#find package helpers

macro(find_package_or_fail _PKG_NAME)

    find_package(${_PKG_NAME})

    string(TOUPPER ${_PKG_NAME} _PKG_NAME_UP)

    if(NOT ${_PKG_NAME_UP}_FOUND)

        message(SEND_ERROR "Missing ${_PKG_NAME}! Please install it and rerun cmake.")

    endif(NOT ${_PKG_NAME_UP}_FOUND)

endmacro(find_package_or_fail _PKG_NAME)

macro(find_package_or_disable _PKG_NAME _VAR_NAME)

    find_package(${_PKG_NAME})

    string(TOUPPER ${_PKG_NAME} _PKG_NAME_UP)

    if(NOT ${_PKG_NAME_UP}_FOUND)

        message(SEND_ERROR "Missing ${_PKG_NAME}! Rerun cmake with -D${_VAR_NAME}=1 to build without it.")

    endif(NOT ${_PKG_NAME_UP}_FOUND)

endmacro(find_package_or_disable _PKG_NAME _VAR_NAME)

macro(find_package_or_disable_msg _PKG_NAME _VAR_NAME _MSG)

    if(NOT ${_VAR_NAME})

        find_package_or_disable(${_PKG_NAME} ${_VAR_NAME})

    else(NOT ${_VAR_NAME})

        message(STATUS "${_PKG_NAME} disabled. ${_MSG}")

        string(TOUPPER ${_PKG_NAME} _PKG_NAME_UP)

        set(${_PKG_NAME_UP}_FOUND false)

    endif(NOT ${_VAR_NAME})

endmacro(find_package_or_disable_msg _PKG_NAME _VAR_NAME _MSG)

#variable manipulation macros

macro(add_flag_append _VAR_NAME _FLAG)

    set(${_VAR_NAME} "${${_VAR_NAME}} ${_FLAG}")

endmacro(add_flag_append _VAR_NAME _FLAG)

macro(add_flag_prepend _VAR_NAME _FLAG)

    set(${_VAR_NAME} "${_FLAG} ${${_VAR_NAME}}")

endmacro(add_flag_prepend _VAR_NAME _FLAG)

macro(add_linker_flag _FLAG)

    list(APPEND haskell_flags "-optl" "${_FLAG}")

    add_flag_append(CMAKE_Pascal_FLAGS "-k${_FLAG}")

    add_flag_append(CMAKE_EXE_LINKER_FLAGS "-Wl,${_FLAG}")

    add_flag_append(CMAKE_SHARED_LIBRARY_C_FLAGS "-Wl,${_FLAG}")

    add_flag_append(CMAKE_SHARED_LIBRARY_CXX_FLAGS "-Wl,${_FLAG}")

endmacro(add_linker_flag _FLAG)

#TODO: find_package_or_bundle