CMake biz: Instead of providing elusive prints of missing dependencies for required features and continuing the build configuration, fail fast instead; user can easily disable the feature or fix the paths for the dependency.

src/ifcwrap/CMakeLists.txt

@@ -18,8 +18,9 @@
 ################################################################################
 
 FIND_PACKAGE(SWIG)
-
-IF(SWIG_FOUND)
+IF(NOT SWIG_FOUND)
+	MESSAGE(FATAL_ERROR "BUILD_IFCPYTHON enabled, but unable to find SWIG. Disable BUILD_IFCPYTHON or fix SWIG paths to proceed.")
+ENDIF()
 
 INCLUDE(${SWIG_USE_FILE})
 
@@ -33,8 +34,9 @@ IF(NOT "$ENV{PYTHON_LIBRARY}" STREQUAL "")
 ENDIF()
 
 FIND_PACKAGE(PythonLibs)
-
-IF(PYTHONLIBS_FOUND)
+IF(NOT PYTHONLIBS_FOUND)
+	MESSAGE(FATAL_ERROR "BUILD_IFCPYTHON enabled, but unable to find Python. Disable BUILD_IFCPYTHON or fix Python paths to proceed.")
+ENDIF()
 
 INCLUDE_DIRECTORIES(${PYTHON_INCLUDE_PATH})
 
@@ -70,7 +72,3 @@ INSTALL(FILES
 		"${CMAKE_CURRENT_SOURCE_DIR}/../ifcopenshell-python/ifcopenshell/geom/__init__.py"
 		DESTINATION "${python_package_dir}/ifcopenshell/geom")
 INSTALL(TARGETS _ifcopenshell_wrapper DESTINATION "${python_package_dir}/ifcopenshell")
-
-ENDIF(PYTHONLIBS_FOUND)
-
-ENDIF(SWIG_FOUND)

src/qtviewer/CMakeLists.txt

@@ -17,12 +17,6 @@
 #                                                                              #
 ################################################################################
 
-OPTION( QT_USE_QTVIEWER "IfcOpenShell QT GUI Viewer, QT environment required" OFF )
-
-
-IF (QT_USE_QTVIEWER)
-
-
 # Find QT header files
 SET(QT_MIN_VERSION "4.5.0")
 FIND_PACKAGE(Qt4 REQUIRED)
@@ -59,6 +53,3 @@ ADD_EXECUTABLE(  QTviewer ${QTviewer_SRCS} ${QTviewer_MOC_SRCS})
 #http://www.qtcentre.org/wiki/index.php?title=Compiling_Qt4_apps_with_CMake
 
 TARGET_LINK_libRARIES (QTviewer IfcParse IfcGeom ${QT_LIBRARIES} ${OPENCASCADE_LIBRARIES})
-
-
-ENDIF (QT_USE_QTVIEWER)