Re: Multiple definition of VERSION, PACKAGE and so on

[Patrick Guio]

On Wed, 24 Mar 2004, Tim Van Holder wrote:

>
> For simple cases like the above, one way would be to do something
> like this:
>
> [configure.ac]
> ...
> if ...; then
>    my_real_type_var=double
> else
>    my_real_type_var=float
> fi
> ...
> AC_SUBST([BLITZ_REAL_TYPE], $my_real_type_var)
> ...
> AC_CONFIG_FILES([pack1-defs.h:pack1-defs-h.in])
> ...
>
> [pack1-defs-h.in]
> ...
> typedef @BLITZ_REAL_TYPE@ pack1Real;
> ...
>
>
> In your code, the #error suggests that it would be OK for the client
> code to provide FLOAT_FIELD or DOUBLE_FIELD, when in fact that decision
> has already been made during pack1's configuration.  What's more, you
> leave the inclusion of pack1's config.h up to the user (who has to
> define HAVE_CONFIG_H for you).
> Typically, every installed file that in some way depends on
> configuration-time variables will be an autoconf output file.

Thank you very much. This clarifies some points I missed.

> AX_PREFIX_CONFIG_HEADER is a way around this for cases where there are
> so many relevant #defines that the approach shown becomes impractical.
>

Is this macro part of the autoconf (2.59) distrbution or is it an
extension? I cannot make it works properly as mentionned in my earlier
mail.

Regards, Patrick