Re: how to prefix definitions in config.h

[Guido Draheim]

Es schrieb Clinton Roy:
> 
> Guido Draheim <address@hidden> writes:
> 
> > may I ask what you are *really* trying to achieve?  Personally, I
> > would like to depracate to prefix a config.h file in place, even
> > more if you would really install it along with your library - I've
> > seen to many include-order conflicts for this case, so please don't
> > do that.
> That's exactly what we're trying to do ;)
> 
> If the config.h header is installed in $prefix/include/package/config.h,
> and all it's definitions are prefixed with the package name, we think
> we've done everything needed to avoid name clashes.
> 
> > Secondly, if I read your post well, then you try to modify a file,
> > but not twice, but want to rerun it. Am I confused?
> Hrm. Maybe not you, but I definitely am ;)
> 
> I would like config.h generated in the normal way via
> AC_CONFIG_HEADER, then prefixed with our package name.

I see,
I'm doing the same thing, and in fact, all libraries should put
their headers with a subdir prefix, sadly not all of them do it,
and automake's support for such a style is limited. Anyway,
two ways.

a) I'm using package/_config.h - this even hint the reader that this
   file is not a normal header (it is generated!) and it does not
   get confused for the standard config.h file.
b) look at the argument of AC_CONFIG_HEADER - you can specify a
   different output-file, so that you don't need to have the two
   same-named.

sadly, there is not enough automatism in my ac-macro that it will
detect the different ac_config_header, so you have to give it as
an explicit argument. 

so much for the problem of the same-named file, the other is...

> 
> > Well, might be. Anyway, I don't expect things to be easy, for the
> > case that the input and output file are in the same position.
> That's the main problem I've had with AC_CREATE_PREFIX_CONFIG_H, it
> doesn't store the output of it's sed command in a temporary file and
> move it across the original, so in my case the original is lost.
> 
> > Thirdly, you didn't mention that the ac-macro has a few optional
> > arguments, one being input-file, the other being output-file, which
> > you didn't mention again. What's wrong with that, and if it is not
> > sufficient, why didn't you contact me?
> Not contacting you directly was an oversight on my behalf. I really am
> quite confused as to why prefixing of definitions isn't a standard
> option already. The other problem I can see with
> AC_CREATE_PREFIX_CONFIG_H is that it doesn't get put into
> config.status and thus I think it would only be run once.

... the other problem is that the prefixing is not done during 
reconfig, and in fact, the items in my ac-macro should be appended
to the config.status file, which I didn't bother to do so far,
and I didn't have enough time to figure it out.

> 
> Unfortunately when I try to use AC_CONFIG_COMMANDS to get the
> prefixing done automatically on reconfiguration, I don't know what to
> use as the tag to always have the command run, and it only gets run in
> the initial configure invocation.
> 

... and btw, of course, I do not need the intermediate config.h file
either, I wouldn't have a problem if s.o. could come up with a macro
reading AC_PREFIXED_OUTPUT_HEADER that would be put in the place of
AC_OUTPUT_HEADER today - I do only ifdefs on the prefixed stuff, not
the original config stuff, so there's no need for the intermediate
file ;-)

cheers,
-- guido                                    http://freespace.sf.net/guidod
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