source: pacpussensors/trunk/Vislab/lib3dv/eigen/bench/btl/cmake/MacroOptionalAddSubdirectory.cmake@ 136

# - MACRO_OPTIONAL_ADD_SUBDIRECTORY() combines ADD_SUBDIRECTORY() with an OPTION()
# MACRO_OPTIONAL_ADD_SUBDIRECTORY( <dir> )
# If you use MACRO_OPTIONAL_ADD_SUBDIRECTORY() instead of ADD_SUBDIRECTORY(),
# this will have two effects
# 1 - CMake will not complain if the directory doesn't exist
#     This makes sense if you want to distribute just one of the subdirs
#     in a source package, e.g. just one of the subdirs in kdeextragear.
# 2 - If the directory exists, it will offer an option to skip the 
#     subdirectory.
#     This is useful if you want to compile only a subset of all
#     directories.

# Copyright (c) 2007, Alexander Neundorf, <neundorf@kde.org>
#
# Redistribution and use is allowed according to the terms of the BSD license.
# For details see the accompanying COPYING-CMAKE-SCRIPTS file.


MACRO (MACRO_OPTIONAL_ADD_SUBDIRECTORY _dir )
   GET_FILENAME_COMPONENT(_fullPath ${_dir} ABSOLUTE)
   IF(EXISTS ${_fullPath})
      IF(${ARGC} EQUAL 2)
        OPTION(BUILD_${_dir} "Build directory ${_dir}" ${ARGV1})
      ELSE(${ARGC} EQUAL 2)
        OPTION(BUILD_${_dir} "Build directory ${_dir}" TRUE)
      ENDIF(${ARGC} EQUAL 2)
      IF(BUILD_${_dir})
         ADD_SUBDIRECTORY(${_dir})
      ENDIF(BUILD_${_dir})
   ENDIF(EXISTS ${_fullPath})
ENDMACRO (MACRO_OPTIONAL_ADD_SUBDIRECTORY)