cmake/EnsureFileInclude.cmake

# Ensure that an include file is provided by the system
# Add the check about the mandatory status to the check_include_file macro 
# provided by cmake

include (${CMAKE_ROOT}/Modules/CheckIncludeFile.cmake)

macro(ensure_file_include INCLUDE_FILENAME VARIABLE_NAME MANDATORY_STATUS)

#message(WARNING "INCLUDE_FILENAME=${INCLUDE_FILENAME} \n"
#                "VARIABLE_NAME=${VARIABLE_NAME} \n"
#                "MANDATORY_STATUS=${MANDATORY_STATUS}")

CHECK_INCLUDE_FILE(${INCLUDE_FILENAME} ${VARIABLE_NAME})

#message(WARNING "INCLUDE_FILENAME=${INCLUDE_FILENAME} \n"
#                "VARIABLE_NAME=${VARIABLE_NAME} \n"
#                "VARIABLE_NAME_VALUE=${${VARIABLE_NAME}} \n"
#                "MANDATORY_STATUS=${MANDATORY_STATUS}")

if (NOT ${${VARIABLE_NAME}})
  if (${MANDATORY_STATUS})
    message(FATAL_ERROR "The file ${INCLUDE_FILENAME} is mandatory but not found on your system")
  endif()
endif()

endmacro()