Re: [libxml++] [patch] Global initialization code

[Christophe de V. <cde...@al...>]

Le Vendredi 17 Juin 2005 10:04, Thomas Jarosch a =E9crit=A0:
> > > > I think so, with the global init doing nothing IF an environnement
> > > > variable "LIBXMLPP_NO_STATIC_INIT" has been defined.
> > >
> > > This still requires recompilation and is therefore not ABI compatible,
> > > IMHO.
> >
> > I think I disagree : the current global initialisation is done by
> > Init::Init. We can, without breaking the ABI, change its behavior so it
> > does nothing when a particular environment variable is set.
> > We can add another class, let's say InitNG, which does what you suggest=
ed
> > for Init.
> > This way people who want to do manual initialisation can do it by setti=
ng
> > this variable.
>
> Sorry, missed the environment part while reading
> as you wrote the french version ;-)

Sorry :-)

> I would take the the environment variable as last option
> because that's not very intuitive for the end user.
> (f.e. program crashes because he/she forget to set it)

I don't think it's a good solution either.

> > Another way I just thought about is not to change Init::Init behavior,
> > but adding both another init class and a free function (probably a stat=
ic
> > function of the new init class) which undo what Init have done and forc=
es
> > it's destructor not to do anything.
> > The advantage is that the proper behavior of the program does not depend
> > on a user intervention.
>
> That would be an option, though it's still messy.

A bit messy, but still better than the environment variable solution (it do=
es=20
not rely on the user, so it's reliable), and not breaking the ABI.
=46or now I don't see another way to achieve your goal not breaking the abi=
 and=20
being reliable.
The only other way would need a specific compilation of libxml++ for your=20
project, which break the ABI.

> Is there a garantuee=20
> from the compiler in which order global objects are created?

Unfortunately no. That would be too easy :-) I know that with gcc we can be=
=20
pretty sure the library global initialisation is done before the main progr=
am=20
one. But we can't rely on it, as other compilers will cause problems.

Regards,

Christophe