pkgconfig under Windows ? Was: review FindBlueZ.cmake

[Alexander Neundorf]

On Saturday 01 October 2011, Patrick Spendrin wrote:
> Am 01.10.2011 21:33, schrieb Alexander Neundorf:
> > On Wednesday 21 September 2011, Raphael Kubo da Costa wrote:
> >> Michael Jansen <kde at michael-jansen.biz> writes:
> >>> Not sure here. After a (short) talk to some kde windows guys i remember
> >>> he said there is pkgconfig for windows but it is considered completly
> >>> broken. I think thats why most modules do that magic. Do ignore it on
> >>> windows even if there.
> >> 
> >> I've often times heard non-KDE people say pkgconfig used to be broken
> >> but should work fine nowadays, so I'm a bit confused here. It'd be nice
> >> if the kde-windows guys could provide more details on what's the current
> >> state of pkgconfig for them.
> > 
> > Yes.
> > Also, whenever I said somewhere that our cmake files must be able to find
> > stuff also without pkgconfig, people replied that nowadays it works just
> > fine under Windows.
> > 
> > So, Windows developers: what's the current state of pkg-config under
> > Windows ? Does it work ?
> 
> Well, it runs.
> 
> > Do you use it ?
> 
> Not in a sense where I want to.
> 
> > Does it work with mingw ?
> > Does it work with MSVC ?
> 
> The issue with pkgconfig and also the point why we don't use it is the
> following: pkgconfig uses .pc files to find out about the layout of a
> library. This means that e.g. the installation path is hardcoded into
> that file, which makes sense as long as you don't send around packages
> containing these files: on a different system those paths will not have
> any meaning, so it is completely useless to put those paths in there. So
> what to do? One could argue to add an option to pkgconfig to replace
> those paths, which is not the best idea either - also it would involve
> somebody (in the end: me) hacking on pkgconfig.
> 
> To conclude:
> At the moment it doesn't make sense to use pkgconfig for us on Windows -
> we only gain more work load from it. It might make sense for really
> small projects or corner cases to use pkgconfig (e.g. if you'd need to
> rewrite the buildsystem for glib otherwise), but for us, it has only
> disadvantages.

So, I'm not sure what the conclusion is.
It sounds like the find-modules have to find the stuff successfully also 
without pkg-config under Windows.
And if this is a requirement, then I ask myself, if the find-modules have to 
be written in a way that they work without pkg-config just as good as with 
pkg-config, then why do we need the pkg-config stuff in them at all, I mean 
e.g. under Linux ?

Alex