disabling cookbook by default and make cmake fail when dependencies f…

…or meta examples are not met

CMakeLists.txt

@@ -661,28 +661,35 @@ ENDIF()
 FIND_PACKAGE(PythonInterp REQUIRED)
 
 OPTION(BUILD_META_EXAMPLES "Generate API examples from meta-examples" ON)
-find_package(PLY)
-find_package(PYPARSING)
-IF(NOT PLY_FOUND AND NOT PYPARSING_FOUND)
-    message("-- Python module PYPARSING or PLY required for meta examples. Disabling.")
-    SET(BUILD_META_EXAMPLES 0)
+include(FindPythonModule)
+find_python_module(ply REQUIRED)
+IF(NOT PY_PLY)
+    find_python_module(pyparsing REQUIRED)
+    IF(NOT PY_PYPARSING)
+        message(FATAL_ERROR "Python modules pyparsing or ply required for meta examples.")
+    ELSE()
+        message(WARNING "Python module ply was not found. Falling back to pyparsing. This may cause meta example parsing to be very slow.")
+    ENDIF()
 ENDIF()
+
 IF(BUILD_META_EXAMPLES)
-    # allow meta examples without adding examples dir
+    # allow meta examples without adding examples dir itself
     add_subdirectory(${CMAKE_CURRENT_SOURCE_DIR}/examples/meta)
 ENDIF()
 
-OPTION(BUILD_COOKBOOK "Build Shogun API cookbook" ON)
-IF(NOT BUILD_META_EXAMPLES)
-    message("-- Meta examples are required for building cookbook. Disabling.")
-    SET(BUILD_COOKBOOK 0)
+OPTION(BUILD_COOKBOOK "Build Shogun API cookbook" OFF)
+IF(BUILD_COOKBOOK)
+    IF(NOT BUILD_META_EXAMPLES)
+        message(FATAL_ERROR
+                "Meta examples need to be enabled to build cookbook.")
+    ENDIF()
+
+    find_package(Sphinx)
+    IF(NOT SPHINX_FOUND)
+        message(FATAL_ERROR "Sphinx is required to build cookbook.")
+    ENDIF()
 ENDIF()
 
-find_package(Sphinx)
-IF(NOT SPHINX_FOUND)
-    message("-- Sphinx is required for building cookbook. Disabling.")
-    SET(ENABLE_COOKBOOK 0)
-ENDIF()
 
 # JSON
 OPTION(BUNDLE_JSON "Bundle JSON" OFF)

cmake/FindPythonModule.cmake

@@ -0,0 +1,20 @@
+function(find_python_module module)
+	string(TOUPPER ${module} module_upper)
+	if(NOT PY_${module_upper})
+		if(ARGC GREATER 1 AND ARGV1 STREQUAL "REQUIRED")
+			set(${module}_FIND_REQUIRED TRUE)
+		endif()
+		# A module's location is usually a directory, but for binary modules
+		# it's a .so file.
+		execute_process(COMMAND "${PYTHON_EXECUTABLE}" "-c" 
+			"import re, ${module}; print re.compile('/__init__.py.*').sub('',${module}.__file__)"
+			RESULT_VARIABLE _${module}_status 
+			OUTPUT_VARIABLE _${module}_location
+			ERROR_QUIET OUTPUT_STRIP_TRAILING_WHITESPACE)
+		if(NOT _${module}_status)
+			set(PY_${module_upper} ${_${module}_location} CACHE STRING 
+				"Location of Python module ${module}")
+		endif(NOT _${module}_status)
+	endif(NOT PY_${module_upper})
+	find_package_handle_standard_args(PY_${module} DEFAULT_MSG PY_${module_upper})
+endfunction(find_python_module)

examples/meta/CMakeLists.txt

@@ -3,12 +3,6 @@
 # Check which interfaces are turned on
 # Add CMakeLists file for each turned on interface
 
-
-# Check if PLY is installed, warn if not. Check if pyparsing is installed otherwise. Throws error if not.
-IF(NOT PLY_FOUND)
-    message(WARNING "Python module PLY was not found. This may cause Shogun's meta example generation to be very slow.")
-ENDIF()
-
 # Disabled (temporary) as non-portable solution. This is replaced by allowing any [a-zA-Z_][a-zA-Z0-9_]* as shogun keyword
 # Generate type list
 # execute_process(COMMAND sh ${CMAKE_CURRENT_SOURCE_DIR}/generator/types/get_type_list.sh > ${CMAKE_CURRENT_SOURCE_DIR}/generator/types/typelist)