Add CMake function GenerateBinaryHeader to replace xxd steps

    message(FATAL_ERROR "${PKG1} package needs LAMMPS to be build with ${PKG2}")

  endif()

endmacro()

# CMake-only replacement for bin2c and xxd

function(GenerateBinaryHeader varname outfile files)

    message("Creating ${outfile}...")

    file(WRITE ${outfile} "// CMake generated file\n")

    math(EXPR ARG_END   "${ARGC}-1")

    foreach(IDX RANGE 2 ${ARG_END})

        list(GET ARGV ${IDX} filename)

        file(READ ${filename} content HEX)

        string(REGEX REPLACE "([0-9a-f][0-9a-f])" "0x\\1," content "${content}")

        string(REGEX REPLACE ",$" "" content "${content}")

        file(APPEND ${outfile} "const unsigned char ${varname}[] = { ${content} };\n")

        file(APPEND ${outfile} "const unsigned int ${varname}_size = sizeof(${varname});\n")

    endforeach()

endfunction(GenerateBinaryHeader)