# Based on CheckLibraryExists.cmake from CMake

#=============================================================================

# Copyright 2002-2009 Kitware, Inc.

#

# Distributed under the OSI-approved BSD License

#

# This software is distributed WITHOUT ANY WARRANTY; without even the

# implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

# See the License for more information.

#=============================================================================

macro(CHECK_HASKELL_MODULE_EXISTS MODULE FUNCTION PARAMCOUNT LIBRARY)

  set(VARIABLE "HS_MODULE_${LIBRARY}_${FUNCTION}")

  if(${VARIABLE} MATCHES ^${VARIABLE}$)

    message(STATUS "Looking for ${FUNCTION} in ${MODULE}")

    set(PARAMETERS "")

    if(PARAMCOUNT GREATER 0)

        foreach(__TRASH__ RANGE 1 ${PARAMCOUNT})

            set(PARAMETERS "${PARAMETERS} undefined")

        endforeach()

    endif()

    set(PARAMETERS "")

    execute_process(COMMAND ${GHC_EXECUTABLE}

                    "-DMODULE=${MODULE}"

                    "-DFUNCTION=${FUNCTION}"

                    "-DPARAMETERS=${PARAMETERS}"

                    -cpp

                    -c "${CMAKE_MODULE_PATH}/checkModule.hs"

                    RESULT_VARIABLE COMMAND_RESULT

                    ERROR_VARIABLE BUILD_ERROR

                    OUTPUT_STRIP_TRAILING_WHITESPACE

                    )

    if(${COMMAND_RESULT} EQUAL 0)

      message(STATUS "Looking for ${FUNCTION} in ${MODULE} - found")

      set(${VARIABLE} 1 CACHE INTERNAL "Have module ${MODULE}")

      file(APPEND ${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/CMakeOutput.log

        "Determining if the function ${FUNCTION} exists in the ${MODULE} passed\n\n")

    else()

      message(STATUS "Looking for ${FUNCTION} in ${MODULE} - not found")

      set(${VARIABLE} "" CACHE INTERNAL "Have module ${MODULE}")

      file(APPEND ${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/CMakeError.log

        "Determining if the function ${FUNCTION} exists in the ${MODULE} "

        "failed with the following output:\n"

        "${BUILD_ERROR}\n\n")

      message(FATAL_ERROR "Haskell library '${LIBRARY}' required")

    endif()

  endif()

endmacro()