add_cotire

## If you have a prefix inculde header (says precompile.h) for all module of your project, 
## then together with Cotire, do set(GLOBAL PROPERTY COTIRE_CXX_PREFIX_HEADER_INIT_DEFAULT precompile.h)
## and then add_cotire(target_module)

function (add_cotire _target)
    get_property(_pch_target GLOBAL PROPERTY COTIRE_CXX_PCH_TARGET)
    get_property(_pch_header GLOBAL PROPERTY COTIRE_CXX_PREFIX_HEADER_INIT_DEFAULT)

    if("${_pch_target}" STREQUAL "")
        set_target_properties(${_target} PROPERTIES COTIRE_CXX_PREFIX_HEADER_INIT ${_pch_header})
        cotire(${_target})
        message("COTIRE_CXX_PCH_TARGET  ${_target}")
        set_property(GLOBAL PROPERTY COTIRE_CXX_PCH_TARGET ${_target})
    else()
        set_target_properties(${_target} PROPERTIES COTIRE_ENABLE_PRECOMPILED_HEADER FALSE)
        get_target_property(_pch_file ${_pch_target} COTIRE_CXX_PREFIX_HEADER)
        get_target_property(_is_enabled ${_pch_target} COTIRE_ENABLE_PRECOMPILED_HEADER)
        if(_is_enabled)
            target_compile_options(${_target} BEFORE PRIVATE -include ${_pch_file} -Winvalid-pch -D${_pch_target}_EXPORTS)
            message("${_target} uses ${_pch_file}")
        else()
            ## Fallback to -include
            set_target_properties(${_target} PROPERTIES COTIRE_CXX_PREFIX_HEADER_INIT ${_pch_header})
            message("${_target} -include ${_pch_header}")
        endif()

        cotire(${_target})
    endif()
endfunction()