Re: Problems with AC_CONFIG_AUX_DIR/AC_CONFIG_AUX_DIR_DEFAULT

[Akim Demaille]

| Akim,
| I just updated my autoconf and rebuilt it.  This modification still
| did not help.
| 
| Akim Demaille wrote:
| > I think this is fixed now.  It looks like another incarnation of
| > 
| > 2000-11-03  Akim Demaille  <address@hidden>
| > 
| >         AC_REQUIRE and AC_DEFUN_ONCE don't work properly together. This
| >         caused strange messages about AC_ARG_PROGRAM.
| > Could you please confirm?
| 
| I am still seeing two errors that may be associated with AC_REQUIRE.
| And actually, the subject one may be something else.
| 
| One is the inclusion of AC_PROG_CC twice via AC_CHECK_FUNC even though
| it is already included.  This configure.in should demonstrate that
| for you.
| 
|   AC_INIT(aps,2.4,address@hidden)
|   AC_PROG_CC(cc gcc)
|   AC_CHECK_FUNC(sincos)
|   AC_OUTPUT
| 
| The second may be a case of making AC_CONFIG_AUX_DIR and
| AC_CONFIG_AUX_DIR_DEFAULTS mutually exclusive.  If the user includes
| AC_CONFIG_AUX_DIR(FILE) in their configure.in, then the _DEFAULTS
| should not be included.  The fact that AC_PROG_INSTALL requires
| DEFAULTS may be an okay assumption.  To make them mutually exclusive,
| then, it could be that AC_CONFIG_AUX_DIR should AC_PROVIDE for
| AC_CONFIG_AUX_DIR_DEFAULTS.  That way, when the user includes
| AC_CONFIG_AUX_DIR(FILE), he overwrites the _DEFAULTS version which
| (hopefully) won't be included when AC_REQUIRED.

Arg, I thought it was a deep single small problem, but it's two
surface problems, distinct.  

The AC_PROG_CC problem is a nasty problem.  I'll think about this this
weekend.  Basically we are paying the fact that Autoconf promotes
AC_LANG_COMPILER, but still uses AC_PROG_CC as the main
implementation.  The delicateness of the problem is related to other
projects redefining AC_PROG_CC (see Libtool for instance).

We *really* need to understand what these people need, and have them
stop redefining macros...

And the second problem is not clear to me yet.  Your analysis is
right, but you missed one fact: AC_CONFIG_AUX_DIRS AC_PROVIDE's
AC_CONFIG_AUX_DIR_DEFAULTS itself.  I'm on it.