# - Try to find the Glasgow Haskell Compiler executable

# Once done this will define

#

#  GHC_VERSION        - GHC version

#  GHC_EXECUTABLE     - GHC executable

#  GHC_PKG_VERSION    - ghc-pkg version

#  GHC_PKG_EXECUTABLE - ghc-pkg executable

#

# Copyright (c) 2013, Vittorio Giovara <vittorio.giovara@gmail.com>

#

# Redistribution and use is allowed according to the terms of the BSD license.

# For details see the accompanying COPYING-CMAKE-SCRIPTS file.

find_program(GHC_EXECUTABLE

    NAMES ghc

    PATHS /opt/local/bin /usr/local/bin /usr/bin

    )

find_program(GHC_PKG_EXECUTABLE

    NAMES ghc-pkg

    PATHS /opt/local/bin /usr/local/bin /usr/bin

    )

if (GHC_EXECUTABLE)

    # check ghc version

    execute_process(COMMAND ${GHC_EXECUTABLE} -V

                    OUTPUT_VARIABLE GHC_VERSION_OUTPUT

                    ERROR_VARIABLE GHC_VERSION_ERROR

                    RESULT_VARIABLE GHC_VERSION_RESULT

                    OUTPUT_STRIP_TRAILING_WHITESPACE

                    )

    if(${GHC_VERSION_RESULT} EQUAL 0)

        string(REGEX MATCH "([0-9]+)" GHC_VERSION ${GHC_VERSION_OUTPUT})

    else()

        message(SEND_ERROR "Command \"${GHC_EXECUTABLE} -V\" failed with output: ${GHC_VERSION_ERROR}")

    endif()

endif()

if (GHC_PKG_EXECUTABLE)

    # check ghc-pkg version

    execute_process(COMMAND ${GHC_PKG_EXECUTABLE} -V

                    OUTPUT_VARIABLE GHC_PKG_VERSION_OUTPUT

                    ERROR_VARIABLE GHC_PKG_VERSION_ERROR

                    RESULT_VARIABLE GHC_PKG_VERSION_RESULT

                    OUTPUT_STRIP_TRAILING_WHITESPACE

                    )

    if(${GHC_PKG_VERSION_RESULT} EQUAL 0)

        string(REGEX MATCH "([0-9]+)" GHC_PKG_VERSION ${GHC_PKG_VERSION_OUTPUT})

    else()

        message(SEND_ERROR "Command \"${GHC_PKG_EXECUTABLE} -V\" failed with output: ${GHC_PKG_VERSION_ERROR}")

    endif()

endif()

include(FindPackageHandleStandardArgs)

find_package_handle_standard_args(GHC DEFAULT_MSG GHC_EXECUTABLE GHC_VERSION)

mark_as_advanced(GHC_VERSION)