[CMake] Differentiate between Linux and FreeBSD

[Horacio Sanson]

On Wed, Apr 23, 2008 at 5:39 PM, Pau Garcia i Quiles
<pgquiles at elpauer.org> wrote:
> Quoting Horacio Sanson <hsanson at gmail.com>:
>
>  Either you have not re-run CMake or your CMake is broken. Did you install
> it from Ubuntu packages?
>

I have tried this in two separate systems with the same result:

Hardy Heron (clean installation) with cmake 2.4-patch7 from Ubuntu repositories
FreeBSD 7.1 with cmake 2.4-patch 7 from FreeBSD ports.

In both cases running cmake causes an error about
CMAKE_FIND_LIBRARY_PREFIXES missing.

my CMakeLists.txt file :

#########################################
EXEC_PROGRAM(uname OUTPUT_VARIABLE SYSTEM_NAME)
SET(SYSTEM_NAME "${SYSTEM_NAME}" CACHE INTERNAL "")

IF(SYSTEM_NAME STREQUAL "Linux")
  MESSAGE("LINUX BOX")
  LINK_LIBRARIES(sctp)
ENDIF(SYSTEM_NAME STREQUAL "Linux")

IF(SYSTEM_NAME STREQUAL "FreeBSD")
  MESSAGE("FREEBSD BOX")
ENDIF(SYSTEM_NAME STREQUAL "FreeBSD")

FIND_LIBRARY(SCTP_LIBRARY sctp)
IF(SCTP_LIBRARY)
  MESSAGE("GOT SCTP LIBRARY")
ENDIF(SCTP_LIBRARY)

PROJECT(echo_demo)
ADD_EXECUTABLE(echo_server echo_server.c)
ADD_EXECUTABLE(echo_client echo_client.c)
##########################################

regards,
Horacio

Most probably a bug in the Ubuntu package??  Will
>
> >
> >
> >
> > 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
> > >  __________________________
> > >
> > >
> >
> > _______________________________________________
> > CMake mailing list
> > CMake at cmake.org
> > http://www.cmake.org/mailman/listinfo/cmake
> >
> >
>
>
>
>  --
>  Pau Garcia i Quiles
>  http://www.elpauer.org
>  (Due to my workload, I may need 10 days to answer)
>
>
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