[CMake] Differentiate between Linux and FreeBSD

[Horacio Sanson]

On Wed, Apr 23, 2008 at 1:53 PM, Alan W. Irwin
<irwin at beluga.phys.uvic.ca> wrote:
> On 2008-04-22 21:48-0400 Amitha Perera wrote:
>
>
> > Horacio Sanson wrote:
> >
> > > The problem is that in linux I have to add the sctp library (i.e.
> > > -lsctp) if not compilation fails and in FreeBSD adding that library
> > > would cause the compiler to complain.
> > >
> > > if there is a better way to do this I am eager to learn it.
> > >
> >
> > Not necessarily "better", but if sctp exists on Linux, but not on FreeBSD
> (or more generally, if sctp should be linked against whenever it is found),
> an option is
> >
> > find_library( SCTP_LIBRARY sctp )
> >
> > target_link_libraries( your_exec ${SCTP_LIBRARY} )
> >
>
>  Good idea, but I believe you would also need the following modification to
>  the above logic
>
>
>  find_library( SCTP_LIBRARY sctp )
>  if(SCTP_LIBRARY)
>
>   target_link_libraries( your_exec ${SCTP_LIBRARY} )
>  endif(SCTP_LIBRARY)
>
Running this CMake script gives me:

CMake Error: Error required internal CMake variable not set, cmake may
be not be built correctly.
Missing variable is:
CMAKE_FIND_LIBRARY_PREFIXES

I have cmake from Kubuntu Hardy Heron installed.

Horacio
>  The reason for the extra logic is that if libsctp is not found then
>  SCTP_LIBRARY with be set to "SCTP_LIBRARY-NOTFOUND" which would screw up
> "target_link_libraries" without the "if" protection.
>
>  Alan
>  __________________________
>  Alan W. Irwin
>
>  Astronomical research affiliation with Department of Physics and Astronomy,
>  University of Victoria (astrowww.phys.uvic.ca).
>
>  Programming affiliations with the FreeEOS equation-of-state implementation
>  for stellar interiors (freeeos.sf.net); PLplot scientific plotting software
>  package (plplot.org); the libLASi project (unifont.org/lasi); the Loads of
>  Linux Links project (loll.sf.net); and the Linux Brochure Project
>  (lbproject.sf.net).
>  __________________________
>
>  Linux-powered Science
>  __________________________
>