Re: [Vala] Five bugs in Vala integration

[Jürg Billeter]

On Wed, 2010-09-08 at 20:02 +0200, Ralf Wildenhues wrote:
> [ trying to add vala-list; this is
>   <http://thread.gmane.org/gmane.comp.sysutils.automake.bugs/5008> ]
> 
> * Valentin David wrote on Wed, Sep 08, 2010 at 03:08:00PM CEST:
> > On Wed, Sep 8, 2010 at 7:53 AM, Ralf Wildenhues wrote:
> > > Well, are the derived sources portable, i.e., not depending on the
> > > system on which they are created?
> > 
> > Unfortunately no. "Starting with version 0.7.0, Vala supports the
> > preprocessing directives #if, #elif, #else, and #endif."
> > 
> > http://live.gnome.org/Vala/FAQ#Does_Vala_have_a_preprocessor.3F
> 
> Well, that's a blow, but it's not necessarily the end of portable
> derived sources, iff developers are careful to never (ab)use this
> feature to create nonportable derived sources.

Yes, when using Vala with Automake, the idea is that the derived sources
are always portable, and #if shouldn't be used to handle configure
options or similar.

> I'm not qualified to judge that.  I'm fine with changing the semantics
> in Automake (so that vala derived sources are not distributed), but
> please do Cc: vala-list for such Vala-related changes in Automake, in
> case they have comments; in fact, this whole thread may be of interest
> to them so I've added the list in Cc: now.

While I certainly see some merit in allowing to drop vala derived
sources from distribution, there are also reasons for the current
semantics: Vala users may want to use features of recent Vala versions
without imposing such a recent Vala version as tarball build dependency.

While we are careful about not breaking backwards compatibility in the
language itself, at least some of the bindings are still a moving
target. Distributing derived sources helps to mitigate this.

Last but not least, Vala itself distributes .c files to avoid
bootstrapping issues.

If it is possible to support both semantics in Automake, I'm all for it,
however, please don't break what we currently have.

Thanks,
Jürg