[cmake-developers] cmake --find-package (was: Roadmap to CMake 3.0)

[Alexander Neundorf]

On Wednesday, April 23, 2014 09:22:09 Alan W. Irwin wrote:
> On 2013-10-19 20:16+0200 Alexander Neundorf wrote:
> > On Thursday 17 October 2013, Stephen Kelly wrote:
> >> Brad King wrote:
> >>> On 10/17/2013 04:58 PM, Alexander Neundorf wrote:
> >>>> Yes, that was the idea, but I can't rely anymore on a Foo_LIBRARIES
> >>>> variable (or a slight variation) being set after a successful
> >>>> find_package(Foo):
> >>>> http://lists.kde.org/?l=kde-core-devel&m=138198795723680&w=2 I.e. in
> >>>> the
> >>>> future there will be Find-modules which typically export one of
> >>>> (Foo|FOO)_(LIBRARIES|LIBRARY), some Config.cmake files which do that
> >>>> too, and a big number, probably majority, of Config.cmake files, which
> >>>> do not export such variables.
> >>>> 
> >>>> The only chance I see would be to simply collect all library targets
> >>>> and
> >>>> return what they provide, but this doesn't feel good. I would have much
> >>>> prefered using a clear interface like the Foo_LIBRARIES variable.
> >>> 
> >>> Perhaps we need to establish a convention for find modules and package
> >>> configuration files to interact with --find-package mode.  I have no
> >>> thoughts on the specifics of how that would work though.
> >> 
> >> A new, similar --find-target mode or similar may be more appropriate:
> >>  cmake --find-target --package Qt5Widgets --target Qt5::Widgets ...
> >>  
> >>  # KF5Config exports 3 independent targets:
> >>  cmake --find-target --package KF5Config --target KF5::ConfigCore ...
> >>  cmake --find-target --package KF5Config --target KF5::ConfigGui ...
> >>  cmake --find-target --package KF5Config --target KF5::ConfigWidgets ...
> > 
> > Yes, that will work.
> > And a new command/option is not even necessary.
> > The name of the target could be given as additional option.
> > If none is given, it will use the variables as it does now, if a target is
> > given, it will use this target and its properties.
> > 
> > I'll work on that when I find the time (and nobody is faster).
> 
> How is that going, Alex?

I have more or less given up on this.
Due to all the changes in cmake recently (not recommending setting variables 
anymore in find_package(), and all the target property stuff), this would 
require quite some work, and I seriously don't have that much time for cmake 
currently.
Also, one of the big benefits, not having to read documentation for every 
package anymore, but having a standard interface, is lost, AFAICS.

So, if somebody wants to pick that up, feel free.

Sorry
Alex