style: m4_toupper

[Thien-Thi Nguyen]

here is a fragment from a AC_DEFUN body:

  AM_CONDITIONAL(m4_toupper([HAVE_$1]), test x$enable_$1 = xyes)
  
  if test x$enable_$1 = xyes ; then
    m4_toupper([HAVE_$1])=1
    AC_SUBST(m4_toupper([HAVE_$1]))
  fi

i wonder if there is a  better way to express:

  m4_toupper([HAVE_$1])

any tips from autoconf gurus?  the documentation
  (info "(autoconf)Programming in M4sh")
tantalizes w/ AS_TR_CPP as it warns that m4sh
"is not mature enough to be widely used".  hmmm.

thi