AC_PROG_CXX warning

[Ted Irons]

In configure.in, I have 2 calls to AC_PROG_CXX with the
2nd  call being an argument to AC_REQUIRE.  I'm getting
the following warning; what does it mean?

   warning: AC_PROG_CXX(CC g++ gcc) is m4_require'd but is not m4_defun'd

I'm running autoconf-2.52, automake-1.5,  and libtool-1.4b.

Thanks,
- Ted