config.status

on localhost.localdomain

config.status:982: creating makefile
config.status:982: creating config.h
config.status:1196: executing depfiles commands
config.status:1196: executing default-1 commands


What is a simple explanation for AC_CONFIG_FILES not configing file?

Thanks,

Dave