Re: AC_DEFINE* with 2 args discouraged?

[Guido Draheim]

Ralf Wildenhues wrote:
> * Guido Draheim wrote on Mon, Dec 01, 2003 at 09:25:39AM CET:
>
> > Ralf Wildenhues wrote:
>
> *snip*
>
> > > Now current CVS autoheader (2.59a) gives me
> > > |autoheader: warning: missing template: _LIBFOO_FEATURE_BAZ
> > > |autoheader: Use AC_DEFINE([_LIBFOO_FEATURE_BAZ], [], [Description])
> > >
> > > Is this deprecated usage?  How is my goal best accomplished?
> > > Is having duplicate sets of defines in config.h/libfoo_conf.h the
> > > solution of choice?  Then I'd suggest the description in
> > > info '(autoconf.info)Defining Symbols' to be more precise (where
> > > only the usage with one parameter is explicitly discouraged).
> >
> > You do know about AX_PREFIX_CONFIG_H, do you?
>
>
> No, I didn't before.  Looks like a good idea, except for the minor
> cosmetic issue of having numerous exposed macros which do not belong
> to the library interface.  Thanks for the suggestion, though, this
> looks like the easiest and least error-prone solution.

yes and yes and yes. It puts in a lot but those defines are not
for the library user anyway - make up derived exported #defines
in your main library header and document them. It's simply a very
easy and safe solution, and it makes it a _lot_ easier to turn
some procedure package into a library project. It just needs an
extra macro and an extra #include, the rest will follow. ;-)

> BTW, current CVS autotools will break the example given in
> ax_prefix_config_h.m4 unless obsolete AM_CONFIG_HEADER is replaced
> with AC_CONFIG_HEADERS.

It does work on my system but those are not cvs level. Hmmmm.

> Still there is the Autoconf documentation issue with AC_DEFINE*,
> namely that I would like to know if usage with 2 args is deprecated.

the autoconf.info manual says "`autoheader' needs you to document all
of the symbols that you might use; i.e., there must be at least one
`AC_DEFINE' or one `AC_DEFINE_UNQUOTED' call with a third argument for
each symbol" ... here I see "there MUST be (at least one)".

have fun,
-- guido                                  http://google.de/search?q=guidod
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