RFC: pkgconfigdir: where?

[tlaronde at kergis.com]

On Mon, Mar 04, 2024 at 10:41:31AM -0800, Alan Coopersmith wrote:
> On 3/4/24 01:49, tlaronde at kergis.com wrote:
> > As written in a previous mail, I'm trying to adjust meson to provide
> > the same rope as AC.
> > 
> > For xorg-sgml-doctools, there was a small discrepancy if the user was
> > not selecting the defaults. This is easy to fix (diff attached), but I
> > now wonder about pkgconfig .pc files directory.
> > 
> > In generated aclocal.m4, pkgconfigdir is said to be, by default,
> > ${libdir}/pkgconfig, and supposed to be settable with
> > --with-pkgconfigdir (it is not settable in fact: the option is not
> > recognized).
> > 
> > We put .pc files in ${datadir}/pkgconfig. By default, datadir ==
> > datarootdir, but this can be changed (with AC) so that X11 stuff is
> > put in a dedicated subdir, while pkgconfig files are reachable in a
> > more general dir.
> > 
> > In fact, on my OS (NetBSD), pkgconfig files are placed in
> > ${libdir}/pkgconfig and not ${datarootdir}/pkgconfig.
> > 
> > So is there some rule about this for X11 stuff?
> 
> X11 follows the general rules for pkg-config file installation:
> ${libdir}/pkgconfig for architecture-specific stuff,
> ${datarootdir}/pkgconfig for architecture-independent stuff.
> 
> Normally this means if your pkgconfig file specifies linking against a
> library, it goes in ${libdir} so it gets the settings right for whatever
> library you're actually linking against (32-bit vs. 64-bit, cross-compiling
> for another architecture, etc.).
> 
> Stuff that ends up in ${datarootdir}/pkgconfig tends to be the same for
> all OS'es/CPU's, things like the xorgproto header files and the
> xorg-sgml-doctools XML files, and isn't used in linking binaries.

OK.

In this case, the pkgconfigdir (meson) option that I have added
(defaulting to ${datadir}/pkgconfig) in xorg-sgml-doctools
can perhaps be suppressed (it does no harm, but is useless: setting
datadir to some value distinct from datarootdir with autotools will
indeed put the pc files elsewhere; and having added a 'datarootdir'
option to meson, the exact same can now be achieved with meson in
xorg-sgml-doctools).

-- 
        Thierry Laronde <tlaronde +AT+ kergis +dot+ com>
                     http://www.kergis.com/
                    http://kertex.kergis.com/
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