required-before-expanded warning, next instance

[Ralf Wildenhues]

Hello m4sugar hackers,

with current git Autoconf, I get a warning with this setup (distilled
from the OpenMPI):

AC_DEFUN([A],
[pristine_CC=$CC
AC_PROG_CC
echo "before: $pristine_CC, after: $CC"
])

AC_DEFUN([B],
[AC_REQUIRE([A])
AC_REQUIRE([AM_PROG_CC_C_O])
])

AC_INIT(a,1)
AM_INIT_AUTOMAKE([foreign])
B
AC_CONFIG_FILES([Makefile])
AC_OUTPUT


| configure.ac:14: warning: AC_REQUIRE: `AC_PROG_CC' was expanded before it was 
required
| ../../../autoconf/lib/autoconf/c.m4:560: AC_PROG_CC_C_O is expanded from...
| aclocal.m4:620: AM_PROG_CC_C_O is expanded from...
| configure.ac:7: B is expanded from...
| configure.ac:14: the top level

What can be done about this, ideally without compromising the
factorization into macros and without the $pristine_CC variable
set/usage losing meaning?  (Similar issues exist for other macros.)

Thanks,
Ralf