Providing FindFoo.cmake for a kde module "foo"

[Alexander Neundorf]

Hi,

On Sunday 08 July 2007 14:53, Andreas Pakulat wrote:
> On 08.07.07 20:49:23, Ralf Habacker wrote:
> > Andreas Pakulat schrieb:
> > > On 08.07.07 19:31:49, Andreas Pakulat wrote:
> > >> On 08.07.07 11:06:32, Matt Rogers wrote:
> > >>> On Jul 8, 2007, at 9:35 AM, Andreas Pakulat wrote:
> > >>>> due to a problem (I'd call it a bug actually) in cmake its not
> > >>>> possible
> > >>>> to install 2 kde modules where one depends on the other into
> > >>>> separate directories (and separate directories from kdelibs). For
> > >>>> packaging KDE module's however its needed that each module is
> > >>>> installed into its own prefix.
> > >>>
> > >>> You'll need to explain this more clearly. I have no idea what you're
> > >>> talking about. IIRC, all of KDE needs to be installed in the same
> > >>> prefix.
> > >>
> > >> That would be a regression over KDE3 and is not needed at all (there
> > >> have recently been some fixes to allow this in the buildsystem).
> > >
> > > Ooops, forgot about the more clearly part :)
> > >
> > > But during some trials with cmake it turns out that one can tell cmake
> > > its CMAKE_MODULE_PATH even providing multiple paths:
> > >
> > > cmake -DCMAKE_MODULE_PATH="/dir1;/dir2"
> > >
> > > So actually this is a non-issue, except the totally wrong error
> > > message:
> > >
> > > CMake Error: KDevPlatform_DIR is not set.  It must be set to the
> > > directory containing KDevPlatformConfig.cmake in order to use
> > > KDevPlatform.

Depends on your definition of "totally wrong", it does what the docs say:
"If no such file (FindKDevPlatform.cmake) is found, it is expected that the 
package is another project built by CMake that has a "<name>Config.cmake" 
file. A cache entry called <name>_DIR is created and is expected to be set to 
the directory containing this file. If the file is found, it is read and 
processed by CMake to load the settings of the package. If <name>_DIR has not 
been set during a configure step, the command will generate an error 
describing the problem unless the QUIET argument is specified."

> > I have added the following stuff to a new file in
> > <kdelibs-install-dir>/lib/kdevplatform/KDevPlatformConfig.cmake
> >
> > if(WIN32)
> >     file(TO_CMAKE_PATH "$ENV{ProgramFiles}" ProgramFiles)
> >     SET(CMAKE_MODULE_PATH  ${CMAKE_MODULE_PATH}
> > ${ProgramFiles}/kdevplatform/share/apps/cmake/modules)
> >     find_package(KDevPlatform REQUIRED)
> > endif(WIN32)
> >
> > which let me configure kdevelop on win32 without any error.
>
> Hmm.... So we could generate that file and install it along with
> kdevplatform..
>
> Did you need to add the
> -DKDevPlatform_DIR=<kdelibs-install-dir>/lib/kdevplatform/ ?

This would be the wrong approach. Creating a <package>Config.cmake file and 
then telling cmake manually where this file resides doesn't make sense. Then 
you can also just tell cmake where the stuff itself actually is. 
The idea would be that if project A wants to use project B, A needs access to 
a FindB.cmake file, either provided by cmake or by project A itself. This 
file can be minimal (as e.g. FindKDE4.cmake or FindVTK.cmake coming with 
cmake) and once they found the location of project B, they can load a file 
installed by project B which can set more advanced stuff, macros, 
dependencies etc.

Alex