AC_ARG_VAR

[Akim Demaille <akim at epita dot fr>]

Hi,

I've just checked in the patch to handle AC_ARG_VAR(var, doc).  It
would be good that people test it.  To test it, I just documented
CFLAGS in AC_PROG_CC.  The vars that Autoconf iself should document is 
still to be decided, this is just a sample so that you may try it.

I used the following code, please comment (in particular the lines
after DIVERT_POP)!  I know there are problems with `case' on some
brain dead HP /bin/shes.  Do we have to fear something here?

dnl AC_ARG_VAR(VARNAME, DOCUMENTATION)
dnl ----------------------------------
dnl Register VARNAME as a variable configure should remember, and
dnl document it in --help.
AC_DEFUN(AC_ARG_VAR,
[AC_DIVERT_PUSH(AC_DIVERSION_NOTICE)dnl
ac_arg_var_help="$ac_arg_var_help
AC_HELP_STRING([$1], [$2], [              ])"
AC_DIVERT_POP()dnl
dnl Prepend instead of appending, so that envvars set on the cmd line
dnl win over the environment.  Don't register envvars not set.
dnl Don't register several times.
case "${$1+set} $ac_configure_args" in
 *" $1="* );;
 "set "*) ac_configure_args="$1='[$]$1' $ac_configure_args";;
esac])

Akim