[cmake-developers] Exporting dependent library targets in multiple export sets

[Alexander Neundorf]

On Thursday 20 September 2012, Brad King wrote:
> On 09/19/2012 04:14 PM, Alexander Neundorf wrote:
> > On Wednesday 19 September 2012, Alexander Neundorf wrote:
> >> Hmm, I was almost done implementing it...
> >> when creating the export file, we do not know how the Config file will
> >> be named, i.e. we do not know the name of the package, so we cannot set
> >> <package>_FOUND to FALSE...
> >> Am I missing something ?
> > 
> > cmFindPackage could set a CMAKE_FIND_PACKAGE_NAME variable, which I could
> > use then...
> 
> Okay with me, but target files may not always be loaded from Config
> files under find_package.  Some projects may load them in other
> contexts.  If CMAKE_FIND_PACKAGE_NAME or one of the other variables
> you need to detect the case is not set then we need to do something
> else (error, warning?).


Like this ?

if(NOT TARGET Foo)
   if(CMAKE_FIND_PACKAGE_NAME)
      set(${CMAKE_FIND_PACKAGE_NAME}_FOUND FALSE)
      set(${CMAKE_FIND_PACKAGE_NAME}_NOT_FOUND_MESSAGE
                   "The required target Foo does not exist !")
   else()
      message(STATUS
                "Warning: the required target Foo does not exist !")
   endif()
endif()


or SEND_ERROR or FATAL_ERROR ?

Alex